反馈滤波器长度对判决反馈均衡器性能的影响

为了使判决反馈均衡器的性能达到最佳，提出了一种判决反馈均衡器变步长可变阈值动态长度算法，并将该算法应用于研究反馈长度对自适应变长判决反馈均衡器性能的影响。结果表明：变长自适应判决反馈均衡器在前馈滤波器长度收敛到一定的范围内、判决延迟保持一定的情况下，反馈长度并不是越长越好。得出了反馈长度与自适应判决反馈均衡器的误差函数之间是一个U形函数关系的结论，该结论可以用于指导判决反馈滤波器的设计。

Effect of Feedback Filter Tap-Length on Decision Feedback Equalizer

In order to improve the performance of decision feedback equalizer, a varying step varying threshold dynamic length algorithm （VSVT-DLA） was proposed, and then the proposed algorithm was applied into investigating the effect of feedback filter tap-length on decision feedback equalizer （DFE） performance. The results show that a longer feedback filter tap-length is not necessarily better when the feedforward filter tap-length converges to a certain range and the decision delay maintains a fixed value. There exists a U-shaped relationship between feedback filter tap-length and error function of DFE and this conclusion may be used to guide the design of DFE.