WO2002049385A2 - Multi-carrier communications with adaptive cluster configuration and switching - Google Patents
Multi-carrier communications with adaptive cluster configuration and switching Download PDFInfo
- Publication number
- WO2002049385A2 WO2002049385A2 PCT/US2001/048701 US0148701W WO0249385A2 WO 2002049385 A2 WO2002049385 A2 WO 2002049385A2 US 0148701 W US0148701 W US 0148701W WO 0249385 A2 WO0249385 A2 WO 0249385A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- subscriber
- cluster
- subcarriers
- clusters
- method defined
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
- H04L1/0009—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the channel coding
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
- H04L1/0023—Systems modifying transmission characteristics according to link quality, e.g. power backoff characterised by the signalling
- H04L1/0025—Transmission of mode-switching indication
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
- H04L1/0023—Systems modifying transmission characteristics according to link quality, e.g. power backoff characterised by the signalling
- H04L1/0026—Transmission of channel quality indication
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L5/00—Arrangements affording multiple use of the transmission path
- H04L5/02—Channels characterised by the type of signal
- H04L5/023—Multiplexing of multicarrier modulation signals
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/50—Allocation or scheduling criteria for wireless resources
- H04W72/54—Allocation or scheduling criteria for wireless resources based on quality criteria
- H04W72/542—Allocation or scheduling criteria for wireless resources based on quality criteria using measured or perceived quality
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/20—Control channels or signalling for resource management
- H04W72/21—Control channels or signalling for resource management in the uplink direction of a wireless link, i.e. towards the network
Definitions
- the invention relates to the field of wireless communications; more particularly, the invention relates to multi-cell, multi-subscriber wireless systems using orthogonal frequency division multiplexing (OFDM).
- OFDM orthogonal frequency division multiplexing
- Orthogonal frequency division multiplexing is an efficient modulation scheme for signal transmission over frequency-selective channels.
- OFDM orthogonal frequency division multiplexing
- a wide bandwidth is divided into multiple narrow-band subcarriers, which are arranged to be orthogonal with each other.
- the signals modulated on the subcarriers are transmitted in parallel.
- Cimini, Jr. "Analysis and Simulation of a Digital Mobile Channel Using Orthogonal Frequency Division Multiplexing," IEEE Trans. Co mun., vol. COM-33, no. 7, July 1985, pp. 665-75; Chuang and Sollenberger, "Beyond 3G: Wideband Wireless Data Access Based on OFDM and Dynamic Packet Assignment," IEEE Communications Magazine, Vol. 38, No.
- OFDM frequency division multiple access
- TDMA time division multiple access
- OFDMA Orthogonal frequency division multiple access
- FDMA frequency division multiple access
- Multipath causes frequency-selective fading.
- the channel gains are different for different subcarriers.
- the channels are typically uncorrelated for different subscribers.
- the subcarriers that are in deep fade for one subscriber may provide high channel gains for another subscriber. Therefore, it is advantageous in an OFDMA system to adaptively allocate the subcarriers to subscribers so that each subscriber enjoys a high channel gain. For more information, see Wong et al., “Multiuser OFDM with Adaptive Subcarrier, Bit and Power Allocation,” IEEE J.
- the subscribers can be coordinated to have different subcarriers in OFDMA.
- the signals for different subscribers can be made orthogonal and there is little intracell interference.
- frequency reuse plan e.g., the same spectrum is used for multiple neighboring cells, the problem of intercell interference arises.
- the intercell interference in an OFDMA system is also frequency selective and it is advantageous to adaptively allocate the subcarriers so as to mitigate the effect of intercell interference.
- a method and apparatus for allocating subcarriers in an orthogonal frequency division multiple access (OFDMA) system comprises allocating at least one diversity cluster of subcarriers to a first subscriber and allocating at least one coherence cluster to a second subscriber.
- OFDMA orthogonal frequency division multiple access
- Figure 1A illustrates subcarriers and clusters.
- Figure IB is a flow diagram of one embodiment of a process for allocating subcarriers.
- Figure 2 illustrates time and frequency grid of OFDM symbols, pilots and clusters.
- Figure 3 illustrates subscriber processing.
- Figure 4 illustrates one example of Figure 3.
- Figure 5 illustrates one embodiment of a format for arbitrary cluster feedback.
- Figure 6 illustrates one embodiment of a partition the clusters into groups.
- Figure 7 illustrates one embodiment of a feedback format for group-based cluster allocation.
- Figure 8 illustrates frequency reuse and interference in a multi-cell, multi- sector network.
- Figure 9 illustrates different cluster formats for coherence clusters and diversity clusters.
- Figure 10 illustrates diversity clusters with subcarrier hopping.
- Figure 11 illustrates intelligent switching between diversity clusters and coherence clusters depending on subscribers mobility.
- Figure 12 illustrates one embodiment of a reconfiguration of cluster classification.
- Figure 13 illustrates one embodiment of a base station.
- a method and apparatus for allocating subcarriers in an orthogonal frequency division multiple access (OFDMA) system comprises allocating at least one diversity cluster of subcarriers to a first subscriber and allocating at least one coherence cluster to a second subscriber.
- OFDMA orthogonal frequency division multiple access
- the techniques disclosed herein are described using OFDMA (clusters) as an example. However, they are not limited to OFDMA-based systems. The techniques apply to multi-carrier systems in general, where, for example, a carrier can be a cluster in OFDMA, a spreading code in CDMA, an antenna beam in SDMA (space-division multiple access), etc. In one embodiment, subcarrier allocation is performed in each cell separately.
- each subscriber For downlink channels, each subscriber first measures the channel and interference information for all the subcarriers and then selects multiple subcarriers with good performance (e.g., a high signal-to-interference plus noise ratio (SINR)) and feeds back the information on these candidate subcarriers to the base station.
- the feedback may comprise channel and interference information (e.g., signal-to-interference-plus-noise-ratio information) on all subcarriers or just a portion of subcarriers.
- a subscriber may provide a list of subcarriers ordered starting with those subcarriers which the subscriber desires to use, usually because their performance is good or better than that of other subcarriers.
- the base station Upon receiving the information from the subscriber, the base station further selects the subcarriers among the candidates, utilizing additional information available at the base station, e.g., the traffic load information on each subcarrier, amount of traffic requests queued at the base station for each frequency band, whether frequency bands are overused, and/ or how long a subscriber has been waiting to send information.
- the subcarrier loading information of neighboring cells can also be exchanged between base stations.
- the base stations can use this information in subcarrier allocation to reduce inter-cell interference.
- the selection by the base station of the channels to allocate, based on the feedback results in the selection of coding/modulation rates.
- Such coding/modulation rates may be specified by the subscriber when specifying subcarriers that it finds favorable to use. For example, if the SINR is less than a certain threshold (e.g., 12 dB), quadrature phase shift keying (QPSK) modulation is used; otherwise, 16 quadrature amplitude modulation (QAM) is used. Then the base station informs the subscribers about the subcarrier allocation and the coding/modulation rates to use.
- a certain threshold e.g. 12 dB
- QPSK quadrature phase shift keying
- QAM quadrature amplitude modulation
- the feedback information for downlink subcarrier allocation is transmitted to the base station through the uplink access channel, which occurs in a short period every transmission time slot, e.g., 400 microseconds in every 10-millisecond time slot.
- the access channel occupies the entire frequency bandwidth.
- the base station can collect the uplink SINR of each subcarrier directly from the access channel.
- the SINR as well as the traffic load information on the uplink subcarriers are used for uplink subcarrier allocation.
- the base station makes the final decision of subcarrier allocation for each subscriber.
- the present invention also relates to apparatus for performing the operations herein.
- This apparatus may be specially constructed for the required purposes, or it may comprise a general purpose computer selectively activated or reconfigured by a computer program stored in the computer.
- a computer program may be stored in a computer readable storage medium, such as, but is not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, and magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), EPROMs, EEPROMs, magnetic or optical cards, or any type of media suitable for storing electronic instructions, and each coupled to a computer system bus.
- a machine-readable medium includes any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer).
- a machine-readable medium includes read only memory ("ROM”); random access memory (“RAM”); magnetic disk storage media; optical storage media; flash memory devices; electrical, optical, acoustical or other form of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.); etc.
- Subcarrier Clustering The techniques described herein are directed to subcarrier allocation for data traffic channels. In a cellular system, there are typically other channels, pre- allocated for the exchange of control information and other purposes. These channels often include down link and up link control channels, uplink access channels, and time and frequency synchronization channels.
- Figure 1A illustrates multiple subcarriers, such as subcarrier 101, and cluster 102.
- a cluster such as cluster 102, is defined as a logical unit that contains at least one physical subcarrier, as shown in Figure 1 A.
- a cluster can contain consecutive or disjoint subcarriers.
- the mapping between a cluster and its subcarriers can be fixed or reconfigurable. In the latter case, the base station informs the subscribers when the clusters are redefined.
- the frequency spectrum includes 512 subcarriers and each cluster includes four consecutive subcarriers, thereby resulting in 128 clusters.
- Figure IB is a flow diagram of one embodiment of a process for allocation clusters to subscribers.
- the process is performed by processing logic that may comprise hardware (e.g., dedicated logic, circuitry, etc.), software (such as that which runs on, for example, a general purpose computer system or dedicated machine), or a combination of both.
- each base station periodically broadcasts pilot OFDM symbols to every subscriber within its cell (or sector) (processing block 101).
- the pilot symbols often referred to as a sounding sequence or signal, are known to both the base station and the subscribers.
- each pilot symbol covers the entire OFDM frequency bandwidth.
- the pilot symbols may be different for different cells (or sectors).
- the pilot symbols can serve multiple purposes: time and frequency synchronization, channel estimation and signal-to-interference /noise (SINR) ratio measurement for cluster allocation.
- SINR signal-to-interference /noise
- each subscriber continuously monitors the reception of the pilot symbols and measures the SINR and/ or other parameters, including inter-cell interference and intra-cell traffic, of each cluster (processing block 102). Based on this information, each subscriber selects one or more clusters with good performance (e.g., high SINR and low traffic loading) relative to each other and feeds back the information on these candidate clusters to the base station through predefined uplink access channels (processing block 103). For example, SINR values higher than 10 dB may indicate good performance. Likewise, a cluster utilization factor less than 50% may be indicative of good performance.
- each subscriber selects the clusters with relatively better performance than others. The selection results in each subscriber selecting clusters they would prefer to use based on the measured parameters.
- each subscriber measures the SINR of each subcarrier cluster and reports these SINR measurements to their base station through an access channel.
- the SINR value may comprise the average of the SINR values of each of the subcarriers in the cluster.
- the SINR value for the cluster may be the worst SINR among the SINR values of the subcarriers in the cluster.
