Hoang Dinh Nguyen

US Patent:

7738925, Jun 15, 2010

Filed:

Mar 2, 2007

Appl. No.:

11/713480

Inventors:

Hoang Nguyen - Burlington MA, US
Balaji Raghothaman - Hollis NH, US

Assignee:

Nokia Corporation - Espoo

International Classification:

H04M 1/00

US Classification:

4555621, 455 634, 455 25, 4555757

Abstract:

A wireless communication system including receiving and base stations. The receiving station includes a detector that measures a downlink channel correlation matrix for multiple antennas of a base station. The detector computes an antenna weight increment vector normal to an antenna weight vector for multiple beams from the multiple antennas of the base station. The detector quantizes the antenna weight increment vectors to produce a respective quantized antenna weight increment vector. The receiving station includes a transmitter that sends the quantized antenna weight increment vectors to the base station. The base station includes a beamformer selector that receives from the receiving station and re-orthogonalizes the quantized antenna weight increment vector for each of the multiple beams. The base station includes a weight vector modifier that modifies the antenna weight vector for the multiple beams by adding an increment proportional to the respective re-orthogonalized quantized antenna weight increment vector.

US Patent:

20070191067, Aug 16, 2007

Filed:

Feb 13, 2007

Appl. No.:

11/706510

Inventors:

Hoang Nguyen - Burlington MA, US
Balaji Raghothaman - Hollis NH, US

International Classification:

H04M 1/00

US Classification:

4555621

Abstract:

A wireless communication system including receiving and base stations. The receiving station includes a detector that measures a downlink channel correlation matrix for multiple antennas of the base station, computes an antenna weight increment vector normal to a previous antenna weight vector rendering positive a directional derivative of total received power from the multiple antennas of the base station, and quantizes the antenna weight increment vector to produce a quantized antenna weight increment vector. The receiving station also includes a transmitter that sends the quantized antenna weight increment vector to the base station. The base station includes a beamformer selector that re-orthogonalizes the quantized antenna weight increment vector, and a weight vector modifier that calculates an antenna weight vector by adding an increment to the previous antenna weight vector proportional to the re-orthogonalized quantized antenna weight increment vector and renormalizes the antenna weight vector to unit length.