Time and Spatial Jitter Influence on the Performance of FSO Links with DF Relays and OC Diversity Over Turbulence Channels
Time and Spatial Jitter Influence on the Performance of FSO Links with DF Relays and OC Diversity Over Turbulence Channels
复制标题
时间和空间抖动对带有 DF 中继的 FSO 链路性能的影响以及湍流信道上的 OC 分集
作者：
P. J. Gripeos;H. Nistazakis;A. Tsigopoulos;V. Christofilakis;E. Roditi
FSO通信是光无线通信中的一种病毒技术，引起了研究人员和制造商的兴趣。这是因为与FSO通信相关的许多优点，包括高数据速率，可靠性，安全性和经济性。然而，有几个不可避免的缺点，阴影的FSO系统的性能。例如，大气湍流是与信道的天气条件相关的众所周知的问题，其引起闪烁效应。此外，由于指向误差引起的空间抖动是链路性能的关键因素，其由发射器和接收器之间的偶尔未对准引起。此外，时间抖动是另一个限制因素，它使总吞吐量恶化，引起由不同步脉冲的到达引起的比特流误检测。所有这三种效应都得到了详尽的研究，文献中提出了许多统计模型和有趣的解决方案，以估计其大小并补偿其影响。本文采用Málaga分布来处理湍流效应，采用非零的bohort模型来调节空间抖动效应，采用广义高斯分布来模拟时间抖动效应。研究了各种调制方案，沿着在接收端采用了DF多跳和最优合并分集技术。得到了新的、精确的平均误码性能的数学表达式，并通过数值计算得出了有价值的结论。
FSO communication is a viral technology among optical wireless communications, gathering the interest of both researchers and manufacturers. This is because of the many advantages associated with FSO communication, including high data rates, reliability, safety, and economy. However, there are several unavoidable drawbacks that shadow the performance of FSO systems. For example, atmospheric turbulence is a well-known problem related to the weather conditions of the channel, which causes the scintillation effect. Also, spatial jitter due to pointing errors is a critical factor of the link’s performance, caused by occasional misalignments between the transmitter and the receiver. Moreover, time jitter is another limiting agent that deteriorates the total throughput, inducing bit stream misdetections, caused by the arrival of out-of-sync pulses. All three effects have been exhaustively studied and many statistical models and interesting solutions have been proposed in the literature to estimate their magnitude and compensate for their impact. In this work, the turbulence effect was treated by Málaga distribution, the spatial jitter effect was regulated by the non-zero boresight model, and the time jitter effect was modeled by the generalized Gaussian distribution. Various modulation schemes were studied, along with DF multi-hop and optimal combining diversity techniques at the receiver’s end. New, accurate mathematical expressions of average BER performance have been obtained, and valuable conclusions were drawn thanks to the presented numerical results.