Comparative Performance Analysis of MLSE and MMSE (Frequency Domain) Equalization for BPSK, QPSK, 8PSK, and 16QAM Modulation Schemes

This paper presents a comprehensive comparative analysis of MLSE equalization and MMSE (frequency domain) equalization techniques for BPSK, QPSK, 8PSK, and 16QAM modulation schemes under known channel conditions, focusing on their SER and BER performance characteristics. The implementation typically involves: - Generating modulated signals using constellation mapping functions - Applying channel models with known impulse response characteristics - Implementing MLSE using Viterbi algorithm with trellis decoding structure - Designing MMSE equalizers in frequency domain using FFT operations and Wiener filter principles - Calculating SER/BER through Monte Carlo simulations with error counting modules Key algorithmic considerations include: - MLSE's optimal performance through exhaustive sequence search but with computational complexity O(2^L) where L is channel memory - MMSE's frequency-domain implementation using overlap-add/save methods for block processing - Proper signal-to-noise ratio (SNR) scaling and normalization techniques - Decision-directed adaptation mechanisms for practical implementations The analysis provides detailed performance comparisons, implementation trade-offs, and discussion of complexity-performance relationships for different modulation orders and equalization strategies.