Simulation of Wavelet-Based OFDM CDMA System with Convolutional Coding

This paper presents a MATLAB simulation code for a wavelet-based Orthogonal Frequency Division Multiplexing Code Division Multiple Access (OFDM CDMA) system designed for multipath fading channel environments. The system incorporates a convolutional encoder to enhance reliability and error correction capabilities. The implementation includes key components such as: - Wavelet transform operations for signal modulation instead of traditional FFT-based approaches - Convolutional encoding with specified constraint length and generator polynomials - Multipath channel modeling using tapped delay line filters with Rayleigh fading characteristics - CDMA spreading codes implementation for multiple user access - Receiver modules with Viterbi decoder for convolutional code recovery The code structure follows a comprehensive simulation workflow including signal generation, wavelet-based OFDM modulation, CDMA spreading, channel transmission through multipath fading, and the corresponding demodulation process with error correction decoding. Performance metrics such as bit error rate (BER) calculations under varying signal-to-noise ratio conditions are systematically evaluated.