John P Ketchum

US Patent:

6771706, Aug 3, 2004

Filed:

Mar 23, 2001

Appl. No.:

09/816481

Inventors:

Fuyun Ling - San Diego CA
Jay R. Walton - Westford MA
Steven J. Howard - Ashland MA
Mark Wallace - Bedford MA
John W. Ketchum - Harvard MA

Assignee:

Qualcomm Incorporated - San Diego CA

International Classification:

H04B 702

US Classification:

375267, 375260, 375296, 375347, 375349, 455101

Abstract:

Techniques for transmitting data from a transmitter unit to a receiver unit in a multiple-input multiple-output (MIMO) communication system. In one method, at the receiver unit, a number of signals are received via a number of receive antennas, with the received signal from each receive antenna comprising a combination of one or more signals transmitted from the transmitter unit. The received signals are processed to derive channel state information (CSI) indicative of characteristics of a number of transmission channels used for data transmission. The CSI is transmitted back to the transmitter unit. At the transmitter unit, the CSI from the receiver unit is received and data for transmission to the receiver unit is processed based on the received CSI.

US Patent:

7411929, Aug 12, 2008

Filed:

Jul 30, 2004

Appl. No.:

10/903066

Inventors:

Fuyun Ling - San Diego CA, US
Jay R. Walton - Westford MA, US
Steven J. Howard - Ashland MA, US
Mark Wallace - Bedford MA, US
John W. Ketchum - Harvard MA, US

Assignee:

QUALCOMM Incorporated - San Diego CA

International Classification:

H04L 27/00

US Classification:

370334, 375299

Abstract:

Techniques for transmitting data from a transmitter unit to a receiver unit in a multiple-input multiple-output (MIMO) communication system. In one method, at the receiver unit, a number of signals are received via a number of receive antennas, with the received signal from each receive antenna comprising a combination of one or more signals transmitted from the transmitter unit. The received signals are processed to derive channel state information (CSI) indicative of characteristics of a number of transmission channels used for data transmission. The CSI is transmitted back to the transmitter unit. At the transmitter unit, the CSI from the receiver unit is received and data for transmission to the receiver unit is processed based on the received CSI.

US Patent:

7590182, Sep 15, 2009

Filed:

Feb 24, 2004

Appl. No.:

10/786856

Inventors:

Fuyun Ling - San Diego CA, US
Jay R. Walton - Westford MA, US
Steven J. Howard - Ashland MA, US
Mark Wallace - Bedford MA, US
John W. Ketchum - Harvard MA, US

Assignee:

QUALCOMM Incorporated - San Diego CA

International Classification:

H04K 1/10
H04L 27/28

US Classification:

375260, 375219, 375220, 375261, 375267, 4554521, 4554522, 455101

Abstract:

Techniques for transmitting data from a transmitter unit to a receiver unit in a multiple-input multiple-output (MIMO) communication system. In one method, at the receiver unit, a number of signals are received via a number of receive antennas, with the received signal from each receive antenna comprising a combination of one or more signals transmitted from the transmitter unit. The received signals are processed to derive channel state information (CSI) indicative of characteristics of a number of transmission channels used for data transmission. The CSI is transmitted back to the transmitter unit. At the transmitter unit, the CSI from the receiver unit is received and data for transmission to the receiver unit is processed based on the received CSI.

US Patent:

7949060, May 24, 2011

Filed:

Sep 4, 2009

Appl. No.:

12/554608

Inventors:

Fuyun Ling - San Diego CA, US
Jay R. Walton - Carlisle MA, US
Steven J. Howard - Ashland MA, US
Mark Wallace - Bedford MA, US
John W. Ketchum - Harvard MA, US

Assignee:

QUALCOMM Incorporated - San Diego CA

International Classification:

H04K 1/10
H04L 27/28

US Classification:

375260, 375219, 375220, 375261, 375267, 4554521, 4554522, 455101

Abstract:

Techniques for transmitting data from a transmitter unit to a receiver unit in a multiple-input multiple-output (MIMO) communication system. In one method, at the receiver unit, a number of signals are received via a number of receive antennas, with the received signal from each receive antenna comprising a combination of one or more signals transmitted from the transmitter unit. The received signals are processed to derive channel state information (CSI) indicative of characteristics of a number of transmission channels used for data transmission. The CSI is transmitted back to the transmitter unit. At the transmitter unit, the CSI from the receiver unit is received and data for transmission to the receiver unit is processed based on the received CSI.

