Journal of Computer Applications ›› 2013, Vol. 33 ›› Issue (03): 631-634.DOI: 10.3724/SP.J.1087.2013.00631

• Network and communications • Previous Articles     Next Articles

Echo cancellation based on additional signal

LI Huiya1*, YANG Jianpo2, YIN Yongchao1, WANG Fang1, WANG Zhenchao1   

  1. 1.College of Electronic and Information Engineering, Hebei University, Baoding Hebei 071002, China;
    2. Allwin Telecommunication Company Limited, Guangzhou Guangdong 510000, China
  • Received:2012-09-20 Revised:2012-11-15 Online:2013-03-01 Published:2013-03-01

基于附加信号的回波抵消技术

李会雅1*,杨建坡2,尹永超1,王芳1,王振朝1   

  1. 1.河北大学 电子信息工程学院,河北 保定 071002;
    2.奥维通信股份有限公司,广州 510000
  • 通讯作者: 李会雅
  • 作者简介:李会雅(1981-),女,河北衡水人,讲师,硕士,主要研究方向:直放站回波抵消、频谱空穴检测算法、数字语音处理; 杨建坡(1968-),男,河北蔚县人,工程师,主要研究方向:网络通信、无线通信; 尹永超(1986-),男,河北衡水人,硕士研究生,主要研究方向:数字通信; 王芳(1980-),女,河北石家庄人,讲师,硕士,主要研究方向:低压电力线载波通信; 王振朝(1958-),男,山东鄄城人,教授,博士,主要研究方向:现代通信、低压电力线载波通信、网络通信。
  • 基金资助:

    保定市科学技术研究与发展指导计划项目(12ZG016)。

Abstract: An echo cancellation algorithm based on additional signal was proposed to eliminate the spatial co-channel interference of digital repeater in mobile communication network. Firstly, the paper studied the formation and characteristics of the echo, and established the model of true echo channel parameter matrix. Secondly, the single frequency sinusoidal signal was attached to the frequency spectrum hole of the base station, and the channel parameters of the estimated-echo matrix were estimated by making use of the convolution relationship of the cross-correlation function of the mixed-signal received by repeater, the transponder signal and the additional signal. Finally, the estimated-echo of the transponder signal was subtracted from the received mixed signal, which was achieved by the estimated-echo channel, in order to eliminate the echo interference. The simulation results show that the relative error of the attenuation coefficient of main path is 1.8493×10-5 in the frequency selective fading channel model of COST 207 standard. The estimated-echo can track the actual-echo better, so as to avoid self-excited phenomenon effectively.

Key words: digital repeater, additional signal, cross-correlation function, deconvolution, echo-channel estimation, echo cancellation

摘要: 针对移动通信网络中数字直放站的空间同频干扰问题,提出一种基于附加信号的回波抵消算法。首先对直放站真实回波信号的成因及特性进行了研究,建立了真实回波信道参数矩阵的模型; 然后在直放站接收的基站下行载波信号频谱空穴处附加单频正弦信号,利用直放站接收的混合信号、转发信号与附加信号之间互相关函数的卷积关系估计出回波信道的参数矩阵; 最后将接收的混合信号与转发信号通过估计回波信道得到的模拟回波相减,达到消除回波干扰的目的。仿真结果表明,该算法在COST 207标准的频率选择性衰落信道模型下,主径衰减系数的相对误差为1.8493×10-5,模拟回波能较好地跟踪真实回波,从而有效避免自激现象。

关键词: 直放站, 附加信号, 互相关函数, 解卷积, 回波信道估计, 回波抵消

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