A low-complexity DCO-GFDM waveform for visible light communications

Abstract

Visible light communication (VLC) has recently gained significant attention due to its broad spectrum and advantages over radio frequency systems. VLC typically utilizes light-emitting diodes or laser diodes as a light source, which requires real and positive signals through intensity modulation and direct detection. Direct current-biased optical orthogonal frequency division multiplexing is a common type of modulation used in VLC. However, this technique suffers from a high peak-to-average power ratio (PAPR), which causes clipping distortions at the light source. On the other hand, generalized frequency division multiplexing (GFDM) technology offers high flexibility, high spectrum efficiency, and less out-of-band and PAPR, making it a promising technology for VLC systems but at the cost of complexity. This study proposes a novel real-signal GFDM for VLC, eliminating the need for Hermitian symmetry to reduce computational complexity. This method aims to reduce computational complexity while maintaining system performance. It significantly reduces the required number of complex multiplication and addition by lowering the IFFT/FFT size to half compared to traditional methods. The new approach reduces the complexity and size of hardware and power consumption compared to the conventional DCO-GFDM, making it a more practical solution for the next communications generations.