基于四阶累积量的宽带OFDM信号DOA估计  

Fourth-Order Cumulant Based DOA Estimation of Wideband OFDM Signals

作　　者：闵威[1] 刘小忠[2] 徐保根 万义和 汤四龙 饶中初 万群[1] 

机构地区：[1]电子科技大学,成都611731 [2]中国电子科技集团第38研究所,合肥230088 [3]同方电子科技有限公司,九江332007

出　　处：《火控雷达技术》2014年第3期1-5,共5页Fire Control Radar Technology

基　　金：国家自然科学基金(61172140);短波超短波阵列信号处理联合实验室项目(0206112)

摘　　要：当宽带OFDM(Orthogonal Frequency Division Multiplexing)独立信号和相干信号共存时,传统四阶累积量方法无法估计出宽带OFDM相干信号的来波方向,针对这个问题提出了一种新算法。该算法首先通过离散傅里叶变换,将宽带阵列接收数据分解为若干个窄带信号,通过四阶累积量方法估计出各个频点处独立信号的来波方向,将各个频点处的独立信号的DOA估计相加求平均即为宽带OFDM独立信号的DOA估计;然后分离出独立信号的信息,构造出一个只包含OFDM相干信号信息的矩阵,最后通过稀疏重构的方法估计出OFDM相干信号的DOA。计算机仿真结果证明该算法适用于非高斯信号和色噪声情况。The traditional fourth - order cumulant method can not estimate direction of arrival （DOA） of coherent wideband orthogonal frequency division multiplexing （OFDM） signals when independent and coherent wideband OFDM signals coexist. To solve this problem, a new algorithm was introduced. Firstly, wideband array data are broken down into several narrowband signals independent signals at each frequency bins through discrete Fourier transform （DFT） ; then the DOA estimation of could be estimated by fourth -order cumulant method, mean value of DOA estimations for independent signals at each frequency is the DOA estimation of wideband independent OFDM signals. Secondly, a matrix that only contains the information of coherent OFDM signals can be formulated by elimi- nating the contribution of uncorrelated signals. Finally, the DOA estimation of coherent OFDM signals can be ob- tained by using spare reconstruction method. The results of computer simulations demonstrate that the proposed method is not sensitive to non -Gaussian signals and colored noise.

关 键 词：宽带OFDM信号 相干信号 四阶累积量 DOA估计 稀疏重构 

分 类 号：TN911.7[电子电信—通信与信息系统]