基于累积量和循环平稳参量的OFDM信号盲检测  

Blind detection of OFDM signals based on HOC and cyclostationarity parameters extraction

作　　者：郭黎利 吴丹[2] 孙志国 

机构地区：[1]哈尔滨工程大学通信技术研究所,黑龙江哈尔滨150001 [2]北京机电工程研究所,北京100074

出　　处：《电路与系统学报》2010年第6期68-74,62,共8页Journal of Circuits and Systems

基　　金：国家自然科学基金资助项目(60772129)

摘　　要：为解决正确检测和识别OFDM信号的问题,提出一种新的OFDM盲检测方案。该方案在缺乏先验知识的条件下,充分利用OFDM时域包络渐近高斯性分布的特点,对已有基于累积量的识别特征参量提取进行改进,有效的抑制了瑞利衰落及高斯噪声对接收端信号调制模式识别性能的影响。在此基础上,为改善现有累积量算法无法区分OFDM与高斯信号的不足,应用二阶循环平稳性分析分选OFDM及高斯信号,构成OFDM信号检测的总体方案。仿真实验评估了该方案的有效性:验证该方案可在瑞利衰落信道下正确识别OFDM调制模式并在多径信道及较低信噪比下分选出OFDM信号。A blind comprehensive detection scheme is proposed to detect OFDM （Orthogonal Frequency Division Multiplexing） signals correctly. Under the condition of no prior knowledge, by using the asymptotic Gaussian distribution of OFDM in time domain, an improved distinctive signatures abstraction method using HOC （Higher Order Cumulants） is applied to distinguish OFDM from other single carrier modulations. The method can counteract the impact of both Rayleigh fading and Gaussian noise on receiving identification rate effectively. On the base of this, in order to remedy the deficiency of HOC algorithm which is not able to distinguish OFDM from plain Gaussian signals, cyclosatationarity test is exploited as the accomplishment of the detection scheme. Simulation experiments evaluate the validity of the scheme： demonstrate that it can recognize the OFDM modulation under Rayleigh fading channel effectively, and select out OFDM from Gaussian signals at multi-path fading channel at lower SNR.

关 键 词：正交频分复用 盲检测 渐近高斯性 高阶累积量 循环平稳 

分 类 号：TN911.7[电子电信—通信与信息系统]