- a weighted averaging of SINR values of the subcarriers in the cluster is used to generate an SINR value for the cluster. This may be particularly useful in diversity clusters where the weighting applied to the subcarriers may be different.
- the feedback of information from each subscriber to the base station contains a SINR value for each cluster and also indicates the coding/modulation rate that the subscriber desires to use.
- No cluster index is needed to indicate which SINR value in the feedback corresponds to which cluster as long as the order of information in the feedback is known to the base station.
- the information in the feedback is ordered according to which clusters have the best performance relative to each other for the subscriber. In such a case, an index is needed to indicate to which cluster the accompanying SINR.value corresponds.
- the base station Upon receiving the feedback from a subscriber, the base station further selects one or more clusters for the subscriber among the candidates (processing block 104).
- the base station may utilize additional information available at the base station, e.g., the traffic load information on each subcarrier, amount of traffic requests queued at the base station for each frequency band, whether frequency bands are overused, and how long a subscriber has been waiting to send information.
- the subcarrier loading information of neighboring cells can also be exchanged between base stations. The base stations can use this information in subcarrier allocation to reduce inter-cell interference.
- the base station After cluster selection, the base station notifies the subscriber about the cluster allocation through a downlink common control channel or through a dedicated downlink traffic channel if the connection to the subscriber has already been estabUshed (processing block 105). In one embodiment, the base station also informs the subscriber about the appropriate modulation/coding rates.
- each subscriber can continue to send the feedback to the base station using a dedicated traffic channel (e.g., one or more predefined uplink access channels).
- a dedicated traffic channel e.g., one or more predefined uplink access channels.
- the base station allocates all the clusters to be used by a subscriber at once.
- the base station first allocates multiple clusters, referred to herein as the basic clusters, to establish a data link between the base station and the subscriber.
- the base station then subsequently allocates more clusters, referred to herein as the auxiliary clusters, to the subscriber to increase the communication bandwidth.
- Higher priorities can be given to the assignment of basic clusters and lower priorities may be given to that of auxiliary clusters.
- the base station first ensures the assignment of the basic clusters to the subscribers and then tries to satisfy further requests on the auxiliary clusters from the subscribers.
- the base station may assign auxiliary clusters to one or more subscribers before allocating basic clusters to other subscribers. For example, a base station may allocate basic and auxiliary clusters to one subscriber before allocating any clusters to other subscribers. In one embodiment, the base station allocates basic clusters to a new subscriber and then determines if there are any other subscribers requesting clusters. If not, then the base station allocates the auxiliary clusters to that new subscriber.
- processing logic performs retraining by repeating the process described above (processing block 106).
- the retraining may be performed periodically. This retraining compensates for subscriber movement and any changes in interference.
- each subscriber reports to the base station its updated selection of clusters and their associated SINRs. Then the base station further performs the reselection and informs the subscriber about the new cluster allocation.
- Retraining can be initiated by the base station, and in which case, the base station requests a specific subscriber to report its updated cluster selection. Retraining can also be initiated by the subscriber when it observes channel deterioration.
- Adaptive Modulation and Coding are used to support reliable transmission over channels with different SINR. Signal spreading over multiple subcarriers may also be used to improve the reliability at very low SINR.
- An example coding/modulation table is given below in Table 1.
- 1/8 spreading indicates that one QPSK modulation symbol is repeated over eight subcarriers.
- the repetition/spreading may also be extended to the time domain.
- one QPSK symbol can be repeated over four subcarriers of two OFDM symbols, resulting also 1/8 spreading.
- the coding/modulation rate can be adaptively changed according to the channel conditions observed at the receiver after the initial cluster allocation and rate selection.
- each base station transmits pilot symbols simultaneously, and each pilot symbol occupies the entire OFDM frequency bandwidth, as shown in Figures 2A-C.
- pilot symbols 201 are shown traversing the entire OFDM frequency bandwidth for cells A, B and C, respectively.
- each of the pilot symbols have a length or duration of 128 microseconds with a guard time, the combination of which is approximately 152 microseconds.
- After each pilot period there are a predetermined number of data periods followed by another set of pilot symbols.
- there are four data periods used to transmit data after each pilot and each of the data periods is 152 microseconds.
- a subscriber estimates the SINR for each cluster from the pilot symbols.
- the subscriber first estimates the channel response, including the amplitude and phase, as if there is no interference or noise. Once the channel is estimated, the subscriber calculates the interference/noise from the received signal.
- the estimated SINR values may be ordered from largest to smallest SINRs and the clusters with large SINR values are selected.
- the selected clusters have SINR values that are larger than the minimum SINR which still allows a reliable (albeit low-rate) transmission supported by the system.
- the number of clusters selected may depend on the feedback bandwidth and the request transmission rate.
- the subscriber always tries to send the information about as many clusters as possible from which the base station chooses.
- the estimated SINR values are also used to choose the appropriate coding/modulation rate for each cluster as discussed above.
- an SINR index may also indicate a particular coding and modulation rate that a subscriber desires to use.
- Pilot symbols serve an additional purpose in determining interference among the cells. Since the pilots of multiple cells are broadcast at the same time, they will interfere with each other (because they occupy the entire frequency band). This collision of pilot symbols may be used to determine the amount of interference as a worst case scenario. Therefore, in one embodiment, the above SINR estimation using this method is conservative in that the measured interference level is the worst-case scenario, assuming that all the interference sources are on. Thus, the structure of pilot symbols is such that it occupies the entire frequency band and causes collisions among different cells for use in detecting the worst case SINR in packet transmission systems. [0059] During data traffic periods, the subscribers can determine the level of interference again.
- the data traffic periods are used to estimate the intra-cell traffic as well as the inter-cell interference level. Specifically, the power difference during the pilot and traffic periods may be used to sense the (intra- cell) traffic loading and inter-cell interference to select the desirable clusters.
- the interference level on certain clusters may be lower, because these clusters may be unused in the neighboring cells. For example, in cell A, with respect to cluster A there is less interference because cluster A is unused in cell B (while it is used in cell C). Similarly, in cell A, cluster B will experience lower interference from cell B because cluster B is used in cell B but not in cell C.
- the modulation/ coding rate based on this estimation is robust to frequent interference changes resulted from bursty packet transmission.
- a subscriber utilizes the information available from both the pilot symbol periods and the data traffic periods to analyze the presence of both the intra-cell traffic load and inter-cell interference.
- the goal of the subscriber is to provide an indication to the base station as to those clusters that the subscriber desires to use.
- the result of the selection by the subscriber is clusters with high channel gain, low interference from other cells, and high availability.
- the subscriber provides feedback information that includes the results, listing desired clusters in order or not as described herein.
- Figure 3 illustrates one embodiment of subscriber processing.
- the processing is performed by processing logic that may comprise hardware (e.g., dedicated logic, circuitry, etc.), software (such as that which runs on, for example, a general purpose computer system or dedicated machine), or a combination of both.
- channel/interference estimation processing block 301 performs channel and interference estimation in pilot periods in response to pilot symbols.
- Traffic/interference analysis processing block 302 performs traffic and interference analysis in data periods in response to signal information and information from channel/ interference estimation block 301.
- Cluster ordering and rate prediction processing block 303 is coupled to outputs of channel/interference estimation processing block 301 and traffic/interference analysis processing block 302 to perform cluster ordering and selection along with rate prediction.
- cluster ordering processing block 303 requests clusters and modulation/ coding rates. Indications of these selections are sent to the base station.
- the SINR on each cluster is reported to the base station through an access channel. The information is used for cluster selection to avoid clusters with heavy intra-cell traffic loading and/or strong interference from other cells. That is, a new subscriber may not be allocated use of a particular cluster if heavy intra-cell traffic loading already exists with respect to that cluster. Also, clusters may not be allocated if the interference is so strong that the SINR only allows for low-rate transmission or no reliable transmission at all.
- the channel/interference estimation by processing block 301 is well- known in the art by monitoring the interference that is generated due to full- bandwidth pilot symbols being simultaneously broadcast in multiple cells.
- the interface information is forwarded to processing block 302 which uses the information to solve the following equation:
- H,.S i + / i +n 1 . y,.
- S represents the signal for subcarrier (freq. band) i
- I t is the interference for subcarrier i
- n t is the noise associated with subcarrier i
- y is the observation for subcarrier i .
- i may range from 0 to 511.
- the / ; and n ⁇ are not separated and may be considered one quantity.
- the interference/noise and channel gain H i are not know.
- the signal S representing the pilot symbols, and the observation y i are knowns, thereby allowing determination of the channel gain H i for the case where there is no interference or noise. Once this is known, it may be plugged back into the equation to determine the interference /noise during data periods since H ( , S f and y t are all known.
- the interference information from processing blocks 301 and 302 are used by the subscriber to select desirable clusters.
- the subscriber orders clusters and also predicts the data rate that would be available using such clusters.
- the predicted data rate information may be obtained from a look up table with precalculated data rate values. Such a look up table may store the pairs of each SINR and its associated desirable transmission rate.
- the subscriber selects clusters that it desires to use based on predetermined performance criteria.
- the subscriber requests the desired clusters along with coding and modulation rates known to the subscriber to achieve desired data rates.
- Figure 4 is one embodiment of an apparatus for the selection of clusters based on power difference.
- the approach uses information available during both pilot symbol periods and data traffic periods to perform energy detection.
- the processing of Figure 4 may be implemented in hardware, (e.g., dedicated logic, circuitry, etc.), software (such as is run on, for example, a general purpose computer system or dedicated machine), or a combination of both.
- a subscriber includes SINR estimation processing block 401 to perform SINR estimation for each cluster in pilot periods, power calculation processing block 402 to perform power calculations for each cluster in pilot periods, and power calculation processing block 403 to perform power calculations in data periods for each cluster.
- Subtractor 404 subtracts the power calculations for data periods from processing block 403 from those in pilot periods from processing block 402.
- the output of subtractor 404 is input to power difference ordering (and group selection) processing block 405 that performs cluster ordering and selection based on SINR and the power difference between pilot periods and data periods.
- the signal power of each cluster during the pilot periods is compared with that during the traffic periods, according to the following:
- P p is the measured power corresponding to each cluster during pilot periods
- P D is the measured power during the traffic periods
- R s is the signal power
- R 7 is the interference power
- P N is the noise power
- the subscriber selects clusters with relatively large P p /(Pp - R D ) (e.g., larger than a threshold such as lOdB) and avoids clusters with low P p /(Pp - P D ) (e.g., lower than a threshold such as lOdB) when possible.
- the difference may be based on the energy difference between observed samples during the pilot period and during the data traffic period for each of the subcarriers in a cluster such as the following:
- a subscriber sums the differences for all subcarriers.
