In many practical scenarios, single-photon avalanche diodes (SPADs) are good solutions to improve the performance of optical communication systems due to their high sensitivity to photon arrival. SPAD receivers can be implemented in large arrays to achieve higher data rates and additional protection against background light; however, they suffer from a significant intersymbol interference (ISI) if the SPAD dead time is comparable or larger than the symbol duration, i.e., sub-dead-time signal transmission. This work proposes a novel detection scheme designed for high-speed SPAD-based systems to effectively mitigate the degradation induced by ISI. Different from traditional receivers, in the proposed scheme, the information extracted from both the counts and arrival times of photons are utilised for the optimal symbol detection in the presence of non-linear and random ISI effect due to dead time. Our extensive numerical and experimental results demonstrate the superiority of the proposed photon time information based detection (PTID) scheme in terms of both BER performance and background light tolerance of the communication link. In addition, a linear approximation of the SPAD-based channel is investigated, which illustrates that the traditional equalization methods are effective under some specific circumstances.

中文翻译：

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用于亚死区信号传输的最佳光子计数接收器

在许多实际场景中，单光子雪崩二极管（SPAD）由于对光子到达的高灵敏度而成为提高光通信系统性能的良好解决方案。SPAD 接收器可以在大型阵列中实施，以实现更高的数据速率和额外的背景光保护；然而，如果SPAD死区时间可比或大于符号持续时间，即子死区时间信号传输，则它们会遭受显着的符号间干扰(ISI)。这项工作提出了一种新的检测方案，专为基于高速 SPAD 的系统设计，以有效减轻 ISI 引起的退化。与传统接收器不同，在所提出的方案中，在存在非线性和随机 ISI 效应的情况下，从光子的计数和到达时间中提取的信息被用于最佳符号检测。我们广泛的数值和实验结果证明了所提出的基于光子时间信息的检测 (PTID) 方案在通信链路的 BER 性能和背景光耐受性方面的优越性。此外，研究了基于SPAD的信道的线性近似，这说明传统的均衡方法在某些特定情况下是有效的。我们广泛的数值和实验结果证明了所提出的基于光子时间信息的检测 (PTID) 方案在通信链路的 BER 性能和背景光耐受性方面的优越性。此外，研究了基于SPAD的信道的线性近似，这说明传统的均衡方法在某些特定情况下是有效的。我们广泛的数值和实验结果证明了所提出的基于光子时间信息的检测 (PTID) 方案在通信链路的 BER 性能和背景光耐受性方面的优越性。此外，研究了基于SPAD的信道的线性近似，这说明传统的均衡方法在某些特定情况下是有效的。