基于小波分解和IIR滤波器的最优均衡器设计

Optimal Equalizer Design Based on Wavelet Decomposition and IIR Filter

图示均衡器实质上是一组带宽和中心频率固定且增益可控的滤波器,以补偿的方式修补传输系统的固有缺陷,降低传输系统对输入信号造成的失真程度。图示均衡器一般采用高阶滤波器,存在计算量大、时延高以及相邻频带相互干扰等问题。针对这些问题,从优化的角度出发,提出一种基于小波分解和无限脉冲响应(Infinite Impulse Response,IIR)滤波器的图示均衡器设计方法。仿真结果显示,该方法设计出的均衡器能将衰减至-30 dB的信号恢复至大约20 dB,提供有效均衡化,同时降低时延和计算量,避免相邻频带相互干扰。

Graphic equalizer is a set of filters with a fixed passband,a fixed center frequency and a controllable gain.It compensates the inherent defects of the transmission system and reduces the distortion caused by the transmission system to the input signal.In general,the graphic equalizer is implemented by filters.However,it suffers from a lot of problems such as the high delay,the high computational power and the interference from the adjacent frequency bands.To solve these problems,this paper proposes a wavelet decomposition and Infinite Impulse Response(IIR)filter based optimal graphic equalizer design method.The computer numerical simulation result shows that the equalizer designed by this method can recover the signal attenuated by more than-30 dB to about 20 dB.This effective equalization method reduces the system delay and the required computational power as well as avoids the interference from the adjacent frequency bands.