基于FFT的非线性通道均衡算法研究

A Study on FFT-based Nonlinear Channel Equalization Algorithm

在频域通道均衡中求得均衡函数后,一个关键技术是寻找恰当的均衡滤波器。本文针对传统均衡中宽带信号高频部分拟合精度较差的问题,利用FFT(快速傅里叶变换),提出了雷达通道非线性均衡处理算法。通过雷达信号和雷达通道的仿真数据,将运用该算法和传统算法均衡处理的结果进行了直观效果和失配指标比较。实验结果表明,基于FFT的非线性通道均衡算法能有效地抑制高频失配;而且由该算法得到的幅度失配和相位失配指标均优于基于FFT的传统的线性通道均衡算法和基于最小二乘的均衡算法。

After finding the equalization function in frequency-domain channel equalization, one of the most crucial techniques is to seek a proper equalization filter. In order to solve the problem of worse precision that traditional equalization algorithms approximate the high-frequency components of wide-band signals, utilizing the fast Fourier transform, a nonlinear equalization algorithm about radar channels is put forward. Using the simulated data of radar signal and radar channel, the results by applying such an algorithm and the traditional equalization algorithms are compared according to the intuitionistic impression and the mismatch parameters. The experimental results show that the FFT-based nonlinear channel equalization algorithm can restrain high frequency mismatch, and for the equalization filter with high order, the amplitude mismatch and phase mismatch obtained by this algorithm are smaller than those obtained by the FFT-based linear channel equalization algorithm and the least square equalization algorithms.