In this paper, an experimental demonstration of an indoor optical wireless multiple-input-multiple-output (MIMO) system with a non-imaging receiver is proposed. The system setup consists of a 2×2 array of white light-emitting diodes (LEDs) with spacing 15cm, and a 2×2 photo-detector array with spacing 10cm. A bit rate of 2 Mb/s/channel can be achieved in this system, with bit-error rate (BER) operation at different vertical height, separating transmitter and receiver.
In order to detect the transmitted information, zero-forcing (ZF) detection and minimum-mean-square-error (MMSE) detection are utilized, analysed and compared. An overview of the design specification, optical design and experimental setup are reported in this paper, together with results and discussion of how the system might be improved.