Performance Comparison of Maximum Ratio Combining, Equal Gain Combining, and Selection Combining

In this section, we conduct a comprehensive performance comparison of three distinct signal combining methodologies: Maximum Ratio Combining (MRC), Equal Gain Combining (EGC), and Selection Combining (SC). Maximum Ratio Combining optimally weights each received signal branch according to its signal-to-noise ratio (SNR), requiring accurate channel state estimation. In code implementation, this typically involves calculating weighting factors using channel magnitude estimates and applying complex conjugate multiplication before summation. Equal Gain Combining simplifies MRC by applying uniform phase alignment to all branches while maintaining equal amplitudes. From a programming perspective, this method requires phase compensation through complex multiplication followed by direct signal summation without amplitude weighting, resulting in reduced computational complexity compared to MRC. Selection Combining operates by continuously monitoring signal quality metrics (typically SNR) across all branches and selecting only the highest-quality signal path. Algorithm implementation involves real-time SNR comparison logic and a switching mechanism that activates the optimal branch while discarding others, making it the simplest to implement but potentially underutilizing available diversity. Through systematic performance evaluation across various channel conditions, we analyze key metrics including bit error rate (BER), outage probability, and implementation complexity. This comparison enables informed selection of the most suitable combining strategy based on specific application requirements, hardware constraints, and performance trade-offs between computational efficiency and signal quality optimization.