Simulate Bit Error Rate for BPSK in Rayleigh Channel Using Simulink

This tutorial demonstrates how to simulate Bit Error Rate (BER) for Binary Phase Shift Keying (BPSK) modulation in a Rayleigh channel using Simulink (MATLAB). In the Simulink model, begin by creating a BPSK modulator block that converts binary input signals into phase-modulated waveforms. The modulator implementation typically uses the Communications Toolbox's BPSK Modulator Baseband block, which applies phase shifts of 0° and 180° to represent binary 0 and 1 respectively. Next, add a Rayleigh Fading Channel block from the Communications Toolbox to simulate realistic wireless transmission environments. This channel model generates complex Gaussian random variables to represent multipath fading effects, where you can configure parameters like Doppler shift and path delays to match specific propagation conditions. Following the channel, implement a BER calculation system using the Error Rate Calculation block. This block compares the transmitted and received signals, calculating the bit error ratio by dividing the number of erroneous bits by the total number of transmitted bits. The calculation algorithm typically uses frame-based processing with synchronization mechanisms. You can observe BER performance variations by adjusting the Signal-to-Noise Ratio (SNR) parameter through the AWGN channel component or channel block settings. The SNR adjustment allows systematic performance evaluation across different noise conditions, typically implemented using dB scale parameters in the channel configuration. To enhance realism, consider incorporating additional channel characteristics such as multipath fading profiles and attenuation models. The Multipath Rayleigh Fading Channel block supports configurable path gains and delays, while the Path Loss block can model distance-based signal attenuation using logarithmic distance formulas. Finally, run the simulation and analyze results using MATLAB's visualization tools. The BER vs SNR curve plotting can be automated using scripting commands like 'semilogy()' to display logarithmic-scale performance graphs, helping researchers understand BPSK signal robustness in Rayleigh channel conditions through quantitative performance metrics.