中文摘要：

为了实现直序扩频扩展的二元相移键控（DS—SS／EBPSK）调制的多址通信，研究了一种DS-SS／EBPSK调制的码分多址实现方法。首先对DS．SS／EBPSK调制信号进行分析，公式化表述了DS—SS／EBPSK的调制过程，得到了可用于解扩和码分多址的等效扩频序列；在此基础上，设计了相关接收机对DS-SS／EBPSK调制信号进行检测，利用不同用户扩频序列互相关很小的特点实现多址传输；最后以m序列为例，仿真了期望用户的误码性能与用户数量和m序列周期长度的关系。仿真结果验证了此种码分多址实现方式的可行性，同时也表明多用户的干扰程度取决于扩频序列之间的互相关性。

英文摘要：

In order to realize muhiple-access communication of direct sequence spread spectrum extended binary phase shift keying （DS-SS/EBPSK） modulation, a realization method based on code-division was researched. Firstly, based on the analysis of DS-SS/EBPSK modulation signal, the effective spread spectrum sequence which can be used for dispreading and code division multiple-access was obtained by formulizing the DS-SS/EBPSK modulation process. Then, the correlation receiver for DS-SS/EBPSK modulation signal detection was designed and the multiple-access transmission was realized by making use of the small-scale cross-correlation of different spread spectrum sequences. Finally, take m sequence for example, the relationship between bit error rate （BER） performance of the expected user and the number of users was simulated, so did the relationship between BER performance of the expected user and the cycle length of m sequence. The simulation results demonstrate the feasibility of the code-division multiple-access realization method and indicate that the interference degree depends on the cross-correlation of the spread spectrum sequences.