公开(公告)号：EP1476958B1

公开(公告)日：2008-07-09

申请号：EP03709263.2

申请日：2003-02-19

申请人： QUALCOMM INCORPORATED

发明人： MEDVEDEV, Irina ,  WALTON, Jay R. ,  KETCHUM, John W.

IPC分类号： H04B7/005 ,  H04B7/04

CPC分类号： H04B7/0417 ,  H04B7/0619 ,  H04L1/0001 ,  H04L1/06 ,  H04W52/42

摘要： 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, CCMI-SC, 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.

公开(公告)号：EP1582084A2

公开(公告)日：2005-10-05

申请号：EP04700635.8

申请日：2004-01-07

申请人： Qualcomm, Incorporated

发明人： SMEE, John E. ,  WALTON, Jay R. ,  MALLADI, Durga P. ,  WILLENEGGER, Serge

IPC分类号： H04Q7/38 ,  H04L27/26

CPC分类号： H04W36/30

摘要： A method and apparatus for performing handoff in a wireless communication system with multi-carrier modulation (MCM) for a forward link and CDMA for a reverse link. In one embodiment, a method of performing handoff on the forward link for a terminal is provided in which signal quality of pilots received by the terminal from a plurality of base stations in the system is determined. A particular base station for subsequent data transmission on the forward link to the terminal is selected based on the signal quality determined for the plurality of base stations. A request to be handed off to the particular base station is initiated if the particular base station is different than a currently selected base station.

摘要翻译： 一种用于在具有用于前向链路的多载波调制（MCM）和用于反向链路的CDMA的无线通信系统中执行切换的方法和装置。 在一个实施例中，提供了一种在终端的前向链路上执行越区切换的方法，其中确定终端从系统中的多个基站接收的导频的信号质量。 基于为多个基站确定的信号质量来选择用于在到该终端的前向链路上的后续数据传输的特定基站。 如果特定基站不同于当前选择的基站，则发起切换到特定基站的请求。

公开(公告)号：EP1451991A2

公开(公告)日：2004-09-01

申请号：EP02780563.9

申请日：2002-10-31

申请人： QUALCOMM Incorporated

发明人： BJERKE, Bjorn A. ,  KETCHUM, John W. ,  WALTON, Jay R.

IPC分类号： H04L27/26 ,  H04L1/00 ,  H04L1/06

CPC分类号： H04L1/005 ,  H04B7/0413 ,  H04B7/0854 ,  H04L1/0003 ,  H04L1/0009 ,  H04L1/0059 ,  H04L1/0066 ,  H04L1/0071 ,  H04L1/06 ,  H04L5/0023 ,  H04L25/03171 ,  H04L25/03305 ,  H04L25/03891 ,  H04L25/067 ,  H04L27/2647

摘要： Techniques to iteratively detect and decode data transmitted in a wireless MIMO-OFDM communication system. The iterative detection and decoding is performed by iteratively passing soft 'a priori' information between a detector and a decoder. The detector receives modulation symbols, performs a detection function that is complementary to the symbol mapping performed at the transmitter, and provides soft-decision symbols for transmitted coded bits. 'Extrinsic information' in the soft-decision symbols is then decoded by the decoder to provide its extrinsic information, which comprisesthe a priori information used by the detector in the detection process. The detection and decoding may be iterated a number of times. The soft-decision symbols and the a priori information may be represented using log-likelihood ratios. Techniques are provided to reduce the computational complexity associated with deriving the LLRs, including interference nulling to isolate each transmitted signal and 'dual-maxima' approximation.

公开(公告)号：EP1516448B1

公开(公告)日：2009-11-25

申请号：EP03761175.3

申请日：2003-06-20

申请人： Qualcomm, Incorporated

发明人： KETCHUM, John W. ,  WALTON, Jay R.

