Self-encoded Spread Spectrum Communication Synchronization Capture

Spread-spectrum (SS) technique has been widely used in military and civiliancommunications for its advantages, such as anti-jamming (AJ) and low probability ofdetection (LPD). However, with the development of electronic counterwork, thetransmission security of conventional spread-spectrum communication with fixedPseudo-Noise (PN) codes has been threatened. Although time varying and randomspreading sequences are expected, they have not been practically implemented before,because the data recovery at the receiver requires the prior knowledge of thespreading sequences.In this thesis, we present a novel spread spectrum communication system,Self-Encoded Spread Spectrum (SESS) system, which does not use PN codes. Itemploys random spreading sequences that are extracted from the information data.Appropriate data compression methods are needed to assure the random nature of theinformation source and to enlarge its entropy.In Self-Encoded Spread Spectrum (SESS) system, spreading sequences areunknown, which are extracted from the information data. Therefore, fast and reliablesynchronization algorithm is one of key technologies in SESS system. In this thesis,an efficient synchronization algorithm is present.In this thesis, first, we present the acquisition theory of conventional spreadspectrum communication system and the theory of SESS system. Then the acquisitionmethod of SESS system is discussed in detail. Finally, a acquisition model of SESSsystem is built and simulated in the AWGN channel, in the Raleigh fading channeland in multi-address interfere condition. The simulation results show the acquisitionmethod of SESS system can be just as reliable as the conventional DSSS systems.Finally, the thesis summarizes the work that had been done and pointout some directions need to study in the future.