一种基于超奈奎斯特信号的鲁棒判决反馈均衡器的设计

摘要

Faster-than-Nyquist (FTN) signaling is a promising technique for future wireless communication systems as it is able to increase data rate without sacrificing spectrum efficiency. However, inter-symbol interference (ISI) coexists with FTN signaling, which offsets the performance gain by FTN signaling. In this paper, in order to suppress ISI introduced by FTN signaling, we proposed to apply a robust Decision Feedback Equalizer (DFE) with a Sphere Detector (SD) for wireless communication systems, which will significantly reduce the system bit error rate and realize Maximum Likelihood (ML) detection. Through simulations, it is shown that the performance of our proposed algorithm is very close to the Shannon Limit for optimal decoder with FTN signaling. Compared to the traditional DFE, bit error rate will have the advantage of 1-2dB.%超奈奎斯特(Faster Than Nyquist， FTN)信号是一种很有前途的无线通信技术，它能够在不影响频谱效率的情况下提高无线通信系统的数据传输速率。然而，FTN会存在符号间干扰(inter-symbol interference，ISI)，这样会使FTN的增益受损。为了抑制ISI带来的影响，本文使用一个鲁棒的带有Sphere Detector (SD)的判决反馈均衡器(Decision Feedback Equalizer， DFE)去处理FTN导致的ISI。它能大大降低系统的误码率并实现最大似然(Maximum Likeli-hood， ML)检测。通过仿真实验，结果表明，提出的算法性能更接近香农极限，相比传统的DFE，误码率会有1～2 dB的优势。