光学学报, 2018, 38 (7): 0706002, 网络出版: 2018-09-05
Gamma-Gamma大气湍流下相干光通信分集接收技术研究 下载: 1142次
Diversity Reception Technology in Coherent Optical Communication over Gamma-Gamma Atmospheric Turbulence Channel
大气光学 大气湍流 相干光通信 分集接收 atmospheric optics atmospheric turbulence coherent optical communication diversity receiving
摘要
大气湍流引起的光强闪烁使得自由空间光通信(FSO)系统性能恶化,而分集接收技术可有效改善这一影响。为进一步分析分集接收技术对相干接收系统性能的影响,基于二进制相移键控(BPSK)调制和外差相干接收技术,建立了Gamma-Gamma大气湍流信道模型下自由空间光通信分集接收系统模型。在不同大气湍流强度和接收天线数情况下,分别采取最大比合并(MRC)、选择合并(SC)和等增益合并(EGC),分析了对应的系统误码率(BER)和通信中断概率(OP),并与相同接收口径下的传统单天线接收系统的性能进行了比较。结果表明:MRC、EGC分集接收对大气湍流下的相干通信系统性能有明显改善,而SC分集接收仅当平均信噪比低于某一阈值时对相干通信系统的性能有所优化。
Abstract
The performance of free space optical communication (FSO) system will deteriorate with the existence of light scintillating caused by atmospheric turbulence. But the performance of FSO can be improved effectively by means of diversity reception technology. To further analyze its impact on the performance of coherent receiving system, we use binary phase-shift keying (BPSK) modulation and heterodyne detection to establish FSO system model with spatial diversity over Gamma-Gamma atmospheric turbulence channel. Bit-error rate (BER) and outage probabilities (OP) of maximum ratio combining (MRC), selection combining (SC) and equal gain combining (EGC) with different numbers of receiving antennas and turbulence regions are analyzed. In addition, the BER and the OP of MRC, SC and EGC are compared with the performance of the traditional single-antenna receiving system with the same receiving aperture. The results show that spatial diversity based on MRC and EGC can improve the performance of coherent communication system over atmospheric turbulence, and the spatial diversity based on SC can improve the performance of the system only when the average signal to noise rate (SNR) is below a certain threshold.
孙晶, 黄普明, 幺周石. Gamma-Gamma大气湍流下相干光通信分集接收技术研究[J]. 光学学报, 2018, 38(7): 0706002. Jing Sun, Puming Huang, Zhoushi Yao. Diversity Reception Technology in Coherent Optical Communication over Gamma-Gamma Atmospheric Turbulence Channel[J]. Acta Optica Sinica, 2018, 38(7): 0706002.