CN101873292A - Signal emission and reception method of transform domain communication system and functional module framework - Google Patents
Signal emission and reception method of transform domain communication system and functional module framework Download PDFInfo
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Abstract
The invention belongs to a signal emission and reception method of a transform domain communication system based on orthogonal frequency-division multiplexing and a functional module framework. The method comprises the following steps of: an emission procedure: converting data, carrying out differential coding treatment, generating a CCSK frequency-domain primary function, storing the CCSK frequency-domain primary function, carrying out modulation treatment, converting a signal and transmitting the signal; and a reception procedure: generating the CCSK frequency-domain primary function, storing the CCSK frequency-domain primary function, receiving the signal, converting a time/frequency signal, carrying out demodulation treatment, carrying out differential decoding treatment and converting the data. The used functional module framework comprises a functional module group corresponding to the emission procedure in a transmitter and a functional module group corresponding to the reception procedure in a receiver. In the invention, differential coding is carried out on the data in emission, differential decoding is carried out on the data in the reception procedure after the data are demodulated, and channel estimation and the like are not needed; and moreover, the invention has the characteristics that the data transmission efficiency and the spectrum efficiency can be effectively enhanced, the expense of the system is low, the data still can be reliably transmitted under the conditions that the signal-to-noise ratio is very low and only part of the spectrum can be used and the like.
Description
Technical field
The invention belongs to signal emission, reception technique field in the wireless communication technology, signal emission, method of reseptance and the functional module framework of particularly a kind of transform domain communication system (OFDM-TDCS) based on OFDM.
Background technology
Transform domain communication system (Transform Domain Communication System, TDCS) be by in given spectral range, dynamically change the spectrum waveform that transmits avoid with authorized user (licensed user) between mutual interference mutually.Transform domain communication system uses cyclic shift keying (Cyclic Code Shift Keying, CCSK), its modulation and demodulation process is to select a fixing sequence as the CCSK basic function in transmitter earlier, according to data to be sent basic function is carried out cyclic shift then, the sequence after will being shifted at last sends; And receiver selects the sequence identical with transmitter as the CCSK basic function, restores the data that sent according to the shift amount of receiving sequence and CCSK basic function.
2006, a kind of based on OFDM (Orthogonal Frequency Division Multiplexing, OFDM) transform domain communication system is suggested that (content sees Chuan Han for details, Jun Wang, Yaling Yang, and Shaoqian Li, " Addressing the control channel design problem:OFDM-basedtransform domain communication system in cognitive radio ", Elsevier ComputerNetworks Journal, vol.52, no.4, pp.795-815, Mar.2008).OFDM-TDCS is on the basis of transform domain communication system, in conjunction with the OFDM radiation pattern, the transform domain communication system of traditional single carrier transmission is expanded to multicarrier transmission mode; Simultaneously, adopt the frequency spectrum mark to distinguish available or disabled frequency, simplified the generative process of spectrum waveform.Therefore, the OFDM-TDCS system can be used as the signaling transmission technology in a kind of cognitive radio (CR) network.Being CN1829211A, denomination of invention at publication number promptly belongs to this type of technology for what the patent documentation of " a kind of based on interweaving and the transform domain communication system of OFDM " was put down in writing; This patented technology improves the transmission performance of OFDM-TDCS system under the continuous available situation of frequency spectrum by data map with interweaving, and its method mainly comprises:
One. the emission flow process, referring to Fig. 1:
Step 1: generate the CCSK basic function, be used for modulating to sending data; Concrete steps comprise:. spectrum estimation; . idle frequency spectrum mark (frequency status indication); Random phase generates; Idle frequency spectrum label vector and random phase multiplication of vectors are handled; Generate CCSK basic function and stores processor;
Step 2: data-modulated and interleaving treatment, its step comprises: adopt the CCSK modulation and each is sent data map to become a vector; Vector after element in the vector that is generated done to interweave, to obtain interweaving;
Step 3: generate signal phasor and launch, comprising: with corresponding the multiplying each other of element of CCSK basic function with the vector of step 2 generation by the OFDM mode; Add Cyclic Prefix and emission;
Two. receive flow process, referring to Fig. 2:
Step 1 .OFDM receives: the time-domain signal that receives is handled through the OFDM receiver and is obtained receiving vector;
Step 2: adopt the technology identical to obtain an idle frequency spectrum label vector and random phase vector, to be used for the signal demodulation with transmitter;
Step 3: get conjugation, and after synchronously with the reception vector in corresponding the multiplying each other of element, obtain vector
Step 4: to vector
In element do deinterleaving;
Step 5: the vector after the deinterleaving in the step 4 is carried out inverse discrete Fourier transformer inverse-discrete, and (Inverse DiscreteFourier Transform IDFT), obtains vector
Step 6: get vector
Real part, obtain a real vector;
Step 7: generate new sequence and get of the estimation of the subscript of its greatest member as the transmission data.
