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公开(公告)号：CA2472574A1
公开(公告)日：2003-07-17
申请号：CA2472574
申请日：2002-12-31
Applicant: QUALCOMM INC
Inventor： MEDVEDEV IRINA , KETCHUM JOHN W , WALLACE MARK , WALTON JAY ROD
Abstract: Techniques to assign terminals for data transmission in a MIMO-OFDM system. A scheduler forms sets of terminals, called a hypothesis, for data transmission for each of a number of frequency bands. One or more sub-hypotheses may be further formed for each hypothesis, with each sub-hypothesis corresponding to (1) specific assignments of transmit antennas to the terminal(s) in the hypothesis, or, (2) a specific order for processing the uplink data transmissions from the terminal(s). The performance of each sub-hypothesis is then evaluated. One sub-hypothesis is then selected for each frequency band based on the evaluated performance, and, the set of terminals in each selected sub-hypothesis are then scheduled for data transmission on the corresponding frequency band.
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公开(公告)号：CA2650431C
公开(公告)日：2014-07-08
申请号：CA2650431
申请日：2007-05-22
Applicant: QUALCOMM INC
Inventor： WALTON J RODNEY , WALLACE MARK S , MEDVEDEV IRINA , HOWARD STEVEN J
Abstract: Techniques for performing phase correction for wireless communication are described. Received pilot symbols and received data symbols may be obtained from an orthogonal frequency division multiplexing (OFDM) and/or multiple-input multiple-output (MIMO) transmission. First phase information is obtained based upon the received pilot symbols. Second phase information is obtained based upon the received data symbols. The phase of the received data symbols is corrected based upon the first and second phase information (directly and/or indirectly). For example, the phase of the received data symbols may be corrected based upon the first phase information, detection may be performed on the phase corrected data symbols to obtain estimated data symbols, the second phase information may be obtained based upon the estimated data symbols, and the phase of the estimated data symbols may be corrected based upon the second phase information. The phase correction may also be performed in other manners.
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33.发明专利
公开(公告)号：CA2579208C
公开(公告)日：2012-09-04
申请号：CA2579208
申请日：2005-09-02
Applicant: QUALCOMM INC
Inventor： WALLACE MARK S , MEDVEDEV IRINA , WALTON JAY RODNEY
Abstract: A receiving entity (150) obtains received symbols for a data transmission having at least one data symbol stream sent with space-time transmit diversity (STTD). The receiving entity derives an overall channel response matrix in accordance w ith the STTD encoding scheme used for the data transmission, derives a spatial f ilter matrix based on the overall channel response matrix, and performs spatial matched filtering on a vector of received symbols for each 2-symbol interval to obtain a vector of detected symbols for the 2-symbol interval. The receiving ent ity may perform post-processing (e.g., conjugation) on the detected symbols if n eeded. Alternatively, the receiving entity derives a spatial filter matrix based on an effective channel response matrix, performs spatial matched filtering on the received symbols for each symbol period to obtain detected symbols for that symbol period, A receiving entity obtains received symbols for a data transmissi on having at least one data symbol stream sent with space-time transmit diversit y (STTD). The receiving entity derives an overall channel response matrix in acc ordance with the STTD encoding scheme used for the data transmission, derives spatial filter matrix based on the overall channel response matrix, and performs spatial matched filtering on a vector of received symbols for each 2-symbol int erval to obtain a vector of detected symbols for the 2-symbol interval. The rece iving entity may perform post-processing (e.g., conjugation) on the detected sym bols if needed. Alternatively, the receiving entity derives a spatial filter mat rix based on an effective channel response matrix, performs spatial matched filt ering on the received symbols for each symbol period to obtain detected symbols for that symbol period, and combines multiple estimates obtained for each data s ymbol sent with STTD.
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公开(公告)号：BRPI0712106A2
公开(公告)日：2012-01-31
申请号：BRPI0712106
申请日：2007-05-22
Applicant: QUALCOMM INC
Inventor： WALTON J RODNEY , WALLACE MARK S , MEDVEDEV IRINA , HOWARD STEVEN J
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公开(公告)号：BRPI0618716A2
公开(公告)日：2011-09-06
申请号：BRPI0618716
申请日：2006-11-20
Applicant: QUALCOMM INC
Inventor： BJERKE BJORN , MEDVEDEV IRINA , KETCHUM JOHN W , WALLACE MARK S , WALTON JAY RODNEY
Abstract: Techniques for performing detection and decoding at a receiver are described. In one scheme, the receiver obtains R received symbol streams for M data streams transmitted by a transmitter, performs receiver spatial processing on the received symbols to obtain detected symbols, performs log-likelihood ratio (LLR) computation independently for each of D best data streams, and performs LLR computation jointly for the M - D remaining data streams, where M > D ¥ 1 and M > 1. The D best data streams may be selected based on SNR and/or other criteria. In another scheme, the receiver performs LLR computation independently for each of the D best data streams, performs LLR computation jointly for the M - D remaining data streams, and reduces the number of hypotheses to consider for the joint LLR computation by performing a search for candidate hypotheses using list sphere detection, Markov chain Monte Carlo, or some other search technique.
