Low-Complexity Receiver for HACO-OFDM in Optical Wireless Communications

In this letter, a low-complexity receiver (Rx) is proposed for hybrid asymmetrically clipped optical orthogonal frequency division multiplexing (HACO-OFDM). Owing to the special time-domain property of HACO-OFDM, overlaid asymmetrically clipped OFDM (ACO-OFDM) and pulse-amplitude-modulated discrete multitoned (PAM-DMT) signals can be distinguished in the time domain to reduce its computational complexity. Besides, the near-optimal optical power allocation is further applied to optimize the proposed system performance. Theoretical analysis and simulation results demonstrate that, the proposed Rx can achieve nearly the same bit error rate (BER) performance as the BER-optimal iterative Rx but with an effective complexity reduction, thus demonstrating its application potential in high-speed optical communication systems.