Perfect and imperfect successive interference cancellation for channel decoding in downlink visible light non-orthogonal multiple access network

Abstract

This paper exploits perfect and imperfect-successive interference cancellation (SIC) technique for channel decoding in downlink visible light-non-orthogonal multiple access (VL-NOMA) communication networks. A light-emitting-diode (LED) is used as a carrier transmitting signal to the two users (near- and far-user) as they are placed at different locations in the indoor environment. The power allocation technique uses power levels to effectively distribute information to the two users while the superposition coding (SC) encodes the two signals into one simultaneously. The SIC decodes the interference notice in the sub-channels until each user receives a better signal strength with the same resources (at the same time and frequency). The imperfect SIC which is a practical scenario, is experienced during the decoding process when a fraction residue at the channel-information properties is left due to an SIC error. This is because the VL channel properties uncertainty creates an interference when the NOMA is deployed with imperfect SIC to decode the signal, while the NOMA with perfect SIC is taken based on known channel pieces of information. The NOMA communication systems with imperfect SIC performs better than that of the perfect SIC in terms of bit-error-rate (BER). We have observe changes in the near-user and far-user at the channel, then SC is performed. MATLAB software tool is used for the simulation results.