Simulation of BER Performance for BPSK and QPSK over SISO and SIMO (1×2, 1×4) Systems for Image Transmission under Flat Fading Channel Conditions

Abstract

This study presents a detailed simulation-based analysis of Bit Error Rate (BER) performance for Binary Phase Shift Keying (BPSK) and Quadrature Phase Shift Keying (QPSK) modulation schemes, focusing on their application in image transmission over wireless communication systems. The performance evaluation is conducted over both Single-Input Single-Output (SISO) and Single-Input Multiple-Output (SIMO) configurations, specifically 2 and 1×4 antenna systems, under the influence of flat fading channel conditions. The primary objective is to assess how the introduction of receive diversity via multiple antennas impacts the robustness and efficiency of data transmission. The study replicates realistic wireless channel conditions by employing a flat Rayleigh fading model, allowing for an accurate evaluation of modulation performance in fading environments. Simulation results indicate that SIMO systems, particularly those with higher diversity orders (e.g., 1×4), exhibit significantly improved BER performance compared to SISO systems. Both BPSK and QPSK show enhanced resilience to channel impairments when used with multiple receive antennas. While BPSK demonstrates superior error performance in severe fading conditions, QPSK offers higher spectral efficiency with a moderate trade-off in BER. Furthermore, the study examines the degradation of image quality as a function of channel fading severity, offering practical insights for the design of reliable wireless image transmission systems.