摘要
空间分集接收能补偿大气湍流造成的信道衰落。在给出相干检测分集接收的系统模型和晴朗大气信道模型的基础上,考虑子孔径间信号相关性,分析了等增益合并分集和最大比合并分集的误码率性能,并就中断概率与选择分集进行了比较。分析结果表明,空间分集接收能够明显改善相干光通信系统的性能,并且接收信号间的空间相关性越小分集接收的性能越好,其中最大比合并分集性能相对其他两种合并方式优势明显,选择分集性能最差,但它与等增益合并分集的差距不大,同时选择分集实现相对容易,在工程应用中要综合考虑实现的难易程度和性能。
Spatial diversity reception can be used over wireless optical links to mitigate atmospheric turbulence. Based on the clear atmospheric channel model and the model of diversity coherent receivers for laser communication, considering the spatial correlation of received signals, the error rates of both equal gain combining （EGC） and maximum ratio combining （MRC） are analyzed, and the outage probability of them are compared with that of selection combining （SC）. The impact of spatial correlation of received signals on the diversity of coherent laser communication system is studied. The less spatial correlation of received signals is, the better the diversity reception for coherent free-space laser communication is. Simulations show that diversity can improve the performance of coherent laser communication. The performance of MRC is much better than those of EGC and SC, but SC is simpler and more convenient. Both performance and feasibility should be considered in applications.
出处
《激光与光电子学进展》
CSCD
北大核心
2012年第1期50-55,共6页
Laser & Optoelectronics Progress
基金
国家自然科学基金(60902017)
安徽省自然科学基金(1004060Q60)资助课题
关键词
无线光通信
相干探测
分集接收
大气湍流
wireless optical communication
coherent detection
diversity
atmospheric turbulence
