CN100583725C - Communication terminal and method for timing the detection of communication-medium characteristics - Google Patents

Abstract

The present invention is a communication terminal which modulates and demodulates a packet for transmission and reception based on a communication parameter for modulation and demodulation determined according to a communication-medium characteristic. The communication terminal according to the present invention includes: information-element extracting means which extracts, with each predetermined cycle, information indicative of either one of transmission efficiency and reception quality of the packet as an information element; difference calculating means which calculates, with each said cycle, a difference between a first information element extracted by the information-element extracting means and a second information element previously extracted by the information-element extracting means; and detecting-scheme performance determining means which determines, based on the difference between the first information element and the second information element calculated by the difference calculating means, with each said cycle, whether a scheme of detecting the communication-medium characteristic for changing the communication parameter is to be performed.

Description

Be used for communication terminal and method regularly carried out in the detection of communication media feature

Technical field

The present invention relates to communication terminal and method that modulation and demodulation are used to the data of launching/receiving, relate in particular to the feature that is used to detect communication media, change the messaging parameter that is used for modulating/demodulating so that messaging parameter is followed the state of communication media and based on the communication terminal and the method for messaging parameter emission/reception modulated/demodulated data.

Background technology

Generally speaking, therein under the situation of the system that fluctuates in time of the feature of communication media (for example, the wireless communication system of multipath fading or the electric line communication system that is influenced by group delay wherein take place), the communication media feature depends on the position relation between launch terminal and the receiving terminal and fluctuates significantly.Therefore, in the communication system of using the multi-carrier transmission pattern, wherein such as selecting to be used to communicate by letter according to the communication media feature for messaging parameters such as the subcarrier that uses and modulation schemes, detection communication media feature is selected messaging parameter between launch terminal and receiving terminal.In this manual, detect the communication media feature and become communication media feature detection scheme below with a series of processes of selecting messaging parameter.In this communication media feature detection scheme, assess the quality of the communication media on each subcarrier.Therefore, communication media feature detection pattern is also referred to as channel estimating.Especially, in the communication system of using the multi-carrier transmission scheme, when changing messaging parameter according to the state of the communication media of each subcarrier and to each subcarrier, the subcarrier that may command worsens, thereby make it not be used (for example, in discrete multitone (DMT) scheme) in order to prevent the purpose that data are launched on the subcarrier of this deterioration.In this communication plan, use the special assessment series of packets of all subcarriers to be used for the communication media estimation, estimate all subcarriers thus and carried out communication media feature detection scheme (channel estimating) (for example, Japanese patent application publication No. 2002-158675).

This conventional method of carrying out this communication media feature detection scheme depends on the feature unique to communication media (for example, Japanese patent application publication No. 2000-184061) significantly.

Do not rely in the known arrangement of the feature unique as much as possible in the method that makes to communication media, with the predetermined cycle, or when estimating when packet retransmission is counted a predetermined level is exceeded the communication media characteristic deterioration, executive communication dielectric attribute detection scheme (for example, Japanese patent application publication No. 2002-158675).

In another program, measure transmission speed, error rate and received signal intensity and determine transmission plan (for example, Japanese patent application publication No. 2003-209537).

Figure 12 illustrates to be used to be independent of the conventional scheme of the unique feature of communication media being determined the timing of executive communication dielectric attribute detection scheme.In Figure 12, launch terminal 9000 is used to detect the assessment series of packets 9001 of communication media feature to receiving terminal 9100 emission, to be identified for defining the messaging parameter of scheme that modulation will be transmitted into the data of receiving terminal 9100.Receiving terminal 9100 uses these a series of assessment groupings 9001 from launch terminal 9000, come each subcarrier is detected the communication media feature, launch the assessment result grouping 9002 that comprises about the information of detected communication media feature to launch terminal 9000 then.Based on this assessment result grouping 9002, launch terminal 9000 is determined the communication quality of each subcarrier, and determines the messaging parameter of each subcarrier.Launch terminal 9000 uses determined messaging parameter to come modulating data then, comprises the data sequence 9003 of a plurality of groupings then to receiving terminal 9100 emissions.As shown in figure 12, packet loss takes place in supposition herein when transmission of data sequences 9003.When this packet loss takes place when, the grouping of launch terminal 9000 retransmits lost.Surpass predetermined value unless retransmit number of times, otherwise launch terminal 9000 transmission of data sequences under the situation of not executive communication dielectric attribute detection scheme, up to the following one-period of executive communication dielectric attribute detection scheme.When the following one-period of executive communication dielectric attribute detection scheme arrives, launch terminal 9000 emission assessment series of packets 9004.Then, as mentioned above, launch terminal 9000 uses the assessment result grouping 9005 from receiving terminal 9100, determines the messaging parameter of each subcarrier, and to modulate based on messaging parameter, transmission of data sequences 9006 then.

As shown in figure 12, packet loss takes place in supposition herein when transmission of data sequences 9006.When this packet loss takes place when, the grouping of launch terminal 9000 retransmits lost.When retransmitting number of times above predetermined number, launch terminal 9000 determines that the state of communication medias worsens, and emission is used to detect the assessment series of packets 9007 of communication media feature then.Receiving terminal returns assessment result grouping 9008 to launch terminal 9000.Based on assessment result grouping 9008, launch terminal 9000 is determined messaging parameters, to modulate based on this messaging parameter and to launch subsequent packets.

Thus, in the communication system of routine, communication media feature detection scheme is periodically carried out, or when the repeating transmission number of times of grouping surpasses predetermined number, carry out, determined that thus messaging parameter is to follow the current state of communication media.

Figure 13 is the chart that is illustrated in the relation between the traffic rate and communication media state under the regular situation of executive communication dielectric attribute detection scheme periodically.Herein, traffic rate is by the communication speed that messaging parameter calculates is set.

In Figure 13, T1011 and T1012 represent to begin the moment of communication media feature detection scheme constantly.As shown in figure 13, in the method for executive communication dielectric attribute detection scheme periodically, be in next time period before T1012 arrives constantly, to use at the messaging parameter that previous moment T1011 determines, even the state of communication media has fluctuation.In this time period, can not use the subcarrier or the modulation scheme that are applicable to the fluctuation in the communication media state.Therefore, the grouping of launching from launch terminal can not normally arrive receiving terminal, has reduced throughput thus unfriendly.For example, in section P1 shown in Figure 13,, increased losing and having reduced throughput of the grouping that to launch thus even the state deteriorating of communication media is also attempted communication with high traffic rate.Equally, exist from the state of communication media have fluctuation the time be carved into the long problem of time period in the moment that changes messaging parameter.

A kind of method that addresses these problems is to shorten the cycle of executive communication dielectric attribute detection scheme, to follow the fluctuation of communication media state.In communication media feature detection scheme, receiving terminal is assessed the reception CINR (carrier wave is to disturbing and noise power ratio) of each subcarrier.For improving the accuracy of CINR assessment, the launch terminal emission has the assessment series of packets of long data length (code element number).Therefore, when the number of times of executive communication dielectric attribute detection scheme increased, the time portion of assessment series of packets also increased in communication system.For this reason, even the fluctuation in the communication media state was followed by the shortening cycle, but do not improve the throughput of whole system.

Figure 14 is illustrated under the regular situation of executive communication dielectric attribute detection scheme when the packet retransmission number of times surpasses predetermined value the chart of the relation between traffic rate and the communication media state.In Figure 14, constantly T1013 and T1015 represent to detect the moment that cycle of communication media feature arrives.T1014 represents because the packet retransmission number of times surpasses predetermined value and the moment of executive communication dielectric attribute detection scheme constantly.As shown in figure 14, when surpassing predetermined value in the method for executive communication dielectric attribute detection scheme when the packet retransmission number of times, if the state deteriorating of communication media then changes modulation parameter, to follow this deterioration, the traffic rate of Jiang Diing thus.Yet even the state of communication media changes improved state into from degradation mode, communication also is to be applicable to (with reference to the P2 part of Figure 14) that the messaging parameter of the degradation mode of communication media is carried out by use.Therefore, this has caused such problem, even the state of communication media is improved, throughput is not improved yet.

Thus, conventional problem comprises the decline of the throughput of whole communication system, because messaging parameter can not be followed the state of communication media, especially when the state of communication media changes the improvement state into from degradation mode; And from the state of communication media take place fluctuation the time be carved into long-time section of moment of changing messaging parameter.These problems can further cause such problem, and for example, because the communication media state deteriorating, the user can't check the video flowing with satisfactory quality in the time period before messaging parameter changes suitable parameter into continuously.

Disclosure of the Invention

Therefore, the purpose of this invention is to provide a kind of being used for by feature that detects communication media and the state of following communication media, come the communication terminal and the method for the data that modulation and demodulation are used to transmit and receive, wherein, when changing the improvement state into, degradation mode also can follow messaging parameter at the communication media state even allow.

For addressing the above problem, the present invention has following feature.The present invention is directed to a kind of communication terminal based on the grouping that comes modulation and demodulation to be used to transmit and receive according to the definite messaging parameter that is used for modulation and demodulation of communication media feature, comprise: the information element extracting device, it in any information of the emission effciency of each predetermined periodicity extraction indication grouping and the quality of reception as information element; The difference calculation element, first information element that it is extracted by the information element extracting device in each described computation of Period and poor by previous second information element that extracts of this information element extracting device; And the detection scheme performance determines device, and it is poor based on the first information element that is calculated by the difference calculation element and second information element, determines whether to carry out the scheme that the communication media feature changes messaging parameter that detects in each described cycle.

Preferably, this communication terminal is positioned at a side of emission grouping, and the information element extracting device extracts the emission branch

Organize and retransmit the average number of packets that ratio takes place and do not launch as yet, as the information element of the emission effciency of indicating grouping.

Preferably, this communication terminal is positioned at a side that receives grouping, and the information element extracting device extracts the information element of the error correction rate of reception grouping as the quality of reception of indication grouping.Preferably, this communication terminal is positioned at a side of emission grouping, and the information element extracting device extracts the information element that indication receives the grouping quality based on being included in from being arranged in the characteristic information of the indication grouping quality of reception that ACK grouping that the communication terminal that receives grouping one side returns comprises.

