Comparison of optical OFDM-IDMA and optical OFDMA for uplink visible light communications

In this paper we compare two candidate multiple access schemes for visible light communications (VLC), namely, optical orthogonal frequency division multiplexing interleave division multiple access (O-OFDM-IDMA) and optical orthogonal frequency division multiple access (O-OFDMA). Both of them belong to multicarrier transmission schemes and are tailored for VLC channels by asymmetrically clipping at zero after OFDM modulation. We compare their bit error rate (BER) performance, receiver complexities as well as peak-to-average power ratios (PAPRs) in different scenarios. Simulations show that O-OFDM-IDMA is more power efficient than O-OFDMA, especially for higher throughput, at the cost of higher computational complexity. The PAPRs of O-OFDM-IDMA and O-OFDMA do not show much difference. Those results provide a useful guidance for the design of future networks based on VLC.