Photon counting detectors such as single-photon avalanche diode (SPAD) arrays can be employed to achieve reliable optical wireless communication at power limited regimes. However, SPAD-based receivers suffer from significant dead-time induced intersymbol interference (ISI) especially when the incident photon rate is relatively high and the dead time is comparable or even larger than the symbol duration, i.e., sub-dead-time regime. In this work, we propose a novel time-gated SPAD receiver to mitigate such ISI effects and improve the communication performance. When operated in the gated mode, the SPAD can be activated and deactivated in well-defined time intervals. We investigate the statistics of the detected photon count for the proposed time-gated SPAD receiver. It is demonstrated that the gate-ON time interval can be optimized to achieve the best bit error rate (BER) performance. Our extensive performance analysis illustrates the superiority of the time-gated SPAD receiver over the traditional free-running receiver in terms of the BER and data rate performance and the tolerance to background light.

中文翻译：

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用于光无线通信的时间选通光子计数接收器


可以采用单光子雪崩二极管 (SPAD) 阵列等光子计数探测器在功率有限的情况下实现可靠​​的光学无线通信。然而，基于SPAD的接收器遭受显着的死区时间引起的符号间干扰(ISI)，特别是当入射光子率相对较高且死区时间与符号持续时间相当或什至更大时，即子死区时间状态。在这项工作中，我们提出了一种新颖的时间选通 SPAD 接收器来减轻这种 ISI 影响并提高通信性能。当在门控模式下操作时，SPAD 可以在明确定义的时间间隔内激活和停用。我们研究了所提出的时间选通 SPAD 接收器检测到的光子计数的统计数据。结果表明，可以优化选通时间间隔以实现最佳误码率 (BER) 性能。我们广泛的性能分析表明，时间选通 SPAD 接收器在 BER 和数据速率性能以及背景光耐受性方面优于传统的自由运行接收器。