频谱重叠度对扩频通信的性能影响分析

摘要 传统对扩频通信的分析都是从时域进行分析处理的,且相关的分析研究都是针对伪随机码元波形(PCW)采用二值矩形波的. 为此,从干扰和扩频信号频谱重叠的角度对扩频通信的抗干扰误码率(BER)进行分析,提出了频谱重叠度(SOD)的概念. 从频域的角度对BER公式进行分析,使得理论和直观的物理概念一致;给出了BER和SOD的数学表达式,推导证明了BER为SOD的单调递增函数,为扩频系统提供了一个规避干扰的扩频信号设计准则. 此外,给出了任意伪随机码元波形下扩频通信系统的BER性能分析. 实验结果验证了SOD理论的正确性.
The classic bit error rate (BER) performance analysis comes from the time domain and the existing research aimed at the condition of rectangular pseudo-random code waveform (PCW). A method was proposed to analyze the BER performance of the spread-spectrum system by the overlap between the spectrum of the spread-spectrum signals and the interference. The concept of spectrum overlap degree (SOD) was given. It can make theory analysis and intuitionistic physical conception consistent so that the BER in the frequency domain can be deduced. Besides, the mathematical expression of BER and SOD was given and BER was proved to be proportional to SOD. Analysis and derivation about SOD gives a criterion to design spread spectrum signal to avoid interference. Furthermore, The given BER is suitable for arbitrary PCW. The validity about SOD was verified through simulation.