Ren Hao, Wang Zixiong, Du She, He Yuxuan, Chen Jian, Han Shiying, Yu Changyuan, Xu Chao, Yu Jinlong
Opt Express. 2018 Nov 12;26(23):29796-29806. doi: 10.1364/OE.26.029796.
Non-orthogonal multiple access (NOMA) can increase the overall spectral efficiency of visible light communication (VLC) system. In this paper, we proposed a novel scheme to improve the bit error rate (BER) performance of a two-user NOMA VLC system by adjusting superposition constellation. The corresponding closed-form BER expressions are derived. Convex optimization is used to find the optimal parameters of the adjusted superposition constellation, where the overall BER is minimized. The BER performances are evaluated by theoretical analysis, Monte-Carlo (MC) simulation and experiment. The results illustrate that 8.9-dB and 8.1-dB signal-to-noise ratios (SNRs) are reduced to achieve BER of 10 for the two users, whose power allocation coefficients are 0.6 and 0.4, respectively.
非正交多址接入（NOMA）能够提高可见光通信（VLC）系统的整体频谱效率。在本文中，我们提出了一种新颖的方案，通过调整叠加星座来改善两用户NOMA VLC系统的误码率（BER）性能。推导了相应的闭式BER表达式。利用凸优化来寻找调整后的叠加星座的最优参数，使整体BER最小化。通过理论分析、蒙特卡洛（MC）仿真和实验对BER性能进行了评估。结果表明，对于功率分配系数分别为0.6和0.4的两个用户，为实现BER为10，信噪比（SNR）分别降低了8.9 dB和8.1 dB。