Preferably, the difference calculation element calculate to retransmit take place than in difference and poor in the average number of packets of emission not as yet, and the detection scheme performance determines that the definite difference that takes place in the ratio when repeating transmission of device is equal to or greater than the predetermined threshold that the difference in the ratio takes place in repeating transmission, or as yet not the difference in the average number of packets of emission to carry out detection scheme greater than as yet not during the predetermined threshold of difference in the average number of packets of emission.

Preferably, the detection scheme performance determines that device also determines will carry out detection scheme when emission rate value of setting during less than the threshold value of the emission rate value of setting.

Preferably, poor in the difference calculation element computing error correction rate, and the detection scheme performance determines that device determines will carry out detection scheme when the difference in the error correction rate is equal to or greater than the threshold value of the difference in the error correction rate.

Preferably, characteristic information is the information of the size of grouping that indication is received by the communication terminal that the is arranged in receiver side part that requires error correction.

Preferably, the information element extracting device extracts the error correction rate of the quality of reception of indicating the grouping that receives, as the information element based on size.

Preferably, poor in the difference calculation element computing error correction rate, and the detection scheme performance determines that device determines will carry out detection scheme when the difference in the error correction rate is equal to or greater than the threshold value of the difference in the error correction rate.

Preferably, it is serial that grouping comprises the simple assessment with the preassigned pattern that is used to assess the quality of reception, the size of data that should simple assessment series is less than when the data of carrying out the assessment sequence of using when detection scheme is used to assess the communication media feature, and characteristic information is based on the serial data of simple assessment that the grouping that received by the communication terminal that is arranged in receiver side comprises and any of CINR value, SINR value and the received signal intensity of calculating.

Preferably, the information element extracting device extracts any in the mean value of the mean value of the mean value of a plurality of described CINR values, a plurality of described SINR values and a plurality of described received signal intensity, the information element of the quality of reception of the grouping that receives as indication.

Preferably, the difference calculation element calculates any in the difference in the mean value of poor, the received signal intensity in the mean value of poor, the SINR value in the mean value of CINR value, and when the detection scheme performance determines that device determines that when any calculating in the difference in the mean value of difference in the mean value of poor, the SINR value in the mean value of CINR value and received signal intensity one is equal to or greater than predetermined threshold, carry out detection scheme.

Preferably, detection scheme was carried out each predetermined basic cycle, and predetermined period is shorter than the predetermined basic cycle.

Predetermined period can be variable.

Preferably, this communication terminal also comprises the detection scheme final controlling element, when it determines that in the detection scheme performance device is determined to carry out detection scheme, send the assessment series of packets that is used to assess the communication media feature to the communication terminal that is positioned at receiver side, reception comprises the assessment result grouping of the assessment result of the communication media feature of returning from the communication terminal that is positioned at receiver side, and grouping changes messaging parameter based on assessment result.

In addition, the present invention is directed to a kind of definite execution and detect the communication media feature is determined the scheme of the messaging parameter that uses in the grouping modulation and demodulation the method for timing, may further comprise the steps: each predetermined period is extracted the emission effciency of indication grouping and any the information in the quality of reception as information element; Poor to previous second information element that extracts in the first information element that extracts in each described computation of Period information extraction step and the information element extracting step; And poor based on the first information element that in calculation procedure, calculates and second information element, each described cycle is determined whether to carry out the scheme that the communication media feature changes messaging parameter that detects.

Preferably, in the information element extracting step, the characteristic information of the quality of reception of the grouping that the ACK grouping of returning from the communication terminal that is arranged in a side that receives grouping based on indication comprises, the information element of the quality of reception of extraction indication grouping.

Moreover, the present invention is directed to a kind of based on the messaging parameter of determining according to the communication media feature that is used for modulation and demodulation, the integrated circuit of the grouping that modulation and demodulation are used to transmit and receive, comprise: the information element extracting device, it extracts any information of the emission effciency of indication grouping and the quality of reception to each predetermined period, as information element; The difference calculation element, first information element that it is extracted by the information element extracting device each computation of Period and poor by previous second information element that extracts of information element extracting device; The detection scheme performance is determined device, and it is poor based on the first information element that is calculated by the difference calculation element and second information element, and each described cycle is determined whether to carry out the scheme that detection communication media feature changes messaging parameter; And detection scheme final controlling element, it is used to assess the assessment series of packets of communication media to the communication terminal emission that is positioned at receiver side when the detection scheme performance determines that device is determined to carry out detection scheme, reception comprises the assessment result grouping of the assessment result of the communication media feature of returning from the communication terminal that is positioned at receiver side, and grouping changes messaging parameter based on assessment result.

According to the present invention, calculate poor in any information element of the emission effciency of indication grouping and the quality of reception, detect thus the emission effciency and the quality of reception calculated any in whether the fluctuation of predetermined extent has taken place to meet or exceed.If difference is equal to or greater than predetermined threshold, then can estimate the emission effciency and the quality of reception calculated any in the fluctuation of predetermined extent has taken place to meet or exceed, that is, the fluctuation of predetermined extent has taken place to meet or exceed in the communication media state.If estimate that so then communication terminal is determined executive communication dielectric attribute detection scheme, executive communication dielectric attribute detection scheme then.Therefore, detection can not only be carried out when the state deteriorating of communication media, can also carry out when state improves.Equally, information element is based in the normal processes that information that grouping comprised in transmitting and receiving extracts.Therefore, the present invention allows to select messaging parameter, communicates by letter with the state of following communication media, and can not reduce the throughput of whole communication system.

The accompanying drawing summary

Fig. 1 is the block diagram that illustrates according to the structure of the communication terminal 100 of the first embodiment of the present invention.

Fig. 2 is the flow chart that fluction analysis operation of access control unit 101 in the cycle is shown.

Fig. 3 is a precedence diagram of describing the example of the timing of executive communication dielectric attribute detection scheme when the state deteriorating state of communication media changes the improvement state into.

Fig. 4 is the precedence diagram of describing when the state of communication media another example of the timing of executive communication dielectric attribute detection scheme when degradation mode changes the improvement state into.

Fig. 5 illustrates the state of communication media when the communication terminal that uses according to first embodiment and the chart of the relation between the traffic rate.

Fig. 6 is the flow chart that illustrates according to the operation of the access control unit 101 in the structure of the communication terminal 100 of the second embodiment of the present invention.

Fig. 7 is the precedence diagram of describing when the state of the communication media example of the timing of executive communication dielectric attribute detection scheme when degradation mode changes the improvement state into.

Fig. 8 illustrates according to the launch terminal of the third embodiment of the present invention and the precedence diagram of the handling process between the receiving terminal.

Fig. 9 A is the diagram that an example of the data packet format that partly comprises the partial data grouping that is assumed to assessment series is shown.

Fig. 9 B is the diagram that another example of the data packet format that partly comprises the partial data grouping that is assumed to assessment series is shown.

Figure 10 illustrates fluction analysis flow chart according to the operation of the access control unit 101 of the launch terminal of the 3rd embodiment in the cycle.

Figure 11 is the diagram that the whole system configuration when being applied to the high speed power line transmission according to communication terminal of the present invention is shown.

Figure 12 illustrates to be independent of the precedence diagram of conventional method of the unique feature of communication media being determined the timing of executive communication dielectric attribute detection scheme.

Figure 13 is illustrated in the traffic rate of communication media under the regular situation of operation communication dielectric attribute detection scheme periodically and the chart of the relation between the state.

Figure 14 is illustrated in the traffic rate of communication media under the regular situation of executive communication dielectric attribute detection scheme when the packet retransmission number surpasses predetermined value and the diagram of the relation between the state.

Realize optimal mode of the present invention

(first embodiment)

Fig. 1 is the block diagram that illustrates according to the structure of the communication terminal 100 of the first embodiment of the present invention.In Fig. 1, communication terminal 100 comprises access control unit 101, transmit buffer 102, reception buffer 103, correction process unit 104 and modulation/demodulation unit 105.Communication terminal 100 uses the multi-carrier transmission patterns to modulate or demodulation comprises the grouping that will be launched maybe the data that will receive from higher level, or has the control grouping (hereinafter abbreviating grouping as) of lower level, for emission or reception.Below, as a typical example, description is made in the emission or the reception that comprise the grouping that will be launched maybe the data that will receive from higher level.Yet this description also can be applicable to have the emission or the reception of control grouping of lower level etc.Communication terminal 100 is launched grouping according to the access time table of describing to another communication terminal from the timetable grouping of control terminal (not shown) emission on network.Communication media between these communication terminals can be wired or wireless.

Access control unit 101 controls are from the visit of 100 pairs of communication medias of communication terminal.For executive communication dielectric attribute detection scheme, access control unit 101 makes the assessment series of packets be launched into modulation/demodulation unit 105.In response to this, based on the assessment result grouping of returning from the communication terminal that is positioned at receiver side, access control unit 101 is determined the communication media feature of each subcarrier, determines the messaging parameter of each subcarrier, and indication modulation/demodulation unit 105 uses this messaging parameter to be used for modulation or demodulation.This messaging parameter comprises about the information that will use which subcarrier, to the index of the modulation of the subcarrier that will use and about the information to the modulation scheme of the subcarrier that will use.

Transmit buffer 102 comprises one or more emission formation 102a, its each be used for each (or being used for each packet type) as the destinations traffic terminal of communication counterpart, be used for storing the emission grouping.

Reception buffer 103 comprises one or more reception formation 103a, its each be used for emission source communication terminal each (or being used for each packet type), be used to store the grouping of reception.

Correction process unit 104 butt joint contracture groups are carried out error correction, will be stored in through the grouping of error correction then to receive among one of formation 103a.

