Importance of Amplifier Physics in Maximizing the Capacity of Submarine Links
Importance of Amplifier Physics in Maximizing the Capacity of Submarine Links
复制标题
放大器物理对于最大化海底链路容量的重要性
DOI：
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发表时间：
2018
影响因子：
4.7
通讯作者：
K. Bennett
中科院分区：
文献类型：
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作者：
J. K. Perin;J. Kahn;J. Downie;J. Hurley;K. Bennett
海底传输电缆的吞吐量正在接近放大器噪声和克尔非线性所施加的基本限制。超长海底链路的能量限制加剧了这个问题，因为每根光纤的吞吐量进一步受到海底光放大器可用电功率的限制。最近的工作研究了如何利用更多的空间维度来减轻这些限制。在本文中，我们解决了如何最佳地使用每个空间维度的基本问题。具体来说，我们讨论如何优化信道功率分配，以便在电功率约束下最大化信息论容量。我们的公式考虑了放大器物理特性、克尔非线性和供电约束。虽然最近的工作假设光放大器在深度饱和状态下工作，其中功率转换效率（PCE）较高，但我们表明，在给定功率限制的情况下，在较不饱和的状态下工作（PCE较低），支持更宽的带宽和更多的空间维度，从而最大化容量。与最近提出的高容量系统的理论容量相比，这种设计策略将海底链路的容量提高了约 70%。
The throughput of submarine transport cables is approaching fundamental limits imposed by amplifier noise and Kerr nonlinearity. Energy constraints in ultra-long submarine links exacerbate this problem, as the throughput per fiber is further limited by the electrical power available to the undersea optical amplifiers. Recent works have studied how employing more spatial dimensions can mitigate these limitations. In this paper, we address the fundamental question of how to optimally use each spatial dimension. Specifically, we discuss how to optimize the channel power allocation in order to maximize the information-theoretic capacity under an electrical power constraint. Our formulation accounts for amplifier physics, Kerr nonlinearity, and power feed constraints. Whereas recent works assume that the optical amplifiers operate in deep saturation, where power conversion efficiency (PCE) is high, we show that given a power constraint, operating in a less saturated regime, where PCE is lower, supports a wider bandwidth and a larger number of spatial dimensions, thereby maximizing capacity. This design strategy increases the capacity of submarine links by about 70% compared to the theoretical capacity of a recently proposed high-capacity system.