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Patent Agency Ranking
公开(公告)号：AU2003213214C1
公开(公告)日：2009-02-19
申请号：AU2003213214
申请日：2003-02-19
Applicant: QUALCOMM INC
Inventor： MEDVEDEV IRINA , WALLACE MARK , WALTON JAY R
IPC: H04J99/00 , H04B7/005 , H04B7/04 , H04B7/06 , H04B7/08 , H04J11/00 , H04L1/00 , H04L1/06 , H04L27/26
Abstract: Techniques to transmit data on a number of transmission channels in a multi-channel communication system using multiple transmission schemes requiring less channel-state information (CSI). These schemes may include a partial-CSI transmission scheme that transmits a single data stream on each transmit antenna selected for use and a "beam-forming" transmission scheme that allocates all transmit power to a single transmission channel having the best performance. Each transmission scheme may provide good or near-optimum performance for a specific range of operating conditions (or operating SNRs). These multiple transmission schemes may then be combined in a piece-wise fashion to form a "multi-mode" transmission scheme that covers the full range of operating conditions supported by the MIMO system. The specific transmission scheme to be used for data transmission at any given moment would then be dependent on the specific operating condition experienced by the system at that moment.
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公开(公告)号：AU2003265601B2
公开(公告)日：2008-12-18
申请号：AU2003265601
申请日：2003-08-19
Applicant: QUALCOMM INC
Inventor： KETCHUM JOHN W , MEDVEDEV IRINA , WALTON JAY ROD
Abstract: Techniques to perform selective channel inversion per eigenmode in a MIMO system to achieve high spectral efficiency while reducing complexity at both the transmitter and receiver are presented. The available transmission channels are arranged into a number of groups, where each group may include all transmission channels (or frequency bins) for a respective eigenmode of a MIMO channel. The total transmit power is allocated to the groups using a particular group power allocation scheme. Selective channel inversion is then performed independently for each group selected for use for data transmission. For each such group, one or more transmission channels in the group are selected for use, and a scaling factor is determined for each selected channel such that all selected channels for the group achieve similar received signal quality (e.g., received SNR).
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公开(公告)号：DE60322025D1
公开(公告)日：2008-08-21
申请号：DE60322025
申请日：2003-02-19
Applicant: QUALCOMM INC
Inventor： MEDVEDEV IRINA , WALTON JAY R , KETCHUM JOHN W
Abstract: Techniques for controlling the transmit power for a number of data streams in a wireless multi-channel (e.g., MIMO) communication system. In one method, a number of received symbol streams are initially processed in accordance with a particular (e.g., CCMI, CCMISC, MMSE, or MMSE-SC) receiver processing technique to provide a number of detected data streams. The post-detection SNRs of the detected data streams are estimated, and each SNR that exceeds a setpoint is identified. This setpoint may correspond to (1) the SNR needed to achieve the maximum allowed spectral efficiency or (2) the target SNR needed to achieve a specified spectral efficiency. A new (or adjusted) transmit power for each detected data stream associated with a post-detection SNR that exceeds the setpoint is determined and used for the data stream. Different power control schemes are provided for different classes of receiver processing techniques with different characteristics.
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公开(公告)号：AU2002360839B2
公开(公告)日：2008-07-03
申请号：AU2002360839
申请日：2002-12-31
Applicant: QUALCOMM INC
Inventor： WALLACE MARK , MEDVEDEV IRINA , WALTON JAY ROD , KETCHUM JOHN W
Abstract: Techniques to schedule terminals for data transmission on the downlink and/or uplink in a MIMO-OFDM system based on the spatial and/or frequency "signatures" of the terminals. A scheduler forms one or more sets of terminals for possible (downlink or uplink) data transmission for each of a number of frequency bands. One or more subhypotheses may further be formed for each hypothesis, with each sub-hypothesis corresponding to (1) specific assignments of transmit antennas to the terminal(s) in the hypothesis (for the downlinks) or (2) a specific order for processing the uplink data transmissions from the terminal(s) (for the uplink). The performance of each sub-hypothesis is then evaluated (e.g., based on one or more performance metrics).; One sub-hypothesis is then selected for each frequency band based on the evaluated performance, and the one or more terminals in each selected sub-hypothesis are then scheduled for data transmission on the corresponding frequency band.
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公开(公告)号：CA2774221A1
公开(公告)日：2007-11-29
申请号：CA2774221
申请日：2007-05-22
Applicant: QUALCOMM INC
Inventor： WALTON J RODNEY , WALLACE MARK S , MEDVEDEV IRINA , HOWARD STEVEN J
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