CDMA System Rake Receiver Implementation and Performance Analysis

This project implements a CDMA system Rake receiver using MATLAB and compares the performance of Maximum Ratio Combining (MRC), Equal Gain Combining (EGC), and Selective Combining (SC) reception algorithms. The implementation begins by establishing a CDMA system simulation platform in MATLAB, where we simulate multipath fading channels and implement finger receivers for each signal path. The Rake receiver structure includes channel estimation modules using pilot signals and combiner modules implementing different algorithms. For Maximum Ratio Combining, the MATLAB code calculates optimal weighting coefficients based on signal-to-noise ratio (SNR) estimates, providing the best performance when received signals have strong SNRs. The Equal Gain Combining implementation assigns equal weights to all finger outputs, maintaining performance when signal strengths are relatively balanced. Selective Combining algorithm selects the finger with the strongest signal, demonstrating robustness under unbalanced signal strength conditions. The simulation evaluates performance metrics including bit error rate (BER) versus SNR, implemented through Monte Carlo simulations with transmit-receive chain modeling, spreading codes, and channel fading effects. Through comparative experiments, we analyze how each combining technique affects system performance under different channel conditions, providing valuable insights for algorithm selection in practical CDMA systems and guiding future research directions in wireless communication receiver design.