Pergoloni Stefano, Biagi Mauro, Cusani Roberto, Scarano Gaetano
Opt Express. 2018 Aug 6;26(16):19750-19761. doi: 10.1364/OE.26.019750.
In the emerging framework of visible light communications, the limitation of modulation bandwidth of light emitting diodes (LEDs) transmitters is counterbalanced by the use of red-green-blue (RGB) LEDs since they exhibit higher modulation bandwidth. Using RGB LEDs allows to exploit the spatial multiplexing aspects, that is obtaining parallel channels for transmission. In this context, we used at the receiver RGB-tuned photodiodes (PDs). Hence each PD can, in principle, detect only the information its tuning is matched to. The drawback of increasing spectral efficiency is the presence of cross-talk at the single PD due to the signals emitted by the remaining colors when a perfect color filtering is not applied. In this paper we consider amplitude shift keying (ASK) modulation, investigate the issue of the spatial (color) interference and we present a blind multichannel adaptive equalizer able to mitigate the temporary intersymbol interference (ISI) and also the spatial (color) ISI, this latter partially suppressed using suitable color filters. We analyze also the convergence of the adaptive algorithm and compare its performance with the literature.
在新兴的可见光通信框架中，由于红-绿-蓝（RGB）发光二极管（LED）发射器具有更高的调制带宽，其调制带宽的限制可通过使用RGB LED来平衡。使用RGB LED能够利用空间复用特性，即获得并行传输通道。在此背景下，我们在接收器处使用了RGB调谐光电二极管（PD）。因此，原则上每个PD只能检测其调谐所匹配的信息。当未应用完美的颜色滤波时，由于其余颜色发出的信号，提高频谱效率的缺点是单个PD处存在串扰。在本文中，我们考虑幅度键控（ASK）调制，研究空间（颜色）干扰问题，并提出一种盲多通道自适应均衡器，该均衡器能够减轻临时符号间干扰（ISI）以及空间（颜色）ISI，后者通过使用合适的颜色滤波器得到部分抑制。我们还分析了自适应算法的收敛性，并将其性能与文献进行比较。
