光子计数无线光通信系统信噪比分析  

Signal-To-Noise Ratio Analysis of Photon Counting Wireless Optical Communication System

作　　者：印蕾 YIN Lei(Data Center of Jiangsu Military Region,Nanjing Jiangsu 210009,China)

机构地区：[1]江苏省军区数据信息室,江苏南京210009

出　　处：《通信技术》2018年第10期2292-2296,共5页Communications Technology

摘　　要：为了拓展无线光通信距离,提高接收端探测器灵敏度,研究利用盖革模式雪崩光电二极管(GM-APD)阵列检测光信号。基于弱光光子到达的泊松分布与计数过程的二项分布,推导出适用于光子计数通信系统的信噪比(SNR)公式,同时研究单个门内平均信号光子数、信号周期内开门次数、阵列中GM-APD个数对信噪比的影响。理论研究和数值仿真结果表明,提高信号周期内开门次数能有效提高系统信噪比;信号光功率较弱时(小于2个/门),增加信号光功率能明显改善系统信噪比;当GM-APD暗计数较大时(大于8×10-4个/门),阵列中GM-APD个数超过15个将会导致信噪比的恶化。In order to expand the wireless optical communication distance and improve the sensitivity of the receiver at the receiving end, it is explored to detect the optical signal by using array of Geiger-mode avalanche photodiode detector （GM-APD）. Based on the Poisson distribution of weak photon arrivals and the binomial distribution of the counting process, a signal-to-noise ratio （SNR） formula suitable for photon counting communication systems is derived. At the same time, the effects of the average number of signal photons in a single gate, the number of gates in the signal cycle, and the number of GM-APDs in the array on the signal-to-noise ratio are discussed. Theoretical analysis and numerical simulation results indicate that the increasing of the gates number in the signal period could effectively improve the system signal-to-noise ratio; when the signal light power is weak （less than 2 / gate）, the increasing of the signal light power could significantly improve the system signal- to-noise ratio; and when the GM-APD dark count is fairly large （greater than 8×10-4/gate） and the number of GM- APDs in the array exceeds 15, the signal-to-noise ratio would be deteriorated.

关 键 词：盖革雪崩光电二极管 光子计数 无线光通信 信噪比 

分 类 号：TN929.12[电子电信—通信与信息系统]