Evaluation of Conventional and Imaging MIMO OWC Systems Using Linear Array Design

Abstract

Multiple-input-multiple-output (MIMO) optical wireless communication systems are potential candidates for high-speed data transmission in indoor environments. In this work, we present an experimental evaluation of two different MIMO systems, i.e., conventional-MIMO (c-MIMO) and imaging-MIMO (i-MIMO) in terms of design considerations. Both systems use the same transmitter configuration featuring a one-dimensional (light-emitting diode) LED transmitting array. On the receiver side, the c-MIMO system employs a similar one-dimensional receiving avalanche photodetector (APD)-based array, whereas the i-MIMO system uses a customized imaging camera-based receiver design. To assess the performance of the two systems, the channel matrix and the bit-error rate are calculated based on the experimental data. At distances shorter than 50 m, the proposed c-MIMO system demonstrates a good transmission performance, particularly when the maximum likelihood detection (MLD) technique is applied. Whereas, at long distances ranging from 40 m to 65 m, the proposed i-MIMO system can ensure an error-free transmission due to the efficient spatial separation between the emitted optical beams. Furthermore, the experimental results confirm that our systems have the potential for high data rates over longer distances in indoor environments.

Real-time UWOC miniaturized system based on FPGA and LED arrays and its application in MIMO

“…The system improves the frequency spectrum utilization and the throughput of the system by means of the spatial multiplexing, which can solve the problem of original low bandwidth of commercial high-power LED array light sources under SISO scheme. Previous studies have shown that the imaging MIMO-UWOC has lower spatial correlation than the non-imaging MIMO-UWOC, so that it can achieve higher multiplexing gain [26] .…”