Modulation/demodulation unit 105 demodulation by the grouping that communication media receives, send to grouping correction process unit 104 based on the messaging parameter that is provided by access control unit 101 then.Equally, modulation/demodulation unit 105 modulation are stored in the grouping among one of emission formation 102a, launch modulated grouping by communication media then.

In communication terminal 100, be passed to access control unit 101 from the data of higher level via the higher level interface.101 pairs of data packetizing of access control unit, and grouping is stored in is used for each destinations traffic terminal emission formation 102a of (or being used for each packet type).When predetermined emission regularly arrives, access control unit 101 makes and read the emission grouping from transmit buffer 102, make modulation/demodulation unit 105 modulate this grouping, make modulated data be sent to communication media then by using current messaging parameter.Receive the notice that can't normally be received about grouping from the communication counterpart terminal after, access control unit 101 makes that again reading the grouping that can't normally be received from transmit buffer 102 is used for retransmitting.

In communication terminal 100, when receiving grouping, modulation/demodulation unit 105 is according to the grouping that the messaging parameter demodulate reception arrives is set.Then, correction process is carried out in correction process unit 104, will be stored in through the grouping that is received of error correction then to receive among one of formation 103a.Access control unit 101 obtains to be stored in the reception grouping that receives among one of formation 103a, is used for being sent to higher level by the higher level interface.

Access control unit 101 calculates and will make the emission packet count be stored in the transmit buffer 102 then to each packet count of regularly launching (hereinafter being called the emission packet count) of grouping emission each emission distant terminal.

Access control unit 101 is to each emission distant terminal, to receive each timing of the notice that can't normally be received from the terminal that is positioned at receiver side about grouping, or to packet retransmission each regularly, packet retransmission number (hereinafter being called the packet retransmission number) is counted, made the packet retransmission number be stored in the transmit buffer 102 then.

Access control unit 101 is preserved for first timer that the predetermined period of executive communication dielectric attribute detection scheme is counted.When the predetermined period that is used for executive communication dielectric attribute detection scheme by the first timer notice arrived, access control unit 101 notified this as trigger, executive communication dielectric attribute detection scheme.Below, the predetermined period that is used for executive communication dielectric attribute detection scheme is called as the basic cycle.

Equally, access control unit 101 is preserved for contrasting the second timer that the predetermined period of basic cycle fluctuation (will discuss hereinafter) short, that be used for the analytical information element is counted.When the predetermined period that is used for the fluctuation of analytical information element by the second timer notice arrives, the fluctuation of access control unit 101 beginning analytical information elements.Below, the predetermined period that is used for the fluctuation of analytical information element is called as the fluction analysis cycle.Notice that the fluction analysis cycle can be synchronous with the sampling period of analog signal.

Fig. 2 is the flow chart that fluction analysis operation of access control unit 101 in the cycle is shown.With reference to figure 2, the operation of fluction analysis access control unit in the cycle has been described hereinafter.Notice that grouping emission/reception is to carry out concomitantly with operation shown in Figure 2.Therefore, emission packet count and packet retransmission number and operation shown in Figure 2 store concomitantly.

Process shown in Figure 2 begins with the notice from beginning fluction analysis cycle of second timer, and this is notified as trigger.

At first, access control unit 101 is carried out the process (step S100) of extraction and store information element.Herein, information element is the information of state of reflection communication media, and the result who can be used as the grouping emission obtains.Information element according to first embodiment is an information of indication grouping emission effciency.For reducing the processing load on the communication terminal, information element is preferably an information can easily being calculated.In first embodiment, the average number of packets that the use packet retransmission takes place not launch than the Buddhist monk is used for indication grouping emission effciency as information element.Notice that information element described herein only is an example, and and do not mean that restrictive, as long as they are each bar information of indication grouping emission effciency.

Particularly, at step S100, ratio takes place based on launching the sum of grouping and the sum of packet retransmission during the cycle at the beginning fluction analysis, calculate to retransmit in access control unit 101, makes the ratio that is calculated be stored in the transmit buffer 102 then.For example, retransmit to take place than being to calculate according to (sum of packet retransmission)/(sum that the sum of packet retransmission+grouping is launched).

Equally, at step S100, access control unit 101 is based on the result of summation, the packet count of not launching as yet that is included in the emission formation 102a that is used for each communication counterpart is counted, calculate the average number of packets of not launching as yet, make the numeral of being calculated be stored in the transmit buffer 102 then.For example, as yet not the average number of packets of emission be to calculate according to (in the packet count of the beginning last fluction analysis cycle fashion average number of packets of not launching+do not launch in beginning current fluction analysis cycle fashion)/2.The average number of packets of emission is not that indication depends on that the state of communication media is applied to the numerical value of the degree of the complexity in the grouping emission as yet.When the average number of packets of launching as yet was not bigger, load was also bigger.

Then, access control unit 101 determines whether be used for that the data sequence that one group of emission grouping is transmitted into receiver side from emitting side has been launched the data with the amount of state that is enough to estimate communication media.This determines whether be equal to or greater than (the step S101) that predetermined minimum packets number carries out according to the emission packet count that is stored in the emission buffering area 102.If the emission packet count is not more than the minimum packets number, then access control unit 101 advances to the operation of step S106.On the other hand, if the emission packet count is equal to or greater than predetermined minimum packets number, then access control unit 101 advances to the operation of step S102.

At step S102, the repeating transmission of the access control unit current fluction analysis of 101 calculating in the cycle takes place than (first information element) absolute value with the difference of the minimum value (hereinafter be called minimum the repeating transmission ratio takes place) (second information element) of the repeating transmission generation ratio of previous calculating, as retransmit to take place than in difference, determine then the repeating transmission of being calculated take place than in difference whether less than retransmit take place than in the predetermined threshold of difference.Notice that the minimum generation ratio of retransmitting is provided with in the cycle as yet at first fluction analysis, and is 0 therefore., in the cycle value that is provided with at step S106 that further describes is hereinafter compared as minimum the repeating transmission at arbitrary follow-up fluction analysis.

If the difference that repeating transmission takes place in the ratio is not less than the threshold value of retransmitting the difference in the generation ratio, then access control unit 101 advances to the operation of step S105.On the other hand, if retransmit to take place than in difference less than retransmit take place than in the threshold value of difference, then access control unit 101 advances to the operation of step S103.

At step S103, access control unit 101 calculates the emission rate values of setting, determines that then emission rate value of setting of being calculated is whether less than the threshold value of the emission rate value of setting.Particularly, access control unit 101 is based on the messaging parameter that is provided with in the modulation/demodulation unit 105, each subcarrier is calculated can be to the data volume of each 1 block of symbols (bitwise) emission, and the emission rate value of setting is calculated in the data volume request to being calculated then.

If emission rate value of setting of being calculated is not less than the threshold value of the emission rate value of setting, then access control unit 101 advances to the operation of step S106.On the other hand, if emission rate value of setting of being calculated less than the threshold value of the emission rate value of setting, then access control unit 101 advances to the operation of step S104.

At step S104, access control unit 101 with current fluction analysis calculate in the cycle as yet not the emission average number of packets (first information element) with last fluction analysis calculate in the cycle as yet not the emission average number of packets (second information element) difference absolute value divided by as yet not the emission average number of packets, calculate as yet poor in the packet count of emission not thus, determine then to be calculated as yet not the mean difference in the packet count of emission whether greater than the threshold value of the mean difference in this class packet count.Notice that as long as calculated the average number of packets of emission poor of calculating in any of fluction analysis cycle formerly not as yet, this difference just is not limited to the poor of the average number of packets of not launching as yet calculated in the cycle at direct last fluction analysis.

If the mean difference in the packet count of not launching is not more than the threshold value of the difference in this class packet count as yet, then access control unit 101 advances to the operation among the step S106.If the mean difference in the packet count of not launching is greater than the threshold value of the mean value in this class packet count as yet, then access control unit 101 advances to the operation among the step S105.

In step S105, access control unit 101 determines to want executive communication dielectric attribute detection scheme, sends the assessment series of packets to the communication terminal that is positioned at receiver side, and based on the assessment result grouping of returning in the response, messaging parameter resets then.After the operation of step S105, access control unit 101 advances to the operation of step S106.Notice that in case carried out communication media feature detection scheme, can restart the fluction analysis cycle, perhaps the fluction analysis cycle can arrive under the situation that does not change its cycle after this scheme is finished.

At step S106, the minimum value in the ratio takes place in the repeating transmission that access control unit 101 recovers previous in the transmit buffer 102, retransmits as minimum and compares.

Step S100 is to carry out from the beginning and the end thereof in fluction analysis cycle to the operation among the S106.Finish step S100 after the operation of S106, access control unit 101 is waited for, arrives up to the moment in next fluction analysis cycle of beginning, to begin operation shown in Figure 2.

Fig. 3 is the precedence diagram that is used to describe when the state of a communication media example of the selection of time of executive communication dielectric attribute detection scheme when degradation mode changes the improvement state into.Below, with reference to figure 3, the example when the state of the communication media selection of time that the executive communication dielectric attribute detects when degradation mode changes the improvement state into is described.

At first, suppose when being used to begin the moment T300 arrival in fluction analysis cycle, launch terminal (hereinafter meaning the communication terminal that is positioned at emitting side) has been launched a plurality of groupings to receiving terminal (hereinafter meaning the communication terminal that is positioned at receiver side), as data sequence 301.In the moment of emission grouping, access control unit 101 makes emission packet count and packet retransmission number be stored in the transmit buffer 102.When moment T300 arrived, launch terminal calculates retransmitted the average number of packets that generation is not launched than the Buddhist monk, as information element, made that then the value of being calculated is stored in (with reference to the step S100 of figure 2) in the transmit buffer 102.

