OFDM Channel Estimation with Combs Pilots

In this study, we implement and analyze the Combs Pilot-based OFDM channel estimation method in practical scenarios, with detailed performance evaluation under different signal-to-noise ratio (SNR) conditions. The implementation involves generating comb-style pilot patterns inserted at specific subcarrier intervals within OFDM symbols, followed by least-squares or minimum mean-square error (MMSE) estimation algorithms to reconstruct channel frequency responses. We systematically compute bit error rates (BER) by transmitting modulated data through simulated multipath channels and comparing decoded symbols with original transmissions. The performance analysis includes plotting BER versus SNR curves using MATLAB's communication toolbox functions like berawgn for theoretical benchmarks and custom Monte Carlo simulations for empirical results. Furthermore, we investigate how SNR variations impact error performance by testing multiple channel models (e.g., Rayleigh fading, AWGN) and pilot density configurations. These experiments provide insights into estimator robustness, highlighting trade-offs between pilot overhead and estimation accuracy. The findings offer deeper understanding of OFDM channel estimation behavior across diverse signal environments and suggest optimization approaches for improving system reliability.