Applying NOMA to Undersampled Optical Camera Communication for Vehicular Communication

Abstract

Visible Light Communications (VLC) is being developed as an alternative to radio frequency (RF) communication for vehicular applications. It has the advantages of high signal-to-noise ratio (SNR), limited interference due to line-of-sight transmission and dual use of existing hardware (LED lights and cameras) on most modern vehicles. Camera based receivers typically sample light signals at a much slower rate than the frequency at which they are modulated by LED-based transmitters. To address the aliasing due to sampling at sub-Nyquist rate, a range of undersampled encoding methods have been proposed. A common disadvantage of these proposals has been a data rate on the order of ten bits per second, which is too low for most applications. This paper investigates the use of Non-Orthogonal Multiple Access(NOMA) to leverage the high SNR and increase the data rate for undersampled Optical Camera Communication (OCC). A significant increase in data rate can be achieved at the cost of some tradeoff in SNR. Further increase in data rate is possible when used in conjunction with other methods such as Wavelength Division Multiplexing, polarisation and MIMO arrays.