But in the wireless communication system of reality, wireless signal will produce large scale decline and small scale decline in communication process.Large scale decline is meant that the power of wireless signal decays along with the increase of propagation distance; The small scale decline is meant that the power of received signal presents different fading characteristics in time with on the frequency owing to the influence of multipath effect and Doppler effect; The large scale decline only influences the signal to noise ratio of received signal, and the small scale decline then can make the received signal distortion.Therefore, wireless communication system must overcome the distorted signals that causes owing to the small scale decline, could handle signal more accurately.Yet, above-mentioned OFDM-TDCS system signal send and receiving course in not at eliminating the skill link that small scale declines, thereby exist practical application effect poor, defective such as be difficult to apply.
Usually, the OFDM-TDCS system also can reduce the influence of small scale decline by adopting coherent approach and non-coherent approaches.Wherein adopt coherent approach to reduce the small scale decline, the channel impulse response (channel impulseresponse) that becomes when being employing characterizes the small scale fading characteristic; In coherent approach, the channel impulse response that becomes when obtaining this by channel estimating (channel estimation), thereby do compensation to received signal, promptly as " channel estimation technique in the transform domain communication system " (" University of Electronic Science and Technology's journal " 2009 the 38th volumes the 1st phase 40-42 page or leaf, author: Wang Jun, Li Shaoqian, Gong Shuping, Han Chuan).Though this technology can reduce the influence of small scale decline effectively, need in the process that sends signal, add the pilot tone (Pilot) that is used for channel estimating; Yet, signal to noise ratio (Signal-to-NoiseRatio when the system works environment, SNR) extremely low, as≤-condition of 10dB under, need send a large amount of pilot tones based on the OFDM-TDCS system of above-mentioned channel estimation methods and could obtain enough precision of channel estimation; Simulation result shows, in order to reach a good channel estimation effect, in the environment of signal to noise ratio for-20dB, need take 1/5 time transmission pilot tone, this has not only seriously reduced the efficient and the spectrum efficiency of transfer of data, but also has increased considerably hardware spending.And adopt non-coherent approaches to solve the small scale decline, and then be to adopt Differential Detection to reduce the influence of small scale decline, this method does not need channel estimating, therefore can not influence the efficient and the spectrum efficiency of transfer of data, and only need increase the less hardware expense; But because non-coherent approaches can not be obtained the information of channel impulse response, so adopt the transmission performance of non-coherent approaches to be not so good as coherent approach again.Traditional non-coherent approaches under the situation of signal to noise ratio higher (more than the 5dB), with the bit error rate performance difference of coherent approach be 3-4dB; But signal to noise ratio≤-condition of 10dB under, then the bit error rate performance difference with coherent approach will increase to 10dB.Therefore, for the OFDM-TDCS system under being operated in utmost point low signal-to-noise ratio condition, adopt the transmission performance extreme difference of traditional non-coherent approaches, and can't in the wireless communication system of reality, use.
Summary of the invention
The objective of the invention is defective at the background technology existence, the emission of a kind of transform domain communication system signal of research and design, method of reseptance and functional module framework, to reach the influence that under the condition that need not channel estimating and pilot tone etc., overcomes the small scale decline, effectively improve under the condition of work of utmost point low signal-to-noise ratio even at frequency spectrum only under the available condition of work of part, the efficient of system transmissions and spectrum efficiency, reduce overhead, purpose such as be beneficial to apply.
