Study of Interference Immunity of MMSE, ZF, and ML Demodulation Algorithms in MIMO Systems Under High-Order Modulation

This report analyzes the error performance of MIMO technology in wireless networks when using high-level modulation. Different reception methods, such as Minimum Mean Squared Error Detection (MMSE), Zero Forcing (ZF), and Maximum Likelihood (ML) are considered. Curves of error performance for modulation methods QAM-16, QAM-256, QAM-1024, and QAM-4096 are obtained using a 2×2 antenna configuration. It is shown that at high modulation levels, the error performance of MMSE and ZF methods is practically the same, while ML provides significant energy gain compared to these methods. Additionally, it is shown that the gain of the ML method compared to linear MMSE and ZF methods decreases with increasing modulation order.