Coordinated Multi-channel Transmission Scheme for Indoor Multiple Access Points VLC Networks

Visible Light Communications (VLC) is considered as an effective complementary solution for indoor wireless communications to achieve high-speed and secure data transmission. Instead of using RF bandwidth, VLC uses the visible light spectrum to perform lighting and communications functions simultaneously. In a large indoor environment, a multiple ceiling access point VLC network (multi-CAP VLC) is deployed to achieve seamless coverage and high spectral efficiency. In the multi-CAP VLC network, random movement of user equipment (UE) leads to an uneven load distribution between CAPs. Furthermore, the quality of service of cell-edge users who reside at cell edge areas is decreased due to the high attenuation of the received signal. In the paper, to improve the QoS of cell-edge UEs, we propose a coordinated multi-channel transmission scheme (CMcT) for indoor multi-CAP VLC networks. The CMcT performs a coordinated downlink data transmission from different CAPs to a UE simultaneously. Performance results obtained by computer simulation show that the CMcT scheme can significantly improve user throughput and packet delay comparing with those of the single-channel transmission scheme.