On the performance of Space Shift Keying for optical wireless communications

In this paper, we study the performance of Space Shift Keying (SSK) modulation applied to optical wireless channels. The optical Multiple-Input-Single-Output (MISO) channel used here is obtained through measurements. The experimental setup consists of two lasers and an optical receiver. Using the channel measurements, the performance of SSK is compared to the Single-Input-Single-Output (SISO) transmission case. We build upon a recent finding, obtained for a two-transmitter case, that power imbalance at the transmitters can enhance the performance of SSK, especially in highly correlated channels [1]. It is found in this paper that SSK applied to real optical wireless channels outperforms SISO and Single-Input-Multiple-Output (SIMO) transmission if more than four optical transmitters are used. Furthermore, we show that Space Shift Keying can also exceed Multiple-Input-Multiple-Output (MIMO) setups which apply repetition coding as SSK exploits receive-diversity in a better way.