使用变步长频域LMS算法的自适应Volterra均衡器
张晓娟;吴长奇
【期刊名称】《电路与系统学报》 【年(卷),期】2012(017)004
【摘要】Volterra均衡器能够有效地克服卫星信道的非线性失真,但由于非线性均衡器的输入矩阵特征值扩展严重,使得自适应过程收敛缓慢.为克服这个缺点,提出应用变步长的频域LMS算法对Volterra均衡器的权值系数进行自适应更新.算法利用正交变换降低输入序列的相关性,同时动态地调整迭代步长提高均衡器的收敛速度.仿真结果表明与时域算法相比,均衡器的收敛速度提高了25倍左右;均衡器收敛后纠了信号的幅度和相位失真.%Volterra equalizer is an effective technique to compensate the nonlinearity for satellite channels. However, the eigenvalue spreads of input auto-correlative matrix make the equalizer converge slowly. To counteract this problem, variable step-size frequency domain LMS (FDLMS) algorithm is applied to the Volterra equalizer. The algorithm can suppress the correlation of the inputs and adjust the step-size dynamically, so as to raise the convergence rate. Simulation results indicate that the convergence rate is 25 times as time domain algorithm. The converged equalizer also corrects signal amplitude and phase distortions. 【总页数】4页(99-102)
【关键词】Volterra均衡器;卫星信道;非线性失真;变步长;频域LMS算法 【作者】张晓娟;吴长奇
使用变步长频域LMS算法的自适应Volterra均衡器