Herein, at the moment T300 that is used to begin next fluction analysis cycle with constantly between the T302, suppose great fluctuation process does not take place in the state of communication media.In this case, the packet loss rate in the data sequence 301 can not fluctuate significantly.When moment T302 arrived, launch terminal calculates retransmitted the average number of packets that generation is not launched than the Buddhist monk, makes the value of being calculated be stored in (with reference to the step S100 of figure 2) in the transmit buffer 102 then.Because packet loss rate can not fluctuate significantly, therefore the difference in the repeating transmission generation ratio is less than retransmitting the threshold value (with reference to the flow process that arrives "Yes" among the step S102 of figure 2) that the difference in the ratio takes place.At this moment, if the emission rate value of setting is equal to or greater than the threshold value (with reference to the flow process that arrives "No" among the step S103 of figure 2) of the emission rate value of setting, then not executive communication dielectric attribute detection scheme after moment T300.This is in order to prevent under a certain speed and the guaranteed situation of a certain success rate unnecessarily executive communication dielectric attribute detection scheme.Then, access control unit 101 upgrades minimum repeating transmission generation than (with reference to the step S106 among the figure 2).

Then, the state of supposing communication media has had very big improvement after moment T302.In this case, the packet loss rate from the launch terminal to the receiving terminal reduces (with reference to the data sequence among the figure 3 303).Therefore, after being used to begin the moment T304 in fluction analysis cycle, the difference that the repeating transmission of being calculated in step S102 by access control unit 101 takes place in the ratio is increased to the threshold value that is equal to or greater than repeating transmission generation ratio.Be equal to or greater than the threshold value of retransmitting the generation ratio, the then processing of access control unit 101 execution in step S106 if retransmit the difference that takes place in the ratio.

Therefore, launch terminal is to receiving terminal emission assessment series of packets 305.In response, receiving terminal detects the communication media feature of each subcarrier, and the assessment result grouping 306 that will comprise testing result then returns to launch terminal.After receiving assessment result grouping 306, launch terminal is restarted data transmission then based on the assessment result messaging parameter that resets.

Routinely, executive communication dielectric attribute detection scheme just when retransmitting number of times and surpass threshold value only.In the present invention, whether be equal to or greater than the threshold value that the difference in the ratio takes place in repeating transmission, determine whether the state of communication media changes the improvement state into from degradation mode, thereby automatically perform communication media feature detection scheme by determining the difference that repeating transmission takes place in the ratio.Therefore, can determine messaging parameter, to follow the change of communication media feature.

Fig. 4 is the precedence diagram that is used to describe when the state of communication media another example of the timing of executive communication dielectric attribute detection scheme when degradation mode changes the improvement state into.Below, with reference to figure 4, other example when the timing of executive communication dielectric attribute detection scheme when degradation mode changes the improvement state into of the state of communication media is described.

In Fig. 4, at first in the degradation mode of communication media, suppose state not significantly fluctuation after being provided with messaging parameter of communication media.In this case, do not change the load condition of communication media, and therefore change the packet count of not launching as yet in the emission formation 401 and 403 indistinctively.Therefore, the average number of packets that does not send as yet at the moment T400 that is used to begin the fluction analysis cycle with in the difference of the still nonevent average number of packets of moment T402 that is used to begin another fluction analysis cycle threshold value less than the packet count that does not send as yet.Therefore, at fluction analysis that moment T402 begins in the cycle, not executive communication dielectric attribute detection scheme (with reference among the step S104 of figure 2 to the flow process of "No").

Then, the state of supposing communication media after a while improves from degradation mode gradually.In this case,, make traffic rate lower, descend owing to the improvement of communication media state makes packet loss although be provided with messaging parameter.Therefore, grouping becomes and is very easy to pass through, and as shown in emission formation 405 and 407, the packet count of emission does not reduce yet as yet.In this case, at the moment T406 that is used to begin the fluction analysis cycle, in the emission formation 407 as yet not the packet count of emission with launch the still nonevent packet count of formation 405 at the moment T404 place that is used for beginning the last fluction analysis cycle and compared minimizing.Therefore, the difference of the average number of packets of emission can be greater than the difference in this class packet count as yet.Equally, because the state of communication media is assumed that deterioration at first, so the emission rate value of setting is less than the threshold value of the emission rate value of setting.For this reason, operation advancing among the step S103 flow process of "Yes", the "Yes" in the step S104 of Fig. 2 then, and thus, executive communication dielectric attribute detection scheme.Therefore, launch terminal is used to detect the assessment series of packets 408 of communication media feature to the receiving terminal emission.Use assessment series of packets 408, receiving terminal detects the communication media feature, divides into groups 409 to launch terminal notice testing result as assessment result then.After receiving assessment result grouping 409, launch terminal is based on the assessment result messaging parameter that resets, and restarts data transmission.So, even the state of communication media changes the improvement state into from degradation mode, launch terminal also can automatically perform communication media feature detection scheme, has determined messaging parameter thus, to follow the change of communication media feature.

Even after having upgraded messaging parameter, the state of communication media also can hang down fluctuation continuously.Therefore, with the operation of fluction analysis cycle synchronisation ground execution graph 2.Even under the situation that the state of communication media worsens significantly, retransmit and take place than also with in the improved situation of the state of communication media fluctuating significantly similarly.Thus, the threshold value of the difference in the ratio takes place greater than repeating transmission in the difference that repeating transmission takes place in the ratio, and therefore operates the flow process that arrives "No" among the step S102 that advances to Fig. 2, executive communication dielectric attribute detection scheme thus.

Fig. 5 illustrates the state of communication media when the communication terminal that uses according to first embodiment and the chart of the relation between the traffic rate.Hereinafter, with reference to figure 5, the state of communication media and the relation between the traffic rate when the communication terminal according to first embodiment uses are described.

In Fig. 5, vertical axis is represented the value or the traffic rate value of the state of communication media.The satisfied more state of positive more value representation communication media and high more emission rate value of setting on the vertical axis.The solid line of overstriking is represented the change of communication media state aspect.The dotted line of overstriking is represented the change of traffic rate.Fine dotted line is represented the threshold value of the emission rate value of setting.Trunnion axis instruction time.The moment that is used to begin the fluction analysis cycle is represented to S10 constantly by moment S1.In Fig. 5, be represented as CE1 and show the wherein time period of executive communication dielectric attribute detection scheme to the segment table of CE5.

In Fig. 5, when beginning the basic cycle of communication media feature detection scheme, executive communication dielectric attribute detection scheme in section CE1.So, be provided with messaging parameter.In Fig. 5, the traffic rate of deriving from messaging parameter is set is assumed that the threshold value greater than the emission rate value of setting at first.Therefore, process advances among the step S103 of Fig. 2 the flow process of "No", not executive communication dielectric attribute detection scheme thus.

The state that Fig. 5 shows communication media worsens suddenly near moment S3.In this case, at moment S3, repeating transmission generation ratio is bigger with the difference that the minimum repeating transmission is compared.Suppose that the threshold value of the difference in the ratio takes place greater than repeating transmission the difference in the repeating transmission generation ratio herein.In this case, this process advances among the step S102 of Fig. 2 the flow process of "No".Therefore, executive communication dielectric attribute detection scheme (step S105) in section CE2.So, the state that detects communication media changes degradation mode into from satisfied state, and based on the state of the communication media that begins place's (moment of emission assessment series of packets) of section CE2, messaging parameter is set.So, be provided with messaging parameter, to follow the degradation mode of communication media.

To moment S5, the state of communication media is maintained at low state from moment S4.Therefore, near the not minimizing of grouping that moment T3, stores and do not launch as yet.Therefore, this process advances among the step S104 of Fig. 2 the flow process of "No", not executive communication dielectric attribute detection scheme thus.

Afterwards, near moment S6, the state of communication media has shown improved trend.In this case, low even traffic rate is set to, because the packet loss of the noise effect of communication media often also reduces.Therefore, the stored grouping of not launching as yet begins to reduce.Therefore, this process advances among the step S104 of operation shown in Figure 2 the flow process of "Yes", and the moment T6 place execution that is beginning to sample.So, in section CE3, executive communication dielectric attribute detection scheme upgrades messaging parameter, and improves traffic rate.Fig. 4 shows an example of this flow process of this process.

For example, if the state of communication media shows improved trend near moment S6, then the threshold value that the difference in the ratio can become and greater than retransmitting the difference in the ratio take place takes place in repeating transmission.So, this process can advance to the flow process that arrives "No" among the step S102, so executive communication dielectric attribute detection scheme.This process advances among the step S102 one of flow process of the "No" unexpected improved situation of state of communication media in typical case.An example of this flow process of this process is shown in Figure 3.

At moment S7, the state of communication media shows improved trend equally.Therefore, this process advances among the step S104 among the flow process of "Yes" or the step S102 to the flow process of "No", and therefore executive communication dielectric attribute detection scheme in section CE4 upgrades messaging parameter, and improves traffic rate.

Then, after moment S8 reached, the state of communication media showed further improved trend.Yet traffic rate is greater than the threshold value of the emission rate value of setting, so this process advances to the flow process that arrives "No" among the step S103, not executive communication dielectric attribute detection scheme thus.Yet, when next basic cycle arrives, executive communication dielectric attribute detection scheme in section CE5, and be arranged on suitable messaging parameter of this moment.

So, whether to surpass the regular situation of predetermined value different with only determine retransmitting number of times, according to the communication terminal of first embodiment first element to indication grouping emission effciency, such as retransmit take place than or the difference and the predetermined threshold of the packet count of emission do not compare as yet.Therefore, communication terminal can detect the grouping emission effciency and whether change predetermined extent or higher into.In routine techniques, the fact that retransmitting number of times increases is only informed this phenomenon of the characteristic deterioration of communication media.In communication terminal, except that the phenomenon of communication media characteristic deterioration, also can detect the improved phenomenon of communication media feature according to first embodiment.Therefore, in communication terminal,, also can make messaging parameter, to follow the state of communication media suitably even the state of communication media changes the improvement state into from degradation mode according to first embodiment.Therefore, may provide the improvement that allows the whole communication system throughput and reduce from the communication media state take place fluctuation the time be carved into the communication terminal of the time that the moment spent that messaging parameter changes.

