Sequences Design For Wireless Communication System

Pseudo-random sequences play important roles in lots of system, such as spread spectrum system, distance measurement, and stream cipher system. In wireless communication system, pseudo-random sequences are usually used as an important parameter, to control communicating signal. Under the proper sequences controlling, the signal will be much safer, too. Therefore, to design proper pseudo-random sequences is an important part of designing a communication system.This paper mainly studies how to design proper pseudo random sequences for wireless communication system. Including:Firstly, this paper provides a method to construct frequency hopping sequences which are balanced and broad distant. The basic method to construct frequency hopping sequences is based on m sequences, and GMW sequences. To realize broad distance between sequences’ elements, the Dual Frequency Method is needed. The sequences, which are constructed by m sequences and Dual Frequency Method, are not usually balanced. By introducing counters, the first method this paper provided, conquer this drawback. By computer simulation, it turns out that the sequences this method constructing, has good hamming correlation as well.Secondly, this paper provides a method to construct frequency hopping sequences whose frequency set’s size are arbitrary even number. Though analyst, we found that the sequences constructed by the m sequences are only available for some frequency set’s size. For the concrete communication system, this method is far from flexible. To conquer this drawback, the second method provide a method to construct sequences whose frequency set’s size are even number, by the method of modulus. By computer simulation, the sequences are balance, and have good auto hamming correlation.Thirdly, this paper provides a concrete steps to construct M sequence. M sequences are important nonlinear sequences, which are important but hard to study. Cycle-joining method is a basic method to construct M sequences. By cycle-joining method and adjacent graph, this paper provides a concrete method step by step to construct a class of M sequences.