In optical wireless communications, a broadcast channel (BC) employing intensity modulation and direct detection (IM/DD) is often modelled as a peak-constrained BC. A closed-form expression for its capacity region of the peak-constrained BC is not known. This paper presents an analytical capacity inner bound for the peak-constrained Gaussian BC achieved by a class of discrete input distribution, specifically, the evenly-spaced discrete uniform distribution (ESDU). In contrast to the continuous input distribution that provides the benchmark, ESDU is more promising in the application of peak-constrained Gaussian channels. The newly obtained capacity inner bound is easily-computable and is numerically shown to be tighter than the benchmark. Besides, we remark the newly developed analytical upper bound for the ESDU rate, which is tight in all tested settings.

翻译：在光学无线通信中,使用强度调制和直接探测(IM/DD)的广播频道(BC)通常仿照受限制的不列颠哥伦比亚峰值。尚不清楚其受限制的不列颠峰容量区域的封闭式表达方式。本文展示了通过一组离散输入分布,具体来说是平空的离散统一分布(ESDU)实现的受峰值限制的高斯混凝土不列颠哥伦比亚峰值的封闭式传输频道(BC)的内部分析能力。与提供基准的连续输入分布相比,ESDU在应用受峰值限制的高斯海峡频道方面更有希望。新获得的容量内装能力易于计算,在数字上显示比基准更紧。此外,我们评论新开发的ESDU标准分析上限,该比率在所有测试环境下都很紧紧。