Solution of the present invention is on basis of background technology, in the emission flow process data is carried out differential coding and is receiving and in the flow process data after the demodulation are carried out differential decoding, and adopt the functional module framework that adapts to its emission, receives flow process; Thereby under the situation that need not channel estimating and pilot tone, effectively overcome the influence of small scale decline, improve the efficient and the spectrum efficiency of transfer of data, thereby realize its goal of the invention.Thereby signal emission of the present invention, method of reseptance comprise:
One. the emission flow process
Steps A: data transaction: convert the binary bits data flow in the information source to metric original data stream;
Step B: differential coding is handled: each data in the original data stream are carried out differential coding, generate encoded data stream; To overcome the influence of small scale decline;
Step C: generate CCSK frequency domain basic function and storage, to be used for data-modulated; The step that its basic function generates comprises:
C
1. obtain the power spectral value of each frequency:, obtain the power spectral value of each frequency in the working frequency range by conventional spectrum estimating method;
C
2. generate frequency status indication vector: with step C
1The power spectral value of each frequency of gained and predefined threshold value relatively, if when the power spectrum value of frequency surpasses threshold value, then to this frequency mark 0, represent that this frequency is unavailable, otherwise mark 1, represent that this frequency can use; And the mark result of all frequencies formed frequency status indication vector, transmitter promptly sends signal by this label vector by available frequency, to avoid the phase mutual interference;
C
3. generate the pseudo-random phase vector: generate the pseudo-random phase vector by pseudo random sequence, to improve the antijamming capability of signal;
C
4. generate CCSK frequency domain basic function:, the newer vector of gained is carried out that convergent-divergent is handled, generation CCSK frequency domain basic function with corresponding the multiplying each other of element in frequency label vector and the pseudo-random phase vector;
C
5.CCSK the stores processor of frequency domain basic function: at first store by step C
4The CCSK frequency domain basic function that generates; If frequency status indication vector changes, then re-execute step C
1To C
4, generate new CCSK frequency domain basic function after, store stand-by again;
Step D.CCSK modulation treatment: utilize CCSK frequency domain basic function that each coded data that is generated by step B is carried out the CCSK modulation according to a conventional method successively, to convert corresponding frequency-region signal sequence to;
Step e. conversion of signals and transmission: adopting the OFDM mode is time-domain signal sequence and transmission with each the frequency-region signal sequence transformation of step D gained;
Two. receive flow process
Step F: generate CCSK frequency domain basic function and storage, use it for the signal demodulation; The step that its basic function generates comprises:
F
1. obtain the power spectral value of each frequency in the receiving terminal zone: receiver by conventional spectrum estimating method, obtains the power spectral value of each frequency in the receiving terminal zone in the working frequency range identical with transmitter;
F
2. generate frequency status indication vector: with step F
1The power spectral value of each frequency of gained and predefined threshold value relatively, if when the power spectrum value of frequency surpasses threshold value, then to this frequency mark 0, represent that this frequency is unavailable, otherwise mark 1, represent that this frequency can use; And the mark result of all frequencies formed frequency status indication vector, receiver promptly by this frequency status indication vector by available frequency received signal, to avoid the phase mutual interference;
After this: step F
3. generate pseudo-random phase vector, step F
4. generate CCSK frequency domain basic function, reach step F
5.CCSK the stores processor of frequency domain basic function, all with transmission flow in step C
3, step C
4And step C
5Corresponding identical; The CCSK frequency domain basic function storage that is generated is stand-by;
Step G: signal receives in time/the frequency conversion of signals: receiver is received each time-domain signal sequence that transmitting terminal sends, and by the OFDM mode, it is transformed to the frequency-region signal sequence;
Step H: demodulation process: utilize step F gained CCSK frequency domain basic function that each frequency-region signal sequence of step G gained is carried out the CCSK demodulation successively, to determine each encoded data value;
Step I: differential decoding is handled: each encoded data value of step H gained is carried out differential decoding, with the reduction original data stream; Differential decoding helps overcoming the influence of small scale decline;
Step J: data transaction: convert step I gained original data stream to the binary bits data, promptly get the binary bits data flow in the information source.
At step C
1Described in institute's spectrum estimating method be period map method or autoregression figure method, parametric method, filter method, space law.
Carrying out the CCSK modulation described in the step D according to a conventional method successively, its modulator approach is: at first CCSK frequency domain basic function is carried out discrete Fourier transform (DFT), generate CCSK time domain basic function; CCSK time domain basic function carried out cyclic shift again, generate a new sequence, it moves figure place is the corresponding codes data value; At last this new sequence is carried out inverse discrete Fourier transform (IDFT), generate corresponding frequency-region signal sequence.
Carrying out the CCSK demodulation described in the step H according to a conventional method successively, its demodulation method is: at first with the element in each frequency-region signal sequence respectively with CCSK frequency domain basic function in corresponding the multiplying each other of element conjugate, and multiplied result is carried out convergent-divergent handle, obtain new frequency-region signal sequence; Again the new frequency-region signal sequence of gained is carried out inverse discrete Fourier transform (IDFT), generate demodulated sequence; At last each element in the demodulated sequence is taken absolute value respectively, and determine peak value in all absolute values demodulated sequence in sequential bits, its preface item is corresponding codes data value in the encoded data stream of transmission.
