Research On Self-encoded Spread Spectrum Technology

Presently, we use the pseudo-noise (PN) sequences which have random-like properties with low cross correlations critical for achieving good system performance. But a fundamental problem with the deterministic and periodic PN codes is that they can be duplicated, potentially compromising the transmission security. So we proposed Self-Encoded Spread Spectrum (SESS) system, which employs completely random spreading sequences that are extracted from the information data. The proposed system is one of the well secure communication systems.In this context, in 1999 Lim Nguyen first proposed the concept of self-encoded spread spectrum communication. It uses spread-spectrum transmission of data and information generated code, instead of using the m sequences, chaotic sequences such as pseudo-random code generator to ensure the random spreading sequences, dynamic variability and a low interception rate of the signal.We illuminate the theory of SESS communication and its advantage by contrasting the traditional direct sequence spread spectrum (DSSS). We also introduce the application of SESS in hopping frequency, hopping time communication system and multiple access system, etc. Finally, a model of SESS system is built and simulated in the AWGN channel and in Raleigh fading channel. The simulation results show the feasibility and problems of the SESS system, and some improve approaches to the system. We also give the research directions on the SESS system. Finally, through the genetic algorithm and Markov chain analysis method from the theory and simulation of the capture time and track time for a detailed analysis of results showed that the theoretical model and the analysis and simulation are basically consistent, self-encoded spread-spectrum systems for future synchronization of research has a certain significance.