Herein, in first embodiment, such as retransmit to take place than or as yet not the information elements such as packet count of emission be (with reference to the step S100 among the figure 2) that the section start in the fluction analysis cycle calculates.Perhaps, this calculating is (the step S102 of Fig. 2 or the S104) that carries out in the step that difference and threshold value are compared.Equally, as long as the information that obtains to be used for the computing information element (for example, packet retransmission sum, emission total number packets and the packet count of not launching as yet), access control unit 101 just can calculate each information element (retransmitting the packet count that generation is not launched than the Buddhist monk), be stored in the transmit buffer 102 with the element that will be calculated, and as long as the operation among execution in step S100, S102 or the S104, access control unit 101 just can extract stored information element.

Equally, in first embodiment, retransmit for calculating take place than in difference, calculate repeating transmission that current fluction analysis calculates in the cycle and take place than retransmitting the absolute value of the difference that compares with minimum.Perhaps, the current fluction analysis repeating transmission of calculating in the cycle absolute value that the difference that compares than the repeating transmission of calculating in the cycle with last fluction analysis takes place can be used as to retransmit poor in the ratio is taken place.Equally, the repeating transmission generation ratio that replaces direct last fluction analysis to calculate in the cycle, the repeating transmission of calculating in any of previous fluction analysis cycle takes place than the fluctuation that can be used in definite grouping emission effciency.

In addition, in first embodiment, access control unit 101 will be retransmitted the difference and its threshold value that take place in the ratio and compare (step S102), and mean difference and its threshold value in the packet count that will not launch as yet compares (step S104) then.Perhaps, access control unit 101 can compare mean difference and its threshold value in the packet count of not launching as yet, can compare retransmitting the difference and its threshold value that take place in the ratio then.

Moreover, the emission rate value of setting and its threshold value can be compared (step S103).Perhaps, this process can be omitted.

Moreover, in first embodiment, can be used as the emission rate value of setting in the data volume of each 1 block of symbols emission.Perhaps, the number of the subcarrier in the use can be used as the emission rate value of setting.

Moreover, determine that the process whether packet count is equal to or greater than among the step S101 of minimum packets number is not indispensable process.

(second embodiment)

In a second embodiment, the similar of communication terminal is in the structure according to first embodiment.Therefore, also be described with reference to figure 1.Yet in first embodiment, whether executive communication dielectric attribute detection scheme is special definite by the communication terminal that is positioned at emitting side.In a second embodiment, whether executive communication dielectric attribute detection scheme is to determine that by the communication terminal that is positioned at receiver side this communication terminal request is positioned at the communication terminal executive communication dielectric attribute detection scheme of emitting side.At the communication terminal that is arranged in receiver side according to second embodiment, the function of access control unit 101 and modulation/demodulation unit 105 is different with function according to those unit of first embodiment.In a second embodiment afterwards, except as otherwise noted, otherwise access control unit 101 and modulation/demodulation unit 105 are assumed that access control unit 101 and the modulation/demodulation unit 105 that relates to the communication terminal that is positioned at receiver side.

The grouping that modulation/demodulation unit 105 demodulation receive via communication media, and make error correction performance element 104 carry out error correction.At this moment, modulation/demodulation unit 105 makes the bit length (hereinafter be called and receive the grouping bit length) that receives grouping be stored in the reception buffer 103.Equally, modulation/demodulation unit 105 is 105 bit numbers (hereinafter being called the correction bits number) that to need to obtain error correction from the correction process unit, make this number be stored in the reception buffer 103 then.In addition, modulation/demodulation unit 105 is calculated total reception grouping bit length up to now, makes this sum be stored in the reception buffer 103 then.Based on the store status that receives among the formation 103a, access control unit 101 is counted the reception packet count of each launch terminal, makes this number be stored in the reception buffer 103 then.

As be located on the access control unit 101 in the communication terminal of emitting side, access control unit 101 is preserved for timer that the fluction analysis cycle is counted.Yet in essence, the fluction analysis cycle that is positioned at receiver side is synchronized with each other with the fluction analysis cycle that is positioned at emitting side.

Fig. 6 is the flow chart that illustrates according to the operation of the access control unit 101 in the communication terminal 100 of the second embodiment of the present invention.Hereinafter, with reference to figure 6, the operation of fluction analysis access control unit 101 in the cycle is described.Notice that branch group of received and demodulation are to carry out concomitantly with the operation shown in Fig. 6.Therefore, receiving the operation shown in grouping bit length, total reception grouping bit length, correction bits number and total correction bits number and Fig. 6 stores concomitantly.

The notice in the beginning fluction analysis cycle of self-timer begins since the process shown in Figure 6, and this is notified as trigger.

At first, access control unit 101 is carried out the process (step S200) of extraction and store information element.Herein, information element is an information of the state of reflection communication media, and can be used as result's acquisition of grouping emission.Information element according to second embodiment is an information of the indication grouping quality of reception.For reducing the processing load on the communication terminal, information element is preferably an information can easily being calculated.In a second embodiment, use error correction rate, be used for the indication grouping quality of reception as information element.Notice that information element described herein only is an example, and does not mean that restriction, as long as it is an information of the indication grouping quality of reception.

Particularly, at step S200, access control unit 101 is based on total reception grouping bit length and total correction bits number, and the moment computing error correction rate in the beginning fluction analysis cycle makes institute's rate calculated be stored in the reception buffer 103 then.For example, error correction rate calculates according to (total correction bits number)/(total grouping bit length that receives).

Then, access control unit 101 determines whether the reception packet count equals greater than predetermined minimum packets number (step S201).Packet count is not equal to or greater than predetermined minimum packets number, then access control unit 101 advances to the operation among the step S204 if receive.On the other hand, be equal to or greater than predetermined minimum packets number if receive packet count, then access control unit 101 advances to the operation among the step S202.

At step S202, access control unit 101 calculates the poor of minimum value (second information element: hereinafter be called minimum error correction rate) in error correction rate (first information element) that current fluction analysis calculates in the cycle and the previous error correction rate, as the difference in the error correction rate, determine whether the difference in the error correction rate is equal to or greater than the predetermined threshold of the difference in the error correction rate., minimum error correction rate is not set in the cycle herein, and is 0 therefore at first fluction analysis.In any of subsequently fluction analysis cycle, with the value that is provided with in step 204 that further describes hereinafter as minimum error correction rate.

If the difference in the error correction rate is not equal to or greater than the predetermined threshold of the difference in the minimum error correction rate, then access control unit 101 advances to the operation among the step S204.On the other hand, if the difference in the error correction rate is equal to or greater than the predetermined threshold of the difference in the error correction rate, then access control unit 101 advances to the operation among the step S203.

In step S203, access control unit 101 determines whether to want executive communication dielectric attribute detection scheme, then to the communication terminal emission assessment series requests grouping that is positioned at emitting side.In response, be positioned at the communication terminal emission assessment series of packets of emitting side.Then, be positioned at the communication terminal of receiver side to the communication terminal transmission assessment result grouping that is positioned at emitting side.So, executive communication dielectric attribute detection scheme.After the operation in step S203, access control unit 101 advances to the operation among the step S204.

In step S204, the minimum value in the previous error correction rate that access control unit 101 recovers in the reception buffer 103 is as minimum error correction rate.

Step S200 is to carry out from beginning and its end in fluction analysis cycle to the operation among the S204.After having finished the operation of step S200 in S204, access control unit 101 is waited for, arrives up to the moment in next fluction analysis cycle of beginning, to begin operation shown in Figure 6.

Fig. 7 is the precedence diagram that is used to describe when the state of the communication media example of the selection of time of executive communication dielectric attribute detection scheme when degradation mode changes the improvement state into.Below, with reference to figure 7, the example when the timing of executive communication dielectric attribute detection scheme when degradation mode changes the improvement state into of the state of communication media is described.

At first, suppose that launch terminal has been launched a plurality of groupings as data sequence 801 when being used to begin the moment T800 arrival in fluction analysis cycle.

Then, the state of supposing communication media the moment T802 that is used to begin another fluction analysis cycle and after be improved.In this case, error correction rate reduces, and therefore the difference in the error correction rate can be equal to or greater than the threshold value of the difference in the error correction rate.At the moment T804 that is used to begin the another fluction analysis cycle, when the difference in determining error correction rate is equal to or greater than the threshold value of the difference in the error correction rate flow process of "Yes" (in reference to the step S202 of figure 6 to), receiving terminal sends assessment series requests grouping 805 to launch terminal.In response, launch terminal returns assessment series of packets 806 to receiving terminal.Based on assessment series of packets 806, receiving terminal calculates the modulation index of each subcarrier, and the index that is calculated is stored in the assessment result grouping 807, then this grouping is transmitted into launch terminal.Based on assessment result grouping 807, launch terminal changes messaging parameter.So, finished the process of executive communication dielectric attribute detection scheme.After having carried out communication media feature detection scheme, receiving terminal compares the minimum error correction rate and the minimum error correction rate of data sequence 802, then minimum error correction rate is updated to less than the two error rate.

Thus, according to the communication terminal of second embodiment will indicate the grouping quality of reception information element, compare such as difference in the error correction rate and predetermined threshold.Therefore, communication terminal can detect the quality of reception and whether change predetermined degree or higher into.In communication terminal, except that the phenomenon of communication media characteristic deterioration, also can detect the improved phenomenon of communication media feature according to second embodiment.Therefore, in communication terminal,, also can make messaging parameter, to follow the state of communication media suitably even the state of communication media changes the improvement state into from degradation mode according to second embodiment.Therefore, may provide the improvement that allows the whole communication system throughput, and reduce from the state of communication media have fluctuation the time be carved into the communication terminal of the time that the moment spent that changes messaging parameter.

Herein, in a second embodiment, be begin (with reference to the step S200 among the figure 6) that locate to calculate in the fluction analysis cycle such as information elements such as error correction rates.Perhaps, this calculating is (the step S202 among Fig. 6) that carries out in the step that difference and threshold value are compared.

