公开(公告)号：CA2652225A1

公开(公告)日：2007-12-13

申请号：CA2652225

申请日：2007-05-30

Applicant: QUALCOMM INC

Inventor： WALTON J RODNEY ,  HOWARD STEVEN J ,  WALLACE MARK ,  SURINENI SHRAVAN K

IPC: H04L12/28 ,  H04B7/06 ,  H04L1/16 ,  H04L12/56

Abstract: Techniques for quickly sending feedback information for beamforming are d escribed. A transmitter/initiator sends a first frame comprising training sy mbols. A receiver/responder receives the first frame, determines the amount of time to generate feedback information, and determines the amount of time to send the feedback information. The receiver then determines the length of a second frame carrying the feedback information based on the amounts of ti me to generate and send the feedback information. The receiver sends the sec ond frame after waiting a short interframe space (SIFS) period from the end of the first frame, without performing channel access. The receiver generate s the feedback information based on the training symbols and sends the infor mation in the second frame when ready. The transmitter receives the second f rame, derives at least one steering matrix based on the feedback information , and sends a third frame with the at least one steering matrix.

公开(公告)号：AT365405T

公开(公告)日：2007-07-15

申请号：AT02737005

申请日：2002-05-15

Applicant: QUALCOMM INC

Inventor： WALTON JAY ,  WALLACE MARK ,  HOWARD STEVEN

IPC: H04L1/06 ,  H04B7/04 ,  H04B7/06 ,  H04J99/00 ,  H04L1/00 ,  H04W16/00 ,  H04W16/28 ,  H04W84/14

Abstract: Techniques to schedule downlink data transmission to a number of terminals in a wireless communication system. In one method, one or more sets of terminals are formed for possible data transmission, with each set including a unique combination of one or more terminals and corresponding to a hypothesis to be evaluated. One or more sub-hypotheses may further be formed for each hypothesis, with each sub-hypothesis corresponding to specific assignments of a number of transmit antennas to the one or more terminals in the hypothesis. The performance of each sub-hypothesis is then evaluated, and one of the evaluated sub-hypotheses is selected based on their performance. The terminal(s) in the selected sub-hypothesis are then scheduled for data transmission, and data is thereafter coded, modulated, and transmitted to each scheduled terminal from one or more transmit antenna assigned to the terminal.

公开(公告)号：HK1077435A1

公开(公告)日：2006-02-10

申请号：HK05109098

申请日：2005-10-14

Applicant: QUALCOMM INC

Inventor： WALTON JAY ROD ,  KETCHUM JOHN W ,  WALLACE MARK ,  MEDVEDEV IRINA I

IPC: H04L20090101 ,  H04B20090101 ,  H04J99/00 ,  H04L1/06 ,  H04L5/02

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.

公开(公告)号：BR0315561A

公开(公告)日：2005-08-30

申请号：BR0315561

申请日：2003-10-24

Applicant: QUALCOMM INC

Inventor： WALTON JAY RODNEY ,  KETCHUM JOHN W ,  WALLACE MARK ,  HOWARD STEVEN J

IPC: H04B7/005 ,  H04B7/04 ,  H04B7/06 ,  H04B7/08 ,  H04J99/00 ,  H04L1/00 ,  H04L1/06 ,  H04L1/08 ,  H04L1/16 ,  H04L12/28 ,  H04L12/56 ,  H04L25/02 ,  H04L25/03 ,  H04L27/26 ,  H04W28/20 ,  H04W52/50 ,  H04W74/08 ,  H04Q7/38

Abstract: Techniques for facilitating random access in wireless multiple-access communication systems. A random access channel (RACH) is defined to comprise a "fast" RACH (F-RACH) and a "slow" RACH (S-RACH). The F-RACH and S-RACH can efficiently support user terminals in different operating states and employ different designs. The F-RACH can be used to quickly access the system, and the S-RACH is more robust and can support user terminals in various operating states and conditions. The F-RACH may be used by user terminals that have registered with the system and can compensate for their round trip delays (RTDs) by properly advancing their transmit timing. The S-RACH may be used by user terminals that may or may not have registered with the system, and may or may not be able to compensate for their RTDs. The user terminals may use the F-RACH or S-RACH, or both, to gain access to the system.

公开(公告)号：BR0213913A

公开(公告)日：2005-04-26

申请号：BR0213913

申请日：2002-11-05

Applicant: QUALCOMM INC

Inventor： WALTON JAY R ,  WALLACE MARK ,  HOWARD STEVEN J

IPC: H04J99/00 ,  H04B7/04 ,  H04B7/06 ,  H04B7/08 ,  H04J11/00 ,  H04L1/00 ,  H04L1/06

Abstract: Techniques to achieve better utilization of the available resources and robust performance for the downlink and uplink in a multiple-access MIMO system. Techniques are provided to adaptively process data prior to transmission, based on channel state information, to more closely match the data transmission to the capacity of the channel. Various receiver processing techniques are provided to process a data transmission received via multiple antennas at a receiver unit. Adaptive reuse schemes and power back-off are also provided to operate the cells in the system in a manner to further increase the spectral efficiency of the system (e.g., reduce interference, improve coverage, and attain high throughput). Techniques are provided to efficiently schedule data transmission on the downlink and uplink. The scheduling schemes may be designed to optimize transmissions (e.g., maximize throughput) for single or multiple terminals in a manner to meet various constraints and requirements.

