Abstract
The performance of spectrally efficient frequency division multiplexing (SEFDM) in optical communication systems is investigated considering the impact of fiber nonlinearities. Relative to orthogonal frequency division multiplexing (OFDM), sub-carriers within SEFDM signals are packed closer at a frequency spacing less than the symbol rate. In order to recover the data, a specially designed sphere decoding detector is used at the receiver end to compensate for the self-created inter carrier interference encountered in SEFDM signals. Our research demonstrated the benefits of the use of sphere decoding in SEFDM and also demonstrates the performance improvement of long-haul optical communication systems using SEFDM compared to the use of conventional OFDM, when fiber nonlinearities are considered. Different modulation formats ranging from 4QAM to 32QAM are studied and it is shown that, for the same spectral efficiency and information rate, SEFDM signals allow a significant increase in the transmission distance compared to conventional OFDM signals.
Highlights
Optical fiber communication systems carry over 95% of the Internet data and form the major part of current communication infrastructure
Our research demonstrated the benefits of the use of sphere decoding in spectrally efficient frequency division multiplexing (SEFDM) and demonstrates the performance improvement of long-haul optical communication systems using SEFDM compared to the use of conventional orthogonal frequency division multiplexing (OFDM), when fiber nonlinearities are considered
This paper has investigated the predicted performance of orthogonal (OFDM) and non-orthogonal (SEFDM) multicarrier systems in long-haul optical fiber transmission environments where fiber nonlinearities are considered
Summary
Optical fiber communication systems carry over 95% of the Internet data and form the major part of current communication infrastructure. Multiple sub-carrier based orthogonal frequency division multiplexing (OFDM), extensively used in wireless communications, has been widely investigated in the super-channel transmission in optical communication systems to achieve spectral efficiency similar to that of Nyquist-spaced. This paper, for the first time to our knowledge, reports a comparative study of these two approaches (higher-order modulation formats and sub-carrier spacing below the symbol rate) for optical transmission systems suffering fiber Kerr nonlinearities. Multicarrier systems can compress the bandwidth by adopting non-orthogonal multicarrier signals with sub-carrier spacing below the symbol rate, termed spectrally efficient frequency division multiplexing (SEFDM) [9]. This work considers long-haul optical fiber communication scenarios where fiber nonlinearities have significant effects on signal performance, showing the achievable spectral efficiency and transmission distance limits of such optical communication systems
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
