Mc-fh-cdma System Anti-jamming Performance Analysis

MC-FH-CDMA is a combination of MC-CDMA and frequency hopping. Sub-carriers for use are random selected in total available sub-carriers, so it is able to avoid some interference and increases the difficulty of effective interference of enemy. The system combines the advantages of both MC-CDMA and frequency-hopping, with good ability of anti-jamming ,anti-multipath declining and anti-interception capabilities. This dissertation will focus on the theoretical analysis of anti-jamming performance in a variety of interference environment.Chapter one introduces status and development of the current anti-jamming technology, and in this basis, we proposed MC-FH-CDMA system.Chapter two introduces the basic principle of conventional anti-jamming communication systems and analyzes its performance in typical interference environment. We compare its anti-jamming performance with conventional anti-jamming communication systems in the same interference environment. The results show that FH systems have the best anti-jamming performance in single tone interference and multi-tone jamming environment, for the frequency hopping signal have the smallest probability of collisions on the interference. MC-CDMA has the best performance in partial band noise interference environment.Chapter three introduces the basic principle of MC-FH-CDMA and analyzes anti-jamming performance of single-user MC-FH-CDMA in single tone interference, multi-tone jamming interference and partial band noise interference circumstances, respectively AWGN channel and Rayleigh fading channels. In Rayleigh channel, the results show that the maximum ratio combination is better than equal gain combining. Compared with the MC-CDMA system showed performance of the two systems is very close, but the MC-FH-CDMA system can accommodate more users.Chapter four analyzes anti-jamming performance of multi-user MC-FH-CDMA in the co-existence interference environment of a variety of typical interference and multi-user, in AWGN channel and Rayleigh fading channels respectively. Compared with the MC-CDMA system, simulation results show anti-jamming performance of the MC-FH-CDMA system is better than the MC-CDMA system in multi-user interference environment, because the system combines the frequency-hopping and MC-CDMA, not using the entire frequency band, so it can avoid a part of the multi-user interference.Finally, we draw some conclusions of the dissertation, and give the further research issues.