Optical Energy-Constrained Slot-Amplitude Modulation for Dimmable VLC: Suboptimal Detection and Performance Evaluation
Optical Energy-Constrained Slot-Amplitude Modulation for Dimmable VLC: Suboptimal Detection and Performance Evaluation
复制标题
可调光 VLC 的光能量约束缝隙幅度调制：次优检测和性能评估
DOI：
10.1109/twc.2020.3034584
复制
发表时间：
2021
影响因子：
10.4
通讯作者：
Bui T
中科院分区：
文献类型：
--
作者：
Bui T
能量约束槽幅调制（ECSAM）可以实现光调光，消除光闪烁并限制峰值光功率，同时提供稳健的通信链路。然而，基于最大似然（ML）的ECSAM接收机的复杂性随着所需的频谱效率呈指数增长。在真实光照约束和不完全信道估计条件下，对室内多径可见光通信（VLC）信道的ECSAM进行了综合性能评价。提出了一种次优接收算法，该算法采用逐插槽检测算法和插槽校正机制来降低接收复杂度。此外，还提出了设计信号波形时参数的优化选择方法。利用联合界技术导出了ECSAM码元错误率的解析上界。结果表明，次优接收机的误差性能与最优ML接收机相当。与传统的功率或带宽高效VLC调制技术（如多脉冲位置调制（MPPM）和脉冲幅度调制（PAM））相比，ECSAM提供了完全的灵活性，可以修改信号群以达到所需的调光水平，从而最大化频谱效率，并提供鲁棒的误码率性能，特别是在多径传播信道诱导的码间干扰中。
Energy-constrained slot-amplitude modulation (ECSAM) enables light dimming, eliminates light flicker and constrains the peak optical power while providing robust communication links. However, the complexity of the maximum-likelihood (ML) based ECSAM receiver increases exponentially with required spectral efficiency. This paper provides a comprehensive performance evaluation of ECSAM for the indoor visible light communication (VLC) channel with multipath propagation under realistic illumination constraints and imperfect channel estimation. A sub-optimal receiver that employs a slot-by-slot detection algorithm followed by a slot-correction mechanism for reducing the receiver complexity is proposed. Additionally, the method for optimal selection of parameters when designing the signal waveform is presented. The analytical upper bound on the symbol error rate of ECSAM is derived using the union-bound technique. The results show that the error performance of the sub-optimal receiver are comparable to that of the optimal ML receiver. Compared with conventional power or bandwidth efficient VLC modulation techniques such as multiple pulse position modulation (MPPM) and pulse amplitude modulation (PAM), ECSAM provides complete flexibility in modifying the signal constellation for a desired dimming level to maximise the spectral efficiency and provide a robust bit error rate performance especially in the multipath propagation channel induced intersymbol interference.