期望信号功率对 MVDR 算法性能的影响分析

摘要

当接收数据中存在期望信号时，即使是入射信号互相独立，最小方差无失真响应（minimum variance dis-tortionless response，MVDR）算法性能都受期望信号功率的影响。在各入射信号相互独立的前提下，本文先是分析了期望信号功率对期望信号输出功率和干扰加噪声输出功率的影响，接着分析了该影响下的输出信干噪比（sig-nal-to-interference-plus-noise ratio，SINR）以及它的收敛速率的变化情况。分析表明，输出 SINR 在一定范围内是随着期望信号功率的变大而增加，但是当期望信号功率变大到一定程度后，干扰被抑制的强度会随着期望信号功率的变大而减弱，从而导致输出 SINR 不再随期望信号功率的增大发生变化。SINR 的收敛速率也随期望信号功率的增大而变慢。仿真实验验证了分析结果的有效性。%The minimum variance distortionless response (MVDR)algorithm is affected by the desired signal (DS) power even if all signals are uncorrelated with each other when the received array data contalns the DS.Under the assump-tion that all signals are independent with each other,this paper analyses the influence of the DS power on the output DS power and the output power of the interference plus noise at first.Then,it analyses the change of the output signal-to-inter-ference-plus-noise ratio (SINR)and its convergence rate with the impact of the DS power.The analysis shows that the out-put SINR increases with greater DS power within a certaln range.However,for the DS power large enough,the ability of the interference suppression would be weaken,which results in an unchanged output SINR no whatever how large the DS power.Moreover,the output SINR suffers from slower convergence rate for larger DS power.The simulations validate the effectiveness of the analysis.