Signal emission of the present invention, the used functional module framework of method of reseptance comprise transmitter section and receiver section, and key is:
One. transmitter section comprises
A. data modular converter is in order to convert the binary bits data flow in the information source to decimal system original data stream;
B. a differential coding processing module in order to each data in the original data stream are carried out differential coding, generates encoded data stream;
C. one contains the unit module that obtains each frequency power spectral value, the unit module that generates frequency status indication vector, generation pseudo-random phase vector location module, generates CCSK frequency domain basic function unit module and CCSK frequency domain basic function is carried out the storage processing unit module in interior generation of CCSK frequency domain basic function and memory function module;
D. CCSK modulation treatment module is to convert coded data to corresponding frequency-region signal sequence;
E. conversion of signals and send processing module is in order to be the time-domain signal sequence with the sequence transformation of gained frequency-region signal and to send;
Two. receiver section comprises
F. one comprises the unit module that obtains each frequency power spectral value, the unit module that generates frequency status indication vector, generation pseudo-random phase vector location module, generates CCSK frequency domain basic function unit module and CCSK frequency domain basic function is carried out the storage processing unit module in interior generation of CCSK frequency domain basic function and memory function module;
G. signal receives and the conversion process module, the time-domain signal sequence of sending in order to receiver/transmitter, and it is transformed to the frequency-region signal sequence;
H. CCSK demodulation process module is in order to carry out the CCSK demodulation to the frequency-region signal sequence, the reduction coded data;
I. differential decoding processing module is in order to carry out differential decoding with coded data, to obtain initial data.
J. a data modular converter converts the binary bits data in order to the original data stream that will obtain.
The present invention carries out differential decoding to the data after the demodulation owing in the emission flow process data are carried out differential coding in the reception flow process, avoided complexity and the channel estimating of poor efficiency, and it launches, receives the functional module framework of flow process to adopt adaptation, thereby, need not to use pilot tone and reduced overhead in the influence that need not effectively to overcome under the situation of channel estimating the small scale decline; Particularly under utmost point low signal-to-noise ratio and the discontinuous or inconsistent CR scene of transceiver use frequency spectrum, adopt the present invention can transmit data reliably.Emulation testing shows: under the same conditions, compare with the coherent approach that adopts 20% pilot tone ratio, the inventive method had both been avoided channel estimating, had been reduced overhead, and data transmission efficiency is higher; Compare performance excellent approximately (height) 10dB of the inventive method with the traditional differential detection method.Thereby, the present invention has the efficient and the spectrum efficiency that can effectively improve transfer of data, overhead is low, and can only transmit data reliably under the available condition of work of part at utmost point low signal-to-noise ratio even at frequency spectrum, can be widely used in the medium characteristics of wireless communication system.
Description of drawings
Fig. 1 sends for the inventive method signal and receives schematic flow sheet;
Fig. 2 is the structural representation of the used transmitter function module architectures of the inventive method;
Fig. 3 is the structural representation of the used receiver function module architectures of the inventive method.
Embodiment
Present embodiment adopts BT0907012-1-1 type software radio experiment platform as transmitter and receiver apparatus, replaces conventional transmitter and receiver to carry out running experiment.Promptly in the memory (but execute store and data storage) of experiment porch, be provided with respectively: the data conversion module (A) that transmitter is required, differential coding processing module (B), comprise and obtain each frequency power spectral value unit module, frequency status indication vector generation unit module, pseudo-random phase vector generation unit module, CCSK frequency domain basic function generation unit module and CCSK frequency domain basic function storage processing unit module generate and memory function module (C) at interior CCSK frequency domain basic function, CCSK modulation treatment module (D), conversion of signals and transmission processing module (E); Containing that receiver is required obtained each frequency power spectral value unit module, frequency status indication vector generation unit module, pseudo-random phase vector generation unit module, CCSK frequency domain basic function generation unit module and CCSK frequency domain basic function storage processing unit module in interior generation of CCSK frequency domain basic function and memory function module (F), signal receives and conversion process module (G), CCSK demodulation process module (H), differential decoding processing module (I) and data conversion module (J).Whole transmitter and receiver apparatus are provided with each functional module and corresponding parameters by man-machine input interface, also connect and input information source data by man-machine interface, and by the information source data message after the output interface output reduction that is connected with memory module.
