On the Capacity Region of Optical Intensity Broadcast Channels

• Published in: IEEE transactions on communications Vol. 72; no. 4; pp. 1967 - 1982
• Main Authors: Yang, Sufang, Li, Longguang, Wang, Jintao
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.04.2024; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Asymptotic properties; Capacity region; Channel capacity; Channels; Encoding; High-speed optical techniques; Integrated optics; intensity modulation-direct detection; optical broadcast channel; optical wireless communication; peak- or/and average-intensity constraints; Random variables; Signal to noise ratio; Wireless communication
• ISSN: 0090-6778; 1558-0857
• DOI: 10.1109/TCOMM.2023.3345384

This paper investigates the capacity region of the optical intensity broadcast channels (OI-BCs), where the input is subject to a peak-intensity constraint, an average-intensity constraint, or both. By leveraging the decomposition results of several random variables, i.e., uniform, exponential, and truncated exponential random variables, and adopting a superposition coding (SC) scheme, the inner bound on the capacity region is derived. Then, the outer bound is derived by applying the conditional entropy power inequality (EPI). In the high signal-to-noise ratio (SNR) regime, the inner bound asymptotically matches the outer bound, thus characterizing the high-SNR asymptotic capacity region. The bounds are also extended to the general <inline-formula> <tex-math notation="LaTeX">K </tex-math></inline-formula>-user BCs without loss of high-SNR asymptotic optimality.