- a subscriber may use the following metric, a combined function of both SINR and P P - P D , to select the clusters: where / is a function of the two inputs.
- / is weighted averaging (e.g., equal weights).
- a subscriber selects a cluster based on its SINR and only uses the power difference P p - P D to distinguish clusters with similar SINR. The difference may be smaller than a threshold (e.g., l dB).
- Both the measurement of SINR and P p - P D can be averaged over time to reduce variance and improve accuracy.
- a moving-average time window is used that is long enough to average out the statistical abnormity yet short enough to capture the time-varying nature of channel and interference, e.g., 1 millisecond.
- the feedback contains both the indices of selected clusters and their SINR.
- An exemplary format for arbitrary cluster feedback is shown in Figure 5.
- the subscriber provides a cluster index (ID) to indicate the cluster and its associated SINR value.
- the subscriber provides cluster ID1 (501) and the SINR for the cluster, SINR1 (502), cluster ID2 (503) and the SINR for the cluster, SINR2 (504), and cluster ID3 (505), and the SINR for the cluster, SINR3 (506), etc.
- the SINR for the cluster may be created using an average of the SINRs of the subcarriers. Thus, multiple arbitrary clusters can be selected as the candidates.
- the selected clusters can also be ordered in the feedback to indicate priority.
- the subscriber may form a priority list of clusters and sends back the SINR information in a descending order of priority.
- an index to the SINR level instead of the SINR itself is sufficient to indicate the appropriate coding/modulation for the cluster.
- a 3-bit field can be used for SINR indexing to indicate 8 different rates of adaptive coding/modulation.
- the base station assigns desirable clusters to the subscriber making the request.
- the availability of the cluster for allocation to a subscriber depends on the total traffic load on the cluster. Therefore, the base station selects the clusters not only with high SINR, but also with low traffic load.
- FIG. 13 is a block diagram of one embodiment of a base station.
- cluster allocation and load scheduling controller 1301 collects all the necessary information, including the downlink/uplink SINR of clusters specified for each subscriber (e.g., via
- controller 1301 uses this information to make the decision on cluster allocation and load scheduling for each user, and stores the decision information in a memory (not shown). Controller 1301 informs the subscribers about the decisions through control signal channels (e.g., control signal/cluster allocation 1312 via OFDM transceiver 1305). Controller 1301 updates the decisions during retraining. [0080] In one embodiment, controller 1301 also performs admission control to user access since it knows the traffic load of the system. This may be performed by controlling user data buffers 1302 using admission control signals 1310.
- the packet data of User 1 ⁇ N are stored in the user data buffers 1302.
- multiplexer 1303 loads the user data to cluster data buffers (for Cluster 1 ⁇ M) waiting to be transmitted.
- cluster buffer 1304 stores the signal to be transmitted through OFDM transceiver 1305 (for downlink) and the signal received from transceiver 1305.
- each user might occupy multiple clusters and each cluster might be shared by multiple users (in a time- division-multiplexing fashion).
- the clusters are partitioned into groups.
- Each group can include multiple clusters.
- Figure 6 illustrates an exemplary partitioning. Referring to Figure 6, groups 1-4 are shown with arrows pointing to clusters that are in each group as a result of the partitioning.
- the clusters within each group are spaced far apart over the entire bandwidth.
- the clusters within each group are spaced apart farther than the channel coherence bandwidth, i.e. the bandwidth within which the channel response remains roughly the same.
- a typical value of coherence bandwidth is 100 kHz for many cellular systems. This improves frequency diversity within each group and increases the probability that at least some of the clusters within a group can provide high SINR.
- the clusters may be allocated in groups.
- Goals of group-based cluster allocation include reducing the data bits for cluster indexing, thereby reducing the bandwidth requirements of the feedback channel (information) and control channel (information) for cluster allocation.
- Group-based cluster allocation may also be used to reduce inter-cell interference.
- a subscriber After receiving the pilot signal from the base station, a subscriber sends back the channel information on one or more cluster groups, simultaneously or sequentially. In one embodiment, only the information on some of the groups is sent back to the base station. Many criteria can be used to choose and order the groups, based on the channel information, the inter-cell interference levels, and the intra-cell traffic load on each cluster.
- a subscriber first selects the group with the best overall performance and then feedbacks the SINR information for the clusters in that group.
- the subscriber may order the groups based on their number of clusters for which the SINR is higher than a predefined threshold.
- the feedback for each group generally contains two types of information: the group index and the SINR value of each cluster within the group.
- Figure 7 illustrates an exemplary format for indicating a group-based cluster allocation. Referring to Figure 7, a group ID, ID1, is followed by the SINR values for each of the clusters in the group. This can significantly reduce the feedback overhead.
- the cluster allocator at the base station selects multiple clusters from one or more groups, if available, and then assigns the clusters to the subscriber. This selection may be performed by an allocation in a media access control portion of the base station.
- groups can have different priorities associated with different cells. In one embodiment, the subscriber's selection of a group is biased by the group priority, which means that certain subscribers have higher priorities on the usage of some groups than the other subscribers.
- the group index in the feedback information can be omitted, because this information is known to both subscriber and base station by default.
- the pilot signal sent from the base station to the subscriber also indicates the availability of each cluster, e.g., the pilot signal shows which clusters have already been allocated for other subscribers and which clusters are available for new allocations.
- the base station can transmit a pilot sequence 1111 1111 on the subcarriers of a cluster to indicate that the cluster is available, and 1111 -1-1-1-1 to indicate the cluster is not available.
- the subscriber first distinguishes the two sequences using the signal processing methods which are well known in the art, e.g., the correlation methods, and then estimates the channel and interference level.
- the subscriber can prioritize the groups to achieve both high SINR and good load balancing.
- the subscriber protects the feedback information by using error correcting codes.
- the SINR information in the feedback is first compressed using source coding techniques, e.g., differential encoding, and then encoded by the channel codes.
- Figure 8 shows one embodiment of a frequency reuse pattern for an exemplary cellular set up.
- Each cell has hexagonal structure with six sectors using directional antennas at the base stations. Between the cells, the frequency reuse factor is one. Within each cell, the frequency reuse factor is 2 where the sectors use two frequencies alternatively.
- each shaded sector uses half of the available OFDMA clusters and each unshaded sector uses the other half of the clusters. Without loss of generality, the clusters used by the shaded sectors are referred to herein as odd clusters and those used by the unshaded sectors are referred to herein as even clusters.
- the downlink signaling with omni-directional antennas at the subscribers are referred to herein as odd clusters and those used by the unshaded sectors.
- Table 2 Priority ordering for the downlink of the shaded sectors.
- the clusters in Group 1 are selectively assigned. If there are still more subscribers demanding clusters, the clusters in Group 2 are selectively assigned to subscribers, depending on the measured SINR (avoiding the clusters receiving strong interference from Sector Cl). Note that the newly assigned clusters from Group 2 to Sector Al shall not cause interference problem in Sector Bl, unless the load in Sector Bl is so heavy that the clusters in both Group 3 and 1 are used up and the clusters in Group 2 are also used.
- Table 3 shows the cluster usage when less than 2/3 of all the available clusters are used in Sector Al, Bl, and Cl. Table 3: Cluster usage for the downlink of the shaded sectors with less than 2/3 of the full load.
- Table 4 shows the priority orders for the unshaded sectors, which are different from those for the shaded sectors, since the interfering relationship is reversed.
- Table 4 Priority ordering for the downlink of the unshaded sectors.
- coherence clusters containing multiple subcarriers close to each other
- diversity clusters containing multiple subcarriers with at least some of the subcarriers spread far apart over the spectrum.
- the closeness of the multiple subcarriers in coherence clusters is preferably within the channel coherence bandwidth, i.e. the bandwidth within which the channel response remains roughly the same, which is typicaUy within 100 kHz for many ceUular systems.
- the spread of subcarriers in diversity clusters is preferably larger than the channel coherence bandwidth, typically within 100 kHz for many ceUular systems. Of course, the larger the spread, the better the diversity. Therefore, a general goal in such cases is to maximize the spread.
- Figure 9 iUustrates exemplary cluster formats for coherence clusters and diversity clusters for CeUs A-C
- the labeling of frequencies indicates whether the frequencies are part of coherence or diversity clusters.
- those frequencies labeled 1-8 are diversity clusters and those labeled 9-16 are coherence clusters.
- aU frequencies labeled 1 in a ceU are part of one diversity cluster
- aU frequencies labeled 2 in a ceU are part of another diversity cluster, etc.
- whUe the group of frequencies labeled 9 are one coherence cluster
- the group of frequencies labeled 10 are another coherence cluster, etc.
- the diversity clusters can be configured differently for different ceUs to reduce the effect of inter-ceU interference through interference averaging.
- Figure 9 shows example cluster configurations for three neighboring ceUs.
- the interference from a particular cluster in one ceU are distributed to many clusters in other ceUs, e.g., the interference from Cluster 1 in CeU A are distributed to Cluster 1, 8, 7, 6 in CeU B. This significantly reduces the interference power to any particular cluster in CeU B.
- the interference to any particular cluster in one ceU comes from many different clusters in other ceUs. Since not aU cluster are strong interferers, diversity clusters, with channel coding across its subcarriers, provide interference diversity gain. Therefore, it is advantageous to assign diversity clusters to subscribers that are close (e.g., within the coherent bandwidth) to the ceU boundaries and are more subject to inter-ceU interference.
- the subcarriers in a coherence cluster are consecutive or close (e.g., within the coherent bandwidth) to each other, they are Ukely within the coherent bandwidth of the channel fading. Therefore, the channel gain of a coherence cluster can vary significantly and cluster selection can greatly improve the performance. On the other hand, the average channel gain of a diversity cluster has less of a degree of variation due to the inherent frequency diversity among the multiple subcarriers spread over the spectrum. With channel coding across the subcarriers within the cluster, diversity clusters are more robust to cluster mis-selection (by the nature of diversification itself), while yielding possibly less gain from cluster selection.
- Channel coding across the subcarriers means that each codeword contains bits transmitted from multiple subcarriers, and more specificaUy, the difference bits between codewords (error vector) are distributed among multiple subcarriers.
- FIG. 10 iUustrates diversity cluster with subcarrier hopping. Referring to Figure 10, there are four diversity clusters in each of cells A and B shown, with each subcarrier in individual diversity clusters having the same label (1, 2, 3, or 4). There are four separate time slots shown and during each of the time slots, the subcarriers for each of the diversity clusters change.
- subcarrier 1 is part of diversity cluster 1 during time slot 1, is part of diversity cluster 2 during time slot 2, is part of diversity cluster 3 during time slot 3, and is part of diversity cluster 4 during time slot 4.
