基于迭代变步长LMS的数字域自干扰对消

发布时间：2018-07-08 09:55

本文选题：同时同频全双工 + 自干扰对消　；参考：《电子学报》2016年07期

【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6d B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10d B.
[Abstract]:Aiming at the problems of slow convergence speed and low cancellation ratio of existing digital domain interference cancellation methods in Co-frequency and Co-time full Duplex Duplex Duplex (CCFD) systems, an iterative least mean square (LMS) algorithm is proposed in this paper. This algorithm is used to realize fast convergence of high cancellation ratio digital domain interference cancellation. First of all, the Logistic function is improved to shorten the variation interval of the function value from large to small, and then the step size factor value of the nonlinear function is calculated with the iteration times to accelerate the convergence speed of interference cancellation. High precision recursive estimation of self-interference channel parameters, that is, to obtain a high cancellation ratio. Finally, the convergence and computational complexity of the cancellation method are analyzed theoretically, and the closed expression of cancellation ratio under steady condition is obtained. The simulation results show that the cancellation ratio can be increased by more than 6 dB and the convergence rate can be doubled compared with the existing variable step size LMS cancellation method. Compared with the least square channel estimation interference cancellation method, the cancellation ratio is increased by at least 10 dB.
【作者单位】：军械工程学院信息工程系;电子科技大学通信抗干扰技术国家级重点实验室;
【基金】：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)
【分类号】：TN911.4

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