Visible Light Communication System Employing Space Time Coded Relay Nodes and Imaging Receivers

In this paper, authors propose a VLC system, whose source of information is assumed to be a power line, and employs a combination of relaying and multiple-input multiple-output (MIMO) techniques. Precisely, the performance of a VLC system, with relay nodes equipped with a MIMO technique called space time block coding (STBC), is investigated. The bit error rate (BER) performance of the Alamouti coding (AC) scheme, which is a type of STBC, is specifically considered. In order to enhance the overall system reliability, we propose to use an imaging receiver (ImR), in conjunction with the relay-MIMO setup. In comparison to when a nonimaging receiver (NImR) is employed, an improved signal-to-noise ratio (SNR) of 7 dB is observed when an ImR with a specific number of pixels, is used, hence, improving the BER. We also investigate and show that the selected number of pixels and receiver location have an effect on the system BER. SNR values of 9 dB, 11 dB and 15 dB were required to maintain a BER of 10⁻⁴ for imaging receivers with 70, 50 and 20 pixels, respectively.