In this work, a receiver architecture for the detention of on-off-keying (OOK) signals using adaptive signal estimation and threshold setting for free-space optical communications is investigated. It is assumed that the received signal is impaired by channel fading, modeled using Málaga (M) distribution, and an imperfect pointing acquisition. In OOK communications, knowledge of the received signal is required to set the optimum receiver threshold. To that end, a linear estimation technique is utilized to estimate the combined impact of the residual pointing error and channel fading. The performance of the resulting receiver is evaluated and is compared with those of a receiver in which the channel and pointing impairments are ignored and with a receiver in which the channel and pointing impacts are replaced by the statistical averages of those impairments. It is shown that, for reasonable system parameters, the proposed receiver offers a significant improvement in performance in terms of the overall bit error rate (BER) when compared with its alternatives. For a scenario in which a significant pointing error is present, it is observed that channel estimation does not offer a benefit in terms of the overall BER.

中文翻译：

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用于开关键控自由空间光通信的接收器架构，在存在残余空间跟踪误差的情况下进行信道估计

在这项工作中，研究了一种使用自由空间光通信的自适应信号估计和阈值设置来滞留开关键控（OOK）信号的接收器架构。假设接收信号因信道衰落而受损，使用 Málaga (M) 分布建模，并且指向采集不完美。在 OOK 通信中，需要了解接收信号才能设置最佳接收器阈值。为此，利用线性估计技术来估计残余指向误差和信道衰落的组合影响。对所得接收器的性能进行评估，并将其与忽略信道和指向损伤的接收器以及用这些损伤的统计平均值代替信道和指向影响的接收器进行比较。结果表明，对于合理的系统参数，与替代方案相比，所提出的接收器在整体误码率 (BER) 方面的性能有了显着提高。对于存在显着指向误差的情况，可以观察到信道估计在整体 BER 方面没有提供任何好处。