The conventional subspace method cannot accurately estimate the direction of arrival（DOA） of the signal with the presence of a jammer close to it because their combined channel matrix rank is deficient. The paper proposes a novel anti-jamming DOA estimation method by introducing an artificially controllable space-hopping channel and space-hopping pattern. The method causes the equivalent spatial channel of the signal to change dynamically in a symbol cycle, which can promote the channel difference between the jammer and signal source.Therefore, the method can prevent the jammer from influencing the signal, and improve the resolution of the DOA estimation. Because N hops are equivalently regarded as spawning N pairs of virtual arrays in space, the virtual elements and the subspace dimension are greatly increased, which can greatly improve the performance of DOA estimation. The simulation results verify the effectiveness of the algorithm.
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Suxia GUO was born in 1976. She re- ceived the B.E. and M.S. degrees from the PLA Information Engineering Uni- versity, Zhengzhou, China, respectively, in 1995 and 2002. She is a research asso- ciate of China National Digital Switch- ing System Engineering ＆= Technologi- cal R＆=D Center （NDSC）. Her research interests mainly focus on wireless corn-munications, physical layer security, and security.
Xiangyu LI was born in 1987. He received his B.S. degree in 2008 from Peking University and his M.S. de- gree in 2012 from the National Dig- ital Switching System Engineering Technological Research Center （NDSC）. Currently, he is a Ph.D. student at the NDSC, Zhengzhou, China. His re- search interests mainly focus on wire- less communications, physical layer se- curity, and cooperative networks.
通信作者．E—mail：liangjin@263．net Liang JIN was born in 1969. He received the Ph.D. degree from Xi＇an Jiaotong University, Xi＇an, in 1999. Currently, he is a professor at the Na- tional Digital Switching System Engi- neering Technological Research Cen- ter （NDSC）. His research interests in- clude ultra-wideband wireless commu- nication, physical layer security, and smart antennas.
Lu LIU received the B.S. degree in elec- trical engineering from Tsinghua Uni- versity, Beijing, China, in 2010, the M.S. degree in electrical engineering from the PLA Information Engineering University, Zhengzhou, in 2013. Cur- rently, he is a Ph.D. candidate and his research interests include physical layer security and compressive sensing.