MATLAB Implementation of BPSK Modulation and Demodulation with Bit Error Rate Analysis

This example presents a MATLAB implementation of BPSK (Binary Phase Shift Keying) modulation and demodulation, complete with bit error rate curve visualization. MATLAB code implementation: % BPSK modulation and demodulation MATLAB implementation example % Parameter configuration N = 1000; % Number of transmission bits Eb_N0_dB = -10:2:10; % SNR range in dB snr = 10.^(Eb_N0_dB/10); % Convert SNR to linear scale using logarithmic transformation % Generate random bit sequence using uniform distribution bits = randi([0, 1], 1, N); % BPSK modulation: map bits to symbols (0->-1, 1->+1) s = 2*bits - 1; % Add AWGN (Additive White Gaussian Noise) using MATLAB's awgn function received_signal = awgn(s, snr); % BPSK demodulation: decision based on sign detection decoded_bits = sign(received_signal); % Error calculation using bit-wise comparison errors = sum(bits ~= decoded_bits); bit_error_rate = errors/N; % Plot bit error rate curve using logarithmic Y-axis semilogy(Eb_N0_dB, bit_error_rate, 'bo-'); xlabel('Eb/N0 (dB)'); ylabel('Bit Error Rate'); title('BPSK Modulation Bit Error Rate Performance'); grid on; This program demonstrates the complete workflow of BPSK modulation and demodulation techniques while analyzing system performance through bit error rate curves. The implementation includes key communication system components: signal generation, modulation mapping, channel modeling with AWGN, threshold-based demodulation, and performance evaluation. Users can modify parameters and visualization settings to meet specific research or application requirements. The code utilizes MATLAB's built-in functions for random number generation and noise addition, ensuring reliable simulation results.