SSMI cancellation in direct-detection optical OFDM with novel half-cycled OFDM

Fan Li,Jianjun Yu,Xinying Li,Z Cao,Lin Chen

doi:10.1364/oe.21.028543

Abstract

Half-cycled DDO-OFDM transmission and reception was successfully demonstrated to resist SSMI without spectra efficiency reduction for the first time. The receiver sensitivity was improved by 2 and 1.5 dB in QPSK and 16QAM OFDM with 40-km SSMF-28 transmission, respectively.

Highlights

Optical orthogonal frequency division multiplexing (OFDM) has attracted lots of attention due to its high spectral efficiency (SE) and robustness to transmission impairments enabled by digital signal processing (DSP) [1,2,3,4,5,6,7,8]
The BER performance demonstrates that the receiver sensitivity was improved by 2 dB both at optical back to back (OBTB) and after 40km standard singlemode fiber-28 (SSMF-28) transmission after subcarrier– subcarrier mixing interference (SSMI) cancellation with half-cycled OFDM compared to traditional OFDM signal
The receiver sensitivity was improved by 1.5 dB both at OBTB and after 40-km SSMF-28 transmission after SSMI cancellation with half-cycled OFDM compared to traditional OFDM signal

Summary

Introduction

Optical orthogonal frequency division multiplexing (OFDM) has attracted lots of attention due to its high spectral efficiency (SE) and robustness to transmission impairments enabled by digital signal processing (DSP) [1,2,3,4,5,6,7,8]. As reported in [1,2], the frequency guard-band was proposed to prevent SSMI from OFDM signal Another scheme which was called interleaved OFDM was applied in the DDO-OFDM to eliminate the impact of SSMI by inserting data only in even subcarriers [3]. In order to maintain high SE, the bit interleaver and turbo code techniques are proposed to combat the SSMI in the 64-ary quadrature-amplitude-modulation (64QAM) DD-OFDM system with 100-km fiber transmission [6]. These techniques can mitigate the SSMI effectively, but the SE will still be degraded due to the utilization of turbo code. The receiver sensitivity was improved by 2 and 1.5 dB in QPSK and 16QAM OFDM with 40-km standard singlemode fiber-28 (SSMF-28) transmission, respectively

Principle and experimental setup

Experimental results

Conclusions