System's operation and environmental parameter:
The system works frequency range: (Digital Video Broadcasting-Terrestial, DVB-T) 750MHz to 758MHz in the frequency range is as signal emission and the working frequency range that receives in the present embodiment to select Digital Television Terrestrial Broadcasting for use.On the part frequency of this working frequency range, there is more superpower authorization user signal;
Frequency points on the working frequency range: on the bandwidth of this 8MHz of 750MHz to 758MHz, evenly choose 2048 frequencies, on these frequencies, obtain power spectrum;
Information source data: as an information source packet, send by the method among the embodiment with 1100 binary bits data that generate at random.Transmitter needs to send 1000 information source packets altogether;
Wireless channel environment: present embodiment carries out in cognitive radio IEEE802.22 multidiameter fading channel, and this channel can make the wireless signal of emission be subjected to the influence of small scale decline;
Present embodiment emission and the flow process that receives are:
One. signal emission flow process:
Steps A. data transaction: with the 1st information source packet is example, and data conversion module becomes 1 decimal system initial data with per 11 binary bits data transaction in the information source packet, generates 100 initial data; The data value of each initial data is 0,1 ..., certain integer in 2047; For example the 1st to the 4th initial data is respectively 1464,1731,654 and 1090;
Step B: differential coding is handled: it is 0 that the 1st coded data at first is set; From i=1, with i initial data and i coded data addition, with it with divided by 2048 back complementations, the gained remainder is promptly as i+1 coded data more then; Successively each initial data is carried out above-mentioned differential coding, generate 101 coded datas at last; For example preceding 5 coded datas are respectively 0,1464,1147,1801 and 843;
Step C: generate CCSK frequency domain basic function and storage, specifically comprise:
Step C
1: the power spectral value of obtaining each frequency:, obtain the power spectral value (power spectral value has been passed through normalized) of 2048 frequencies on the working frequency range by period map method; For example the 1st power spectral value to the 4th frequency is respectively 0.001,0.001,0.001 and 0.002;
Step C
2: generate frequency status indication vector: with step C
1The power spectral value of 2048 frequencies of gained and predefined threshold value (being set at 0.05) compare, if when the power spectrum value of frequency surpasses threshold value, then to this frequency mark 0, represent that this frequency is unavailable, otherwise mark 1, represent that this frequency can use; And the mark result of all frequencies formed frequency status indication vector.The 1st value to the 1536th element of gained frequency status indication vector is 1, and the 1537th value to the 2048th element is 0, shows that promptly the frequency of front 3/4 part on this working frequency range can be used, and the frequency of back 1/4 part is unavailable;
Step C
3: generate the pseudo-random phase vector: at first distribute one 2048 pseudo random sequence to transmitter, its element value is 0,1 ..., certain integer in 2047; For example preceding 5 elements are respectively 1,2,5,10 and 21; Again each element map is become complex exponential, obtain the pseudo-random phase vector; For example preceding 5 elements in the pseudo-random phase vector are respectively e
J2 π * 1/2048, e
J2 π * 2/2048, e
J2 π * 5/2048, e
J2 π * 10/2048And e
J2 π * 21/2048
Step C
4: generate CCSK frequency domain basic function: corresponding the multiplying each other of element with in frequency label vector and the pseudo-random phase vector, the newer vector of gained is multiplied by a zoom factor, generate a length and be 2048 CCSK frequency domain basic function.K element value of CCSK frequency domain basic function is
Wherein, A
kK element in the expression frequency status indication vector; N represents frequency points, N=2048; m
kK element in the expression pseudo random sequence; Zoom factor
Here SNR represents signal to noise ratio, N
TThe frequency points that the expression transmitter can be used.(10dB), the N of SNR=0.1 in the present embodiment
T=1536.