- more interference diversity can be obtained through subcarrier hopping over time, with further interference diversity achieved by using different hopping patterns for different cells, as shown in Figure 10.
- the manner in which the subscriber changes the subcarriers (hopping sequences) can be different for different ceUs in order to achieve better interference averaging through coding.
- cluster allocation is performed faster than the channel changing rate, which is often measured by the channel Doppler rate (in Hz), i.e. how many cycles the channel changes per second where the channel is completely different after one cycle. Note that selective cluster aUocation can be performed on both coherence and diversity clusters.
- a channel/interference variation detector can be implemented at either the subscriber or the base station, or both. Using the detection results, the subscriber and the base station intelligently selects diversity clusters to mobUe subscribers or fixed subscribers at ceU boundaries, and coherence clusters to fixed subscribers close to the base station.
- the char el/interference variation detector measures the channel (SINR) variation from time to time for each cluster. For example, in one embodiment, the channel/ interference detector measures the power difference between pUot symbols for each cluster and averages the difference over a moving window (e.g., 4 time slots).
- FIG 11 is a flow diagram of one embodiment of a process for intelligent selection between diversity clusters and coherence clusters depending on subscribers mobility. The process is performed by processing logic that may comprise hardware (e.g., circuitry, dedicated logic, etc.), software (such as that which runs on, for example, a general purpose computer system or dedicated machine), or a combination of both.
- processing logic in the base station performs channel/ interference variation detection (processing block 1101).
- Processing logic then tests whether the results of the channel/interference variation detection indicate that the user is mobile or in a fixed position close to the edge of the ceU (processing block 1102). If the user is not mobUe or is not in a fixed position close to the edge of the ceU, processing transitions to processing block 1103 where processing logic in the base station selects coherence clusters; otherwise, processing transitions to processing block 1104 in which processing logic in the base station selects diversity clusters.
- the base station determines whether a subscriber is mobUe or fixed by detecting a rate of change of pUot signals, or the normalized channel variation, and determining that the rate of change is greater than a predetermined threshold.
- the base station determines that the subscriber is mobUe.
- the base station determines that the subscriber is mobUe and aUocates diversity clusters; otherwise, the base station aUocates coherence clusters.
Abstract
Description
Claims
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU2002235217A AU2002235217A1 (en) | 2000-12-15 | 2001-12-13 | Multi-carrier communications with adaptive cluster configuration and switching |
JP2002550747A JP4213466B2 (en) | 2000-12-15 | 2001-12-13 | Multi-carrier communication with adaptive cluster configuration and switching |
MXPA03005311A MXPA03005311A (en) | 2000-12-15 | 2001-12-13 | Multi-carrier communications with adaptive cluster configuration and switching. |
CA2431502A CA2431502C (en) | 2000-12-15 | 2001-12-13 | Multi-carrier communications with adaptive cluster configuration and switching |
KR1020037007963A KR100676667B1 (en) | 2000-12-15 | 2001-12-13 | Multi-carrier communications with adaptive cluster configuration and switching |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/738,086 US6947748B2 (en) | 2000-12-15 | 2000-12-15 | OFDMA with adaptive subcarrier-cluster configuration and selective loading |
US09/738,086 | 2000-12-15 | ||
US09/837,701 US7146172B2 (en) | 2000-12-15 | 2001-04-17 | Multi-carrier communications with adaptive cluster configuration and switching |
US09/837,701 | 2001-04-17 |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2002049385A2 true WO2002049385A2 (en) | 2002-06-20 |
WO2002049385A3 WO2002049385A3 (en) | 2002-11-21 |
Family
ID=27113312
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2001/048701 WO2002049385A2 (en) | 2000-12-15 | 2001-12-13 | Multi-carrier communications with adaptive cluster configuration and switching |
Country Status (6)
Country | Link |
---|---|
JP (1) | JP4213466B2 (en) |
CN (1) | CN1524367A (en) |
AU (2) | AU2002232589A1 (en) |
CA (1) | CA2431502C (en) |
MX (1) | MXPA03005311A (en) |
WO (1) | WO2002049385A2 (en) |
Cited By (72)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1408710A1 (en) * | 2002-09-30 | 2004-04-14 | Samsung Electronics Co., Ltd. | Apparatus and method for allocating resources of a virtual cell in an OFDM mobile communication system |
EP1414255A1 (en) * | 2002-10-24 | 2004-04-28 | Siemens Aktiengesellschaft | Method for managing radio resources |
JP2004159345A (en) * | 2002-11-07 | 2004-06-03 | Samsung Electronics Co Ltd | Ofdm frequency reuse method in mobile communication system |
JP2005130491A (en) * | 2003-10-21 | 2005-05-19 | Alcatel | Method of assigning subcarrier and selecting subcarrier modulation system in wireless multiplex carrier transmission system |
WO2005050939A1 (en) * | 2003-11-21 | 2005-06-02 | Nokia Corporation | Method and system for subcarrier allocation in a communication system |
EP1550228A1 (en) * | 2002-09-20 | 2005-07-06 | Interdigital Technology Corporation | Enhancing reception using intercellular interference cancellation |
WO2005101987A2 (en) | 2004-04-22 | 2005-11-03 | Lg Electronics Inc. | Method of allocating subcarriers in orthogonal frequency division multiplexing (ofdm) cellular system |
JP2005323358A (en) * | 2004-05-04 | 2005-11-17 | Alcatel | Method for terminal support coordinated radio serving and interference avoidance in ofdm mobile communications system |
EP1662825A1 (en) * | 2004-11-24 | 2006-05-31 | Samsung Electronics Co., Ltd. | Method for allocating resources in a multicarrier system and transmission apparatus using same |
DE102005007326A1 (en) * | 2005-02-17 | 2006-09-07 | Siemens Ag | Dynamic allocation of radio resources in a multi-carrier communication system |
EP1712090A1 (en) * | 2003-05-09 | 2006-10-18 | Zion Hadad | Cellular network system and method |
WO2007012538A1 (en) * | 2005-07-26 | 2007-02-01 | Ipwireless Inc | Co-channel interference mitigation for ofdm |
WO2007078712A2 (en) * | 2005-12-22 | 2007-07-12 | Interdigital Technology Corporation | Choice between consecutive and distributed subcarrier allocation for an ofdma link based on the rate of change of the channel in time and frequency |
WO2007099839A1 (en) | 2006-02-24 | 2007-09-07 | Mitsubishi Electric Corporation | Communication device |
JP2007529953A (en) * | 2004-03-19 | 2007-10-25 | クゥアルコム・インコーポレイテッド | Method and apparatus for flexible spectrum allocation in a communication system |
WO2007138664A1 (en) * | 2006-05-26 | 2007-12-06 | Mitsubishi Electric Corporation | Scheduling method and communication apparatus |
US7317930B2 (en) | 2004-02-16 | 2008-01-08 | Sony Corporation | Wireless transmission/reception system |
US7680475B2 (en) | 2004-06-09 | 2010-03-16 | Qualcomm Incorporated | Dynamic ASBR scheduler |
WO2010064835A2 (en) | 2008-12-02 | 2010-06-10 | Samsung Electronics Co., Ltd. | Cluster-based cooperative communication system and method |
EP2242318A1 (en) * | 2009-04-15 | 2010-10-20 | Telefonaktiebolaget L M Ericsson (publ) | OFDMA scheduling method for avoiding leakage at the mobile stations |
US8009616B2 (en) | 2005-06-17 | 2011-08-30 | Fujitsu Limited | Radio access method, radio base station and radio terminal |
US8032145B2 (en) | 2004-07-23 | 2011-10-04 | Qualcomm Incorporated | Restrictive reuse set management algorithm for equal grade of service on FL transmission |
US8045512B2 (en) | 2005-10-27 | 2011-10-25 | Qualcomm Incorporated | Scalable frequency band operation in wireless communication systems |
US8098569B2 (en) | 2000-09-13 | 2012-01-17 | Qualcomm Incorporated | Signaling method in an OFDM multiple access system |
US8160595B2 (en) | 2007-05-01 | 2012-04-17 | Ntt Docomo, Inc. | Base station apparatus and communication control method |
JP2012170116A (en) * | 2003-08-20 | 2012-09-06 | Panasonic Corp | Communication terminal apparatus and transmission method |
US8358603B2 (en) | 2007-08-09 | 2013-01-22 | Huawei Technologies Co., Ltd. | Method, base station, and user terminal for implementing uplink resource indication |
US8379691B2 (en) | 2007-12-12 | 2013-02-19 | Samsung Electronics Co., Ltd. | Method and apparatus for estimating channel in mobile communication network |
US8446892B2 (en) | 2005-03-16 | 2013-05-21 | Qualcomm Incorporated | Channel structures for a quasi-orthogonal multiple-access communication system |
CN102158870B (en) * | 2004-12-22 | 2013-06-05 | 高通股份有限公司 | Minimizing feedback by sending a quality indicator for a non-restrictive reuse set and a vectored quality indicator for other reuse sets |
US8462859B2 (en) | 2005-06-01 | 2013-06-11 | Qualcomm Incorporated | Sphere decoding apparatus |
US8477684B2 (en) | 2005-10-27 | 2013-07-02 | Qualcomm Incorporated | Acknowledgement of control messages in a wireless communication system |
US8565194B2 (en) | 2005-10-27 | 2013-10-22 | Qualcomm Incorporated | Puncturing signaling channel for a wireless communication system |
US8582509B2 (en) | 2005-10-27 | 2013-11-12 | Qualcomm Incorporated | Scalable frequency band operation in wireless communication systems |
US8582548B2 (en) | 2005-11-18 | 2013-11-12 | Qualcomm Incorporated | Frequency division multiple access schemes for wireless communication |
