公开(公告)号：EP1721431B1

公开(公告)日：2015-11-04

申请号：EP05723308.2

申请日：2005-02-18

申请人： Qualcomm, Incorporated

发明人： WALLACE, Mark S. ,  KETCHUM, John W. ,  WALTON, Jay Rodney ,  HOWARD, Steven J.

IPC分类号： H04L25/03 ,  H04B7/06

CPC分类号： H04B7/0421 ,  H04B17/20 ,  H04B17/21 ,  H04L25/03343 ,  H04L2025/03375 ,  H04L2025/03802

公开(公告)号：EP1671443B1

公开(公告)日：2013-12-25

申请号：EP04781671.5

申请日：2004-08-17

申请人： QUALCOMM INCORPORATED

发明人： WALTON, J. Rodney ,  KETCHUM, John W. ,  WALLACE, Mark S. ,  HOWARD, Steven J.

IPC分类号： H04B7/04 ,  H04L1/00 ,  H04L27/26 ,  H04L25/02 ,  H04B7/06

CPC分类号： H04L1/0002 ,  H04B7/0417 ,  H04B7/0617 ,  H04L25/0206 ,  H04L25/0212 ,  H04L25/0242 ,  H04L27/2647

公开(公告)号：EP2027663B1

公开(公告)日：2011-03-30

申请号：EP07784051.0

申请日：2007-05-22

申请人： Qualcomm Incorporated

发明人： WALLACE, Mark S. ,  MENON, Murali,

IPC分类号： H04L1/20

CPC分类号： H04L1/206 ,  H04L25/067

摘要： Techniques for estimating signal quality in a communication system are described. Scaled errors are obtained for inphase (I) and quadrature (Q) components of detected symbols. The scaled errors are determined based on a first function having higher resolution for small errors than large errors between the detected symbols and nearest modulation symbols. The first function may be a square root function or some other function that can provide good resolution for both low and high SNRs. The scaled errors for the I and Q components are combined to obtain combined scaled errors, which are averaged to obtain an average scaled error. A signal quality estimate is then determined based on the average scaled error and in accordance with a second function having non-linearity to compensate for the first function.

公开(公告)号：EP1894329A2

公开(公告)日：2008-03-05

申请号：EP06772504.4

申请日：2006-06-07

申请人： QUALCOMM INCORPORATED

发明人： HOWARD, Steven J. ,  KETCHUM, John W. ,  WALLACE, Mark S. ,  MONSEN, Peter ,  WALTON, Jay Rodney

IPC分类号： H04J1/00

CPC分类号： H04B7/0854 ,  H04B7/0413 ,  H04L25/0246 ,  H04L25/0248 ,  H04L2025/03426 ,  H04L2025/03605 ,  H04L2025/03611

摘要： Techniques to efficiently derive a spatial filter matrix are described. In a first scheme, a Hermitian matrix is iteratively derived based on a channel response matrix, and a matrix inversion is indirectly calculated by deriving the Hermitian matrix iteratively. The spatial filter matrix is derived based on the Hermitian matrix and the channel response matrix. In a second scheme, multiple rotations are performed to iteratively obtain first and second matrices for a pseudo-inverse matrix of the channel response matrix. The spatial filter matrix is derived based on the first and second matrices. In a third scheme, a matrix is formed based on the channel response matrix and decomposed to obtain a unitary matrix and a diagonal matrix. The spatial filter matrix is derived based on the unitary matrix, the diagonal matrix, and the channel response matrix.

公开(公告)号：EP1949561A2

公开(公告)日：2008-07-30

申请号：EP06838163.1

申请日：2006-11-20

申请人： QUALCOMM Incorporated

发明人： BJERKE, Bjorn ,  MEDVEDEV, Irina ,  KETCHUM, John W. ,  WALLACE, Mark S. ,  WALTON, Jay Rodney

IPC分类号： H04B7/08 ,  H04B7/04 ,  H04L25/03 ,  H04L1/06

CPC分类号： H04L27/2647 ,  H04L1/005 ,  H04L1/0052 ,  H04L1/06 ,  H04L25/03171 ,  H04L2025/03414 ,  H04L2025/03426

摘要： 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.

公开(公告)号：EP1817690A2

公开(公告)日：2007-08-15

申请号：EP05851790.5

申请日：2005-11-15

申请人： QUALCOMM INCORPORATED

发明人： HOWARD, Steven J. ,  KETCHUM, John W. ,  WALLACE, Mark S. ,  WALTON, Jay Rodney

IPC分类号： G06F17/16

CPC分类号： G06F17/16 ,  H04B7/0413 ,  H04B7/0617 ,  H04L25/0208 ,  H04L25/0248 ,  H04L27/2647

摘要： For eigenvalue decomposition, a first set of at least one variable is derived based on a first matrix being decomposed and using Coordinate Rotational Digital Computer (CORDIC) computation. A second set of at least one variable is derived based on the first matrix and using a look-up table. A second matrix of eigenvectors of the first matrix is then derived based on the first and second variable sets. To derive the first variable set, CORDIC computation is performed on an element of the first matrix to determine the magnitude and phase of this element, and CORDIC computation is performed on the phase to determine the sine and cosine of this element. To derive the second variable set, intermediate quantities are derived based on the first matrix and used to access the look-up table. Jacobi rotations are performed using CORDIC processing.

