Abstract: A new quasi-orthogonal hybrid spread spectrum communication algorithm and its realized scheme are proposed. The algorithm can achieve BPSK DSSS in the in-phase branch based on the code phase, and the M-ary modulation in the orthogonal branch based on code polority. The system can achieve the starting position of the spread spectrum utilizing the spread spectrum(SS) code in the in-phase branch,and get carrier message with the complementary character of spread spectrum codes in two channels, and it needs no external source of synchronization. The code set of SS codes comes from one SS code by cyclic shifting with the limit of phase area, which is easy to realize. The simulation results demonstrate that the algorithm is effective in improving the utilization ratio of system resources.

Key words: BPSK, direct sequence spread spectrum, hybrid spread spectrum, M-ary