Low-complexity subcarrier-grouping scheme for adaptive resource allocation in multi-user OFDM-NOMA VLC systems

We propose what is believed to be a novel low-complexity subcarrier-grouping scheme for adaptive resource allocation in multi-user orthogonal frequency division multiplexing non-orthogonal multiple access (OFDM-NOMA) visible light communication (VLC) systems. A new, to the best of our knowledge, metric is proposed to evaluate the similarity between subcarriers that carry multiple users with interference between users, while the landmark multi-dimensional scaling technique and the K-means algorithm are employed to categorize similar subcarriers into groups. In this way, all subcarriers within a group can be treated as a single resource unit in adaptive resource allocation. We validate the proposed approach in an SDN-controlled multi-user VLC system with a real-time transmitter. Experimental results show that the proposed method greatly reduces complexity while achieving better or comparable performance to existing methods.