John V Ketchum

US Patent:

6542488, Apr 1, 2003

Filed:

Apr 9, 2001

Appl. No.:

09/829570

Inventors:

Jay R. Walton - Westford MA
John W. Ketchum - Watertown MA
Steven J. Howard - Ashland MA
Mark S. Wallace - Bedford MA

Assignee:

Qualcomm Incorporated - San Diego CA

International Classification:

H04J 1300

US Classification:

370335, 455522

Abstract:

A method and apparatus for controlling the transmission of signals from one or more of a plurality of mobile stations to a base station on a plurality of M multiple access channels. A power control information packet formed from a plurality of power control bits is transmitted from the base station to the one or more mobile stations. Each of the power control bits in the power control information packet has a position that is mapped to a selected access channel and to a time offset within the selected access channel. The power control information packet is received at a first mobile station. A message is then transmitted from the first mobile station to the base station on a first access channel and at a first time offset associated with the first access channel. The message is transmitted from the first mobile station at a power level determined in response to a first power control bit in the power control information packet. The first power control bit is located in a first position in the power control information packet, the first position being mapped to the first access channel and the first time offset.

US Patent:

6731668, May 4, 2004

Filed:

Jan 5, 2001

Appl. No.:

09/737602

Inventors:

John W. Ketchum - Harvard MA

Assignee:

Qualcomm Incorporated - San Diego CA

International Classification:

H04B 1500

US Classification:

375130, 370209, 375267, 375299

Abstract:

In one disclosed embodiment, an input bit stream is supplied to a trellis code block. For example, the trellis code block can perform convolutional coding using a rate 6/7 code. The output of the trellis code block is then modulated using, for example, trellis coded quadrature amplitude modulation with 128 signal points or modulation symbols. The sequence of modulation symbols thus generated can be diversity encoded. The diversity encoding can be either a space time encoding, for example, or a space frequency encoding. The sequence of modulation symbols, or the sequence of diversity encoded modulation symbols, is fed to two or more orthogonal Walsh covers. For example, replicas of the modulation symbol sequences can be provided to increase diversity, or demultiplexing the modulation symbol sequences can be used to increase data transmission rate or âthroughputâ. The outputs of the Walsh covers are fed as separate inputs into a communication channel.

US Patent:

6751187, Jun 15, 2004

Filed:

Jun 26, 2001

Appl. No.:

09/892379

Inventors:

Jay R. Walton - Westford MA
John W. Ketchum - Harvard MA

Assignee:

Qualcomm Incorporated - San Diego CA

International Classification:

H04J 1100

US Classification:

370210, 370334, 370437, 375346, 455522

Abstract:

Techniques to select transmission channels for use for data transmission and to process and transmit data over the selected transmission channels. Transmission channels available for use are segregated into one or more groups, with each group including any number of channels. With selective channel transmission, only âgoodâ channels in each group are selected (e. g. , based on the channels received SNRs and an SNR threshold), âbadâ channels are not used, and the total available transmit power for the group is (e. g. , uniformly) distributed across only the good channels. Each group may also be associated with a respective coding and modulation scheme, and data for each group may be coded and modulated based on the scheme selected for the group. Improved performance is achieved by using only good channels in each group and matching the data processing for the selected channels to the capacity achievable by the channels.

US Patent:

6760388, Jul 6, 2004

Filed:

Dec 7, 2001

Appl. No.:

10/017308

Inventors:

John W. Ketchum - Harvard MA
Mark Wallace - Bedford MA
Steven J. Howard - Ashland MA
Jay Rod Walton - Westford MA

Assignee:

Qualcomm Incorporated - San Diego CA

International Classification:

H04L 2704

US Classification:

375295

Abstract:

Techniques for processing a data transmission at the transmitter and receiver. In an aspect, a time-domain implementation is provided which uses frequency-domain singular value decomposition and âwater-pouringâ results to derive time-domain pulse-shaping and beam-steering solutions at the transmitter and receiver. The singular value decomposition is performed at the transmitter to determine eigen-modes (i. e. , spatial subchannels) of the MIMO channel and to derive a first set of steering vectors used to âpreconditionâ modulation symbols. The singular value decomposition is also performed at the receiver to derive a second set of steering vectors used to precondition the received signals such that orthogonal symbol streams are recovered at the receiver, which can simplify the receiver processing. Water-pouring analysis is used to more optimally allocate the total available transmit power to the eigen-modes, which then determines the data rate and the coding and modulation scheme to be used for each eigen-mode.

