Iterative Symbol Recovery For Power Efficient DC Biased Optical OFDM Systems

TL;DR

This paper introduces an iterative symbol recovery method for power-efficient DCO-OFDM in optical communications, reducing power consumption and improving noise immunity while maintaining reliable data transmission.

Contribution

It presents a novel clipping technique and iterative detection algorithm that significantly lowers optical power and enhances noise resilience in DCO-OFDM systems.

Findings

50% reduction in transmitted optical power

3 dB SNR gain over traditional methods

Achieves SER of 10^{-3} in AWGN channel

Abstract

Orthogonal frequency division multiplexing (OFDM) has proven itself as an effective multi-carrier digital communication technique. In recent years the interest in optical OFDM has grown significantly, due to its spectral efficiency and inherent resilience to frequency-selective channels and to narrowband interference. For these reasons it is currently considered to be one of the leading candidates for deployment in short fiber links such as the ones intended for inter-data-center communications. In this paper we present a new power-efficient symbol recovery scheme for dc-biased optical OFDM (DCO-OFDM) in an intensity-modulation direct-detection (IM/DD) system. We introduce an alternative method for clipping in order to maintain a non-negative real-valued signal and still preserve information, which is lost when using clipping, and propose an iterative detection algorithm for this method. A reduction of $50\%$ in the transmitted optical power along with an increase of signal-independent noise immunity (gaining $3$[dB] in SNR), compared to traditional DCO-OFDM with a DC bias of $2$ standard deviations of the OFDM signal, is attained by our new scheme for a symbol error rate (SER) of $10^{-3}$ in a QPSK constellation additive white gaussian noise (AWGN) flat channel model.