针对前期提出的并行组合扩频超宽带通信系统，采用跳时多址接入方式，通过分析文中系统的误码性能和多用户接入数量，对其多址性能进行研究．仿真结果表明: 跳时多址接入方式的采用改善了并行组合扩频超宽带通信系统的多址性能，大幅提高了系统容量; 在大信噪比环境中，该采用跳时多址接入的系统工作在5 个干扰用户条件下的误码性能仍比在单用户条件下工作的传统超宽带通信系统有较大的提高．进一步分析了该多址系统可容纳的用户数量，认为较多用户干扰时可以考虑采用新的跳时码减少脉冲间发生碰撞的概率，以降低多用户干扰．

This paper deals with the previously-proposed ultra-wideband ( UWB) communication system based on the parallel combinatory spread spectrum,and employs a time-hopping method to investigate the multiple access performance of the proposed system by analyzing the BER performance and the number of multi-user access. Simulated results show that the employment of the time-hopping method improves the multiple access performance and greatly increases the system capacity,and that the proposed system with time-hopping multiple access in the existence
of 5 interference users is still superior to the conventional single-user UWB communication system in terms of BER performance. Moreover,the authors further analyze the system capacity and suggest that,when there are more interference users,it should be considerable to adopt a new time-hopping code to reduce the probability of pulse collision,so as to decrease the multi-user interference.