US8599945B2 (en) | 2005-06-16 | 2013-12-03 | Qualcomm Incorporated | Robust rank prediction for a MIMO system |
US8611284B2 (en) | 2005-05-31 | 2013-12-17 | Qualcomm Incorporated | Use of supplemental assignments to decrement resources |
US8644292B2 (en) | 2005-08-24 | 2014-02-04 | Qualcomm Incorporated | Varied transmission time intervals for wireless communication system |
US8693405B2 (en) | 2005-10-27 | 2014-04-08 | Qualcomm Incorporated | SDMA resource management |
EP2144393A3 (en) * | 2008-07-09 | 2014-04-30 | Fujitsu Limited | Allocation of contiguous or non-contiguous sub-channels |
US8738016B2 (en) | 2007-12-04 | 2014-05-27 | Fujitsu Limited | Scheduling method, wireless base station, and wireless terminal |
US8738020B2 (en) | 2000-12-15 | 2014-05-27 | Adaptix, Inc. | Multi-carrier communications with adaptive cluster configuration and switching |
US8760992B2 (en) | 2004-12-07 | 2014-06-24 | Adaptix, Inc. | Method and system for switching antenna and channel assignments in broadband wireless networks |
US8831607B2 (en) | 2006-01-05 | 2014-09-09 | Qualcomm Incorporated | Reverse link other sector communication |
US8879511B2 (en) | 2005-10-27 | 2014-11-04 | Qualcomm Incorporated | Assignment acknowledgement for a wireless communication system |
US8885628B2 (en) | 2005-08-08 | 2014-11-11 | Qualcomm Incorporated | Code division multiplexing in a single-carrier frequency division multiple access system |
US8917654B2 (en) | 2005-04-19 | 2014-12-23 | Qualcomm Incorporated | Frequency hopping design for single carrier FDMA systems |
US9088384B2 (en) | 2005-10-27 | 2015-07-21 | Qualcomm Incorporated | Pilot symbol transmission in wireless communication systems |
US9130810B2 (en) | 2000-09-13 | 2015-09-08 | Qualcomm Incorporated | OFDM communications methods and apparatus |
US9136974B2 (en) | 2005-08-30 | 2015-09-15 | Qualcomm Incorporated | Precoding and SDMA support |
US9137822B2 (en) | 2004-07-21 | 2015-09-15 | Qualcomm Incorporated | Efficient signaling over access channel |
US9143305B2 (en) | 2005-03-17 | 2015-09-22 | Qualcomm Incorporated | Pilot signal transmission for an orthogonal frequency division wireless communication system |
US9144060B2 (en) | 2005-10-27 | 2015-09-22 | Qualcomm Incorporated | Resource allocation for shared signaling channels |
US9148256B2 (en) | 2004-07-21 | 2015-09-29 | Qualcomm Incorporated | Performance based rank prediction for MIMO design |
US9154211B2 (en) | 2005-03-11 | 2015-10-06 | Qualcomm Incorporated | Systems and methods for beamforming feedback in multi antenna communication systems |
US9172453B2 (en) | 2005-10-27 | 2015-10-27 | Qualcomm Incorporated | Method and apparatus for pre-coding frequency division duplexing system |
US9179319B2 (en) | 2005-06-16 | 2015-11-03 | Qualcomm Incorporated | Adaptive sectorization in cellular systems |
US9184870B2 (en) | 2005-04-01 | 2015-11-10 | Qualcomm Incorporated | Systems and methods for control channel signaling |
US9209956B2 (en) | 2005-08-22 | 2015-12-08 | Qualcomm Incorporated | Segment sensitive scheduling |
US9210651B2 (en) | 2005-10-27 | 2015-12-08 | Qualcomm Incorporated | Method and apparatus for bootstraping information in a communication system |
US9225488B2 (en) | 2005-10-27 | 2015-12-29 | Qualcomm Incorporated | Shared signaling channel |
US9225416B2 (en) | 2005-10-27 | 2015-12-29 | Qualcomm Incorporated | Varied signaling channels for a reverse link in a wireless communication system |
US9246560B2 (en) | 2005-03-10 | 2016-01-26 | Qualcomm Incorporated | Systems and methods for beamforming and rate control in a multi-input multi-output communication systems |
US9307544B2 (en) | 2005-04-19 | 2016-04-05 | Qualcomm Incorporated | Channel quality reporting for adaptive sectorization |
US9419676B2 (en) | 2005-03-07 | 2016-08-16 | Qualcomm Incorporated | Pilot transmission and channel estimation for a communication system utilizing frequency division multiplexing |
US9461859B2 (en) | 2005-03-17 | 2016-10-04 | Qualcomm Incorporated | Pilot signal transmission for an orthogonal frequency division wireless communication system |
US9467268B2 (en) | 2005-08-29 | 2016-10-11 | Samsung Electronics Co., Ltd. | Apparatus and method for feeding back channel quality information and scheduling apparatus and method using the same in a wireless communication system |
US9520972B2 (en) | 2005-03-17 | 2016-12-13 | Qualcomm Incorporated | Pilot signal transmission for an orthogonal frequency division wireless communication system |
US9660776B2 (en) | 2005-08-22 | 2017-05-23 | Qualcomm Incorporated | Method and apparatus for providing antenna diversity in a wireless communication system |
US9686052B2 (en) | 2013-02-20 | 2017-06-20 | Mitsubishi Electric Corporation | Communication-line-quality estimating apparatus, transmitter, and receiver |
US10243705B2 (en) | 2006-01-18 | 2019-03-26 | Telefonaktiebolaget Lm Ericsson (Publ) | Localized and distributed transmission |
US11804870B2 (en) | 2004-01-29 | 2023-10-31 | Neo Wireless Llc | Channel probing signal for a broadband communication system |
Families Citing this family (24)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
MXPA03005311A (en) | 2000-12-15 | 2004-12-02 | Adaptix Inc | Multi-carrier communications with adaptive cluster configuration and switching. |
US7042857B2 (en) | 2002-10-29 | 2006-05-09 | Qualcom, Incorporated | Uplink pilot and signaling transmission in wireless communication systems |
US7039001B2 (en) * | 2002-10-29 | 2006-05-02 | Qualcomm, Incorporated | Channel estimation for OFDM communication systems |
US9585023B2 (en) | 2003-10-30 | 2017-02-28 | Qualcomm Incorporated | Layered reuse for a wireless communication system |
US8611283B2 (en) | 2004-01-28 | 2013-12-17 | Qualcomm Incorporated | Method and apparatus of using a single channel to provide acknowledgement and assignment messages |
KR100965694B1 (en) | 2004-06-15 | 2010-06-24 | 삼성전자주식회사 | System and method for supporting soft handover in a broadband wireless access communication system |
US8891349B2 (en) | 2004-07-23 | 2014-11-18 | Qualcomm Incorporated | Method of optimizing portions of a frame |
US8831115B2 (en) | 2004-12-22 | 2014-09-09 | Qualcomm Incorporated | MC-CDMA multiplexing in an orthogonal uplink |
KR100617835B1 (en) * | 2005-01-05 | 2006-08-28 | 삼성전자주식회사 | Apparatus and method for transmitting/receiving a channel quality information in a communication system |
EP2975785B1 (en) * | 2005-09-22 | 2019-11-20 | Huawei Technologies Co., Ltd. | Communication control apparatus and communication system for reporting reception quality measurements |
CN1968239A (en) | 2005-11-17 | 2007-05-23 | 松下电器产业株式会社 | Carrier allocation method for multi-cell orthogonal frequency division multiple address system |
US7593384B2 (en) * | 2005-12-15 | 2009-09-22 | Telefonaktiebolaget Lm Ericsson (Publ) | Efficient channel quality reporting and link adaptation for multi-carrier broadband wireless communication |
JP4627801B2 (en) | 2006-03-17 | 2011-02-09 | 富士通株式会社 | Base station apparatus, mobile station apparatus, and subcarrier allocation method |
US8131306B2 (en) * | 2006-03-20 | 2012-03-06 | Intel Corporation | Wireless access network and method for allocating data subcarriers within a downlink subframe based on grouping of user stations |
JP5329417B2 (en) * | 2006-11-01 | 2013-10-30 | クゥアルコム・インコーポレイテッド | Sub-band dependent resource management |
US8462758B2 (en) * | 2006-12-20 | 2013-06-11 | Intel Corporation | Channel quality information feedback techniques for a wireless system |
JP4935896B2 (en) | 2007-03-15 | 2012-05-23 | 富士通株式会社 | Base station and method used in mobile communication system |
CN102176787B (en) * | 2007-08-09 | 2015-06-17 | 华为技术有限公司 | Method, base station, and user terminal for realizing uplink resource indication |
JP4734314B2 (en) * | 2007-12-10 | 2011-07-27 | パナソニック株式会社 | Wireless communication apparatus and wireless communication method |
JP4734389B2 (en) * | 2008-09-11 | 2011-07-27 | パナソニック株式会社 | Wireless communication apparatus and wireless communication method |
CN101742668B (en) * | 2008-11-06 | 2012-01-25 | 中兴通讯股份有限公司 | Resource unit mapping method |
JP5388332B2 (en) | 2009-01-07 | 2014-01-15 | 株式会社Nttドコモ | Base station apparatus and information transmission method |
CN102843749B (en) * | 2011-06-23 | 2016-03-09 | 普天信息技术有限公司 | A kind of small region search method of multiplex broadcasting communication system and device |
EP2709393B1 (en) | 2012-09-13 | 2019-05-22 | Alcatel Lucent | Frequency band selection in heterogeneous networks |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5914933A (en) * | 1996-03-08 | 1999-06-22 | Lucent Technologies Inc. | Clustered OFDM communication system |
DE19800953C1 (en) * | 1998-01-13 | 1999-07-29 | Siemens Ag | Resource allocation in radio interface of radio communications system |
Family Cites Families (34)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH01317035A (en) * | 1988-06-17 | 1989-12-21 | Iwatsu Electric Co Ltd | Communication method for communication with mobile object |
JP2636712B2 (en) | 1993-12-08 | 1997-07-30 | 日本電気株式会社 | Mobile communication device |
JP2734952B2 (en) | 1993-12-16 | 1998-04-02 | 日本電気株式会社 | CDMA base station receiver |
JP2658865B2 (en) | 1994-02-28 | 1997-09-30 | 日本電気株式会社 | Mobile satellite communication system |
JPH07264110A (en) | 1994-03-17 | 1995-10-13 | N T T Idou Tsuushinmou Kk | Method for estimating channel complex envelope |
JP3141916B2 (en) | 1994-08-08 | 2001-03-07 | 株式会社エヌ・ティ・ティ・ドコモ | DPSK wave linear prediction differential detection method |
JPH0865233A (en) | 1994-08-25 | 1996-03-08 | Sanyo Electric Co Ltd | Portable telephone set |
JP3279108B2 (en) | 1994-12-28 | 2002-04-30 | 株式会社エヌ・ティ・ティ・ドコモ | Fading data generator and fading data processing device using the same |
