DS/FH Communication System Based On Dual Pseudo-code Match-filter Capture Technology Research And Simulation

Spread spectrum communication technologies play an increasingly important rolein the military struggle. In view of the communication system of the high-speed vehicle,such as aircraft, LEO satellite, etc. it is higher demands for the ability ofanti-interference and resistance to intercept. But, the DS/FH hybrid spread spectrumsystem can meet the current communication system’s requirements, because it combinesthe advantages of DSSS and FHSS. Now, it has been used in aircraft-groundcommunication systems, and also be widely used in the future to high-speed operationof satellites, UAV or other aerospace vehicles and even near–space aircraftcommunication systems or measurement-control systems, as civil context, it also canused in the3G or4G communication system in the future which require high-speed datatransmission. The performance of pseudo-code acquisition is directly related to thenormal operation and the final performance of DS/FH hybrid spread spectrumcommunication system.This article has the background of a actual project, and combined with the basistheoretical of spread spectrum communication technology. In this paper, research thetechnology of DS/FH spread spectrum communication system on the conditions of highdynamic. Done some simulation studies content:1. Researched the technology of the pseudo-code capture and designed thepseudo-codes as DS code and FH sequence in the DS/FH communication system.Summarized DS/FH system’s basic parameters and key technologies, and also,compared and simulated the M, m, Gold codes’ structure fundamentals andperformances. Then have designed two m codes sequences for the frequency-hoppingsequence and DS pseudo-code sequence.2. Studied the DSSS PN code acquisition scheme based on the match-filter anddesigned a new match-filter to the DS system. As the effected by Doppler on the highdynamic conditions, Paper improved the match-filter acquisition algorithm based onexisting algorithm. The improved algorithm can better the noise suppression and improve the size of the correlation output peak, and also is conducive to improve thecapture probability threshold decision.3. Researched the frequency capture methods of the FH system and designed afrequency-match-filter to capture the hopping frequency points in it. Presented a pair ofmatch-filter method for hybrid DS/FH system’s codes acquisition, and then simulatedthe DS/FH communication system. In this system, it makes the De-FH module andDe-DS module independent of each other, and reduces the time of wait the verificationsignal from De-DS module.The contents of this paper have been applied in a construction project, so it has theactual project background and practical significance. Generally speaking, this thesiscompleted the jumping frequency point capture, DS PN code acquisition and Dopplerfrequency offset estimation. Built the DS/FH communication system model onMATLAB/SIMULINK platform, and simulated. It verified the feasibility of thisalgorithm.