QUANTIZED-FEEDBACK OPTIMAL ADAPTIVE BEAMFORMING

摘要

A wireless communication system including receiving and base stations (370, 300). The receiving station (370) includes a detector (390) that measures a downlink channel correlation matrix for multiple antennas (347) of the base station (300), 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 (347) of the base station (300), and quantizes the antenna weight increment vector to produce a quantized antenna weight increment vector. The receiving station (370) also includes a transmitter (380) that sends the quantized antenna weight increment vector to the base station (300). The base station (300) includes a beamformer selector (365) that re-orthogonalizes the quantized antenna weight increment vector, and a weight vector modifier (367) 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.