一种直接在中频信号上实现通道均衡的新方法

A New Method for Channel Equalization Based on Direct IF Signal

通道失配严重制约了多通道雷达的性能,诸如旁瓣对消的对消比、数字波束形成的波束旁瓣和单脉冲测角精度等。传统的通道均衡一般是在数字正交下变频之后的基带复信号上通过复数滤波器实现,分析传统均衡滤波器原理后,提出了一种可直接在中频采样后数字正交下变频之前实现通道均衡的新方法,证明了均衡滤波器可以用实系数FIR滤波器完成,仿真验证了该算法的可行性。与传统方法相比,新方法可以降低工程实现的复杂度和运算量,已成功应用于某跟踪雷达中。

It is indicated that the channel mismatch severely restrict the performance of radar with multiple channels,such as the ratio of cancellation ratio of sidelobe canceller,the sidelobe lever of the digital beam form,and the precision of angle measurement.Traditional channel equalization always implement by complex filter on complex baseband signal after the digital down conversion process.Based on the analysis of the principle of traditional channel equalization,a new method which can implement channel equalization directly after the IF sample whereas before the digital down conversion process is proposed in this paper.The fact that the filter for channel equalization can achieved by real coefficient FIR filter is also proved.The validity of method is demonstrated by simulation results.Compared to traditional method,the new algorithm proposed by this paper can reduce the computational complexity of engineering implementation,the algorithm is also applied in tracking radar successfully.