This paper considers a discrete time-Poisson noise channel which is used to model pulse-amplitude modulated optical communication with a direct-detection receiver. The goal of this paper is to obtain insights into the capacity and the structure of the capacity-achieving distribution for the channel under the amplitude constraint $\mathsf{A}$ and in the presence of dark current $\lambda$. Using recent theoretical progress on the structure of the capacity-achieving distribution, this paper develops a numerical algorithm, based on the gradient ascent and Blahut-Arimoto algorithms, for computing the capacity and the capacity-achieving distribution. The algorithm is used to perform extensive numerical simulations for various regimes of $\mathsf{A}$ and $\lambda$.

翻译：本文考虑一个离散的时间波斯松噪音频道,它用来用直接探测接收器模拟脉搏点调控光学通信。本文件的目的是了解在振幅限制下在暗流$$\lambda$的情况下,在振幅限制下频道实现能力分布的能力和结构。本文件利用能力实现分布结构的最新理论进展,根据梯度升降法和Blahut-Arimoto算法,为计算能力和能力实现分布制定了一种数字算法。该算法用于对各种制度进行广泛的数字模拟,即$\mathsf{A}和$\lambda$。