基于不同位置小波变换的盲均衡器研究*

目前引入小波变换的自适应均衡器均是将正交多小波变换放置在均衡器(前向滤波器)之前以加快收敛。以常模判决反馈均衡器(CMA-DFE)为例,根据平衡正交多小波变换是放置在前向滤波器还是反馈滤波器之前,研究了三个均衡器,即常规的基于前馈正交多小波变换常模判决反馈盲均衡器(MWT-CMA-DFE)、基于反馈正交多小波变换的常模判决反馈盲均衡器(FMWT-CMA-DFE)和基于双正交多小波变换的常模判决反馈盲均衡器(DMWT-CMA-DFE),分析了其各自的复杂度。水声信道仿真结果表明:与CMA-DFE、MWT-CMA-DFE和FMWT-CMA-DFE相比,DMWT-CAM-DFE具有更快的收敛速度和跟踪时变信道的能力,且消除了相位旋转。

Study on blind equalizer based on different place wavelet transform

Currently the adaptive equalizer based on wavelet transform are all placed the orthogonal wavelet transform in the front of the equalizer(forward filter) to speed up convergence. Taking the constant modulus algorithm decision feedback equalizer(CMA-DFE) for example and according to the balance orthogonal wavelet transform place differ , studied the three equa-lizers respectively, that was the forward orthogonal multi-wavelet transform based CMA-DFE(MWT-CMA-DFE), the feedback orthogonal multi-wavelet transform CMA-DFE(FMWT-CMA-DFE) and the dual orthogonal multi-wavelet transform CMA-DFE(DMWT-CMA-DFE), analyzed the complexities of these equalizers respectively. Simulation tests with underwater acoustic channel have indicated that the DMWT-CAM-DFE not only has the faster the performances of convergence and tracking the time vary channel but also can eliminate phase rotation compared with those of MWT-CMA-DFE and FMWT-CMA-DFE.