公开(公告)号：EP1751883A1

公开(公告)日：2007-02-14

申请号：EP05724541.7

申请日：2005-03-03

申请人： Qualcomm, Incorporated

发明人： WALTON, Jay Rodney ,  KETCHUM, John W. ,  WALLACE, Mark S. ,  HOWARD, Steven J. ,  NANDA, Sanjiv

IPC分类号： H04B7/06

CPC分类号： H04B7/0615 ,  H04B7/0413 ,  H04L27/2602

摘要： A multi-antenna transmitting entity transmits data to a single- or multi-antenna receiving entity using (1) a steered mode to direct the data transmission toward the receiving entity or (2) a pseudo-random transmit steering (PRTS) mode to randomize the effective channels observed by the data transmission across the subbands. The PRTS mode may be used to achieve transmit diversity or spatial spreading. For transmit diversity, the transmitting entity uses different pseudo-random steering vectors across the subbands but the same steering vector across a packet for each subband. The receiving entity does not need to have knowledge of the pseudo-random steering vectors or perform any special processing. For spatial spreading, the transmitting entity uses different pseudo-random steering vectors across the subbands and different steering vectors across the packet for each subband. Only the transmitting and receiving entities know the steering vectors used for data transmission.

公开(公告)号：EP1716656A1

公开(公告)日：2006-11-02

申请号：EP05723307.4

申请日：2005-02-18

申请人： Qualcomm, Incorporated

发明人： WALTON, Jay Rodney ,  KETCHUM, John W. ,  WALLACE, Mark S. ,  HOWARD, Steven J. ,  NANDA, Sanjiv

IPC分类号： H04L1/06 ,  H04L27/26 ,  H04L25/02

CPC分类号： H04B7/0413 ,  H04B7/0408 ,  H04B7/0617 ,  H04B7/0695 ,  H04L1/06 ,  H04L5/0023 ,  H04L5/0048 ,  H04L25/0204 ,  H04L25/0226

摘要： A multi-antenna transmitting entity transmits data to a single- or multi-antenna receiving entity using (1) a steered mode to direct the data transmission toward the receiving entity or (2) a pseudo-random transmit steering (PRTS) mode to randomize the effective channels observed by the data transmission across the subbands. The PRTS mode may be used to achieve transmit diversity or spatial spreading. For transmit diversity, the transmitting entity uses different pseudo-random steering vectors across the subbands but the same steering vector across an entire packet for each subband. The receiving entity does not need to have knowledge of the pseudo-random steering vectors or perform any special processing. For spatial spreading, the transmitting entity uses different pseudo-random steering vectors across the subbands and different steering vectors across the packet for each subband. Only the transmitting and receiving entities know the steering vectors used for data transmission.

公开(公告)号：EP1695477B1

公开(公告)日：2011-10-26

申请号：EP04814424.0

申请日：2004-12-15

申请人： Qualcomm, Incorporated

发明人： WALTON, Jay Rodney ,  ZHENG, Lizhong ,  KETCHUM, John W. ,  WALLACE, Mark S. ,  HOWARD, Steven J.

IPC分类号： H04L1/06

CPC分类号： H04B7/0417 ,  H04B7/0456 ,  H04B7/0669 ,  H04B17/336 ,  H04L1/06

摘要： Spatial spreading is performed in a multi-antenna system to randomize an “effective” channel observed by a receiving entity for each transmitted data symbol block. For a MIMO system, at a transmitting entity, data is processed (e.g., encoded, interleaved, and modulated) to obtain ND data symbol blocks to be transmitted in NM transmission spans, where ND≧1 and NM>1. The ND blocks are partitioned into NM data symbol subblocks, one subblock for each transmission span. A steering matrix is selected (e.g., in a deterministic or pseudo-random manner from among a set of L steering matrices, where L>1) for each subblock. Each data symbol subblock is spatially processed with the steering matrix selected for that subblock to obtain transmit symbols, which are further processed and transmitted via NT transmit antennas in one transmission span. The ND data symbol blocks are thus spatially processed with NM steering matrices and observe an ensemble of channels.

公开(公告)号：EP1969794B1

公开(公告)日：2011-10-12

申请号：EP06850946.2

申请日：2006-12-13

申请人： QUALCOMM Incorporated

发明人： WALLACE, Mark S. ,  WALTON, Jay Rodney

IPC分类号： H04L27/26

CPC分类号： H04L27/0014 ,  H04L27/2613 ,  H04L27/2656 ,  H04L27/2657 ,  H04L27/2675 ,  H04L27/2676 ,  H04W74/02 ,  H04W84/12 ,  H04W88/04

摘要： Techniques for extending transmission range in a WLAN are described. In an aspect, a receiving station determines the frequency error between a transmitting station and the receiving station based on one or more initial packet transmissions and corrects this frequency error for subsequent packet transmissions received from the transmitting station. The residual frequency error is small after correcting for the frequency error and allows the receiving station to perform coherent accumulation/ integration over a longer time interval to detect for a packet transmission. The longer coherent accumulation interval improves detection performance, especially at low SNRs for extended transmission range. The techniques may be used whenever the receiving station knows the identity of the transmitting station, e.g., if the subsequent packet transmissions are scheduled. In another aspect, a preamble is generated with a longer spreading sequence and sent with each packet transmission.