BER Evaluation of an Enhanced Maximal Ratio Combiner over Time-Varying Nakagami Fading Channel

Abstract

Wireless communication system has found worldwide acceptability as a backbone of modern digital transformation, enhancing connectivity, efficiency and transformation. However, the system is characterized with severe multipath propagation effects that degrade its performance. Maximal Ratio Combiner (MRC), as one of the techniques being used to address this problem is associated with poor performance in a time-varying channel due to increase in delay time as transmission data rate increases. Hence, in this paper, enhancement of MRC is carried out to improve its performance in a time-varying channel by reducing error rate using Adaptive Coding and Modulation (ACM) transmission technique and the Bit Error Rate (BER) of the enhanced MRC scheme is analytically derived and employed as performance metric. The multiple copies of the received signals at varying paths „L‟ (2, 4) are combined using Conventional MRC (CMRC). The transmitter then selects the appropriate coding rate and constellation size for another transmission slot based on the obtained channel gain through ACM transmission technique. Mathematical expressions using Probability Density Function (PDF) of a time-varying Nakagami fading channel for Bit Error Rate (BER) is also derived. The proposed technique is simulated using MATLAB R2021a. The results obtained revealed that, the enhanced MRC scheme shows a lower BER, which indicate a significant gain in sound quality. Therefore, the proposed technique suggests a practical application in improving next-generation wireless network.