IPC分类号： H04L1/06 ,  H04L25/03 ,  H04L25/02

CPC分类号： H04B7/0417 ,  H04B7/0439 ,  H04B7/0443 ,  H04B7/0626 ,  H04L1/0618 ,  H04L25/0202 ,  H04L25/03343 ,  H04L25/03834

公开(公告)号：EP1556985A2

公开(公告)日：2005-07-27

申请号：EP03781530.5

申请日：2003-10-24

申请人： Qualcomm, Incorporated

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

IPC分类号： H04L1/06 ,  H04L25/02

CPC分类号： H04B7/0421 ,  H04B7/043 ,  H04B7/0615 ,  H04B7/0669 ,  H04B7/0684 ,  H04B7/0697 ,  H04B7/0854 ,  H04L1/0001 ,  H04L1/0003 ,  H04L1/0009 ,  H04L1/0017 ,  H04L1/0071 ,  H04L1/0618 ,  H04L1/08 ,  H04L1/16 ,  H04L5/0023 ,  H04L5/0026 ,  H04L5/0048 ,  H04L5/005 ,  H04L5/006 ,  H04L25/0204 ,  H04L25/0226 ,  H04L25/03343 ,  H04L27/2613 ,  H04L2027/0089 ,  H04W16/28 ,  H04W28/20 ,  H04W52/50

摘要： Pilots suitable for use in MIMO systems and capable of supporting various functions are described. The various types of pilot include-a beacon pilot, a MIMO pilot, a steered reference or steered pilot, and a carrier pilot. The beacon pilot is transmitted from all transmit antennas and may be used for timing and frequency acquisition. The MIMO pilot is transmitted from all transmit antennas but is covered with different orthogonal codes assigned to the transmit antennas. The MIMO pilot may be used for channel estimation. The steered reference is transmitted on specific eigenmodes of a MIMO channel and is user terminal specific. The steered reference may be used for channel estimation. The carrier pilot may be transmitted on designated subbands/antennas and may be used for phase tracking of a carrier signal. Various pilot transmission schemes may be devised based on different combinations of these various types of pilot.

公开(公告)号：EP1516448A1

公开(公告)日：2005-03-23

申请号：EP03761175.3

申请日：2003-06-20

申请人： Qualcomm, Incorporated

发明人： KETCHUM, John W. ,  WALTON, Jay R.

IPC分类号： H04L1/06 ,  H04L25/03 ,  H04L25/02

CPC分类号： H04B7/0417 ,  H04B7/0439 ,  H04B7/0443 ,  H04B7/0626 ,  H04L1/0618 ,  H04L25/0202 ,  H04L25/03343 ,  H04L25/03834

摘要： Techniques for processing a data transmission at a transmitter and receiver, which use channel eigen-decomposition, channel inversion, and (optionally) 'water-pouring'. At the transmitter, (1) channel eigen-decomposition is performed to determine eigenmodes of a MIMO channel and to derive a first set of steering vectors, (2) channel inversion is performed to derive weights (e.g., one set for each eigenmode) used to minimize ISI distortion, and (3) water-pouring may be performed to derive scaling values indicative of the transmit powers allocated to the eigenmodes. The first set of steering vectors, weights, and scaling values are used to derive a pulse-shaping matrix, which is used to precondition modulation symbols prior to transmission. At the receiver, channel eigen-decomposition is performed to derive a second set of steering vectors, which are used to derive a pulse-shaping matrix used to condition received symbols such that orthogonal symbol streams are recovered.

公开(公告)号：EP1476958A2

公开(公告)日：2004-11-17

申请号：EP03709263.2

申请日：2003-02-19

申请人： QUALCOMM Incorporated

发明人： MEDVEDEV, Irina ,  WALTON, Jay R. ,  KETCHUM, John W.

IPC分类号： H04B7/005 ,  H04B7/04

CPC分类号： H04B7/0417 ,  H04B7/0619 ,  H04L1/0001 ,  H04L1/06 ,  H04W52/42

摘要： 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, CCMI-SC, 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.