基于等效 SINR 的 VLC 与 WiFi 垂直切换算法

摘要

For the indoor visible light communication(VLC)networks,existing handoff decision algorithms couldn’t sense the real quality of service (QoS)provided by different wireless networks,so users couldn’t obtain the best wireless service.To solve the problem,this paper proposed a vertical handoff algorithm based on equivalent signal to interference plus noise ratio (SINR),which used in the VLC and WiFi heterogeneous networks.It converted VLC SINR to equivalent WiFi SINR under the condition that both reached the same maximum rate.Based on SINR conversion,first it calculated the difference between target and service network SINR,did handoff triggering according to comparison of the difference and set threshold.Then considering VLC vulnerability to shadow,it introduced a timer to help to make handoff decision.Experimental results show that the algo-rithm can ensure users always get the maximum rate and have desired adaptability for different VLC network layout and indoor light environment,which makes it more applicable to the indoor visible light communication heterogeneous networks.%针对室内可见光异构通信网络中，现有切换算法无法感知不同网络服务质量、不能保证用户始终获得最优网络服务的问题，提出一种基于等效 SINR 的 VLC（visible light communication，可见光通信）与 WiFi 垂直切换算法。算法将达到相同最大传输速率作为转换条件，将 VLC SINR 转换为等效的 WiFi SINR，在此基础上实现切换触发和判决。根据目标网络和服务网络 SINR 差值与设定切换门限的对比结果进行切换触发，考虑到 VLC易受遮挡干扰影响的特点，引入驻留定时器进行切换判决，保证判决准确性。仿真实验表明，该切换算法能保证用户接入到提供最大传输速率的网络中，并且对于不同 VLC 网络布设和室内光环境影响都具有较好的适应性，更加适合室内融合 VLC 异构通信网络。