Equally, as long as correction process is carried out in the grouping that receives, access control unit 101 is with regard to the computing error correction rate.In this case, the error correction rate that is calculated can be stored in the reception buffer 103, and when the process in the execution graph 6, access control unit 101 extracts stored nearest error correction rate and minimum error correction rate, calculate the absolute value of their difference, calculated the difference in the error correction rate thus.

In addition, in first embodiment, be the difference in the computing error correction rate, calculate the absolute value that error correction rate that current fluction analysis calculates in the cycle and minimum are retransmitted the difference that compares.Perhaps, can adopt the absolute value of the difference of the error correction rate that error correction rate that current fluction analysis calculates in the cycle and last fluction analysis calculate in the cycle, as the difference in the error correction rate.Equally, the error correction rate that last fluction analysis calculated in the cycle is not limited to the error correction rate that direct last fluction analysis calculated in the cycle, as long as it is the error correction rate that calculates in formerly any of fluction analysis cycle.

Moreover, equally in a second embodiment, as shown in first embodiment, can come executive communication dielectric attribute detection scheme when needed at launch terminal side executive communication dielectric attribute detection scheme.

Moreover in first and second embodiment, the fluction analysis cycle is constant, but also can be variable.If the fluction analysis cycle is constant, and on network, there are a plurality of terminals, then are used to begin the moment in fluction analysis cycle probably overlap each other.Therefore, communication media feature detection scheme may be carried out simultaneously by a plurality of communication terminals.Therefore, the fluction analysis cycle changes at random mode, perhaps upgrades the fluction analysis cycle of each communication terminal with specific algorithm, prevents this possibility by a plurality of communication terminals executive communication simultaneously dielectric attribute detection schemes thus.Equally, if even an also slight change of messaging parameter when executive communication dielectric attribute detection scheme, that is, if the communication speed slight change, then the fluction analysis cycle can be changed to prolong.Along with the fluction analysis cycle is extended, reduced calculation times and definite number of times of information element, reduced thus and be used on the communication terminal to calculate and processing load that definite information element is required.

Moreover, in first or second embodiment, communication media feature detection scheme can retransmit to take place than or error correction rate in one section preset time, be in continuously under the condition in the predetermined value scope and carry out.State at communication media reaches under the situation of satisfaction to a certain degree from the beginning, retransmits generation ratio or error correction rate and can be approximated to be 0.Therefore, in first or second embodiment,, then retransmit the state that the difference that takes place in ratio or the error correction rate can not be used to estimate communication media if state further improves.For dealing with this problem, as modification to first or second embodiment, communication media feature detection scheme can retransmit to take place than or error correction rate carry out when in one section preset time section, being in the preset range continuously.So, even communication media feature detection scheme also can be performed, allow more suitably to be provided with messaging parameter thus when the state of communication media reaches a certain degree satisfied.

Moreover, launch for multicarrier, the timing of executive communication dielectric attribute detection scheme can be by based on information element, and such as the intensity of the electrical power in the whole acquisition frequency, or the fluctuation of difference that is used for correcting the received signal level of preamble estimates that the state of communication media determines.

(the 3rd embodiment)

In the 3rd embodiment, the similar of communication terminal is in the structure according to first embodiment.Therefore, also with reference to figure 1.

In such as communication systems such as WLAN or power line communications, can't detect the interference between the emission grouping.Therefore, receiving terminal normally returns the success of indication grouping emission or the information of failure is divided into groups as ACK.So, can detect the interference of launching between the grouping.

Fig. 8 illustrates according to the launch terminal of the third embodiment of the present invention and the precedence diagram of the handling process between the receiving terminal.As shown in Figure 8, launch terminal is to receiving terminal transmit data packet 1301.Based on the accepting state of packet 1301, receiving terminal obtains characteristic information, comprises this characteristic information in ACK grouping 1302, then the ACK grouping is transmitted to launch terminal.Launch terminal obtains characteristic information then from the ACK grouping 1302 that is received, to determine whether to want executive communication dielectric attribute detection scheme.As characteristic information, use the correction bits number of the size of the required reception grouping of indication error correction herein.Equally, used CINR (carrier wave is to disturbing and noise power ratio), it is to be obtained about the part as the serial packet of being launched of assessment by receiving terminal.Thus, characteristic information is the information of indication as the grouping quality of reception of result's acquisition of the feature of assessment communication media.

It is relevant with the theory of bit error rate (BER) that the CINR value has.Therefore, the fluctuation in the communication media state can be estimated with the increase or the minimizing of CINR value.Fig. 9 A is the example that the data packet format of the packet that partly comprises a part that is assumed that assessment series is shown.Shown in Fig. 9 A, the whole group head can be used as assessment series and adopts.Fig. 9 B is the diagram that partly comprises another example of the data packet format that is assumed that the packet of assessing a serial part.Shown in Fig. 9 B, assessment series may reside between packet header and the data subject.

The data pattern of the assessment series among the 3rd embodiment is similar to the data pattern that is included in the assessment series of packets of each basic cycle emission, and can use between launch terminal and receiving terminal usually.As routine techniques, each part of assessing the data in the series is pre-determined to use which subcarrier.Therefore, receiving terminal can be to each subcarrier, about assessing CINR from the assessment series of launch terminal emission.The total value of the CINR of the feasible subcarrier separately of receiving terminal is comprised in the ACK grouping as the CINR value, is used to be transmitted into launch terminal.So, launch terminal can detect the state of communication media.

Yet the assessment series among the 3rd embodiment is less in size, therefore with to the assessment series of each basic cycle emission compares, and can not reduce throughput.This is because use size and the approximately uniform assessment series of assessment series that each basic cycle is launched to reduce throughput.

If assessment series is shorter, only can obtain and assess the instantaneous CINR when the communication media state changes.On the other hand, if assessment series is longer, then can on one long period, obtains CINR, and therefore can obtain the mean value of the CINR of section sometime.If the communication media feature is local the observation, then can not be only section be sometime assessed CINR exactly, because feature can fluctuate astatically with the assessment of instantaneous CINR.Therefore, compare with the situation that assessment series is long, the accuracy of CINR is lower in assessment series.Below, the assessment series that each basic cycle is launched is called as normal assessment series, is become simple assessment series and have the assessment series that will be included in the less size in the emission grouping.

The inventor uses the data of 128 code elements of each subcarrier as normal assessment series, and uses the simple assessment series of data conduct of 4 code elements of each subcarrier.Therefore, simple assessment series is to have short length, so that can be comprised in the data in the packet header shown in Fig. 9 A, and so can not reduce throughput.Equally, if data comprise in the mode shown in Fig. 9 B, then this can not cause throughput to reduce.

As further describing hereinafter, according to the 3rd embodiment, the simple assessment that is included in the emission grouping is serial in size less than the assessment series to each basic cycle emission.Therefore, can be lower on accuracy by the CINR that simple assessment series obtains by receiving terminal.Therefore, this CINR with low accuracy is comprised in the ACK grouping, and is launched into launch terminal then.Yet launch terminal is to the CINR summation with low accuracy from ACK grouping, obtaining mean value as information element, and uses difference in the CINR mean value to detect the fluctuation of communication media feature.Therefore, even launch terminal uses the CINR with low accuracy, also can detect the fluctuation in the communication media feature.

Packet header partly is with minimum communication speed and passes through the part that the most redundant modulation scheme is launched, so that can be detected by all terminals in the communication system.Therefore, shown in Fig. 9 A, when the packet header part was regarded assessment series, CINR detected and can realize with higher relatively accuracy.Especially for DMT, the average power of subcarrier is constant in the packet header part, and therefore packet header is applicable to as assessment series.

Herein, the CINR value is the characteristic value of mean value of the CINR of all subcarriers of indication.In the 3rd embodiment, use can be to total bit number of each block of symbols emission as the CINR value, and it is to calculate by the CINR that assesses each subcarrier.That is, use can be in the data volume of each block of symbols emission.

Equally, can use SINR (signal is to the disturbing pulse noise ratio) value to come replaced C INR value as characteristic information.In addition, can use indication to receive the received signal intensity of the receiving intensity that divides into groups as characteristic information.

Launch terminal receives the ACK grouping from receiving terminal, with the characteristic information that obtains to embed.Bit number and the CINR value summation that makes mistakes of 101 pairs of the access control units of launch terminal, they are as long as receive the characteristic information that the ACK grouping just obtains.Equally, access control unit 101 pairs of emissions data length and emitting times summation.Access control unit 101 stores and always corrects bit number, total CINR value, always launches emitting times in data length and the transmit buffer 102 (form that is associated with the emission formation 102a that is used for each destination with them).

Figure 10 is illustrated in fluction analysis flow chart according to the operation of the access control unit 101 of the launch terminal of the 3rd embodiment in the cycle.In the 3rd embodiment, except as otherwise noted, otherwise supposition access control unit 101 refers to the access control unit 101 in the launch terminal.Equally, branch group of received and demodulation are to carry out concomitantly with operation shown in Figure 10.Therefore, always correct bit number, total CINR value, always to launch data length and emitting times be to store concomitantly with operation shown in Figure 10.

Process shown in Figure 10 begins with the notice from the second timer that begins the fluction analysis cycle, and this is notified as trigger.

At first, carry out the process (step S300) of extraction and store information element.Herein, access control unit 101 will always be corrected bit number divided by total emission data length, come the computing error correction rate.Equally, access control unit 101 divided by emitting times, calculates the mean value (hereinafter being called average CINR value) of CINR value with total CINR value.In addition, as first embodiment, access control unit 101 calculates to retransmit and compares.Access control unit 101 adopts error correction rate, average CINR value and retransmits to liken to and is information element.Thus, information element is some information of the state of reflection communication media, and can be used as result's acquisition of grouping emission.Information element according to the 3rd embodiment is some information of the indication grouping emission effciency or the quality of reception.For reducing the processing load on the communication terminal, information element is preferably some information can easily being calculated.

As mentioned above, the normal assessment series of each basic cycle emission of simple assessment series comparison is short.Therefore, for an assessment, only can obtain to have the CINR value of low accuracy.Yet,, can obtain to have the CINR value of high accuracy by the CINR value is sued for peace and averaged redundantly.

