Patent application number | Description | Published |
20090270028 | Rateless Coding for Multiuser Interference Relay Channel - An interference relay channel (IRC) utilizes a single relay to assist communications between multiple source-destination links under the half-duplex (HD) constraint. It is assumed that each source has an independent message and its transmitted signal may cause interference at the other destinations. It is also assumed that each node only estimates its backward channels and has no knowledge of its forward channels as well as the other links. The role of the relay is to generate signals to cooperate with the intended signal and mitigate the interference at all destinations. | 10-29-2009 |
20100074358 | Sparse Channel Estimation for MIMO OFDM Systems - A method for sparse channel estimation in MIMO OFDM systems with a plurality of subchannels having the same sparsity structure is presented. The inventive method comprises initializing a plurality of residual vectors and observation generating matrices modeling the channel, sending a pilot signal for each subcarrier, converting the pilot signals to tap positions, detecting an optimal tap position, updating the residual vectors by removing the one residual vector having the optimal tap position, updating the generating matrices in accordance with the optimal residual vector, calculating weighted residuals based on the updated residual vectors, and repeating the steps, except initializing, until a stopping condition is met, wherein the updated observation matrices estimate the sparse channel. In one embodiment, the observation generating matrices are omitted. In one embodiment, multiple vectors are removed during one iteration. Pilot placement and pilot allocation techniques are presented to optimize the method. | 03-25-2010 |
20100086024 | STREAMING SCALABLE VIDEO OVER FADING WIRELESS CHANNELS - A method and apparatus are provided for streaming scalable video over fading wireless channels. The method includes building a model relating to a relationship between an average data rate and an average peak signal-to-noise ratio for a video sequence encoded using scalable video coding and having a base layer and one or more enhancement layers. The method also includes computing a vector relating to a set of average data rates for a particular boundary point on an achievable rate region for a transmission strategy. The boundary point is a function of a parameter set for a plurality of users. The achievable rate region is based upon the model. The method further includes scheduling the plurality of users to receive the video sequence over a wireless channel, such that at a given transmission time slot a particular one of the plurality of users associated with a maximum value is selected. The maximum value is based on the vector and a channel capacity available to the particular one of the plurality of users. | 04-08-2010 |
20110103501 | INDEXING METHODS AND SYSTEMS - Methods and systems for indexing signal option selections are disclosed. The signal options can be any of a variety of options that permit the establishment of a communication link, including modulation format, coding rate, precoding index and assigned subbands. The selected options can be represented as a vector and the index can be determined by employing a worth function for a particular selected vector element that is dependent on a selection occurrence count of the element and on an element position count of the element. In particular, the index can be the summation of worth function values for each selected element. | 05-05-2011 |
20110105044 | REVERSE INDEXING METHODS AND SYSTEMS - Methods and systems for reversing indexing signal option selections are disclosed. The signal options can be any of a variety of options that permit the establishment of a communication link, including modulation format, coding rate, precoding index and assigned subbands. The selected options can be represented as a vector and the index can be determined by employing a worth function for a particular selected vector element that is dependent on a selection occurrence count of the element and on an element position count of the element. In particular, the index can be the summation of worth function values for each selected element. | 05-05-2011 |
20110194400 | Method of Using a Quantized Beamforming Matrix from Multiple Codebook Entries for Multiple-Antenna Systems - A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink. User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE. | 08-11-2011 |
20110194646 | Transmission with M Antennas using Precoding - Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied. | 08-11-2011 |
20110194647 | Method for Transmitting an Information Sequence - Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied. | 08-11-2011 |
20110194649 | Method of Precoding with a Codebook for a Wireless System With Multiple Transmission Ranks and a Quantized Beamforming Matrix - A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink. User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE. | 08-11-2011 |
