基于频域互相关序列与峰值检测的空频分组码盲识别算法  

Blind recognition algorithm of space frequency block codes based on frequency domain cross correlation sequence and peak detection

作　　者：闫文君 张聿远 凌青 于柯远 谭凯文 刘恒燕 YAN Wenjun;ZHANG Yuyuan;LING Qing;YU Keyuan;TAN Kaiwen;LIU Hengyan(Academy of Aeronautical Operations Service,Naval Aeronautical University,Yantai 264001,China;Unit 92853 of the PLA,Xingcheng 125100,China)

机构地区：[1]海军航空大学航空作战勤务学院,山东烟台264001 [2]中国人民解放军92853部队,辽宁兴城125100

出　　处：《系统工程与电子技术》2021年第12期3709-3715,共7页Systems Engineering and Electronics

基　　金：国家自然科学基金重大研究计划(91538201);泰山学者工程专项经费(Ts201511020)资助课题。

摘　　要：针对复杂电磁环境和非协作通信条件下空频分组码(space-frequency block codes,SFBC)信号识别困难、对先验信息要求高的问题,提出一种基于频域互相关序列与峰值检测的SFBC盲识别方法。首先,通过分析SFBC信号的编码特点,计算得到发送端的互相关函数。然后,考虑频率选择信道、多径传播和噪声的影响,推导了接收信号的互相关函数,并对其进行傅里叶变换得到频域互相关序列。最后,根据频域互相关序列检测其峰值位置识别发射端编码方式。推导和实验结果表明,该算法在低信噪比下的识别性能较好,并且对时间偏差和频率偏差等情况的适应性较强,在复杂电磁环境下具有较好的识别性能,能够应用在认知无线电和频谱检测等场合。该算法不需要知道信道和噪声的先验信息、正交频分复用(orthogonal frequency division multiplexing,OFDM)块大小以及接收端和发射端的同步信息,非常适合于电子侦察等非协作通信场合。In order to solve the problems of difficult recognition of space-frequency block codes(SFBC)and high requirement of prior information in complex electromagnetic environment and non-cooperative communication,a blind recognition method of SFBC based on frequency cross-correlation sequence and peak detection is proposed.Firstly,by analyzing the coding characteristics of SFBC signals,the cross-correlation function of transmitter is calculated.Then,considering the influence of frequency selective channel,multipath propagation and noise,the cross-correlation function of the received signal is derived,and the frequency domain cross-correlation sequence is obtained by Fourier transform.Finally,based on the frequency domain cross-correlation sequence,the peak position is detected to identify the coding mode of the transmitter.The derivation and experimental results show that the algorithm has good recognition performance at low signal to noise ratio(SNR),strong adaptability to time deviation and frequency deviation,and has good recognition performance in complex electromagnetic environment.It can be applied to cognitive radio and spectrum detection.The algorithm does not need to know the priori information of channel and noise,the size of orthogonal frequency division multiplexing(OFDM)block and the synchronization information of receiver and transmitter,so it is very suitable for non-cooperative communication occasions such as electronic reconnaissance.

关 键 词：空频分组码 互相关序列 峰值检测 非协作通信 信号盲识别 

分 类 号：TN911.7[电子电信—通信与信息系统]