DS/FH混合系统多址干扰抑制

根据DS-CDMA(Direct Sequence Code Division Multi-Access)系统中多用户检测的思想,分析了并行干扰抵消PIC(Parallel Interference Cancellation)对系统性能的影响,在此基础上,提出了采用部分并行干扰抵消PPIC(Partial Parallel Interference Cancellation)技术来抑制DS/FH SSMA(Direct Sequence/Frequency Hopping Spread Spectrum Multi-Access)混合系统中的多址干扰MAI ( Multi-Access Interferences).推导了闭环形式的误码率公式,得到系统性能评估的上限表达式.仿真结果表明,采用PPIC技术可有效的提高DS/FH SSMA系统的抗多址干扰的能力,因而可以提高系统的容量.仿真是建立在AWGN信道下的,对于衰落信道和低信噪比环境下,系统的性能会有一定程度的降低.

Multi-access interference suppression in DS/FH communication system

According to the thought of multi users detection(MUD)used in direct sequence code division multi access (DS CDMA) system, partial parallel interference cancellation(PPIC) technology was put forward to suppress multi access interference(MAI) in direct sequence/frequency hopping spread spectrum multi access(DS/FH SSMA)after analyzing the effect on system performance by parallel interference cancellation(PIC). Bit error rate(BER) closed expression was deduced and up limited expression of system performance estimation was also acquired. Simulation results demonstrate that PPIC technology can suppress MAI effectively in DS/FH SSMA, and system capacity can be improved. The simulation was accomplished under AWGN, system performance will deteriorates to some extent under fading channel and low signal noise ratio(SNR)condition.