Then, access control unit 101 determines in the mode that is similar to first embodiment whether the emission packet count is equal to or greater than predetermined minimum packets number (step S301).If the emission packet count is not equal to or greater than predetermined minimum packets number, then access control unit 101 advances to the operation among the step S307.On the other hand, if the emission packet count is equal to or greater than predetermined minimum packets number, then access control unit 101 advances to the operation among the step S302.,, suppose access control unit 101 each timing herein, packet count is stored in the transmit buffer 102 for the emission grouping as first embodiment.

At step S302, as first embodiment, whether the difference in access control unit 101 definite repeating transmission generation ratios is less than the threshold value of retransmitting the difference in the generation ratio.Retransmit the threshold value that the difference in the ratio takes place if this value is not less than, then access control unit 101 advances to the operation among the step S306.If should be worth the threshold value that the difference in the ratio takes place less than retransmitting, then access control unit 101 advances to the operation among the step S303.

At step S303, as first embodiment, access control unit 101 determines that the emission rate values of setting are whether less than the threshold value of the emission rate value of setting.If this value is not less than the threshold value of the emission rate value of setting, then access control unit 101 advances to the operation among the step S307.On the other hand, if this value less than the threshold value of the emission value of setting, then access control unit 101 advances to the operation among the step S304.

At step S304, access control unit 101 is at the absolute value of the difference of error correction rate (first information element) that current fluction analysis calculated in the cycle and the error correction rate (second information element) that calculates in the cycle at last fluction analysis, as the difference in the error correction rate, determine then whether the difference in the error correction rate is equal to or greater than the threshold value of the difference in the error correction rate.Notice that as long as calculated the poor of the error correction rate that calculates in any of fluction analysis cycle formerly, this difference just is not limited to the poor of error correction rate that direct last fluction analysis calculates in the cycle.

If the difference in the error correction rate is equal to or greater than the threshold value of the difference in the error correction rate, then access control unit 101 advances to the operation among the step S306.On the other hand, if the difference in the error correction rate is not equal to or greater than the threshold value of the difference in the error correction rate, then access control unit 101 advances to the operation among the step S305.

At step S305, the absolute value of the difference of the average CINR value (second information element) that average CINR value (first information element) that the current fluction analysis of access control unit 101 calculating calculated in the cycle and last fluction analysis calculated in the cycle, as average CINR difference, determine then whether this average CINR difference is equal to or greater than the threshold value of CINR difference.Notice that as long as calculated the poor of the average CINR value calculated in any of previous fluction analysis cycle, this difference just is not limited to the poor of average CINR value that direct last fluction analysis calculates in the cycle.

If average CINR difference is not equal to or greater than the threshold value of CINR mean value, then access control unit 101 advances to the operation among the step S307.On the other hand, if average CINR difference is equal to or greater than the threshold value of CINR difference, then access control unit 101 advances to the operation among the step S306.

At step S306, access control unit 101 determines to want executive communication dielectric attribute detection schemes, to the communication terminal emission assessment series of packets that is positioned at receiver side, based on the assessment result of returning in the response messaging parameter that divides into groups to reset.Then, access control unit 101 advances to the operation among the step S307.

At step S307, access control unit 101 upgrades retransmits the minimum value that ratio takes place.

Step S300 carries out during the fluction analysis cycle to the operation among the S307.After finishing processing, access control unit is waited for, arrives up to the moment in next fluction analysis cycle of beginning, to begin operation shown in Figure 10.

Thus, according to the 3rd embodiment, launch terminal uses the simple assessment series that can not cause throughput to reduce, to be included in the grouping that is used for being transmitted into receiving terminal.Based on being included in the simple assessment series that receives in the grouping, receiving terminal obtains the characteristic information of CINR value as communication media.Equally, receiving terminal obtains to receive the characteristic information of the correction bits number of grouping as communication media.Receiving terminal makes characteristic information (CINR value, correction bits number) be comprised in to be used for the ACK grouping that is transmitted into launch terminal.Based on this CINR value and correction bits number, they are included in the characteristic information in the ACK grouping, launch terminal computing error correction rate and average CINR value, and they are information elements.Equally, launch terminal calculates to retransmit to liken to and is information element.Launch terminal compares each information element (ratio takes place for error correction rate, average CINR value and repeating transmission) then with predetermined threshold.Therefore, launch terminal can detect in the grouping emission effciency or the quality of reception whether predetermined extent or higher fluctuation have taken place to reach.In the technology of routine, the fact that retransmitting number of times increases is only informed the phenomenon of communication media characteristic deterioration.In communication terminal, except that the phenomenon of communication media characteristic deterioration, also can detect the improved phenomenon of communication media feature according to the 3rd embodiment.Therefore, in communication terminal,, also can make messaging parameter, to follow the state of communication media suitably even the state of communication media changes the improvement state into from degradation mode according to the 3rd embodiment.Therefore, may provide the improvement that allows the whole communication system throughput, the state that reduces communication media simultaneously take place fluctuation the time be carved into the communication terminal of the time that the moment spent that changes messaging parameter.

Equally, in receiving terminal, correction bits number and CINR are the information that obtains easily.Therefore, do not increase processing load on the receiving terminal.In addition, characteristic information (correction bits number and CINR) is comprised in the ACK grouping that requirement all the time is launched, and perhaps short commentary is estimated series (simple assessment series) and is comprised in the part of emission grouping.Therefore, the processing according to the 3rd embodiment can not increase throughput.In addition, the emission owing to dividing into groups from the assessment series requests of receiving terminal does not increase throughput.

In addition, in the 3rd embodiment, the average CINR value and the error correction rate that calculate based on CINR and correction bits number are used as information element.Therefore, can expect to detect more accurately fluctuation in the communication media state.Equally, can expect to make messaging parameter to follow the fluctuation in the communication media state more accurately.

Moreover in the 3rd embodiment, the absolute value of the difference of the error correction rate that error correction rate that the current fluction analysis of access control unit 101 calculating calculated in the cycle and last fluction analysis calculated in the cycle is as the difference in the error correction rate.Perhaps, can calculate the absolute value of error correction rate that current fluction analysis calculates in the cycle and the difference of minimum error correction rate value till the last fluction analysis cycle, as the difference in the error correction rate.In this case, in the step S307 of Figure 10, upgrade minimum value.

Moreover in the 3rd embodiment, the absolute value of the difference of the average CINR value that average CINR value that the current fluction analysis of access control unit 101 calculating calculated in the cycle and last fluction analysis calculated in the cycle is as average CINR difference.Perhaps, can calculate the absolute value of average CINR value that current fluction analysis calculates in the cycle and the difference of minimum average B configuration CINR value till the last fluction analysis cycle, as average CINR difference.In this case, in the step S307 of Figure 10, upgrade minimum value.

Moreover, access control unit 101 can calculate and keep the CINR value when receiving the assessment series of packets, can calculate the absolute value of the difference of the CINR value that the previous moment of average CINR value that current fluction analysis calculates in the cycle and executive communication dielectric attribute detection scheme obtains then, as average CINR difference.This is because if the accuracy of average CINR value is higher, then the CINR value that obtains by communication media feature detection scheme can be compared with this average CINR value, to detect the fluctuation in the communication media feature.

Yet as long as stored the required information (ratio takes place for average CINR value, error correction rate and repeating transmission) of computing information element, access control unit 101 just can calculate this information element for storage.In this case, access control unit 101 determines whether to want executive communication dielectric attribute detection scheme to the stored information element of each fluction analysis periodicity extraction.

Equally, when SINR value and received signal intensity were used as characteristic information, access control unit 101 can extract average SINR value or average received signal strength, and its difference is compared with threshold value, determined whether to want executive communication dielectric attribute detection scheme then.

Moreover step S301, S302, S303, S304 and S305 order can partly be exchanged among Figure 10.

Especially, any of step S304 and S305 can at first be carried out in these two.

Moreover step S302 normally detects the deterioration of communication media state.Therefore, if detect the improvement of communication media state, the then operation of execution in step S304 or S305 before the operation of step S302.

Moreover step S303 prevents that traffic rate is fixed on lower speed, and suppresses unnecessarily with the frequency up to the traffic rate executive communication dielectric attribute detection scheme of a certain degree.Perhaps, the threshold value of the difference in the threshold value of the difference in the error correction rate and the CINR value can be set to little, and can omit the operation among the step S303.

Moreover it is optional to be used among the step S301 determining whether packet count is equal to or greater than the process of minimum packets number.

Moreover the threshold value of the difference in the error correction rate can change according to current emission rate value of setting.The messaging parameter that is provided with under the condition of the state deteriorating of communication media is different from the messaging parameter that is provided with under the gratifying condition of the state of communication media, in the width of the fluctuation that this error correction rate that do not coexist causes owing to the fluctuation of communication media state.The always anti-messaging parameter that make mistakes, highly redundant of the messaging parameter that under the condition of communication media state deteriorating, is provided with.Therefore, if under the condition of the state deteriorating of communication media messaging parameter has been set, even the state of communication media improves, the difference of the fluctuation in the error correction rate is compared less with the messaging parameter that is provided with under the gratifying condition of the state of communication media.Therefore, if the emission rate value of setting is higher, then the threshold value of the difference in the error correction rate is changed to height, and if the emission rate value of setting lower, then the threshold value of the difference in the error correction rate is changed to low.

According to first to the 3rd embodiment, even not executive communication dielectric attribute detection scheme also can be provided with messaging parameter to each basic cycle, to follow the state of communication media.Yet, in first to the 3rd embodiment, provide emission rate that the threshold value of threshold value is set.Therefore, even the state of communication media is all satisfactory continuously in a very long time, then can not make messaging parameter follow this state of communication media.This is the reason to each basic cycle executive communication dielectric attribute detection scheme.

