Patent ID: 6882678
Filing Date: 2005-04-19
Classification: H04B

Abstract:
1. A coded division multiple access (CDMA) receiver, comprising: a plurality of antennas, the antennas receiving multiple users' signals of a first frequency, each user's signal comprising a unique pilot signal; a plurality of RF receivers, down-converting the multiple users' signals to baseband analog signals; a plurality of analog-to-digital converters, converting the baseband analog signals to baseband composite digital signals; a plurality of despreaders, each despreader correlating the baseband composite digital signals with pseudonoise of a desired user with a right timing tracking a corresponding multipath signal to generate a desired user's multipath signal, which includes multiple access interference (MAI); space process means, for each multipath, for weighting the desired user's multipath signal and the MAI from all antennas, and then combining the weighted signals such that a signal-to-interference-plus-noise ratio (SINR) of the combined weighted signal is maximized to mitigate MAI; first maximum ratio combiner (“MRC”), combining all weighted outputs from each multipath, each weighted output being weighted again by a complex conjugate of a channel gain derived from the desired user's pilot signal to generate a maximal signal-to-noise ratio combined signal for the desired user; first estimator, for each user, estimating a bit based on the maximal signal-to-noise ratio combined signal; interference generator, for each user, generating other users' spreaded signals with their channel variation derived from their respective pilot signals; cancellation means, subtracting other users' spreaded signals from the baseband composite digital signals to generate the desired user's multipath signal; second MRC, weighting multipath signals by their respective complex conjugate of the channel gain derived from the desired user's pilot signal to generate maximal ratio combined signal for the desired user; second estimator, for each user, estimating a user's bit based on the maximal ratio combined signal.