紫外分离双脉冲位置调制误码性能分析

基于紫外非视距(NLOS)单次散射信道传输模型,分析了用于无线紫外光通信的分离双脉冲位置调制(SDPPM)方案的误码性能.介绍了SDPPM调制方案的符号结构,将该调制方案与开关键控调制(OOK)、脉冲位置调制(PPM)和双脉冲位置调制(D-PPM)在带宽需求、功率需求方面进行比较.利用光子计数方法,研究了无背景辐射噪声条件下SDPPM的误符率(SER).对PPM、D-PPM和SDPPM紫外通信系统的误码性能进行仿真,分析路径损耗对其影响.结果表明,SDPPM在信源比特分组长度n为5和6 bit时获得了带宽需求与功率需求的较好平衡.当SER达到10-4时,有效通信距离比D-PPM长20 m左右.同时,SDPPM调制方案降低了紫外光散射通信中因多径色散造成的码间串扰(ISI).

Error Performance Analysis of Separated Dual-pulse Pulse Position Modulation for Ultraviolet Communication

Based on the non-line of sight (NLOS) ultraviolet single-scattering channel transmission model, the error performance of separated dual-pulse pulse position modulation (SDPPM) for wireless ultraviolet communications is analyzed. The symbol structure of SDPPM scheme is introduced, then the bandwidth and power requirements are compared among the on-off keying (OOK), pulse position modulation (PPM), and dual-pulse pulse position modulation (D-PPM). The photon counting method is used for study on the symbol error rate (SER) of SDPPM. The error performance of UV communication system with different modulation schemes of PPM, D-PPM and SDPPM is simulated to analyze the effect of path loss. The results show that the value of bandwidth and average power requirements of SDPPM are compromised at 6bit when the (source packet length) m is 5. When the SER is 10-4, the communication distance of SDPPM is about 20m longer than D-PPM. The inter symbol interference (ISI) caused by multipath dispersion in ultraviolet scattering communication is reduced because of its symbol structure.