公开(公告)号：HK1066937A1

公开(公告)日：2005-04-01

申请号：HK04109633

申请日：2004-12-06

Applicant: QUALCOMM INC

Inventor： WALTON JAY R ,  WALLACE MARK ,  KETCHUM JOHN W ,  HOWARD STEVEN J

IPC: H04J99/00 ,  H04B7/06 ,  H04B7/08 ,  H04B7/12 ,  H04L20060101 ,  H04L1/00

Abstract: Techniques to 'successively' process received signals at a receiver unit in a MIMO system to recover transmitted data, and to 'adaptively' process data at a transmitter unit based on channel state information available for the MIMO channel. A successive cancellation receiver processing technique is used to process the received signals and performs a number of iterations to provide decoded data streams. For each iteration, input (e.g., received) signals for the iteration are processed to provide one or more symbol streams. One of the symbol streams is selected and processed to provide a decoded data stream. The interference due to the decoded data stream is approximately removed (i.e., canceled) from the input signals provided to the next iteration. The channel characteristics are estimated and reported back to the transmitter system and used to adjust (i.e., adapt) the processing (e.g., coding, modulation, and so on) of data prior to transmission.

公开(公告)号：HK1063698A1

公开(公告)日：2005-01-07

申请号：HK04106315

申请日：2004-08-24

Applicant: QUALCOMM INC

Inventor： LING FUYUN ,  SINDHUSHAYANA NAGABUSHANA T ,  WALTON JAY R ,  WALLACE MARK ,  FERNANDEZ IVAN

IPC: H04J11/00 ,  H04L20060101 ,  H04B7/04 ,  H04J99/00 ,  H04L1/00 ,  H04L27/26

Abstract: Decoding techniques for a (e.g., OFDM) communication system capable of transmitting data on a number of transmission channels. The received data is processed by generating log likelihood ratio streams, processing these streams and decoding the processed streams to obtain information bit streams.

公开(公告)号：BR0213781A

公开(公告)日：2004-10-13

申请号：BR0213781

申请日：2002-10-31

Applicant: QUALCOMM INC

Inventor： WALTON JAY R ,  KETCHUM JOHN W ,  HOWARD STEVEN J ,  WALLACE MARK

IPC: H04J11/00 ,  H04L1/00 ,  H04Q7/38 ,  H04L27/26

Abstract: Techniques to adaptively control the rate of a data transmission in a wireless (e.g., OFDM) communication system. In an aspect, various types of metrics may be derived and used to select the proper rate for the data transmission. Some types of metrics relate to different characteristics of the communication channel, such as SNR, frequency selectivity, time selectivity, and so on. One type of metric relates to the performance of the data transmission. In another aspect, the various types of metrics may be used in different manners to adaptively control the rate. Some metrics may be used for open-loop control of the rate, other metrics may be used for closed-loop control, and some may be used for both. For example, the channel metrics may be used to determine or select the rate, and the performance metrics may be used to determine whether or not to adjust the rate.

公开(公告)号：HK1060232A1

公开(公告)日：2004-07-30

申请号：HK04103146

申请日：2004-05-05

Applicant: QUALCOMM INC

Inventor： SMEE JOHN E ,  JALALI AHMAD ,  LING FUYUN ,  WALLACE MARK

IPC: H04L27/01 ,  H04B1/7097 ,  H04B7/005 ,  H04L25/03 ,  H04L27/22 ,  H04L ,  H04B

Abstract: A receive filter receives signals from a communication channel. The received signals correspond to original Walsh covered chip sequences transmitted by a transmit filter through the communication channel to the receive filter. The received signals are processed by an equalizer to generate a soft estimate of chip sequences corresponding to the original Walsh covered chip sequences. An N chip Walsh decover is then utilized to generate a soft estimate of code symbols corresponding to the soft estimate of the chip sequences. A number of symbol slicers are then used in parallel to produce a hard estimate of the code symbols corresponding to the soft estimate of code symbols generated by the N chip Walsh decover. Thereafter an N chip Walsh cover is used as part of a scheme to generate a hard estimate of chip sequences corresponding to the hard estimate of the code symbols generated by the symbol slicers. The hard estimate of the chip sequences generated with the aid of the N chip Walsh cover, and the soft estimate of the chip sequences generated by the equalizer, are used to generate a tracking mode error signal to adapt the response of the equalizer to the received signals.

公开(公告)号：AU2003297343A1

公开(公告)日：2004-07-14

申请号：AU2003297343

申请日：2003-12-17

Applicant: QUALCOMM INC

Inventor： WALLACE MARK ,  LUNDBY STEIN A

IPC: H04B7/005 ,  H04B7/06

Abstract: A time-varying transformation is used to correlate the magnitude of the interference between multiple antenna paths. Embodiments incorporating the time-varying transformations provide transmit diversity gains to remote stations that are not configured for transmit diversity reception. In addition, some of the embodiments can be further configured to balance the load between multiple power amplifiers.