JP2693922B2 (en) | 1995-02-13 | 1997-12-24 | 日本電気エンジニアリング株式会社 | Channel switching determination device for mobile wireless terminal |
JPH08265274A (en) | 1995-03-20 | 1996-10-11 | Fujitsu Ltd | Multiple propagation characteristic measuring device |
JP2755210B2 (en) | 1995-04-11 | 1998-05-20 | 日本電気株式会社 | Automatic frequency control circuit |
US5726978A (en) * | 1995-06-22 | 1998-03-10 | Telefonaktiebolaget L M Ericsson Publ. | Adaptive channel allocation in a frequency division multiplexed system |
JPH0951394A (en) | 1995-08-08 | 1997-02-18 | Oki Electric Ind Co Ltd | Traveling object facsimile communication system and message converting device |
JPH0955709A (en) | 1995-08-17 | 1997-02-25 | Fujitsu Ltd | Measuring instrument for multiplex propagation characteristic |
JPH0964804A (en) | 1995-08-29 | 1997-03-07 | Fujitsu Ltd | Multi-propagation characteristic measurement device |
JPH09167982A (en) | 1995-12-14 | 1997-06-24 | Kokusai Electric Co Ltd | Low-speed frequency hopping communication system |
JPH09167990A (en) | 1995-12-15 | 1997-06-24 | Oki Electric Ind Co Ltd | Mobile communication system and mobile object communicating method in mobile object communication system |
JP3011661B2 (en) | 1996-06-28 | 2000-02-21 | アンリツ株式会社 | Radio reception sensitivity diversity measuring method and apparatus |
US5991334A (en) | 1996-11-12 | 1999-11-23 | Lucent Technologies Inc. | Technique for simultaneous communications of analog frequency-modulated and digitally modulated signals using postcanceling scheme |
US5960353A (en) | 1996-12-24 | 1999-09-28 | Lucent Technologies, Inc. | Microcell load measurement using feedback control |
JP3387407B2 (en) | 1997-02-06 | 2003-03-17 | 三菱マテリアル株式会社 | Digital modulation / demodulation method and digital communication device |
US6175550B1 (en) * | 1997-04-01 | 2001-01-16 | Lucent Technologies, Inc. | Orthogonal frequency division multiplexing system with dynamically scalable operating parameters and method thereof |
JP2914444B2 (en) | 1997-07-22 | 1999-06-28 | 日本電気株式会社 | CDMA transceiver |
JP3070670B2 (en) * | 1997-09-02 | 2000-07-31 | 日本電気株式会社 | Pilot signal reception level averaging method |
JPH11113049A (en) | 1997-09-30 | 1999-04-23 | Matsushita Electric Ind Co Ltd | Radio communication system |
JP2934426B1 (en) | 1998-02-09 | 1999-08-16 | 株式会社ワイ・アール・ピー移動通信基盤技術研究所 | Arrival wave estimation method |
EP0938208A1 (en) | 1998-02-22 | 1999-08-25 | Sony International (Europe) GmbH | Multicarrier transmission, compatible with the existing GSM system |
JP3371801B2 (en) * | 1998-04-24 | 2003-01-27 | 三菱電機株式会社 | Frequency hopping type mobile station, base station and mobile communication system |
JPH11313299A (en) | 1998-04-30 | 1999-11-09 | Matsushita Electric Ind Co Ltd | Video information distribution method to mobile object by digital radio communication, central station device and mobile terminal used for the same method |
JP2000091973A (en) | 1998-09-10 | 2000-03-31 | Kokusai Electric Co Ltd | Rake synthesis circuit |
JP3045167B1 (en) | 1999-02-26 | 2000-05-29 | 住友電気工業株式会社 | Road-to-vehicle communication system |
CA2302608A1 (en) | 1999-03-29 | 2000-09-29 | Lucent Technologies Inc. | Multistream in-band-on-channel systems |
JP3236273B2 (en) | 1999-05-17 | 2001-12-10 | 三菱電機株式会社 | Multi-carrier transmission system and multi-carrier modulation method |
MXPA03005311A (en) | 2000-12-15 | 2004-12-02 | Adaptix Inc | Multi-carrier communications with adaptive cluster configuration and switching. |
-
2001
- 2001-12-13 MX MXPA03005311A patent/MXPA03005311A/en active IP Right Grant
- 2001-12-13 CA CA2431502A patent/CA2431502C/en not_active Expired - Fee Related
- 2001-12-13 AU AU2002232589A patent/AU2002232589A1/en not_active Abandoned
- 2001-12-13 WO PCT/US2001/048701 patent/WO2002049385A2/en active Application Filing
- 2001-12-13 JP JP2002550747A patent/JP4213466B2/en not_active Expired - Fee Related
- 2001-12-13 AU AU2002235217A patent/AU2002235217A1/en not_active Abandoned
- 2001-12-13 CN CNA018206522A patent/CN1524367A/en active Pending
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5914933A (en) * | 1996-03-08 | 1999-06-22 | Lucent Technologies Inc. | Clustered OFDM communication system |
DE19800953C1 (en) * | 1998-01-13 | 1999-07-29 | Siemens Ag | Resource allocation in radio interface of radio communications system |
Non-Patent Citations (3)
Title |
---|
NOGUEROLES R ET AL: "Improved performance of a random OFDMA mobile communication system" VEHICULAR TECHNOLOGY CONFERENCE, 1998. VTC 98. 48TH IEEE OTTAWA, ONT., CANADA 18-21 MAY 1998, NEW YORK, NY, USA,IEEE, US, 18 May 1998 (1998-05-18), pages 2502-2506, XP010288120 ISBN: 0-7803-4320-4 cited in the application * |
WONG C Y ET AL: "MULTIUSER OFDM WITH ADAPTIVE SUBCARRIER, BIT, AND POWER ALLOCATION" , IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS, IEEE INC. NEW YORK, US, VOL. 17, NR. 10, PAGE(S) 1747-1758 XP000854075 ISSN: 0733-8716 cited in the application Sections I and II abstract page 1747, left-hand column, line 23 -page 1748, left-hand column, line 30 page 1752, left-hand column, line 29 -right-hand column, line 59 figure 2 * |
YE LI ET AL: "Clustered OFDM with channel estimation for high rate wireless data" MOBILE MULTIMEDIA COMMUNICATIONS, 1999. (MOMUC '99). 1999 IEEE INTERNATIONAL WORKSHOP ON SAN DIEGO, CA, USA 15-17 NOV. 1999, PISCATAWAY, NJ, USA,IEEE, US, 15 November 1999 (1999-11-15), pages 43-50, XP010370695 ISBN: 0-7803-5904-6 * |
Cited By (152)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11032035B2 (en) | 2000-09-13 | 2021-06-08 | Qualcomm Incorporated | Signaling method in an OFDM multiple access system |
US9130810B2 (en) | 2000-09-13 | 2015-09-08 | Qualcomm Incorporated | OFDM communications methods and apparatus |
US8098568B2 (en) | 2000-09-13 | 2012-01-17 | Qualcomm Incorporated | Signaling method in an OFDM multiple access system |
US8098569B2 (en) | 2000-09-13 | 2012-01-17 | Qualcomm Incorporated | Signaling method in an OFDM multiple access system |
US9426012B2 (en) | 2000-09-13 | 2016-08-23 | Qualcomm Incorporated | Signaling method in an OFDM multiple access system |
US10313069B2 (en) | 2000-09-13 | 2019-06-04 | Qualcomm Incorporated | Signaling method in an OFDM multiple access system |
US8743729B2 (en) | 2000-12-15 | 2014-06-03 | Adaptix, Inc. | Multi-carrier communications with adaptive cluster configuration and switching |
US9344211B2 (en) | 2000-12-15 | 2016-05-17 | Adaptix, Inc. | OFDMA with adaptive subcarrier-cluster configuration and selective loading |
US9191138B2 (en) | 2000-12-15 | 2015-11-17 | Adaptix, Inc. | OFDMA with adaptive subcarrier-cluster configuration and selective loading |
US8934375B2 (en) | 2000-12-15 | 2015-01-13 | Adaptix, Inc. | OFDMA with adaptive subcarrier-cluster configuration and selective loading |
US8934445B2 (en) | 2000-12-15 | 2015-01-13 | Adaptix, Inc. | Multi-carrier communications with adaptive cluster configuration and switching |
US8738020B2 (en) | 2000-12-15 | 2014-05-27 | Adaptix, Inc. | Multi-carrier communications with adaptive cluster configuration and switching |
US8743717B2 (en) | 2000-12-15 | 2014-06-03 | Adaptix, Inc. | Multi-carrier communications with adaptive cluster configuration and switching |
US9203553B1 (en) | 2000-12-15 | 2015-12-01 | Adaptix, Inc. | OFDMA with adaptive subcarrier-cluster configuration and selective loading |
US8750238B2 (en) | 2000-12-15 | 2014-06-10 | Adaptix, Inc. | Multi-carrier communications with adaptive cluster configuration and switching |
US9219572B2 (en) | 2000-12-15 | 2015-12-22 | Adaptix, Inc. | OFDMA with adaptive subcarrier-cluster configuration and selective loading |
US8964719B2 (en) | 2000-12-15 | 2015-02-24 | Adaptix, Inc. | OFDMA with adaptive subcarrier-cluster configuration and selective loading |
US8958386B2 (en) | 2000-12-15 | 2015-02-17 | Adaptix, Inc. | Multi-carrier communications with adaptive cluster configuration and switching |
US9210708B1 (en) | 2000-12-15 | 2015-12-08 | Adaptix, Inc. | OFDMA with adaptive subcarrier-cluster configuration and selective loading |
EP1550228A4 (en) * | 2002-09-20 | 2005-11-23 | Interdigital Tech Corp | Enhancing reception using intercellular interference cancellation |
EP1550228A1 (en) * | 2002-09-20 | 2005-07-06 | Interdigital Technology Corporation | Enhancing reception using intercellular interference cancellation |
US7069009B2 (en) | 2002-09-30 | 2006-06-27 | Samsung Electronics Co., Ltd | Apparatus and method for allocating resources of a virtual cell in an OFDM mobile communication system |
EP1408710A1 (en) * | 2002-09-30 | 2004-04-14 | Samsung Electronics Co., Ltd. | Apparatus and method for allocating resources of a virtual cell in an OFDM mobile communication system |
EP1414255A1 (en) * | 2002-10-24 | 2004-04-28 | Siemens Aktiengesellschaft | Method for managing radio resources |
WO2004039114A2 (en) * | 2002-10-24 | 2004-05-06 | Siemens Aktiengesellschaft | Method for radio system resource management |
WO2004039114A3 (en) * | 2002-10-24 | 2004-06-24 | Siemens Ag | Method for radio system resource management |
KR101011406B1 (en) | 2002-10-24 | 2011-01-28 | 지멘스 악티엔게젤샤프트 | Method for radio system resource management |
JP2004159345A (en) * | 2002-11-07 | 2004-06-03 | Samsung Electronics Co Ltd | Ofdm frequency reuse method in mobile communication system |
EP1712090A4 (en) * | 2003-05-09 | 2011-12-07 | Zion Hadad | Cellular network system and method |
EP1712090A1 (en) * | 2003-05-09 | 2006-10-18 | Zion Hadad | Cellular network system and method |
US10819493B2 (en) | 2003-08-20 | 2020-10-27 | Panasonic Corporation | Wireless communication apparatus and wireless communication method |
US10164753B2 (en) | 2003-08-20 | 2018-12-25 | Panasonic Corporation | Wireless communication apparatus and wireless communication method |
