针对可见光通信(VLC)下行链路存在多接入点(AP)重叠覆盖、VLC AP光路易被遮挡和干扰的问题,提出了一种基于服务质量(QoS)决策的异构VLC/无线保真(WiFi)网络联合收发端需求的接入点选择算法。该算法在收端为用户建立面向QoS的加权信息矩阵,为用户偏好提供高信干噪比、高接收功率、低负载、低历史中断概率的VLC AP;在发端为VLC AP偏好选择抗干扰性强的用户服务。基于引力理论改进收发端选择权重值,优化用户的AP接入决策。仿真结果表明:该算法在方形均匀布局和混合圆方形布局中比现有算法的吞吐量分别增大了77.3%和11.4%,业务公平性分别减小了53.1%和41.1%。

Visible light communication (VLC) is prone to overlap coverage of the adjacent VLC access points (APs), receiver occlusion, and light path interference. This study develops an AP selection algorithm for heterogeneous VLC/wireless fidelity (WiFi) networks. By considering the joint demands of transmitting and receiving, the algorithm employs a quality-of-service (QoS)-based decision-making to satisfy the differentiated resource demands of the receiving end and the transmitting equipment. First, it designs a QoS-oriented weighted information matrix for each receiver and guides the user to select the VLC AP with high received signal-to-interference-and-noise ratio, high received power, low traffic load, and low historical interruption probability. Guided by the same algorithm, the selected VLC AP preferentially serves users with strong anti-interference. Finally, to optimize the AP access, we improve the weights of the APs and users based on gravitation theory. In simulations on a uniform square layout and a mixed circular-square layout, the proposed algorithm delivers 77.3% and 11.4% more throughput respectively than the existing algorithms, and reduces the service fairness index by 53.1% and 41.1%, respectively.