中文摘要：

基于差分混沌键控（DCSK）和相关延迟键控（CDSK）提出一种新型的混沌扩频通信方案——改进型多用户正交差分混沌键控（MA-ODCSK）。该方案结合Walsh码和符号函数的各自特点，克服了DCSK和CDSK方案存在的问题，具有传输速率高、可靠性高、保密性好等优点。仿真证明，由于Walsh码的正交性，多用户干扰得到很好的抑制。在用户数一定时，MA-ODCSK比FM-DCSK、FM-EDCSK性能更加优良。

英文摘要：

A novel chaotic spread spectrum communication scheme-multiple access orthogonal differential chaos shift keying （MA- ODCSK） is proposed,which based on differential chaos shift keying （DCSK） and correlation delay shift keying （CDSK）. The scheme combines Walsh codes and symbols function＇s characteristics to overcome the existing problems of DCSK and CDSK,which shows the advantages of high transmission rate, high reliability, good communication seeutity and so on. Simulation results show that the multi-user interference is suppressed due to the orthogonality of Walsh code.The novel MA-DCSK has better performance than frequency modulated differential chaos shift keying （FM-DCSK） and frequency-modulated high efficiency differential chaos shift keying（FM-EDCSK） when the number of users is certain.