20110211651 | Precoding for time or frequency correlated MIMO channels - Systems and methods are disclosed to generate a codebook for channel state information by generating a random codebook; partitioning channel state information into a set of nearest neighbors for each codebook entry based on a distance metric; and updating the codebook by finding a centroid for each partition. | 09-01-2011 |
20110243017 | MU-MIMO-OFDMA SYSTEMS AND METHODS FOR MULTI-RANK CQI COMPUTATION AND PRECODER SELECTION - Methods and systems for determining attributes of communication channels of MU-MIMO users in an OFDMA system are disclosed. One method comprises receiving from a base station, for at least one sub-band of contiguous sub-carriers, an indication of an estimate of or an upper-bound on a total number of streams that are co-scheduled by the base station on the at least one sub-band. In addition, the method further comprises determining one or more signal quality measures for the at-least one sub-band based on the estimate of or the upper-bound on the total number of streams that are scheduled by the base station on the at least one sub-band. Moreover, an indication of the one or more signal quality measures is transmitted to the base station. | 10-06-2011 |
20110243018 | MU-MIMO-OFDMA METHODS AND SYSTEMS FOR SIGNALING MULTI-RANK CQIs AND PRECODERS - Methods and systems for determining attributes of communication channels of MU-MIMO users in an OFDMA system are disclosed. One method includes receiving from a base station, for at least one sub-band of contiguous sub-carriers, an indication of an estimate of or an upper-bound on a total number of streams that are co-scheduled by the base station on the at least one sub-band and an indication of a fraction of a transmit power at the base station that is applied to streams that are scheduled for transmission to a particular user. The method further includes determining one or more signal quality measures for the at least one sub-band based on at least one of the fraction or the estimate of or the upper-bound on the total number of streams that are scheduled by the base station on the at least one sub-band. In addition, an indication of the one or more signal quality measures is transmitted to the base station in the method. | 10-06-2011 |
20110243019 | MU-MIMO-OFDMA MULTI-RANK CQI AND PRECODER SIGNALING SCHEMES - Methods and systems for determining attributes of communication channels of MU-MIMO users in an (OFDMA) system are disclosed. One method includes receiving from a base station, for at least one sub-band of contiguous sub-carriers, an indication of an estimate of or an upper-bound on a total number of streams that are co-scheduled by the base station on the at least one sub-band. The method further includes determining one or more signal quality measures for the at least one sub-band based on the estimate of or the upper-bound on the total number of streams that are scheduled by the base station on the at least one sub-band in accordance with at least one of single-user scheduling rules or multi-user scheduling rules. In addition, the method includes transmitting to the base station an indication of the one or more signal quality measures and at least one tag identifying each signal quality measure as being determined in accordance with the single-user scheduling rules or the multi-user scheduling rules. | 10-06-2011 |
20110255582 | SELECTIVE JOINT DEMODULATION - Systems, methods and apparatuses for jointly demodulating data signals are disclosed. In accordance with the method, pilot signals are received from a base station and are processed. In addition, from a set of expected co-scheduled data streams, a subset of the co-scheduled data streams that are actually transmitted by the base station are determined based on the pilot signals. Further, a group of the transmitted co-scheduled data streams are selected from the determined subset. The data signals are received and jointly demodulated by employing the selected group of co-scheduled data streams and by suppressing non-selected data streams from the determined subset. | 10-20-2011 |
20110255632 | SIGNALING OF MIXTURE COMBINATION SETS - Systems and methods for conveying and determining modulations schemes employed by co-scheduled users are disclosed. In addition, methods and systems for designing signaling schemes that convey such information are also disclosed. In accordance with one method, an index is received and a table of indices in which the received index denotes a plurality of different sets of modulation schemes is referenced. Further, one or more modulation schemes of at least one co-scheduled user is determined based on the referencing. In addition, data signals are received and are processed by utilizing the one or more modulation schemes. | 10-20-2011 |
