Probabilistic Constellation Shaping for Enhancing Spectral Efficiency in NOMA VLC Systems
IEEE Transactions on Wireless Communications(2024)
摘要
The limited modulation bandwidth of the light emitting diodes (LEDs) presents
a challenge in the development of practical high-data-rate visible light
communication (VLC) systems. In this paper, a novel adaptive coded
probabilistic shaping (PS)-based nonorthogonal multiple access (NOMA) scheme is
proposed to improve spectral efficiency (SE) of VLC systems in multiuser uplink
communication scenarios. The proposed scheme adapts its rate to the optical
signal-to-noise ratio (OSNR) by utilizing non-uniformly distributed discrete
constellation symbols and low complexity channel encoder. Furthermore, an
alternate optimization algorithm is proposed to determine the optimal channel
coding rate, constellation spacing, and probability mass function (PMF) of each
user. The extensive numerical results show that the proposed PS-based NOMA
scheme closely approaches the capacity of NOMA with fine granularity. Presented
results demonstrate the effectiveness of our scheme in improving the SE of VLC
systems in multiuser scenarios. For instance, our scheme exhibits substantial
SE gains over existing schemes, namely, the pairwise coded modulation (PCM),
geometric shaping (GS), and uniform-distribution schemes. These findings
highlight the potential of our approach to significantly enhance VLC systems.
更多查看译文
关键词
NOMA,probabilistic shaping,VLC,performance analysis,spectral efficiency
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要