Enhanced asymmetrically-clipped optical OFDM

TL;DR

This paper introduces a new optical OFDM method that significantly improves receiver sensitivity at high spectral efficiencies, outperforming existing techniques in unipolar optical communication channels.

Contribution

The paper proposes a novel enhanced asymmetrically-clipped optical OFDM method that achieves the highest receiver sensitivity at spectral efficiencies above 3 bit/s/Hz.

Findings

7-dB sensitivity advantage over DC-biased OFDM for 1024-QAM

Achieves high spectral efficiency above 3 bit/s/Hz

Outperforms existing methods at same bit rate and power

Abstract

Asymmetrically clipped optical orthogonal frequency-division multiplexing (ACO-OFDM) is a technique that sacrifices spectral efficiency in order to transmit an orthogonally frequency-division multiplexed signal over a unipolar channel, such as a directly modulated direct-detection fiber or free-space channel. Several methods have been proposed to regain this spectral efficiency, including: asymmetrically clipped DC-biased optical OFDM (ADO-OFDM), enhanced U-OFDM (EU-OFDM), and spectral and energy efficient OFDM (SEE-OFDM). This paper presents a new method that offers the highest receiver sensitivity for a given optical power at spectral efficiencies above 3 bit/s/Hz, having a 7-dB sensitivity advantage over DC-biased OFDM for 1024-QAM at 87.5% of its spectral efficiency, at the same bit rate and optical power.