US Patent:

6785341, Aug 31, 2004

Filed:

May 11, 2001

Appl. No.:

09/854235

Inventors:

Jay R. Walton - Westford MA
Mark Wallace - Bedford MA
John W. Ketchum - Harvard MA
Steven J. Howard - Ashland MA

Assignee:

Qualcomm Incorporated - San Diego CA

International Classification:

H04B 702

US Classification:

375267, 375346

Abstract:

Techniques to âsuccessivelyâ process received signals at a receiver unit in a MIMO system to recover transmitted data, and to âadaptivelyâ 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.

US Patent:

6940917, Sep 6, 2005

Filed:

Aug 27, 2002

Appl. No.:

10/228393

Inventors:

Murali Paravath Menon - Waltham MA, US
John W. Ketchum - Harvard MA, US
Mark Wallace - Bedford MA, US
Jay Rod Walton - Carlisle MA, US
Steven J. Howard - Harvard MA, US

Assignee:

Qualcomm, Incorporated - San Diego CA

International Classification:

H04B007/02

US Classification:

375267

Abstract:

Techniques to perform beam-steering and beam-forming to transmit data on a single eigenmode in a wideband multiple-input channel. In one method, a steering vector is obtained for each of a number of subbands. Depending on how the steering vectors are defined, beam-steering or beam-forming can be achieved for each subband. The total transmit power is allocated to the subbands based on a particular power allocation scheme (e. g. , full channel inversion, selective channel inversion, water-filling, or uniform). A scaling value is then obtained for each subband based on its allocated transmit power. Data to be transmitted is coded and modulated to provide modulation symbols. The modulation symbols to be transmitted on each subband are scaled with the subband's scaling value and further preconditioned with the subband's steering vector. A stream of preconditioned symbols is then formed for each transmit antenna.

US Patent:

6956907, Oct 18, 2005

Filed:

Oct 15, 2001

Appl. No.:

09/978337

Inventors:

John W. Ketchum - Harvard MA, US

Assignee:

QUALCOMM, Incorporated - San Diego CA

International Classification:

H04B007/02

US Classification:

375267

Abstract:

In a communication system () with limited power for each antenna, a method, apparatus and a processor () provide for determining bin energy level allocation to each OFDM frequency bin at each transmit antenna. An estimate of a solution vector including elements of the allocation bin energy level to each OFDM frequency bin at each antenna is determined. An error function based on the determined solution vector is also determined. An error magnitude is determined based on the determined error function. The error magnitude is compared to an error threshold. The processor () accepts the estimate of the solution vector with the elements of the allocation bin energy level when the error magnitude is less than the error threshold.

US Patent:

7002900, Feb 21, 2006

Filed:

Sep 29, 2003

Appl. No.:

10/674038

Inventors:

J. Rodney Walton - Carlisle MA, US
John W. Ketchum - Harvard MA, US
Mark S. Wallace - Bedford MA, US
Steven J. Howard - Ashland MA, US

Assignee:

QUALCOMM Incorporated - San Diego CA

International Classification:

H04J 11/00

US Classification:

370208

Abstract:

For transmit diversity in a multi-antenna OFDM system, a transmitter encodes, interleaves, and symbol maps traffic data to obtain data symbols. The transmitter processes each pair of data symbols to obtain two pairs of transmit symbols for transmission from a pair of antennas either (1) in two OFDM symbol periods for space-time transmit diversity or (2) on two subbands for space-frequency transmit diversity. N(N−1)/2 different antenna pairs are used for data transmission, with different antenna pairs being used for adjacent subbands, where Nis the number of antennas. The system may support multiple OFDM symbol sizes. The same coding, interleaving, and modulation schemes are used for different OFDM symbol sizes to simplify the transmitter and receiver processing. The transmitter performs OFDM modulation on the transmit symbol stream for each antenna in accordance with the selected OFDM symbol size. The receiver performs the complementary processing.