Performance of indoor MIMO optical wireless system using linear receiver with prism array

In this paper, we analyze the performance of an indoor MIMO optical wireless system with a linear receiver. The receiver uses an array of prisms to form channel matrices that can achieve angular diversity within a compact receiver structure. The transmission of light through a prism onto a photodetecting surface is analyzed showing that the channel gain depends on the orientation of the prisms. Thus, by arranging the prisms carefully, channel matrices with full rank can be formed in a multiple LED scenario, which facilitates the use of low complexity linear de-multiplexing algorithms, including zero-forcing (ZF) and minimum mean square error (MMSE). We present bit error rate (BER) results in a typical indoor scenario. It is shown that the BER varies with the position of the receiver, with relatively high values for the receiver located at the center and near the corners of the room.