Algorithm on improved M-ary spread-spectrum communication

A new algorithm is proposed to solve the problem that conventional M-ary spread spectrum is difficult to select code set and complex to design. The algorithm adopts DBPSK DSSS in in-phase channel based on code phase, and CPSK M-ary spread spectrum in orthogonal channel based on code polarity. The system can achieve starting position of spread spectrum utilizing spread spectrum code in in-phase channel, and get carrier message with the interdependent relation of spread spectrum codes in two channels. It needs no external source of synchronization. All the spread spectrum codes can be obtained by cyclic shifting one original SS code and its reverse order sequence, which is easy to realize. Simulation results demonstrate that the algorithm is effective in improving the utilization ratio of system resources.