1. Geometric constellation shaping for wireless optical intensity channels
- Author
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Zhou, Suhua, Li, Tianqi, Fang, Zhaoxi, Zhou, Jing, and Zhang, Wenyi
- Subjects
Computer Science - Information Theory - Abstract
A simple geometric shaping method is proposed for optical wireless communication systems based on intensity modulation and direct detection (IM/DD). Constellations consisting of equiprobable levels with exponential-like distribution are obtained. The method possesses asymptotic optimality in the sense that the high-SNR channel capacity can be approached by such constellations with increasing size. By an additional quantization step, all $2^b$ levels ($b \in \mathbb N$) of the obtained constellation can be represented by a basic level and $b+2$ bits, thereby reducing the required resolution of the digital-to-analog converter (DAC) without affecting the asymptotic optimality. Achievable information rate evaluations verify the asymptotic optimality of the proposed method. As an example, error performance results of a simple 16-level LDPC coded modulation scheme show that a shaping gain of 0.8 dB can be obtained by applying the proposed constellation design., Comment: An error in simulation is found and fixed. Fig. 4 is subsequently updated
- Published
- 2024