Ray tracing based channel modeling for visible light communications

In this paper, we characterize visible light communication channels through Zemax®13 software. In our approach, we create a three dimensional indoor environment with specified dimensions in Zemax® and integrate the lighting source (i.e., LED). Using the ray tracing features of Zemax®, we compute the received optical power and the delays of direct/indirect rays. This information is then imported into Matlab® and the corresponding channel impulse response (CIR) for that environment is obtained through proper normalizations. Following this methodology, we present CIRs for a number of rooms with different sizes assuming different transmitter/receiver locations and quantify channel parameters such as mean excess delay, RMS delay spread and DC gain.