Performance evaluation of uplink transmission using space time block coding and beamforming

Abstract

A combination of Alamouti's space time block coded scheme with two transmitter and variable number of receive antennas and minimum variance distortionless response beamforming algorithm with variable number of antenna array elements is used. The combined model is used to study the relative advantages of using varying number of antennas and number of elements in antenna array to combat the effect of noise and cochannel interference in an uplink environment. The uplink multiuser environment is assumed to consist of a primary user, whose signal is of interest, while other users are considered as interfering sources whose directions relative to the base station are generated randomly. Simulation results suggest that in high noise and fading environment the diversity achieved by using large number of antennas combats BER more efficiently than beamforming. On the other hand in low fading environment beamforming plays an important role in reducing BER by minimizing the effect of interference from other cochannel users.