QCOB: a novel QPSK coherent optical OFDM modulation technique for mitigation of fiber impairments

Abstract

Abstract Modern optical communication heavily relies on coherent optical orthogonal frequency division multiplexing (CO-OFDM) modulation. But the usage of optical OFDM for fiber optic communication is still constrained in comparison to other modes of communication like visible light communication (VLC) and wireless communication due to a number of issues such as various sorts of fiber impairments including dispersion and attenuation. In this research paper, a novel optical OFDM modulation technique has been proposed. It is quadrature phase shift keying (QPSK) CO-OFDM modulation with Bessel optical filter in fiber optical link and is named as QCOB. This modulation technique works for optical fiber transmission. Its testing has been carried out for parameters like bit error rate (BER) and quality-factor (Q-factor) over a range of fiber length, fiber dispersion coefficient and input power. This modulation employs coherent optical OFDM with QPSK for subcarrier modulation. The optical link utilizes a Bessel optical filter. Improved results have been achieved over conventional QPSK CO-OFDM (QCO). The obtained results demonstrate the superiority of the QCOB technique in terms of performance enhancement and fiber impairment reduction. In comparison to the QCO technique, the BER performance (reduction in BER) of the QCOB technique shows an improvement of around 7.4, 100, 14.4, 46.4 and 3.4% for dispersion coefficient values of 10, 20, 30, 50 and 100 (in ps/nm-km), respectively.