Nonlinear Adaptive Beamforming Algorithms and Bit Error Rate Analysis for MU MIMO m mWave Communication System

Abstract

Multiuser-multiple input multiple outputs (MUMIMO) can provide a substantial performance for cellular networks by applying a beamforming technique to direct signals in specific required directions. Therefore, this paper presents a basic idea of steering the incoming signals into the signal of interest (SOI) and signal not of interest (SNOI) directions. Moreover, different adaptive beamforming algorithms such as least mean square (LMS), recursive least square (RLS) and constant module algorithm (CMA) are analyzed and evaluated regarding the interference cancelation and steering of incoming data signal. In this regard, to calculate the received output signal, the optimal weight elements of a uniform linear array (ULA) antenna are computed and updated based on the incoming array sensor signals. Furthermore, the paper shows the effect of the beamforming on a bit error rate (BER) when applied a different number of antenna elements at base station (BS). The simulation results confirm that the algorithms likely have the same performance in the interference cancelation. However, the RLS algorithm shows a little enhancement compared with SMI and CMA algorithms. Besides, the results indicate that the beamforming with the different number of antenna elements has a significant impact on the BER performance. Hence, this work can be extended to a higher frequency of mmWave communication with a massive number of antenna elements, which can meet requirement of fifth generation (5G) network systems.