20110268066 | Beamforming Methods in Closed-Loop MIMO - Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied. | 11-03-2011 |
20110268205 | Low-rate Feedback to Enhance Transmission Using Multi-Rank Beamforming - Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied. | 11-03-2011 |
20110268209 | Beamforming In MIMO Systems - A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE. | 11-03-2011 |
20110268210 | Restricted Multi-rank Precoding in Multiple Antenna Systems - A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE. | 11-03-2011 |
20110268211 | Quantized and Successive Precoding Codebook - A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink. User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE. | 11-03-2011 |
20110268212 | Successive Beamforming Strategies and Methods - A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE. | 11-03-2011 |
20110268213 | Quantized Precoding For 2TX Multiple Antenna Systems - A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink. User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE. | 11-03-2011 |
20110268214 | Feedback Generation in Recursive Multi-Rank Beamforming - A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE. | 11-03-2011 |
20110268215 | Space-Time Precoding and Associated Feedback Generation Methods in Multiple Antenna Systems - A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink. User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE. | 11-03-2011 |
20110268219 | Feedback Strategies For Constrained Codebooks Used in MIMO Precoding - Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied. | 11-03-2011 |
20110268220 | Restricted Codebooks And Related Signaling To Perform Beamforming - Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied. | 11-03-2011 |
20110268221 | Quantized Feedback Strategies and Signal Generation - Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied. | 11-03-2011 |
20110268222 | Successive Codebook and Feedback in Precoding Systems - Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied. | 11-03-2011 |
20110268223 | Closed-Loop MIMO Transmission and its Related Signaling - Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied. | 11-03-2011 |
20110268224 | Feedback Generation in Multiple Antenna Systems - A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink. User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE. | 11-03-2011 |
20110274189 | Structured Codebook for 4TX Multiple Antenna Systems - Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied. | 11-10-2011 |
20110274190 | Methods to Transmit and Receive For Low Dimensions MIMO Systems - Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied. | 11-10-2011 |
20110274203 | Codebook With Nested Structure - A multi-rank beamforming (MRBF) scheme in which the downlink channel is estimated and an optimal precoding matrix to be used by the MRBF transmitter is determined accordingly. The optimal precoding matrix is selected from a codebook of matrices having a recursive structure which allows for efficient computation of the optimal precoding matrix and corresponding Signal to Interference and Noise Ratio (SINR). The codebook also enjoys a small storage footprint. Due to the computational efficiency and modest memory requirements, the optimal precoding determination can be made at user equipment (UE) and communicated to a transmitting base station over a limited uplink channel for implementation over the downlink channel. | 11-10-2011 |
20110274207 | Enhancing MIMO Transmission - A multi-rank beamforming (MRBF) scheme in which the downlink channel is estimated and an optimal precoding matrix to be used by the MRBF transmitter is determined accordingly. The optimal precoding matrix is selected from a codebook of matrices having a recursive structure which allows for efficient computation of the optimal precoding matrix and corresponding Signal to Interference and Noise Ratio (SINR). The codebook also enjoys a small storage footprint. Due to the computational efficiency and modest memory requirements, the optimal precoding determination can be made at user equipment (UE) and communicated to a transmitting base station over a limited uplink channel for implementation over the downlink channel. | 11-10-2011 |
20110274208 | Feedback Generator For Codebook With Nested Structure - A multi-rank beamforming (MRBF) scheme in which the downlink channel is estimated and an optimal precoding matrix to be used by the MRBF transmitter is determined accordingly. The optimal precoding matrix is selected from a codebook of matrices having a recursive structure which allows for efficient computation of the optimal precoding matrix and corresponding Signal to Interference and Noise Ratio (SINR). The codebook also enjoys a small storage footprint. Due to the computational efficiency and modest memory requirements, the optimal precoding determination can be made at user equipment (UE) and communicated to a transmitting base station over a limited uplink channel for implementation over the downlink channel. | 11-10-2011 |
