Robust Precoder for Mitigating Inter-Symbol and Inter-Carrier Interferences in Coherent Optical FBMC/OQAM

Abstract

In this paper, a new precoder for a coherent optical filter bank multicarrier with offset quadrature amplitude modulation (FBMC/OQAM) system is proposed. The precoder is designed based on an iterative polynomial eigenvalue decomposition (PEVD) algorithm to jointly mitigate the inter-symbol interference and inter-carrier interference. The PEVD algorithm is used to decompose a polynomial channel matrix into polynomial eigenvectors and eigenvalues matrices, then a precoder is designed based on the decomposed matrices. The precoder acts as a filter applied to each subcarrier and to its adjacent subcarriers. In addition, a new adaptive optimum energy algorithm is proposed to truncate the insignificant precoder filter coefficients produced by the PEVD algorithm and consequently reduce the computational complexity. A mathematical model and algorithm for implementing the precoder are also presented. Robustness of the proposed precoder has been analyzed and compared to existing precoder in optical channel with different dispersion effects. Numerical results demonstrate that the new precoder significantly outperforms the existing precoder in terms of error vector magnitude, bit error rate, Frobenius norm of the error matrix, and computational complexity.

Design and Validation of the Physical Layer Functions of FBMC/OQAM Transceiver With Improved Residual Phase Error Correction

“…is the additional crosstalk caused by intrinsic imaginary interference (IMI), and the prototype filter used in ( 4) is assumed to exhibit good spectral containment so the crosstalk is mainly caused by the adjacent subcarriers 𝑚 ± 1 [2,5]. Based on (4) it is clear that the data symbol 𝑑 𝑚 0 ,𝑛 0 is affected by channel, CFO and PN in addition to the IMI.…”

“…Filter bank multicarrier with off-set quadrature amplitude modulation (FBMC/OQAM) system is a potential waveform candidate for future mobile communication. FBMC has recently attracted attention due to its advantages of better spectrum efficiency, lower side-lobes and higher robustness to narrow-band interference over the conventional orthogonal frequency division multiplexing (OFDM) [1,2]. Despite the advantages of FBMC over OFDM, it has many challenges that limit its implementation.…”

“…A coarse CFO estimator which does not require the channel knowledge was used in the first step. Channel estimation based on least squares (LS) estimator and conventional interference approximation method (IAM) was considered in [2,3,15], and a minimum mean square error (MMSE) estimator in time domain was used in [14]. In [16], an improved joint maximum-likelihood (ML) estimation method for CFO, sampling time offset, and CIR was proposed for OFDM/OQAM based on pilots.…”

Filterbank-Assisted Channel Estimation for Coherent Optical FBMC/OQAM System

“…ilter bank multicarrier with offset-QAM modulation (FBMC/OQAM) is an emerging multicarrier technology that adds filter banks to the traditional orthogonal frequency division multiplexing (OFDM) while eliminating the need for cyclic prefix. Due to its high spectrum efficiency, lower sidelobes and resistance to narrow-band interference, it has recently attracted the attention of many researchers [1,2]. In contrast to OFDM, only in the real field are FBMC subcarriers orthogonal, while in the imaginary field, orthogonality is lost [3,4].…”