Step C
5: the stores processor of CCSK frequency domain basic function: storage is by step C
4The CCSK frequency domain basic function that generates; During system works, frequency status indication vector does not change;
Step D:CCSK modulation treatment: be example with the 2nd coded data 1464 here, at first CCSK frequency domain basic function carried out discrete Fourier transform (DFT), generate CCSK time domain basic function; Again CCSK time domain basic function circulated to the right and move 1464, generate a new sequence; At last this new sequence is carried out inverse discrete Fourier transform (IDFT), generate corresponding frequency-region signal sequence, the length of frequency-region signal sequence is 2048.For example preceding 4 elements be respectively 0.0075+0.000j ,-0.0017+0.0073j ,-0.0067-0.0033j and 0.0048-0.0057j; Usually, with i coded data S '
iK element of pairing frequency-region signal sequence can be expressed as:
Step e: conversion of signals and transmission: adopting the OFDM mode is time-domain signal sequence and transmission with each the frequency-region signal sequence transformation of step D gained; In the OFDM mode, added 352 Cyclic Prefix, so the length of time-domain signal sequence is 2400; For example preceding 4 elements corresponding to the time-domain signal sequence of the 2nd coded data be respectively-0.005-0.0072j, 0.0070+0.0026j ,-0.0045+0.0035j and 0.0025+0.0064j;
Two. signal receives flow process:
Step F: generate CCSK frequency domain basic function and storage, specifically comprise step:
Step F
1: receiver in the working frequency range identical with transmitter (being 750MHz to 758MHz frequency range), obtains the power spectral value of 2048 frequencies in the receiving terminal zone by period map method; For example the 1st power spectral value to the 4th frequency is 0.002,0.002,0.001 and 0.001;
Step F
2. generate frequency status indication vector: with step F
1The power spectral value of 2048 frequencies of gained and predefined threshold value (being set at 0.05) relatively, if when the power spectrum value of frequency surpasses threshold value, then to this frequency mark 0, represent that this frequency is unavailable, otherwise mark 1, represent that this frequency can use; And the mark result of all frequencies formed frequency status indication vector; Because the geographic distance of transmitting terminal and receiving terminal very short (less than 100 meters), so receiver is identical with the frequency status indication vector that transmitter generates, the 1st value to the 1536th element that is frequency status indication vector is 1, and the 1537th value to the 2048th element is 0;
Step F
3. generate pseudo-random phase vector, step F
4. generate CCSK frequency domain basic function, reach step F
5.CCSK the stores processor of frequency domain basic function all with transmission flow in step C
3, step C
4And step C
5Corresponding identical; But in step F
4The middle employed zoom factor of receiver is
N wherein
RThe frequency points that the expression receiver can be used, N
R=1536; Therefore, the CCSK frequency domain basic function that receiver generated is 3.16 times of the CCSK frequency domain basic function that generates of transmitter;
Step G. signal receives in time/the frequency conversion of signals: the time-domain signal sequence that transmitter sends has been subjected to the influence of small scale decline and multidiameter in wireless channel, and the interference of background noise.Receiver is received these time-domain signal sequences, through by the OFDM mode, it is transformed to 2048 frequency-region signal sequence, and carries out 10 times processing and amplifying to received signal; For example corresponding to preceding 4 elements of the frequency-region signal sequence of the 2nd coded data be respectively 0.0054+0.0137j ,-0.0252+0.0344j ,-0.0389+0.0475j and-0.0465+0.0399j;
Step H.CCSK demodulation process: with the element in the step G gained frequency-region signal sequence respectively with the described CCSK frequency domain of step F basic function in corresponding the multiplying each other of element conjugate, obtain a new frequency-region signal sequence, for example its preceding 4 elements be respectively 0.001+0.003j ,-0.006+0.009j ,-0.0010+0.0012j and-0.0012+0.0011j; Again the new frequency-region signal sequence of gained is carried out inverse discrete Fourier transform, generates demodulated sequence, for example its preceding 4 elements be respectively 0.0019+0.0045j, 0.0166+0.0093j ,-0.0783-0.0526j and 0.0878+0.0065j; At last each element in the demodulated sequence is taken absolute value respectively, and know that the peak value in all absolute values is 0.9444, and peak value is in the 1480th in the demodulated sequence, this preface item is promptly as the disengaging value of the 2nd coded data; Restore all coded datas according to this CCSK demodulation step, for example restore preceding 5 coded datas that obtain and be respectively 16,1480,1163,1817 and 859.Compare by preceding 5 coded datas (0,1464,1147,1801 and 843) with transmitting terminal, the encoded data value that can find the receiving terminal recovery is all big by 16 than the encoded data value of transmitting terminal, and this is because the influence that decline of the small scale of wireless channel and multidiameter cause signal.Therefore, need be eliminated by differential decoding;
Step I. differential decoding is handled: from i=1, i+1 coded data and i coded data are subtracted each other, it is differed from divided by 2048 complementations afterwards again, the gained remainder is promptly as the disengaging value of i initial data; Successively each coded data is carried out above-mentioned differential decoding, restore 100 initial data at last; For example restore preceding 4 initial data that obtain and be respectively 1464,1731,654 and 1090, the initial data that restore concerning this moment and the initial data of transmission are identical;
Step J. data transaction: convert 100 initial data of step I gained to 1100 binary bits data, with reduction information source data and output.
Adopt present embodiment to carry out simulation run, its result and background technology contrast: present embodiment compares with the coherent approach that adopts 20% pilot tone ratio, under the suitable situation of the error rate, present embodiment only need improve the signal to noise ratio less than 1dB, because embodiment of the present invention does not need channel estimating, not only overhead is lower, and data transmission efficiency can improve about 25%; Present embodiment is compared with traditional non-coherent approaches, under the suitable situation of the error rate, the present embodiment required signal-to-noise ratio is than it about low 10dB.
