Design and Analysis of an Integrated NOMA-VLPC System: Achieving Positioning via DC and Communication via AC

An integrated visible light positioning and communication (VLPC) system has been proposed on the basis of non-orthogonal multiple access (NOMA), in which the direct current (DC) and alternating current (AC) components of the signal are adopted for positioning and communication, respectively. Specifically, biphase coding, majority vote, and two-stage positioning strategies are introduced to mitigate message randomness, receiver noise, and fingerprinting errors. Besides, the achievable sum rate and energy efficiency (EE) are obtained, and the optimal DC power setting is derived to achieve the best communication performance. Results show that the positioning accuracy improves with the number of light-emitting diodes (LEDs) and as user moves closer to the room center, follows an inverted U-shaped trend with user height, and could achieve the same accuracy as the AC-based positioning method using metaheuristic algorithms but in less time. Moreover, under perfect and imperfect successive interference cancellation (pSIC/ipSIC), both the system sum rate and EE initially increase with DC power and then decrease. A small-scale experiment is also carried out to verify the proposed DC-based positioning method. This work offers a good reference for VLPC system research.