20110274209 | CODEBOOK BASED PRECODING METHODS - Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied. | 11-10-2011 |
20120039411 | FEED-FORWARD CONTROL SIGNALING AND DECODING SCHEMES - Systems and methods for conveying wireless transmission allocation information are disclosed. In accordance with one method, an index indicating selected data stream parameters is received. In addition, an indication of a number of transmit antennas at a transmitter from which the data stream is transmitted is also received. Further, the selected parameters are determined from the index based on the number of transmit antennas at the transmitter. Moreover, data signals are received and processed with a processor in accordance with the selected data stream parameters. | 02-16-2012 |
20120057657 | Precoded Data Receiver - A multi-rank beamforming (MRBF) scheme in which the downlink channel is estimated and an optimal precoding matrix to be used by the MRBF transmitter is determined accordingly. The optimal precoding matrix is selected from a codebook of matrices having a recursive structure which allows for efficient computation of the optimal precoding matrix and corresponding Signal to Interference and Noise Ratio (SINR). The codebook also enjoys a small storage footprint. Due to the computational efficiency and modest memory requirements, the optimal precoding determination can be made at user equipment (UE) and communicated to a transmitting base station over a limited uplink channel for implementation over the downlink channel. | 03-08-2012 |
20120063346 | Method for Transmitting an Information Sequence - Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied. | 03-15-2012 |
20120063538 | Method for Transmitting an Information Sequence - Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied. | 03-15-2012 |
20120087419 | CHANNEL ESTIMATION METHODS AND SYSTEMS BASED ON POWER MEASUREMENT AT RECEIVERS - Methods and systems that enable the determination of accurate channel estimates by measuring only power values of pilot signal transmissions at a receiver are described. Various measurement procedures that are based on average power measurements or short term, per-symbol measurements can be employed. Furthermore, procedures utilizing adaptive pilots generated with receiver feedback and deterministic pilots generated without receiver feedback are also described. | 04-12-2012 |
20120219078 | Subband Indexing Methods and Systems - Methods and systems for indexing subband selections are disclosed. The selected subbands can be represented as a binary sequence and the index can be determined by employing a choose function, where a choose function value for a particular selected bit position is defined by a selection occurrence count of the selected bit position that is chosen from a bit position count of the selected bit position. In particular, the index can be the summation of choose function values for each selected bit position. | 08-30-2012 |
20120236819 | Method for Transmitting an Information Sequence - Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied. | 09-20-2012 |
20120250779 | Method for Transmitting an Information Sequence - Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied. | 10-04-2012 |
20120257685 | Codebook With Nested Structure - A multi-rank beamforming (MRBF) scheme in which the downlink channel is estimated and an optimal precoding matrix to be used by the MRBF transmitter is determined accordingly. The optimal precoding matrix is selected from a codebook of matrices having a recursive structure which allows for efficient computation of the optimal precoding matrix and corresponding Signal to Interference and Noise Ratio (SINR). The codebook also enjoys a small storage footprint. Due to the computational efficiency and modest memory requirements, the optimal precoding determination can be made at user equipment (UE) and communicated to a transmitting base station over a limited uplink channel for implementation over the downlink channel. | 10-11-2012 |
20120269279 | Method of Precoding with a Codebook for a Wireless System - A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink. User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE. | 10-25-2012 |
20120269299 | Precoded Data Receiver - Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied. | 10-25-2012 |
20120275529 | Method for Transmitting an Information Sequence - Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied. | 11-01-2012 |
20120275536 | Codebook With Nested Structure - A multi-rank beamforming (MRBF) scheme in which the downlink channel is estimated and an optimal precoding matrix to be used by the MRBF transmitter is determined accordingly. The optimal precoding matrix is selected from a codebook of matrices having a recursive structure which allows for efficient computation of the optimal precoding matrix and corresponding Signal to Interference and Noise Ratio (SINR). The codebook also enjoys a small storage footprint. Due to the computational efficiency and modest memory requirements, the optimal precoding determination can be made at user equipment (UE) and communicated to a transmitting base station over a limited uplink channel for implementation over the downlink channel. | 11-01-2012 |
