Circular Polarization Division Multiplexing in Visible Light Communication System by Incorporating QPSK and Distortion Compensation Enabled DSP/IDSP

Abstract

Abstract Hybrid polarization division multiplexing (PDM) and Visible Light Communication (VLC) have fostered speedy data transmission in the last few years and emerged as the strong candidate that enables users to leverage the pervasive illumination/communication infrastructure. Circular PDM (CPDM) is replacing the linear PDM (LPDM) variant in wired/wireless systems due to the even scattered light distributions and elimination of polarization axis alignment requirements. In this research work, a 1.6 Tbps multi-wavelength line of sight (LoS) based VLC system is presented and data modulation is performed by employing Quadrature phase shift keying (QPSK). The conventional DSP algorithms such as Viterbi Phase Estimation (VPE), Blind Phase Search (BPS), and Constant Modulus Algorithm (CMA) algorithms are replaced with Gram-Schmidt orthogonalization procedure (GSOP), time-domain equalization algorithm (TEDA), improved Viterbi algorithm (IVA), and least mean square (LMS) algorithm in proposed IDSP. Three different systems are compared such as LPDM-VLC-DSP, CPDM-VLC-DSP, and CPDM-VLC-IDSP at different VLC link ranges, transmitter half angles (THA), incidence half angles (IHA), and optical concentrator areas (OCAs) in terms of error vector magnitude percentage (EVM%), log symbol error rate (log SER), and Q factor. After doing the extensive comprehensive literature survey, it is discerned that the presented CPDM-VLC-IDSP system has covered the longest distance i.e. 14 cm at 1.6 Tbps capacity under the acceptable bit error rate (BER) limits.