Analysis of the single-fft receiver for layered aco-ofdm in visible light communications

Abstract

Layered asymmetrically clipped optical orthogonal frequency division multiplexing (LACO-OFDM) has a high spectral efficiency. However, an iterative detection with a pair of fast Fourier transform (FFT) and inverse fast Fourier transform (IFFT) is required for LACO-OFDM, which increases the complexity for the receiver of LACO-OFDM. In this paper, the performance of the receiver with a single FFT is analyzed for LACO-OFDM in visible light communications. In the single-FFT receiver, the different layers of ACO-OFDM signals are distinguished in time domain without the FFT/IFFT pair. Because only one FFT is employed in the proposed receiver, the complexity of O(Nlog2N) can be achieved, which is much lower than the complexity of the conventional LACO-OFDM receiver. Simulation results illustrate that the proposed scheme has a signal-To-noise ratio (SNR) penalty of 1dB ∼ 3dB compared with the conventional solution in additive white Gaussian noise (AWGN) channel. However, the proposed receiver outperforms conventional LACO-OFDM solution in light emitting diode (LED) nonlinearity channel.