DocumentCode :
74096
Title :
Iterative Receiver for Hybrid Asymmetrically Clipped Optical OFDM
Author :
Qi Wang ; Zhaocheng Wang ; Linglong Dai
Author_Institution :
Dept. of Electron. Eng., Tsinghua Univ., Beijing, China
Volume :
32
Issue :
22
fYear :
2014
fDate :
Nov.15, 15 2014
Firstpage :
4471
Lastpage :
4477
Abstract :
This paper proposes an iterative receiver to enhance the performance of hybrid asymmetrically clipped optical orthogonal frequency division multiplexing (HACO-OFDM) in optical wireless communication systems. In HACO-OFDM scheme, asymmetrically clipped optical OFDM (ACO-OFDM) and pulse-amplitude-modulated discrete multitone (PAM-DMT) signals are transmitted simultaneously, which is more spectrally efficient compared with ACO-OFDM and PAM-DMT. However, the existing HACO-OFDM receiver directly recovers the signals in the frequency domain, which could not eliminate the interference thoroughly between ACO-OFDM and PAM-DMT signals and limits its performance. In our proposed receiver, the ACO-OFDM and PAM-DMT signals are detected in the frequency domain and regenerated in the time domain. After that, they are subtracted from the received signals iteratively. Thus, ACO-OFDM and PAM-DMT signals can be distinguished. By taking advantage of the signal symmetry properties of ACO-OFDM and PAM-DMT in the time domain, pairwise clipping is utilized to further reduce the effect of noise and estimation error, resulting in improved performance. In addition, unequal power allocation is proposed to guarantee that ACO-OFDM and PAM-DMT signals have similar performance in HACO-OFDM systems. Simulation results show that the proposed method provides significant signal-to-noise ratio gain over the conventional receiver for both equal and unequal power allocations at the cost of slightly increased complexity.
Keywords :
OFDM modulation; frequency-domain analysis; optical communication; optical modulation; optical receivers; optical signal detection; pulse amplitude modulation; time-domain analysis; HACO-OFDM scheme; PAM-DMT; estimation error; frequency domain; hybrid asymmetrically clipped optical orthogonal frequency division multiplexing; iterative receiver; noise effect; optical wireless communication systems; pairwise clipping; pulse-amplitude-modulated discrete multitone signal detection; signal symmetry properties; signal-to-noise ratio gain; time domain; unequal power allocation; Bit error rate; Frequency-domain analysis; Noise; OFDM; Receivers; Resource management; Time-domain analysis; Asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM); hybrid asymmetrically clipped optical orthogonal frequency division multiplexing (HACO-OFDM); iterative receiver; optical wireless communications; pulse-amplitude-modulated discrete multitone (PAM-DMT);
fLanguage :
English
Journal_Title :
Lightwave Technology, Journal of
Publisher :
ieee
ISSN :
0733-8724
Type :
jour
DOI :
10.1109/JLT.2014.2358611
Filename :
6901211
Link To Document :
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