Performance Enhancement of Amplify Quantize and Forward Cooperative Relaying Technique in a Wireless Communication System

Abstract

Wireless communication systems are of paramount importance in the telecommunication infrastructure and have been playing a leading role in the development of nations. However, the system is characterized by multipath propagation effects that degrade the performance of the system. Amplify Quantize and Forward (AQF) cooperative relaying technique used to address the problem is characterized by poor performance due to signal amplification and obstruction along the propagating channel between the relay and destination. Hence, in this paper, the Enhancement of AQF (E-AQF) cooperative relaying protocol is carried out to improve the performance of the Conventional AQF (C-AQF) technique in a wireless communication system. The transmitted signal from the sourceis received at the relay node and the received signal is made to pass through spectral subtraction. The resultant signal is amplified using relay gain. The amplified signal at the relay node is quantized using uniform quantization before being forwarded to the destination during second hop transmission using angular beamforming. The multiple copies of the received signal at a varying path (L = 2, 4) are combined at the destination using Equal Gain Combiner (EGC). Mathematical expressions of Bit Error Rate (BER) and Throughput (TP) are derived using PDF. The performance of the proposed technique is evaluated using BER and TP by comparing it with the C-AQF cooperative relay technique. The proposed E-AQF gave better performance with reduced BER and increased TP than the C-AQF. The proposed E-AQF can be deployed to improve the performance of wireless communication systems.