Impact of Receiver Orientation on OLED-based Visible-Light D2D Communications

The use of organic light emitting diodes (OLEDs) is being growing in public places, mobile phones, and wearable smartwatches and computers, which facilitate simultaneous illumination, display, and data communications. Therefore, there is a high demand to model the OLED-based visible light communications (VLC) channel in device-to-device (D2D) communications. This paper proposes D2D communications where the information data is transmitted via the smartphone's display pixels and received using the built-in cameras of another smartphone. The impact of the receiver orientation on the channel characteristics is investigated, where two static users face each other and the receiver is intentionally oriented towards the transmitter. It is shown that, in an empty room, the range of delay spreads are around 6 to 7.5 ns and 6 to 10 ns when the distances of the transmitter from the wall are 1.5 and 7.5 m, respectively. Furthermore, in a furnished room, there is a drop in the delay spread at the cost of increased optical path loss compared to the empty room.