20120275542 | Method for Transmitting an Information Sequence - Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied. | 11-01-2012 |
20120281776 | Precoding for Time or Frequency Correlated MIMO Channels - A method implemented in a base station is disclosed. The method includes precoding data with a precoder, and transmitting the precoded data to a user equipment, and the precoder can be expressed as multiplication OV where V is a first matrix corresponding to a first indication of the precoder for a group of transmitted symbols, and O is a second matrix corresponding to a second indication of the precoder for a variation in a channel. Other methods and apparatuses also are disclosed. | 11-08-2012 |
20120294381 | Multi-User Multiple Input Multiple Output Wireless Communications - A method implemented in a user equipment used in a multi-user multiple input multiple output (MU-MIMO) wireless communications system is disclosed. The method includes receiving from a base station an indication of a first modulation type for the user equipment, receiving a first data signal for the user equipment, receiving a second data signal for a co-scheduled user equipment, where a second modulation type for the co-scheduled user equipment is unknown to the user equipment, and deciding the second modulation type. Other methods, systems, and apparatuses also are disclosed. | 11-22-2012 |
20130040705 | Method of Precoding with a Codebook for a Wireless System - A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink. User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE. | 02-14-2013 |
20130170445 | Multi-user downlink linear MIMO precoding system - A method implemented in a base station used for a downlink multi-user (MU) multi-input multi-output (MIMO) system is disclosed. The method includes receiving an indication of a quantized matrix from each of a plurality of scheduled user equipments, precoding data streams for the plurality of scheduled user equipments, transmitting the precoded data to the plurality of scheduled user equipments. Other methods and some apparatuses for wireless communications also are disclosed. | 07-04-2013 |
20130286971 | SIGNALING OF MIXTURE COMBINATION SETS - A method implemented in a user terminal used in a wireless communications system is disclosed. The method comprises receiving an index, referencing a table of indices in which the received index denotes at least a total number of co-scheduled streams and one or more modulation schemes, determining at least one modulation scheme of at least one co-scheduled user based on the referencing, and receiving data signals and processing the data signals by utilizing the at least one modulation scheme, wherein each index of a plurality of the indices in the table denotes a total number of co-scheduled streams and denotes one or more stream indices for a user terminal to which the index is directed. Other methods, systems, and apparatuses also are disclosed. | 10-31-2013 |
20130329677 | FEED-FORWARD CONTROL SIGNALING AND DECODING SCHEMES - A method implemented in a base station used in a wireless communications system is disclosed. The method comprises transmitting an index indicating data stream parameters, and transmitting an indication of the number of transmit antennas at the base station, wherein the data stream parameters for 8 transmit antennas are indicated by the index according to a first table, and wherein the data stream parameters for 4 transmit antennas are indicated by the index according to a second table. Other methods, apparatuses, and systems also are disclosed. | 12-12-2013 |
20140233414 | MU-MIMO-OFDMA METHODS AND SYSTEMS FOR SIGNALING MULTI-RANK CQIs AND PRECODERS - A method for determining attributes of communication channels of multi-user (MU)-multiple input multiple output (MIMO) users in an orthogonal frequency division multiplexing based multiple access (OFDMA) system is disclosed. The method comprises receiving from a base station, for at least one sub-band of contiguous sub-carriers, an indication of an estimate of or an upper-bound on a total number of streams that are co-scheduled by the base station on the at least one sub-band or an indication of a fraction of a transmit power at the base station that is applied to streams that are scheduled for transmission to a particular user, determining one or more signal quality measures for the at least one sub-band based on at least one of the fraction or the estimate of or the upper-bound on the total number of streams that are scheduled by the base station on the at least one sub-band, and transmitting to the base station an indication of the one or more signal quality measures. Other methods, apparatuses, and systems also are disclosed. | 08-21-2014 |