Exact BER Performance of Antenna Array-Based Receiver using Multi-user Detection in a Multipath Channel

Smart or adaptive antenna promises to provide significant increases in system capacity and performance in wireless systems. In this paper, a simplified, near-optimum array receiver is proposed, which is based on the angular gain of the spatial filter. This detection is then analyzed by calculating the exact error probability. When there is spread of the Direction of Arrival (DoA) of the incident radio waves, the proposed detector significantly gains over an adaptive antenna array (which forms a weighted sum of the received antenna signals). Also, for this adaptive array, a simple way to account the multi-access interference can be exploited to evaluate the average probability of error when the users are randomly distributed within an angular sector. The proposed model confirms the benefits of adaptive antennas in reducing the overall interference level (intercell/intracell) and to find an accurate approximation of the error probability. We extend the method that has been proposed for propagation over Nakagami-m fading channels, the model shows good agreements with simulation results.