Research On Anti-interference Of OFDM-FH Communication System

As one of the most important part of the electronic war, communication countermeasure has received much attention. Among the area of communication countermeasure, anti-interference is a big problem. OFDM-FH is a technology that combines frequency-hopping (FH) and Orthogonal Frequency Division Multiplexing (OFDM). It inherits the anti-multipath fading ability of OFDM systems and anti-interference of FH technology. It can not only effectively enhance the transmission rate and capacity of the wireless communication system but also effectively combat multi- path fading and interfere. In this dissertation, the basic theories of channel estimation, which are suitable for static, or fast varying channel, and their applications in FH-OFDM system are wildly studied.This thesis introduces the structure, characteristics of the OFDM-FH system, describing performance of anti-interference of the system and the relationship between OFDM-FH technical parameters and anti-interference. Attention is paid on topics including OFDM FH frequency-hopping pattern anti-interference .In this system, QPSK is used into the base-band modulation of OFDM-FH and a new frequency-hopping pattern is applied. Under the circumstance of AGWN and human-interference the anti-interference performance of this system is simulated by MATLAB to show that which system is better between the FH system with OFDM and without OFDM.