Notice that the foregoing description also can be by making computer realization can make CPU realize that the above-mentioned program that is stored in the processing procedure in the memory device (for example, ROM, RAM, hard disk etc.) realizes equally.In this case, this program can realize after it is stored in the memory device by recording medium, perhaps can directly realize from recording medium.Term described herein " recording medium " refers to ROM, RAM, such as semiconductor memories such as flash memories, such as magnetic disc stores such as floppy disk, hard disks, such as CD-ROM, DVD or blue ray disc CD or storage cards such as (BD).Term " recording medium " also refers to comprise communication medias such as telephone wire, carrier path as used herein.

Notice that access control unit 101 can be implemented as integrated on a large scale (LSI) circuit.This functional block can be implemented as and comprise its part or all single chip.Select the group that the LSI circuit can constitute from the integrated circuit by various degree of integration, for example IC, system LSI, super LSI, LSI etc. very.In addition, be used to realize that the integrated technology of aforesaid circuit is not limited to the LSI technology, and aforesaid integrated circuit can use special circuit or general processor to realize.Also may use the field programmable gate array (FPGA) that after manufacturing, to programme, perhaps can use reconfigurable processor, make the connection of its circuit unit and setting thereof to be reconfigured.In addition, under the situation of introducing the novel circuit integrated technology, substitute the LSI technology, because the progress of semiconductor technology or other correlation technique, it is integrated that the above-mentioned functions piece can use this new technology.Can conceive, biotechnology etc. can be applied to the integrated of functional block.

The example that the foregoing description is applied to a real network system is below described.Figure 11 is the diagram that whole system configuration when being applied to high speed power line transmission according to communication terminal of the present invention is shown.As shown in figure 11, communication terminal of the present invention is as providing such as the interface between multimedia device such as Digital Television (DTV), personal computer (PC), DVD register and the power line.Multimedia device can be connected to communication terminal of the present invention by IEEE 1394 interfaces, USB interface or Ethernet interface.Adopt this structure, communications network system is by structuring, so that by launching such as numerical datas such as multi-medium datas via the power line as communication media at a high speed.Therefore, different with the situation of conventional wired lan, may use previous at home, the power line installed such as office is as grid line, and do not provide network cable again.Therefore, the convenience of this system is quite high for cost of installing and simplification.

In the example depicted in fig. 11, communication terminal of the present invention is to provide as being used for the adapter that individual interface with existing multimedia device is fitted to power line communications interface.Yet communication terminal of the present invention can be included in such as in the multimedia devices such as personal computer, DVD register, Digital Television, home server system.This permission transmits data via its power line between multimedia device.In this case, may eliminate the electric wire and IEEE-1394 cable or the USB cable that are used for adapter is connected to power line, simplify system's line thus.

In addition, in the communications network system of electrification line, to the internet, the connection of WLAN or conventional wired lan can make via router and/or hub, and therefore, expansion adopts the LAN system of communications network system of the present invention to have no difficulty.

In addition, can not intercepted by the communication data of power line via the power line transmission emission, unless intercepting is to pass through to the direct connection of power line to carry out, and therefore, in fact less than the data leak that is caused by intercepting, and this is the shortcoming of WLAN.Therefore, power line transmission is favourable from the fail safe viewpoint.Much less, the data by the power line emission can be used for Security Architecture (IPsec), the encrypted content itself of Internet protocol or adopt other Digital Right Management (DRM) technology to be protected by employing.

Industrial usability

The invention provides a kind of communication terminal that can carry out transmission path feature detection scheme, and a kind of true Surely carry out the method for the timing of transmission path feature detection scheme, this can improve the efficiency of transmission of whole communication system, And can be applicable to field and other industrial circle of AV transmission. Industrial usability of the present invention is extremely wide and huge Big.

Claims (18)

1. communication terminal, the grouping that described communication terminal comes modulation and demodulation to be used to transmit and receive based on the messaging parameter that is used for modulation and demodulation, the described messaging parameter that is used for modulation and demodulation is determined according to the communication media feature, it is characterized in that this communication terminal comprises:

The information element extracting device, it extracts any information of the emission effciency of the described grouping of indication and the quality of reception to each predetermined period, as information element;

The difference calculation element, it calculates by described information element extracting device at the first information element of current periodicity extraction with by second information element poor of described information element extracting device in periodicity extraction last time each described predetermined period; And

Detection scheme is carried out and is determined device, and it is poor based on the described first information element that is calculated by described difference calculation element and second information element, and each described predetermined period is determined whether to carry out the scheme that the communication media feature changes messaging parameter that detects,

Described information element extracting device extracts the repeating transmission generation ratio of emission grouping, as the described information element of the emission effciency of indicating described grouping.

2. communication terminal as claimed in claim 1 is characterized in that:

Described information element extracting device extracts as yet the not average number of packets of emission, as the information element of the emission effciency of indicating described grouping.

3. communication terminal as claimed in claim 1 is characterized in that:

Described information element extracting device extracts the error correction rate that receives grouping, as the information element of the quality of reception of indicating described grouping.

4. communication terminal as claimed in claim 1 is characterized in that:

Described information element extracting device extracts the information element of the quality of reception of the described grouping of indication based on being included in the characteristic information ACK grouping, that indicate the quality of reception of described grouping that returns from the communication terminal that is arranged in a side that receives described grouping.

5. communication terminal as claimed in claim 2 is characterized in that:

Described difference calculation element calculate described repeating transmission take place than in difference and described poor in the average number of packets of emission not as yet; And

Described detection scheme execution determines that the definite difference that takes place in the ratio when described repeating transmission of device is equal to or greater than the predetermined threshold that the difference in the ratio takes place in described repeating transmission, or when described as yet not the difference in the average number of packets of emission as yet not during the predetermined threshold of difference in the average number of packets of emission, carry out described detection scheme greater than described.

6. communication terminal as claimed in claim 5 is characterized in that:

Described detection scheme is carried out and is determined that device also determines to carry out described detection scheme when emission rate value of setting during less than the threshold value of described emission rate value of setting.

7. communication terminal as claimed in claim 3 is characterized in that:

Described difference calculation element calculates poor in the described error correction rate; And

Described detection scheme is carried out and is determined that device is definite when the difference in the described error correction rate is equal to or greater than the predetermined threshold of the difference in the described error correction rate, carries out described detection scheme.

8. communication terminal as claimed in claim 4 is characterized in that:

Described characteristic information is the information of the size of grouping that indication is received by the communication terminal that the is arranged in receiver side part that requires error correction.

9. communication terminal as claimed in claim 8 is characterized in that:

Described information element extracting device is based on the described big or small error correction rate that extracts the quality of reception of indicating the grouping that is received, as described information element.

10. communication terminal as claimed in claim 9 is characterized in that:

Described difference calculation element calculates poor in the described error correction rate; And

Described detection scheme is carried out and is determined that device is definite when the difference in the described error correction rate is equal to or greater than the predetermined threshold of the difference in the described error correction rate, carries out described detection scheme.

11. communication terminal as claimed in claim 4 is characterized in that:

Described grouping comprises the simple assessment series with the preassigned pattern that is used to assess the described quality of reception;

The size of the data of the assessment series that the size of the data of described simple assessment series is used when assessing described communication media feature when the execution detection scheme; And

The carrier wave that described characteristic information is based on the data computation that is included in the simple assessment series in the grouping that is received by the communication terminal of receiver side to disturb and noise power ratio CINR value, signal in disturbing pulse noise ratio SINR value, the received signal intensity any.

12. communication terminal as claimed in claim 11 is characterized in that:

Described information element extracting device extract a plurality of described carrier waves to disturb and the mean value of noise power ratio CINR value, a plurality of described signal in the mean value of the mean value of disturbing pulse noise ratio SINR value and a plurality of described received signal intensity any, as the information element of the quality of reception of indicating the grouping that is received.

13. communication terminal as claimed in claim 12 is characterized in that:

Described difference calculation element calculates described carrier wave to any to the difference in the mean value of poor, the described received signal intensity in the mean value of disturbing pulse noise ratio SINR value of poor, the described signal in the mean value of interference and noise power ratio CINR value; And

Described detection scheme is carried out and is determined that device determines to carry out described detection scheme when described carrier wave is equal to or greater than predetermined threshold to poor, the described signal in the mean value of interference and noise power ratio CINR value to any of the difference in the mean value of the poor and described received signal intensity in the mean value of disturbing pulse noise ratio SINR value.

14. communication terminal as claimed in claim 1 is characterized in that:

Described detection scheme was carried out each predetermined basic cycle; And

Described predetermined period is shorter than the described predetermined basic cycle.

15. communication terminal as claimed in claim 1 is characterized in that:

Described predetermined period is variable.

16. communication terminal as claimed in claim 1 is characterized in that, also comprises:

The detection scheme final controlling element, when it determines that in described detection scheme execution device is determined to carry out described detection scheme, the assessment series of packets that is used to assess described communication media feature to the communication terminal emission of described receiver side, reception comprises the communication media feature evaluation result's who returns from the communication terminal of described receiver side assessment result grouping, and changes described messaging parameter based on described assessment result grouping.

17. one kind is used for definite method of carrying out the timing of the scheme that detects the communication media feature, the scheme of described detection communication media feature is used to be identified for the messaging parameter of modulation and demodulation grouping, it is characterized in that this method may further comprise the steps:

Each predetermined period is extracted any information of the emission effciency of the described grouping of indication and the quality of reception, as information element;

To each described predetermined period, calculate in described information element extracting step the first information element of current periodicity extraction with in described information element extracting step second information element poor of periodicity extraction last time; And

Poor based on the described first information element that calculates in described calculation procedure and second information element to each described predetermined period, determines whether to carry out the scheme that the communication media feature changes messaging parameter that detects,

Described information element extracting step is extracted the repeating transmission generation ratio of emission grouping, as the described information element of the emission effciency of indicating described grouping.

18. method as claimed in claim 17 is characterized in that, also comprises:

In described information element extracting step, indicate the information element of the quality of reception of described grouping to be based on to be included in the characteristic information of the quality of reception of returning from the communication terminal that is arranged in a side that the receives grouping ACK grouping, the described grouping of indication to extract.

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