Experimental demonstration of non-iterative interpolation-based partial ICI compensation in100G RGI-DP-CO-OFDM transport systems

Abstract

We experimentally investigate the performance of a low-complexity non-iterative phase noise induced inter-carrier interference (ICI) compensation algorithm in reduced-guard-interval dual-polarization coherent-optical orthogonal-frequency-division-multiplexing (RGI-DP-CO-OFDM) transport systems. This interpolation-based ICI compensator estimates the time-domain phase noise samples by a linear interpolation between the CPE estimates of the consecutive OFDM symbols. We experimentally study the performance of this scheme for a 28 Gbaud QPSK RGI-DP-CO-OFDM employing a low cost distributed feedback (DFB) laser. Experimental results using a DFB laser with the linewidth of 2.6 MHz demonstrate 24% and 13% improvement in transmission reach with respect to the conventional equalizer (CE) in presence of weak and strong dispersion-enhanced-phase-noise (DEPN), respectively. A brief analysis of the computational complexity of this scheme in terms of the number of required complex multiplications is provided. This practical approach does not suffer from error propagation while enjoying low computational complexity.

Iterative detection of CO‐OFDM signals with phase errors using circular random variables

“…. The mean and variance can be computed by substituting the variables M p nþ1 !X ϕ nþ1 , V p nþ1 !X ϕ nþ1 , M nþ1 BW , and V nþ1 BW , instead of the respective variables in (11) and (12). The details are omitted here.…”

“…However, the use of several pilots has an effect on the spectral efficiency. In Mousa-Pasandi et al, 10,11 linear interpolation-based approaches have been used. These algorithms improve the estimate using linear interpolation for partial mitigation of the interference.…”

Gaussian wavelet basis expansion based phase noise suppression method for coherent optical OFDM systems

“…Due to the characteristics of fiber optic transmission medium, the phase noise in CO-OFDM system may be more serious, and the impact on system performance is more significant. Common phase error (CPE) and inter-carrier interference (ICI) caused by laser phase noise are important interferences in CO-OFDM transmission system [3,5]. It causes the receiver to be unable to accurately demodulate and decode the signal, thus increasing the bit error rate (BER) and reducing the capacity and reliability of the system [6].…”

Development of discrete Fourier transform‐based channel estimation algorithms for a coherent optical orthogonal frequency division multiplexing transmission system

“…Its key advantages can be highlighted focusing on its scalability to the ever increasing data rates and transponder adaptability. Studies show that CO-OFDM also represents the ultimate performance in receiver sensitivity and spectral efficiency [3][4][5][6][7][8][9][10][11]. However, its optical channel impairments, such as chromatic dispersion, polarisation mode dispersion and fibre non-linearity, have become the major limiting factors in CO-OFDM transmission systems, in particular when speed rates reaching up to 100 Gbit/s or higher.…”