关键词: 并行组合扩频, 超宽带, 多址干扰, 误码率, 脉冲位置调制

Abstract:

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.

Key words: parallel combinatory spread spectrum, ultra-wideband, multiple access interference, bit error rate, pulse position modulation