北京邮电大学学报

  • EI核心期刊

北京邮电大学学报 ›› 2012, Vol. 35 ›› Issue (4): 64-67.doi: 10.13190/jbupt.201204.64.liyl

• 论文 • 上一篇    下一篇

瑞利衰落信道中基于分集技术的 MQAM信号的识别

李艳玲1,2,李兵兵1,刘明骞1   

  1. 1西安电子科技大学 综合业务网理论及关键技术国家重点实验室, 西安 710071; 2河南农业大学 信息与管理科学学院
  • 收稿日期:2011-07-08 修回日期:2012-02-15 出版日期:2012-08-28 发布日期:2012-07-08
  • 通讯作者: 李艳玲 E-mail:lyl_lingling@163.com
  • 作者简介:李艳玲(1976-),女,博士生,Email:lyl_lingling@163.com 李兵兵(1955-),男,教授,博士生导师
  • 基金资助:

    国家自然科学基金项目(61271299);国家高技术研究发展计划项目(2007AA01Z88);高等学校学科创新引智计划项目(B08038)

Spatial Diversity Based MQAM Modulation Classification in  Rayleigh Fading Channel

LI Yan-ling1,2, LI Bing-bing1, LIU Ming-qian1   

  1. 1National Key Laboratory of Integrated Services Networks, Xidian University2School of Information and Management Science, Henan Agricultural University)
  • Received:2011-07-08 Revised:2012-02-15 Online:2012-08-28 Published:2012-07-08
  • Supported by:

    the National Natural Science Foundation of China;the 111 Project

摘要:

针对在瑞利衰落信道下正交幅度调制 (QAM)信号识别难的问题,利用多天线空间分集可以提高接收信号信噪比的特点,提出了一种基于多天线接收分集技术的识别方法. 首先给出等增益分集用于调制分类的模型,然后使用非线性最小二乘估计器联合估计正交幅度调制信号的载波频偏和衰落相位,并推导合并器输出信号的四阶累积量和六阶累积量的理论值,最后使用四阶累积量和六阶累积量两个特征联合进行分类识别. 仿真结果表明所述算法的有效性和正确性, 且与已有的混合似似然比检测(qHLRT)方法相比,有较小的计算复杂度和较强的实用性.

关键词: 调制识别, Rayleigh衰落信道, 累积量, 等增益合并

Abstract:

Considering the difficulty in classifying quadrature amplitude modulation (MQAM) signals over rayleigh fading channel, an algorithm based on antenna arrays for identifying MQAM signals in Rayleigh fading channels is presented. The characteristic that spatial diversity reception can improve the SNR of received signals is used. First, the equal gain diversity model for modulation classification is given. Then, the nonlinear leastsquares estimator is presented to estimate the frequency offsets and phase offsets. Finally the normalized fourthorder and sixthorder cumulants of the signal at the output of the combiner are estimated, that can be used as modulation classification features. Simulations demonstrate that the proposed scheme is efficient in rayleigh fading channel. Compared to the existing quasi hybrid likelihood ratio test (qHLRT) method, the proposed method has lower computational complexity and stronger practicability.

Key words: modulation classification, rayleigh fading channel, cumulant, equal gain combining

中图分类号: