title,doi,url,abstract,journal,publication_year,pmid,arxiv
Digital Signal Processing Of Coherent and Generation Detection of QPSK Signal, https://doi.org/10.32628/IJSRCSEIT, https://ijsrcseit.com/CSEIT184325, We demonstrate an optical quadrature phase-shift keying (QPSK) signal transmitter and an optical receiver for demodulating optical QPSK signal with homodyne detection and digital signal processing (DSP). DSP on the homodyne detection scheme is employed without locking the phase of the local oscillator (LO). In this paper we present an extracting one-dimensional array of down-sampling method for reducing unwanted samples of constellation diagram measurement. Such a novel scheme embodies the following major advantages over the other conventional optical QPSK signal detection methods. First this homodyne detection scheme does not need strict requirement on LO in comparison with linear optical sampling such as having at spectral density and phase over the spectral support of the source under test. Second the LabVIEW software is directly used for recovering the QPSK signal constellation without employing complex DSP circuit. Third this scheme is applicable to multilevel modulation formats such as M-ary PSK and quadrature amplitude modulation (QAM) or higher speed signals by making minor changes., International Journal of Scientific Research in Computer Science Engineering and Information Technology, 2018, CSEIT184325