Spreading Sequence Spread Spectrum Communication System Design Study

The design of conventional m-sequence is researched in the paper firstly. Shortage of generating m-sequence based on GF(2) is found. The design method of generating m-sequences applied copy theory is advanced. It generates m-sequence without knowing about creating polynomial. In the same time, an efficient computer search model and its new algorithm are presented. By the way of making computer to search and select, we can make a great deal m-sequences optimum pairs and the correlation congregate. Then in the third part, the paper researches Walsh code a certain extent, and it bring out a new way to generate Walsh function compared with traditional way.The fourthly part in this paper analyzes the spectrum sequence in chaotic communication system finally, for example, Logistic -map and its modified chaotic sequence and Kent chaotic sequence. It introduces the realizing way for simulative Logistic -map chaotic sequences, and it compares the correlation performance of simulative chaotic sequences with theory analyzing. Then this paper derives the mathematical expression of statistical properties of chaotic sequences generated by improved Logistic -map. The simulation results are very close to theoretical values. Finally, the Kent binary chaotic sequence is investigated and compared with the improved logistic binary chaotic sequence in respect of the performance of autocorrelation, cross-correlation, run and balance. It is pointed out that this two chaotic sequences are applicable in spread spectrum communication, especially, the Kent chaotic sequence makes it highly applicable in secrete and anti-jamming occasion.