论文标题
光子限制自由空间光学通信的自适应采集方案
Adaptive Acquisition Schemes for Photon-Limited Free-Space Optical Communications
论文作者
论文摘要
由于光学信号的定向性质，采集和跟踪系统构成了自由空间光学通信的重要组成部分。为了在不确定性/搜索区域中搜索和定位非常狭窄的激光光束，需要采集子系统。在本文中，我们提出并分析了两种自适应搜索方案，用于采集系统，这些方案的检测可能性低于螺旋扫描方法。这些方案中的第一个，即自适应螺旋搜索，通过将搜索区域分为多个较小的子区域，并优先在较高概率质量质量的区域中进行搜索，从而提供了更好的获取时间性能。第二种技术--- shot弹枪方法---通过根据高斯分布对搜索区域进行采样，以随机的方式搜索区域。自适应螺旋方案在获取时间方面优于shot弹枪方法，尤其是如果搜索子区域的数量足够大。但是，自适应螺旋搜索需要更高的指向精度才能精确搜索该区域。另一方面，shot弹枪扫描方法不需要这种严格的指向精度。
Acquisition and tracking systems form an important component of free-space optical communications due to directional nature of the optical signal. Acquisition subsystems are needed in order to search and locate the receiver terminal in an uncertainty/search region with very narrow laser beams. In this paper, we have proposed and analyzed two adaptive search schemes for acquisition systems that perform better---for the low probability of detection---than the spiral scanning approach. The first of these schemes, the adaptive spiral search, provides a better acquisition time performance by dividing the search region into a number of smaller subregions, and prioritizing search in regions of higher probability mass. The second technique---the shotgun approach---searches the region in a random manner by sampling the search region according to a Gaussian distribution. The adaptive spiral scheme outperforms the shotgun approach in terms of acquisition time, especially if the number of search subregions is large enough. However, a higher pointing accuracy is required by the adaptive spiral search in order to search the region precisely. On the other hand, the shotgun scanning approach does not require such stringent pointing accuracy.
