一种零中频数字接收机镜像抑制新算法

A New Image Rejection Algorithm for Zero-IF Digital Receiver

首先提出在零中频接收机中由于I/Q信号不平衡导致产生镜像干扰信号的数学模型,然后根据复随机信号的二阶统计特性,详细推导提出一种零中频数字接收机镜像抑制算法,并对算法实现的运算量进行合理的简化和分析,仿真结果表明:镜像抑制算法能够有效地抑制宽带信号和窄带信号在零中频接收机中产生的镜像信号,同时算法实现复杂度低。

In this paper, firstly, the mathematical model of the image interference signal is derived in the zero-IF receiver due to the imbalance of the I/Q signal. Then, according to the second-order statistics of complex random signal, an image rejection algorithm for zero-IF digital receiver is deduced in detail. The computational complexity of the proposed algorithm is feasibly simplified and analyzed. The simulation results show that the image rejection algorithm can not only effectively suppress the mirror signal of broadband and narrow-band signals generated in zero-IF receivers, but also achieve low computational complexity.