A simple combined conjugate gradient beamforming and interference cancellation scheme for DS-CDMA in a multipath fading channel
N.A. Mohamed, James George Dunham · 2003
A simple DS-CDMA receiver that combines adaptive beamforming together with parallel interference cancellation in a multipath fading channel is presented. A fast adaptation, a conjugate gradient (CG) algorithm is used to find the optimum beamformer weights. By CG beamforming, the desired user's signal is enhanced and the cochannel interference from other directions is reduced. For in-beam multiple access interference reduction, a parallel interference canceller is used in each RAKE finger. The average uncoded bit error rate (BER) as a function of the average antenna signal-to-noise ratio (SNR) and the number of receiving antennas is examined in a frequency selective Rayleigh fading channel. Simulation results show an increase in system capacity as a function of the number of antennas and the number of interferers canceled per finger.