US Patent:

8160183, Apr 17, 2012

Filed:

May 4, 2010

Appl. No.:

12/773722

Inventors:

John W. Ketchum - San Diego CA, US
Mark S. Wallace - San Diego CA, US
J. Rodney Walton - San Diego CA, US
Steven J. Howard - San Diego CA, US

Assignee:

QUALCOMM Incorporated - San Diego CA

International Classification:

H04L 23/02
H03H 7/30
H04N 7/12
H04J 3/00
H04J 1/00

US Classification:

375341, 375229, 375265, 375262, 370480, 370497, 370498, 370529

Abstract:

For eigenmode transmission with minimum mean square error (MMSE) receiver spatial processing, a transmitter performs spatial processing on NS data symbol streams with steering vectors to transmit the streams on NS spatial channels of a MIMO channel. The steering vectors are estimates of transmitter steering vectors required to orthogonalize the spatial channels. A receiver derives a spatial filter based on an MMSE criterion and with an estimate of the MIMO channel response and the steering vectors. The receiver (1) obtains NR received symbol streams from NR receive antennas, (2) performs spatial processing on the received symbol streams with the spatial filter to obtain NS filtered symbol streams, (3) performs signal scaling on the filtered symbol streams with a scaling matrix to obtain NS recovered symbol streams, and (4) processes the NS recovered symbol streams to obtain NS decoded data streams for the NS data streams sent by the transmitter.

US Patent:

8462653, Jun 11, 2013

Filed:

May 12, 2010

Appl. No.:

12/778911

Inventors:

Irina Medvedev - San Diego CA, US
John W. Ketchum - San Diego CA, US
J. Rodney Walton - San Diego CA, US

Assignee:

QUALCOMM Incorporated - San Diego CA

International Classification:

H04L 12/26

US Classification:

370252, 370236

Abstract:

Techniques to select a suitable transmission mode for a data transmission in a multi channel communication system with multiple spatial channels having varying SNRs are presented in this disclosure. For certain embodiments, a closed-loop technique may be applied, in which back-off factors used to calculate an effective SNR value fed back to a transmitter are adjusted. An open-loop rate control scheme is also presented in which a transmitter may select a data rate and number of streams based on whether transmitted packets are received in error at a receiver.

US Patent:

8472306, Jun 25, 2013

Filed:

Jun 10, 2010

Appl. No.:

12/813461

Inventors:

J. Rodney Walton - San Diego CA, US
John W. Ketchum - San Diego CA, US
Steven J. Howard - San Diego CA, US
Mark Wallace - San Diego CA, US

Assignee:

QUALCOMM Incorporated - San Diego CA

International Classification:

H04J 11/00
H04B 7/216

US Classification:

370208, 370335, 370342

Abstract:

In one aspect of a multiple-access OFDM-CDMA system, the data spreading is performed in the frequency domain by spreading each data stream with a respective spreading code selected from a set of available spreading codes. To support multiple access, system resources may be allocated and de-allocated to users (e. g. , spreading codes may be assigned to users as needed, and transmit power may be allocated to users). Variable rate data for each user may be supported via a combination of spreading adjustment and transmit power scaling. Interference control techniques are also provided to improve system performance via power control of the downlink and/or uplink transmissions to achieve the desired level of performance while minimizing interference. A pilot may be transmitted by each transmitter unit to assist the receiver units perform acquisition, timing synchronization, carrier recovery, handoff, channel estimation, coherent data demodulation, and so on.

US Patent:

8478776, Jul 2, 2013

Filed:

Oct 30, 2009

Appl. No.:

12/610255

Inventors:

J. Rodney Walton - San Diego CA, US
John W. Ketchum - San Diego CA, US

Assignee:

QUALCOMM Incorporated - San Diego CA

International Classification:

G06F 17/00

US Classification:

707769, 709226, 709248

Abstract:

A collection of nodes in a peer-to-peer (P2P) network can have a larger aggregate coverage footprint than any given single node. This inherent multi-site property of P2P wireless networks can provide each node with benefits of multi-user diversity. This can improve the effective coverage of nodes within a P2P wireless network and improve discovery of devices in the P2P network.