Claims (5)
1. transform domain communication system signal emission, method of reseptance comprise:
One. the emission flow process
Steps A: data transaction: convert the binary bits data flow in the information source to metric original data stream;
Step B: differential coding is handled: each data in the original data stream are carried out differential coding, generate encoded data stream; To overcome the influence of small scale decline;
Step C: generate CCSK frequency domain basic function and storage, to be used for data-modulated; The step that its basic function generates comprises:
C
1. obtain the power spectral value of each frequency:, obtain the power spectral value of each frequency in the working frequency range by conventional spectrum estimating method;
C
2. generate frequency status indication vector: with step C
1The power spectral value of each frequency of gained and predefined threshold value relatively, if when the power spectrum value of frequency surpasses threshold value, then to this frequency mark 0, represent that this frequency is unavailable, otherwise mark 1, represent that this frequency can use; And the mark result of all frequencies formed frequency status indication vector, transmitter promptly sends signal by this label vector by available frequency, to avoid the phase mutual interference;
C
3. generate the pseudo-random phase vector: generate the pseudo-random phase vector by pseudo random sequence, to improve the antijamming capability of signal;
C
4. generate CCSK frequency domain basic function:, the newer vector of gained is carried out that convergent-divergent is handled, generation CCSK frequency domain basic function with corresponding the multiplying each other of element in frequency label vector and the pseudo-random phase vector;
C
5.CCSK the stores processor of frequency domain basic function: at first store by step C
4The CCSK frequency domain basic function that generates; If frequency status indication vector changes, then re-execute step C
1To C
4, generate new CCSK frequency domain basic function after, store stand-by again;
Step D.CCSK modulation treatment: utilize CCSK frequency domain basic function that each coded data that is generated by step B is carried out the CCSK modulation according to a conventional method successively, to convert corresponding frequency-region signal sequence to;
Step e. conversion of signals and transmission: adopting the OFDM mode is time-domain signal sequence and transmission with each the frequency-region signal sequence transformation of step D gained;
Two. receive flow process
Step F: generate CCSK frequency domain basic function and storage, use it for the signal demodulation; The step that its basic function generates comprises:
F
1. obtain the power spectral value of each frequency in the receiving terminal zone: receiver by conventional spectrum estimating method, obtains the power spectral value of each frequency in the receiving terminal zone in the working frequency range identical with transmitter;
F
2. generate frequency status indication vector: with step F
1The power spectral value of each frequency of gained and predefined threshold value relatively, if when the power spectrum value of frequency surpasses threshold value, then to this frequency mark 0, represent that this frequency is unavailable, otherwise mark 1, represent that this frequency can use; And the mark result of all frequencies formed frequency status indication vector, receiver promptly by this frequency status indication vector by available frequency received signal, to avoid the phase mutual interference;
After this: step F
3Generate pseudo-random phase vector, step F
4Generate CCSK frequency domain basic function, reach step F
5The stores processor of CCSK frequency domain basic function, all with transmission flow in step C
3, step C
4And step C
5Corresponding identical; The CCSK frequency domain basic function storage that is generated is stand-by;
Step G: signal receives in time/the frequency conversion of signals: receiver is received each time-domain signal sequence that transmitting terminal sends, and by the OFDM mode, it is transformed to the frequency-region signal sequence;
Step H: demodulation process: utilize step F gained CCSK frequency domain basic function that each frequency-region signal sequence of step G gained is carried out the CCSK demodulation successively, to determine each encoded data value;
Step I: differential decoding is handled: each encoded data value of step H gained is carried out differential decoding, with the reduction original data stream; Differential decoding helps overcoming the influence of small scale decline;
Step J: data transaction: convert step I gained original data stream to the binary bits data, promptly get the binary bits data flow in the information source.
2. by the emission of the described transform domain communication system signal of claim 1, method of reseptance, it is characterized in that described spectrum estimating method is period map method or autoregression figure method, parametric method, filter method, space law.
3. by the described transform domain communication system signal emission of claim 1, method of reseptance, it is characterized in that the described CCSK modulation of carrying out successively according to a conventional method, its modulator approach is: at first CCSK frequency domain basic function is carried out discrete Fourier transform, generate CCSK time domain basic function; CCSK time domain basic function carried out cyclic shift again, generate a new sequence, it moves figure place is the corresponding codes data value; At last this new sequence is carried out inverse discrete Fourier transform, generate corresponding frequency-region signal sequence.
