光电工程, 2020, 47 (1): 190337, 网络出版: 2020-02-24
M 分布模型下多跳相干 OFDMFSO系统的性能研究
Performance study of multi-hop coherent OFDM FSO system over M distribution model
自由空间光通信 正交频分复用 多跳 M分布模型 正交相移键控 free space optical orthogonal frequency division multiplexing multi-hop M distribution model quadra-ture phase shift keying
摘要
本文在涵盖了从弱湍流到强湍流的所有信道条件, 能够表征现有大多数湍流信道的 M分布模型下, 采用 QPSK调制方式研究了多跳相干 OFDM FSO系统的性能。系统在中继辅助链路的发射机和接收机之间使用 DF中继协议。考虑大气湍流、路径损耗以及瞄准误差对大气信道衰落模型的联合作用, 分别推导出系统的中断概率和误符号率的 Meijer G形式的闭合表达式。通过仿真分析了中继链路长度、中继节点数以及子载波个数等关键因素对系统的中断性能和误符号率性能的影响。本研究为中继系统的实际应用奠定了理论基础。
Abstract
The performance of multi-hop coherent orthogonal frequency division multiplexing (OFDM) free space optical (FSO) system is studied by using quadrature phase shift keying (QPSK) modulation in this paper. A genera-lized model called M distribution is selected, which is suitable for all categories of turbulence ranging from weak to strong and characterizes other existing statistical models of atmospheric turbulence induced fading as its special case. The system uses decode and forward (DF) relay protocol between the transmitter and receiver of the relay auxiliary link. Considering the joint attenuation effects of atmospheric turbulence, path loss and pointing error on the atmospheric channel fading model, we derive the Meijer G closed-form expressions of outage probability and symbol error rate (SER). Furthermore, the effects of key factors, such as relay link length, the number of relay nodes and subcarriers on the outage and SER performance of OFDM FSO system are analyzed through simulations. This work lays a theoretical foundation for the practical application of the relay system.
吴昊, 王怡. M 分布模型下多跳相干 OFDMFSO系统的性能研究[J]. 光电工程, 2020, 47(1): 190337. Wu Hao, Wang Yi. Performance study of multi-hop coherent OFDM FSO system over M distribution model[J]. Opto-Electronic Engineering, 2020, 47(1): 190337.