基于点判决域的多模盲均衡算法及其FPGA实现

Multi-modulus blind equalization algorithm based on point decision and FPGA implement

恒模算法无法克服信号的相位失真问题,且稳态误差大;修正恒模算法可以恢复信号相位,但均衡器收敛后,稳态误差依然很大。针对这一问题,提出一种基于点域判决的多模盲均衡算法,算法利用信号的判决值,在不增加设备复杂性的前提下,可以降低均衡器的稳态误差。给出了多模算法的FPGA设计方案,基于Xilinx公司的ISE设计平台,在Modelsim中进行了时序仿真分析,并和MATLAB仿真进行了比较。实验结果表明盲均衡器可以克服信号的幅度和相位失真,并且具有稳态误差低的优势。

Constant modulus algorithm （CMA） was unable to counteract phase distortion and the steady state error was high. Modified constant modulus algorithm （MCMA） could recover signal phase, but the steady state en-or remained high. To solve the problem, a multi-modulus blind equalization algorithm （MMA） based on point decision was proposed. Taking advantage of decision value of signals, the steady state error was diminished without increasing the complexities of receiver. FPGA design scheme of the new algorithm is described. Sequence simulations were implemented with Modelsim based on ISE platform of Xilinx and compared with MATLAB simulations. Experimental results indicate the blind equalizer can counteract amplitude and phase distortion, and the steady state error is low.