Expansion Of Anti-jamming Performance Of Frequency Hopping Systems Analysis And Simulation

In the information age, the information is playing more and more important leading role in humanity's every domain, especially in military field. In the bad environment of electronic warfare, how to effectively suppress enemy's interference, and transmit the information promptly and accurately to the tactical army, becomes the key to the success of the war. As the hybrid DS/FH spread-spectrum system combine the DSSS technology and FHSS technology , the signal's power spectral density may be lower than the noise by DSSS to keep security, and the system can also obtain ultra great frequency spectrum width by the FH, so the system has a very strong anti-jamming ability. The channel coding inserts the verification position such as parity check position in the data and enables the receiver to correct the data error which appears in the transmission process by decoding, so it's also a good measure to anti-jaming.This thesis has conducted the research to the below aspects of the hybrid DS/FH spread-spectrum system. First we study the performance of DS/SFH system under the wide-band, the partial-band and the multi-tone jamming, analyze the influence caused by the assignment of DS gain and FH gain to the system performance, study the best jamming ratio which exists under the partial-band and the multi-tone jamming. Then we study the performance of DS/FFH system under the wide-band, the partial-band and the multi-tone jamming, analyze the influence of the frequency-hopping times for every data to the system performance, study the influence caused by the assignment of DS gain and FH gain under different jamming power spectral density to the system performance. Next we analyze the performance of hybrid DS/SFH spread-spectrum system using BCH codes under the wide-band, the partial-band and the multi-tone jamming, study the best jamming ratio which causes most error data number and exists under the partial-band and the multi-tone jamming. Finally we study how to set coding gain, DS gain and FH gain to obtain best system performance.