4. by the described transform domain communication system signal emission of claim 1, method of reseptance, it is characterized in that the described CCSK demodulation of carrying out successively according to a conventional method, its demodulation method is: at first with the element in each frequency-region signal sequence respectively with CCSK frequency domain basic function in corresponding the multiplying each other of element conjugate, and multiplied result is carried out convergent-divergent handle, obtain new frequency-region signal sequence; Again the new frequency-region signal sequence of gained is carried out inverse discrete Fourier transform (IDFT), generate demodulated sequence; At last each element in the demodulated sequence is taken absolute value respectively, and determine peak value in all absolute values demodulated sequence in sequential bits, its preface item is corresponding codes data value in the encoded data stream of transmission.
5. by the described transform domain communication system signal emission of claim 1, the used functional module framework of method of reseptance, comprise transmitter section and receiver section, it is characterized in that:
One. transmitter section comprises
A. data modular converter is in order to convert the binary bits data flow in the information source to decimal system original data stream;
B. a differential coding processing module in order to each data in the original data stream are carried out differential coding, generates encoded data stream;
C. one comprises the unit module that obtains each frequency power spectral value, the unit module that generates frequency status indication vector, generation pseudo-random phase vector location module, generates CCSK frequency domain basic function unit module and CCSK frequency domain basic function is carried out the storage processing unit module in interior generation of CCSK frequency domain basic function and memory function module;
D. CCSK modulation treatment module is to convert coded data to corresponding frequency-region signal sequence;
E. conversion of signals and send processing module is in order to be the time-domain signal sequence with the sequence transformation of gained frequency-region signal and to send;
Two. receiver section comprises
F. one contains the unit module that obtains each frequency power spectral value, the unit module that generates frequency status indication vector, generation pseudo-random phase vector location module, generates CCSK frequency domain basic function unit module and CCSK frequency domain basic function is carried out the storage processing unit module in interior generation of CCSK frequency domain basic function and memory function module;
G. signal receives and the conversion process module, the time-domain signal sequence of sending in order to receiver/transmitter, and it is transformed to the frequency-region signal sequence;
H. CCSK demodulation process module is in order to carry out the CCSK demodulation to the frequency-region signal sequence, the reduction coded data;
I. differential decoding processing module is in order to carry out differential decoding with coded data, to obtain initial data.
J. a data modular converter converts the binary bits data in order to the original data stream that will obtain.
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102386961A (en) * | 2011-10-14 | 2012-03-21 | 褚振勇 | Method for establishing satellite overlap communication link based on TDCS (Train Operation Dispatching Command System) |
| CN104104641A (en) * | 2014-07-31 | 2014-10-15 | 电子科技大学 | Signal transmitting method and signal receiving method based on TDCS (Transform Domain Communication System) differential transmission |
| CN104168243A (en) * | 2014-08-11 | 2014-11-26 | 电子科技大学 | Signal transmitting and receiving method based on TDCS |
| WO2016101295A1 (en) * | 2014-12-22 | 2016-06-30 | 深圳Tcl数字技术有限公司 | Method for protecting terminal device against signal interference, and terminal device |
| CN106230573A (en) * | 2016-08-31 | 2016-12-14 | 电子科技大学 | A kind of TDCS multiple access based on sequential design accesses improved method |
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4707839A (en) * | 1983-09-26 | 1987-11-17 | Harris Corporation | Spread spectrum correlator for recovering CCSK data from a PN spread MSK waveform |
| CN1722849A (en) * | 1997-11-05 | 2006-01-18 | 索尼公司 | Digital signal conversion method and digital signal conversion device |
| CN1829211A (en) * | 2006-04-13 | 2006-09-06 | 电子科技大学 | Transform domain communication method based on interlaced and orthogonal frequency division multiplex |
-
2010
- 2010-05-24 CN CN201010186524A patent/CN101873292A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4707839A (en) * | 1983-09-26 | 1987-11-17 | Harris Corporation | Spread spectrum correlator for recovering CCSK data from a PN spread MSK waveform |
| CN1722849A (en) * | 1997-11-05 | 2006-01-18 | 索尼公司 | Digital signal conversion method and digital signal conversion device |
| CN1829211A (en) * | 2006-04-13 | 2006-09-06 | 电子科技大学 | Transform domain communication method based on interlaced and orthogonal frequency division multiplex |
Non-Patent Citations (1)
| Title |
|---|
| 盛孟刚 等: "外军数据链波形的建设与发展", 《计算机与网络》, no. 1, 31 December 2008 (2008-12-31) * |
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| CN102386961A (en) * | 2011-10-14 | 2012-03-21 | 褚振勇 | Method for establishing satellite overlap communication link based on TDCS (Train Operation Dispatching Command System) |
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| CN104168243A (en) * | 2014-08-11 | 2014-11-26 | 电子科技大学 | Signal transmitting and receiving method based on TDCS |
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