Performance of Adaptive MIMO System Based on Beam-Nulling

Abstract

In this paper, "beam-nulling" is proposed to send signals over a generated subspace orthogonal to the weakest spatial subchannel fed back from the receiver. Signal-to-interference-plus-noise ratio (SINR) of MMSE receiver is derived for beam-nulling. Then the associated average bit-error rate (BER) of beam-nulling is given numerically and verified by simulation results. Simulation results are provided to compare beam-nulling with beamforming at the same data rate. To improve performance further, beam-nulling is concatenated with linear dispersion code. Simulation results are also provided to compare the concatenated scheme with beamforming.