US9762371B2 (en) | 2003-08-20 | 2017-09-12 | Panasonic Corporation | Wireless communication apparatus and wireless communication method |
JP2012170116A (en) * | 2003-08-20 | 2012-09-06 | Panasonic Corp | Communication terminal apparatus and transmission method |
US10554371B2 (en) | 2003-08-20 | 2020-02-04 | Panasonic Corporation | Wireless communication apparatus and wireless communication method |
US11356227B2 (en) | 2003-08-20 | 2022-06-07 | Panasonic Holdings Corporation | Wireless communication apparatus and wireless communication method |
US9504050B2 (en) | 2003-08-20 | 2016-11-22 | Panasonic Corporation | Wireless communication apparatus and wireless communication method |
US9565688B2 (en) | 2003-08-20 | 2017-02-07 | Panasonic Corporation | Wireless communication apparatus and wireless communication method |
US9055599B2 (en) | 2003-08-20 | 2015-06-09 | Panasonic Intellectual Property Corporation Of America | Wireless communication apparatus and wireless communication method |
US9198189B2 (en) | 2003-08-20 | 2015-11-24 | Panasonic Intellectual Property Corporation Of America | Wireless communication apparatus and wireless communication method |
US9967078B2 (en) | 2003-08-20 | 2018-05-08 | Panasonic Corporation | Wireless communication apparatus and wireless communication method |
JP2005130491A (en) * | 2003-10-21 | 2005-05-19 | Alcatel | Method of assigning subcarrier and selecting subcarrier modulation system in wireless multiplex carrier transmission system |
WO2005050939A1 (en) * | 2003-11-21 | 2005-06-02 | Nokia Corporation | Method and system for subcarrier allocation in a communication system |
US11804870B2 (en) | 2004-01-29 | 2023-10-31 | Neo Wireless Llc | Channel probing signal for a broadband communication system |
US7317930B2 (en) | 2004-02-16 | 2008-01-08 | Sony Corporation | Wireless transmission/reception system |
JP2013219794A (en) * | 2004-03-19 | 2013-10-24 | Qualcomm Inc | Methods and apparatus for flexible spectrum allocation in communication systems |
JP2007529953A (en) * | 2004-03-19 | 2007-10-25 | クゥアルコム・インコーポレイテッド | Method and apparatus for flexible spectrum allocation in a communication system |
EP2280508A3 (en) * | 2004-03-19 | 2014-06-18 | Qualcomm Incorporated(1/3) | Methods and apparatus for flexible spectrum allocation in communication systems |
JP2011019229A (en) * | 2004-03-19 | 2011-01-27 | Qualcomm Inc | Method and apparatus for flexible spectrum allocation in communication system |
WO2005101987A2 (en) | 2004-04-22 | 2005-11-03 | Lg Electronics Inc. | Method of allocating subcarriers in orthogonal frequency division multiplexing (ofdm) cellular system |
WO2005101987A3 (en) * | 2004-04-22 | 2007-05-10 | Lg Electronics Inc | Method of allocating subcarriers in orthogonal frequency division multiplexing (ofdm) cellular system |
JP2005323358A (en) * | 2004-05-04 | 2005-11-17 | Alcatel | Method for terminal support coordinated radio serving and interference avoidance in ofdm mobile communications system |
US7680475B2 (en) | 2004-06-09 | 2010-03-16 | Qualcomm Incorporated | Dynamic ASBR scheduler |
US10237892B2 (en) | 2004-07-21 | 2019-03-19 | Qualcomm Incorporated | Efficient signaling over access channel |
US10194463B2 (en) | 2004-07-21 | 2019-01-29 | Qualcomm Incorporated | Efficient signaling over access channel |
US9148256B2 (en) | 2004-07-21 | 2015-09-29 | Qualcomm Incorporated | Performance based rank prediction for MIMO design |
US9137822B2 (en) | 2004-07-21 | 2015-09-15 | Qualcomm Incorporated | Efficient signaling over access channel |
US11039468B2 (en) | 2004-07-21 | 2021-06-15 | Qualcomm Incorporated | Efficient signaling over access channel |
US10849156B2 (en) | 2004-07-21 | 2020-11-24 | Qualcomm Incorporated | Efficient signaling over access channel |
US10517114B2 (en) | 2004-07-21 | 2019-12-24 | Qualcomm Incorporated | Efficient signaling over access channel |
US8032145B2 (en) | 2004-07-23 | 2011-10-04 | Qualcomm Incorporated | Restrictive reuse set management algorithm for equal grade of service on FL transmission |
EP1662825A1 (en) * | 2004-11-24 | 2006-05-31 | Samsung Electronics Co., Ltd. | Method for allocating resources in a multicarrier system and transmission apparatus using same |
US7593420B2 (en) | 2004-11-24 | 2009-09-22 | Samsung Electronics Co., Ltd | Method for allocating resources in a multicarrier system and transmission apparatus using the same |
US8797970B2 (en) | 2004-12-07 | 2014-08-05 | Adaptix, Inc. | Method and system for switching antenna and channel assignments in broadband wireless networks |
US8760992B2 (en) | 2004-12-07 | 2014-06-24 | Adaptix, Inc. | Method and system for switching antenna and channel assignments in broadband wireless networks |
US8675509B2 (en) | 2004-12-22 | 2014-03-18 | Qualcomm Incorporated | Feedback to support restrictive reuse |
CN102158870B (en) * | 2004-12-22 | 2013-06-05 | 高通股份有限公司 | Minimizing feedback by sending a quality indicator for a non-restrictive reuse set and a vectored quality indicator for other reuse sets |
US8483734B2 (en) | 2005-02-17 | 2013-07-09 | Michael Einhaus | Dynamic allocation of radio resources in a multicarrier communication system |
DE102005007326A1 (en) * | 2005-02-17 | 2006-09-07 | Siemens Ag | Dynamic allocation of radio resources in a multi-carrier communication system |
US9419676B2 (en) | 2005-03-07 | 2016-08-16 | Qualcomm Incorporated | Pilot transmission and channel estimation for a communication system utilizing frequency division multiplexing |
US9246560B2 (en) | 2005-03-10 | 2016-01-26 | Qualcomm Incorporated | Systems and methods for beamforming and rate control in a multi-input multi-output communication systems |
US9154211B2 (en) | 2005-03-11 | 2015-10-06 | Qualcomm Incorporated | Systems and methods for beamforming feedback in multi antenna communication systems |
US8446892B2 (en) | 2005-03-16 | 2013-05-21 | Qualcomm Incorporated | Channel structures for a quasi-orthogonal multiple-access communication system |
US8547951B2 (en) | 2005-03-16 | 2013-10-01 | Qualcomm Incorporated | Channel structures for a quasi-orthogonal multiple-access communication system |
US9520972B2 (en) | 2005-03-17 | 2016-12-13 | Qualcomm Incorporated | Pilot signal transmission for an orthogonal frequency division wireless communication system |
US9143305B2 (en) | 2005-03-17 | 2015-09-22 | Qualcomm Incorporated | Pilot signal transmission for an orthogonal frequency division wireless communication system |
US9461859B2 (en) | 2005-03-17 | 2016-10-04 | Qualcomm Incorporated | Pilot signal transmission for an orthogonal frequency division wireless communication system |
US9184870B2 (en) | 2005-04-01 | 2015-11-10 | Qualcomm Incorporated | Systems and methods for control channel signaling |
US8917654B2 (en) | 2005-04-19 | 2014-12-23 | Qualcomm Incorporated | Frequency hopping design for single carrier FDMA systems |
US9307544B2 (en) | 2005-04-19 | 2016-04-05 | Qualcomm Incorporated | Channel quality reporting for adaptive sectorization |
US9036538B2 (en) | 2005-04-19 | 2015-05-19 | Qualcomm Incorporated | Frequency hopping design for single carrier FDMA systems |
US9408220B2 (en) | 2005-04-19 | 2016-08-02 | Qualcomm Incorporated | Channel quality reporting for adaptive sectorization |
US8611284B2 (en) | 2005-05-31 | 2013-12-17 | Qualcomm Incorporated | Use of supplemental assignments to decrement resources |
US8462859B2 (en) | 2005-06-01 | 2013-06-11 | Qualcomm Incorporated | Sphere decoding apparatus |
US8599945B2 (en) | 2005-06-16 | 2013-12-03 | Qualcomm Incorporated | Robust rank prediction for a MIMO system |
US9179319B2 (en) | 2005-06-16 | 2015-11-03 | Qualcomm Incorporated | Adaptive sectorization in cellular systems |
US8009616B2 (en) | 2005-06-17 | 2011-08-30 | Fujitsu Limited | Radio access method, radio base station and radio terminal |
WO2007012538A1 (en) * | 2005-07-26 | 2007-02-01 | Ipwireless Inc | Co-channel interference mitigation for ofdm |
WO2007012635A1 (en) * | 2005-07-26 | 2007-02-01 | Ipwireless Inc | Co-channel interference mitigation for ofdm |
US8514958B2 (en) | 2005-07-26 | 2013-08-20 | Nvidia Corporation | Interference mitigation for orthogonal frequency division multiplexing communication |
US8229008B2 (en) | 2005-07-26 | 2012-07-24 | Nvidia Corporation | Interference mitigation for orthogonal frequency division multiplexing communication |
US8885628B2 (en) | 2005-08-08 | 2014-11-11 | Qualcomm Incorporated | Code division multiplexing in a single-carrier frequency division multiple access system |
US9693339B2 (en) | 2005-08-08 | 2017-06-27 | Qualcomm Incorporated | Code division multiplexing in a single-carrier frequency division multiple access system |
US9660776B2 (en) | 2005-08-22 | 2017-05-23 | Qualcomm Incorporated | Method and apparatus for providing antenna diversity in a wireless communication system |
US9209956B2 (en) | 2005-08-22 | 2015-12-08 | Qualcomm Incorporated | Segment sensitive scheduling |
US9240877B2 (en) | 2005-08-22 | 2016-01-19 | Qualcomm Incorporated | Segment sensitive scheduling |
US9860033B2 (en) | 2005-08-22 | 2018-01-02 | Qualcomm Incorporated | Method and apparatus for antenna diversity in multi-input multi-output communication systems |
US9246659B2 (en) | 2005-08-22 | 2016-01-26 | Qualcomm Incorporated | Segment sensitive scheduling |
US8787347B2 (en) | 2005-08-24 | 2014-07-22 | Qualcomm Incorporated | Varied transmission time intervals for wireless communication system |
US8644292B2 (en) | 2005-08-24 | 2014-02-04 | Qualcomm Incorporated | Varied transmission time intervals for wireless communication system |
US10432382B2 (en) | 2005-08-29 | 2019-10-01 | Samsung Electronics Co., Ltd. | Apparatus and method for feeding back channel quality information and scheduling apparatus and method using the same in a wireless communication system |
