Dispersive Optical Wireless Indoor Channels—From Frequency-Domain Modeling to Bit-Error-Rate Prediction

Methods for calculating the impulse response of dispersive optical wireless channels have been known for a long time. However, a comprehensive procedure for predicting resulting bit error rates, starting from a highly accurate channel emulation method, has not yet been presented. To fill this gap, we propose a methodology for modeling realistic dispersive optical wireless channels that can be used directly for corresponding bit error rate simulations. The importance of proper power normalization of the multipath components is emphasized. Moreover, the optical channel model is embedded in an end-to-end electrical channel model suitable for intensity-modulation/direct detection schemes under linear operation. To significantly reduce the simulation time, a so-called chip-rate model is presented. Finally, based on the proposed modeling approach for dispersive channels, bit error rate simulations are performed for selected intensity modulation schemes with and without equalization at the receiver and are compared within a common and consistent framework.