MATLAB Implementation of OFDM Signal with QPSK Modulation and BER Analysis

This implementation demonstrates how to generate OFDM signals using MATLAB with QPSK (Quadrature Phase Shift Keying) modulation. The code includes essential components such as: serial-to-parallel data conversion, QPSK symbol mapping, inverse fast Fourier transform (IFFT) for orthogonal subcarrier generation, cyclic prefix insertion to mitigate inter-symbol interference, and AWGN channel modeling. The BER curve plotting functionality allows comprehensive analysis of signal transmission performance under varying signal-to-noise ratio (SNR) conditions. Key MATLAB functions employed include: qammod for QPSK modulation, ifft for OFDM symbol generation, and berawgn for theoretical BER calculation. This implementation enables comparative analysis of different modulation schemes by modifying the modulation parameters, facilitating optimal modulation selection for specific application requirements. The code structure supports easy extension to higher-order modulation schemes like 16-QAM or 64-QAM by adjusting the modulation constellation parameters.