Detailed derivations of two bounds of the minimum mean-square error (MMSE) of complex-valued multiple-input multiple-output (MIMO) systems are proposed for performance evaluation. Particularly, the lower bound is derived based on a genie-aided MMSE estimator, whereas the upper bound is derived based on a maximum-likelihood (ML) estimator. Using the famous relationship between the mutual information (MI) and MMSE, two bounds for the MI are also derived, based on which we discuss the asymptotic behaviours of the average MI in the high-signal-to-noise ratio (SNR) regime. Theoretical analyses suggest that the average MI will converge its maximum as the SNR increases and the diversity order is the same as receive antenna number.

翻译：提议进行绩效评估时,应详细推算复杂价值的多投入多产出(MIMO)系统最低平均差(MMSE)的两个界限,特别是,下限是根据基因辅助MMSE测算器得出的,而上限则根据最大相似性估测器得出的。利用相互信息(MI)和MMSE之间的著名关系,还推算出两条界限,据此我们讨论高信号对噪音比率制度中平均MI的失学行为。理论分析表明,平均MI将随着SNR的增加而趋同,多样性顺序与接收天线号码相同。