三维射线跟踪和有限状态马尔可夫链的非空室内可见光信道表征参数

Channel Characterization Parameters of the Non-Empty Indoor Visible Light Communication Based on the Three-Dimension Ray Tracing and Finite State Markov Chain

采用三维射线追踪对非空旷室内可见光传输环境中的信道冲击响应和光源位于天花板不同位置时的均方根(RMS)时延扩展进行估算。在此基础上采用有限状态马尔可夫链对室内可见光衰落信道进行建模,得到非空室内可见光信道冲击响应的分布。研究结果表明,随机分布反射物对非视距(NLOS)传输环境的信道冲击响应的影响相比视距(LOS)传输环境要大,光源位于天花板角落时均方根时延扩展比其他位置要大,多径效应也更为明显。

By the means of three-dimension ray tracing method, the channel impulse response under the nonempty indoor visible light transmission environment and the root-mean-square（RMS） delay spread when light source locates in different positions of the ceiling are estimated. Based on this, the finite state Markov chain is used to model the indoor visible light fading channel, and the distribution of the non-empty indoor visible light channel impulse response is obtained. The results demonstrate that random distribution reflector imposes greater effects on the channel impulse response in the non- line of sight（NLOS） transmission environment than that in the line of sight（LOS） situation. Besides, the RMS delay spread is obvious when the light source locates at the corner of the ceiling instead of other positions, which means that the multipath effect is more obvious at this place.