From September 2007 to now, the doctoral fund of Yantai University-"Research on Multi-user UWB Wireless Communication Based on LFM Spread Spectrum" studies the design and generation of orthogonal/quasi-orthogonal Chirp, CSS mixed spread spectrum multiple access scheme and the influence of multi-user interference on system performance. 2006. 12-2007.8, participated in the national natural fund project-"research on the bearing effect of scattered electromagnetic waves in communication networks",No.: 6067 1055. The intermodulation coupling and parasitic modulation effect of broadband wireless communication system based on multi-dimensional multiple access Chirp signal and scattered electromagnetic wave are studied, and the "red" signal information is extracted and recovered. June, 2006-June, 2007 12, horizontal topic-"Performance and EMC Analysis of Broadband Power Line (BPLC) Communication System", Innovation Fund of Huawei University, main participant. The theoretical modeling, system performance analysis, radiation and transmission loss analysis of broadband power line communication system based on OFDM technology are studied. Adaptive modulation and OFDMA technology are applied to broadband power line communication. The research team submitted three patents. From April 2004 to July 2007, the Key Laboratory of the Ministry of Education of Optical Communication of Beijing University of Posts and Telecommunications started the project "Research on Broadband Access Technology Combining Optical Fiber and Wireless" and served as the project leader of the laboratory. In this paper, a scheme of realizing wireless multimedia home network by ultra-wideband wireless communication technology (UWB) is proposed after adopting broadband passive optical network (BPON) to realize fiber to the home. Based on the research of passive optical network, broadband wireless access and optical fiber access are combined. The ultra-wideband pulse shaping, spectrum storage of narrowband system, anti-jamming, modulation and coding technologies are studied. Linear frequency modulation spread spectrum technology and excellent error control coding technology are applied to UWB. In the multi-user dense multi-path environment, according to different modulation and coding technologies, reception and detection technologies and multiple access technologies, the relationship among bit error rate, signal-to-noise ratio, throughput and distance of UWB system is analyzed. In this paper, the conversion between optical access protocol and future ultra-wideband transmission protocol is studied, and broadband gateways are designed for various services with different rate requirements. From August 2003 to March 2004, the horizontal project, the main participant, studied the information security of mobile communication terminals, the theoretical analysis of the influence of strong external interference on mobile phone antennas, and the analysis and test of stray radiation signals of mobile phone circuit boards. From April, 2002 to May, 2004, he cooperated with Shenzhen Tong Fei Optoelectronics Co., Ltd. to develop the horizontal project "EPON system based on Ethernet" and served as the project leader of the laboratory. Conclusion It has reached the level of standard protocol simulation and experimental demonstration system. The architecture of EPON access network technology and key technologies such as multiplexing and transmission are emphatically analyzed. The concrete implementation schemes of EPON system, simple network management system and ONU and OLT control module are designed, and the connection control management between ONU and OLT, burst synchronization at ONU side and P2P simulation are realized. The design scheme of EPON system is proposed and realized, including hierarchical structure, initial connection, ranging, dynamic bandwidth allocation, P2P, burst synchronization, information agitation, FEC and so on. According to the MPCP protocol of OLT and ONU, the hardware platform of EPON system is designed and realized by using FPGA devices, and a set of experimental demonstration system including OLT and ONU is developed. 200 1.9-2002.7, participated in the research on Tempest technology of computer information leakage and replication. The electromagnetic radiation of the braided cable between the host and the display is analyzed by FDTD method, and the radiation signal is processed to recover the transmission information.