电子学报 ›› 2016, Vol. 44 ›› Issue (7): 1530-1538.DOI: 10.3969/j.issn.0372-2112.2016.07.002

• 学术论文 • 上一篇    下一篇

基于迭代变步长LMS的数字域自干扰对消

刘建成1, 全厚德1, 赵宏志2, 唐友喜2   

  1. 1. 军械工程学院信息工程系, 河北石家庄 050003;
    2. 电子科技大学通信抗干扰技术国家级重点实验室, 四川成都 611731
  • 收稿日期:2015-02-25 修回日期:2015-09-23 出版日期:2016-07-25 发布日期:2016-07-25
  • 作者简介:刘建成 男,1987年7月出生,河北邱县人.2010年毕业于解放军电子工程学院通信对抗工程专业,并于本校攻读硕士研究生,2013年考入解放军军械工程学院,攻读导航制导与控制工程专业博士研究生,主要进行超短波无线通信抗干扰的有关研究.E-mail:liujiancheng1987@126.com;全厚德 男,1963年生,辽宁人.现为解放军军械工程学院信息工程系教授,博士生导师.研究方向主要包括:无线通信技术、指挥控制系统、通信设备性能测试等
  • 基金资助:

    国家自然科学基金(No.61531009,No.61271164,No.61471108,No.61201266,No.61501093);重大专项(No.2014ZX03003001-002);国家863高技术研究发展计划(No.2014AA01A704,No.2014AA01A706,No.2015AA01A701);国家电网公司科技项目(No.SGSCDKJLZJKJ1400099)

Digital Self-Interference Cancellation Based on Iterative Variable Step-Size LMS

LIU Jian-cheng1, QUAN Hou-de1, ZHAO Hong-zhi2, TANG You-xi2   

  1. 1. Department of Information Engineering, Ordnance Engineering College of PLA, Shijiazhuang, Hebei 050003, China;
    2. National Key Laboratory of Science and Technology on Communications, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, China
  • Received:2015-02-25 Revised:2015-09-23 Online:2016-07-25 Published:2016-07-25

摘要:

针对同时同频全双工(Co-frequency and Co-time Full Duplex,CCFD)系统已有的数字域干扰对消方法收敛速度慢和对消比低的问题,本文提出了迭代变步长最小均方(Least Mean Square,LMS)算法,利用该算法实现了快速收敛的高对消比数字域干扰对消.首先,改进Logistic函数,缩短其函数值由大至小的变化区间,再利用该非线性函数计算随迭代次数变化的步长因子值,从而加快干扰对消的收敛速度,高精度递推估计自干扰信道参数,即获得高的对消比.最后,理论分析了该对消方法收敛性和计算复杂度,得到了稳态条件下对消比的闭合表达式.仿真表明,该方法与已有变步长LMS对消方法相比,对消比可增加6dB以上,收敛速度可提高1倍,与最小二乘信道估计干扰对消方法相比,对消比提高了至少10dB.

关键词: 同时同频全双工, 自干扰对消, 变步长LMS

Abstract:

Recently,the co-frequency co-time full duplex (CCFD) has been widely studied for its higher spectral efficiency.However,it must avoid the strong co-channel self-interference to put this technology into practice,and the existing digital interference cancellation methods usually have slow convergence and small cancellation-ratio.Considering this obstacle,the digital cancellation method based on iterative variable step-size least mean square algorithm (IVSSLMS) is proposed in this paper.Firstly,the function of Logistic is modified to accelerate its tendency for value changing lower.Then,the iterative variable step-size is obtained through the modified nonlinear function.Consequently,convergence of interference cancellation is speeded up,and accurate parameters of self-interference channel are estimated to achieve high cancellation-ratio is derited.Finally,the convergence and complexity of this digital interference cancellation method are analyzed and the closed expression of steady-state cancellation-ratio is derived.Simulations verify that the cancellation-ratio of this method could achieve more than 6dB and 10dB in comparison with the existing variable step-size LMS methods and cancellation method based on least square channel estimation respectively,and the convergence speed could be enhanced doubled.

Key words: co-frequency and co-time full duplex, self-interference cancellation, variable step-size LMS

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