系统工程与电子技术 ›› 2020, Vol. 42 ›› Issue (7): 1605-1613.doi: 10.3969/j.issn.1001-506X.2020.07.24

• 通信与网络 • 上一篇    下一篇

噪声鲁棒变步长LMS算法及其在OFDM水声信道均衡中的应用

隋泽平1,2(), 鄢社锋1,2,*()   

  1. 1. 中国科学院声学研究所, 北京 100190
    2. 中国科学院大学, 北京 100049
  • 收稿日期:2019-12-27 出版日期:2020-06-30 发布日期:2020-06-30
  • 通讯作者: 鄢社锋 E-mail:suizeping@mail.ioa.ac.cn;sfyan@ieee.org
  • 作者简介:隋泽平(1995-),男,博士研究生,主要研究方向为水声通信、水声信号处理。E-mail:suizeping@mail.ioa.ac.cn
  • 基金资助:
    国家自然科学基金(61725106);国家自然科学基金(61901467)

Noise robust variable step-size LMS algorithm and its application in OFDM underwater channel equalization

Zeping SUI1,2(), Shefeng YAN1,2,*()   

  1. 1. Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2019-12-27 Online:2020-06-30 Published:2020-06-30
  • Contact: Shefeng YAN E-mail:suizeping@mail.ioa.ac.cn;sfyan@ieee.org
  • Supported by:
    国家自然科学基金(61725106);国家自然科学基金(61901467)

摘要:

针对最小均方(least mean square, LMS)算法在低信噪比(signal to noise ratio, SNR)条件下性能较差的问题,提出一种噪声鲁棒变步长LMS(noise robust variable step-size LMS, NRVSLMS)算法。该算法通过结合改进的双sigmoid函数和误差信号自相关函数,在迭代过程中动态调整步长的大小,解决了传统LMS算法中收敛速度、跟踪性能和稳态性能互相矛盾的问题。理论分析和仿真结果表明,与其他变步长算法相比, NRVSLMS算法抗噪声能力强,具有良好的跟踪速度和稳态性能。将该算法应用于正交频分复用(orthogonal frequency division multiplexing, OFDM)水声信道均衡中,与现有LMS类自适应均衡方法相比,基于NRVSLMS算法的信道均衡方法能够显著降低系统误码率(bit error rate, BER)和均方误差(mean square error, MSE)。

关键词: 自适应信道均衡, 正交频分复用, 最小均方, 水声通信

Abstract:

Aiming at the problem of poor performance in least mean square (LMS) algorithm under low signal to noise ratio (SNR) environments, a noise robust variable step-size LMS (NRVSLMS) algorithm is proposed. By combining the improved double sigmoid function and the error signal autocorrelation function, the NRVSLMS algorithm dynamically adjusts its step-size during the iteration process to solve the problem that the convergence speed, the tracking performance and the steady-state performance are contradictory in the traditional LMS algorithm. Theoretical analysis and simulation results show that the NRVSLMS algorithm has stronger anti-noise ability, faster tracking speed and better steady state performance compared with other variable step-size algorithms. The proposed algorithm is applied to orthogonal frequency division multiplexing (OFDM) underwater acoustic communications, the proposed equalization method base on the NRVSLMS algorithm improves the performance in terms of the bit error rate (BER) and mean square error (MSE) sufficiently in comparison with the existing ones.

Key words: adaptive channel equalization, orthogonal frequency division multiplexing (OFDM), least mean square (LMS), underwater acoustic communication

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