US10129002B2 (en) | 2005-08-29 | 2018-11-13 | Samsung Electronics Co., Ltd. | Apparatus and method for feeding back channel quality information and scheduling apparatus and method using the same in a wireless communication system |
US9831998B2 (en) | 2005-08-29 | 2017-11-28 | Samsung Electronics Co., Ltd. | Apparatus and method for feeding back channel quality information and scheduling apparatus and method using the same in a wireless communication system |
US9819468B2 (en) | 2005-08-29 | 2017-11-14 | Samsung Electronics Co., Ltd. | Apparatus and method for feeding back channel quality information and scheduling apparatus and method using the same in a wireless communication system |
US10256962B2 (en) | 2005-08-29 | 2019-04-09 | Samsung Electronics Co., Ltd. | Apparatus and method for feeding back channel quality information and scheduling apparatus and method using the same in a wireless communication system |
US10965431B2 (en) | 2005-08-29 | 2021-03-30 | Samsung Electronics Co., Ltd. | Apparatus and method for feeding back channel quality information and scheduling apparatus and method using the same in a wireless communication system |
US9467268B2 (en) | 2005-08-29 | 2016-10-11 | Samsung Electronics Co., Ltd. | Apparatus and method for feeding back channel quality information and scheduling apparatus and method using the same in a wireless communication system |
US9136974B2 (en) | 2005-08-30 | 2015-09-15 | Qualcomm Incorporated | Precoding and SDMA support |
US10805038B2 (en) | 2005-10-27 | 2020-10-13 | Qualcomm Incorporated | Puncturing signaling channel for a wireless communication system |
US8477684B2 (en) | 2005-10-27 | 2013-07-02 | Qualcomm Incorporated | Acknowledgement of control messages in a wireless communication system |
US9144060B2 (en) | 2005-10-27 | 2015-09-22 | Qualcomm Incorporated | Resource allocation for shared signaling channels |
US8045512B2 (en) | 2005-10-27 | 2011-10-25 | Qualcomm Incorporated | Scalable frequency band operation in wireless communication systems |
US8693405B2 (en) | 2005-10-27 | 2014-04-08 | Qualcomm Incorporated | SDMA resource management |
US9172453B2 (en) | 2005-10-27 | 2015-10-27 | Qualcomm Incorporated | Method and apparatus for pre-coding frequency division duplexing system |
US9088384B2 (en) | 2005-10-27 | 2015-07-21 | Qualcomm Incorporated | Pilot symbol transmission in wireless communication systems |
US8879511B2 (en) | 2005-10-27 | 2014-11-04 | Qualcomm Incorporated | Assignment acknowledgement for a wireless communication system |
US9225416B2 (en) | 2005-10-27 | 2015-12-29 | Qualcomm Incorporated | Varied signaling channels for a reverse link in a wireless communication system |
US8842619B2 (en) | 2005-10-27 | 2014-09-23 | Qualcomm Incorporated | Scalable frequency band operation in wireless communication systems |
US8582509B2 (en) | 2005-10-27 | 2013-11-12 | Qualcomm Incorporated | Scalable frequency band operation in wireless communication systems |
US8565194B2 (en) | 2005-10-27 | 2013-10-22 | Qualcomm Incorporated | Puncturing signaling channel for a wireless communication system |
US9225488B2 (en) | 2005-10-27 | 2015-12-29 | Qualcomm Incorporated | Shared signaling channel |
US9210651B2 (en) | 2005-10-27 | 2015-12-08 | Qualcomm Incorporated | Method and apparatus for bootstraping information in a communication system |
US8681764B2 (en) | 2005-11-18 | 2014-03-25 | Qualcomm Incorporated | Frequency division multiple access schemes for wireless communication |
US8582548B2 (en) | 2005-11-18 | 2013-11-12 | Qualcomm Incorporated | Frequency division multiple access schemes for wireless communication |
WO2007078712A2 (en) * | 2005-12-22 | 2007-07-12 | Interdigital Technology Corporation | Choice between consecutive and distributed subcarrier allocation for an ofdma link based on the rate of change of the channel in time and frequency |
WO2007078712A3 (en) * | 2005-12-22 | 2007-08-23 | Interdigital Tech Corp | Choice between consecutive and distributed subcarrier allocation for an ofdma link based on the rate of change of the channel in time and frequency |
US8831607B2 (en) | 2006-01-05 | 2014-09-09 | Qualcomm Incorporated | Reverse link other sector communication |
US10243705B2 (en) | 2006-01-18 | 2019-03-26 | Telefonaktiebolaget Lm Ericsson (Publ) | Localized and distributed transmission |
US11025379B2 (en) | 2006-01-18 | 2021-06-01 | Telefonaktiebolaget Lm Ericsson (Publ) | Localized and distributed transmission |
WO2007099839A1 (en) | 2006-02-24 | 2007-09-07 | Mitsubishi Electric Corporation | Communication device |
EP1988728A4 (en) * | 2006-02-24 | 2011-02-02 | Mitsubishi Electric Corp | Communication device |
EP1988728A1 (en) * | 2006-02-24 | 2008-11-05 | Mitsubishi Electric Corporation | Communication device |
EP2023516A4 (en) * | 2006-05-26 | 2012-05-02 | Mitsubishi Electric Corp | Scheduling method and communication apparatus |
KR100976298B1 (en) | 2006-05-26 | 2010-08-16 | 미쓰비시덴키 가부시키가이샤 | Scheduling method and communication apparatus |
WO2007138664A1 (en) * | 2006-05-26 | 2007-12-06 | Mitsubishi Electric Corporation | Scheduling method and communication apparatus |
US8223703B2 (en) | 2006-05-26 | 2012-07-17 | Mitsubishi Electric Corporation | Scheduling method and communication apparatus |
EP2023516A1 (en) * | 2006-05-26 | 2009-02-11 | Mitsubishi Electric Corporation | Scheduling method and communication apparatus |
US8160595B2 (en) | 2007-05-01 | 2012-04-17 | Ntt Docomo, Inc. | Base station apparatus and communication control method |
US9320028B2 (en) | 2007-08-09 | 2016-04-19 | Futurewei Technologies, Inc. | Method, base station, and user terminal for implementing uplink resource indication |
US8520573B2 (en) | 2007-08-09 | 2013-08-27 | Huawei Technologies Co., Ltd. | Method, base station, and user terminal for implementing uplink resource indication |
US10098101B2 (en) | 2007-08-09 | 2018-10-09 | Huawei Technologies Co., Ltd. | Method, base station, and user terminal for implementing uplink resource indication |
US8358603B2 (en) | 2007-08-09 | 2013-01-22 | Huawei Technologies Co., Ltd. | Method, base station, and user terminal for implementing uplink resource indication |
US8547886B2 (en) | 2007-08-09 | 2013-10-01 | Huawei Technologies Co., Ltd. | Method, base station, and user terminal for implementing uplink resource indication |
US8738016B2 (en) | 2007-12-04 | 2014-05-27 | Fujitsu Limited | Scheduling method, wireless base station, and wireless terminal |
US8379691B2 (en) | 2007-12-12 | 2013-02-19 | Samsung Electronics Co., Ltd. | Method and apparatus for estimating channel in mobile communication network |
EP2144393A3 (en) * | 2008-07-09 | 2014-04-30 | Fujitsu Limited | Allocation of contiguous or non-contiguous sub-channels |
WO2010064835A2 (en) | 2008-12-02 | 2010-06-10 | Samsung Electronics Co., Ltd. | Cluster-based cooperative communication system and method |
EP2353224A4 (en) * | 2008-12-02 | 2016-06-22 | Samsung Electronics Co Ltd | Cluster-based cooperative communication system and method |
EP2242318A1 (en) * | 2009-04-15 | 2010-10-20 | Telefonaktiebolaget L M Ericsson (publ) | OFDMA scheduling method for avoiding leakage at the mobile stations |
WO2010118983A1 (en) * | 2009-04-15 | 2010-10-21 | Telefonaktiebolaget L M Ericsson (Publ) | Ofdma scheduling method for avoiding leakage at the mobile stations |
US8804581B2 (en) | 2009-04-15 | 2014-08-12 | Telefonaktiebolaget L M Ericsson (Publ) | OFDMA scheduling method for avoiding leakage at the mobile stations |
US9686052B2 (en) | 2013-02-20 | 2017-06-20 | Mitsubishi Electric Corporation | Communication-line-quality estimating apparatus, transmitter, and receiver |
Also Published As
Publication number | Publication date |
---|---|
JP2004529524A (en) | 2004-09-24 |
CA2431502A1 (en) | 2002-06-20 |
JP4213466B2 (en) | 2009-01-21 |
CN1524367A (en) | 2004-08-25 |
MXPA03005311A (en) | 2004-12-02 |
AU2002232589A1 (en) | 2002-06-24 |
CA2431502C (en) | 2012-07-17 |
AU2002235217A1 (en) | 2002-06-24 |
WO2002049385A3 (en) | 2002-11-21 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US9210708B1 (en) | OFDMA with adaptive subcarrier-cluster configuration and selective loading | |
CA2431849C (en) | Multi-carrier communications with group-based subcarrier allocation | |
CA2431502C (en) | Multi-carrier communications with adaptive cluster configuration and switching |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A2 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ OM PH PL PT RO RU SD SE SG SI SK SL TJ TM TR TT TZ UA UG UZ VN YU ZA ZM ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A2 Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
AK | Designated states |
Kind code of ref document: A3 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ OM PH PL PT RO RU SD SE SG SI SK SL TJ TM TR TT TZ UA UG UZ VN YU ZA ZM ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A3 Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG |
|
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
WWE | Wipo information: entry into national phase |
Ref document number: 2431502 Country of ref document: CA |
|
WWE | Wipo information: entry into national phase |
Ref document number: PA/a/2003/005311 Country of ref document: MX Ref document number: 2002550747 Country of ref document: JP Ref document number: 1020037007963 Country of ref document: KR |
|
WWE | Wipo information: entry into national phase |
Ref document number: 018206522 Country of ref document: CN |
|
WWP | Wipo information: published in national office |
Ref document number: 1020037007963 Country of ref document: KR |
|
REG | Reference to national code |
Ref country code: DE Ref legal event code: 8642 |
|
122 | Ep: pct application non-entry in european phase |