Open AccessNoise statistics of and BER estimation using demodulated signals for direct detection differential polarization-phase-shift keying
Author(s) -
Yan Han,
Guifang Li
Publication year - 2005
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/opex.13.002761
Subject(s) - gaussian noise , phase shift keying , phase noise , keying , physics , optics , noise (video) , demodulation , bit error rate , quantum noise , differential phase , statistics , mathematics , algorithm , telecommunications , computer science , decoding methods , quantum mechanics , channel (broadcasting) , artificial intelligence , image (mathematics) , quantum
The noise statistics of optically demodulated signal of the recently proposed modulation format, namely differential polarization-phase-shift keying, are analyzed. It is found that, in the linear regime, the Gaussian approximation is reasonably accurate in estimating the BER. In the nonlinear regime, the noise of the demodulated signal is dominated by the effect of nonlinear phase noise and obeys chi-squared statistics with a degree of freedom of one. Gaussian approximation underestimates the BER in the nonlinear regime. A two-step BER estimation method accounting for both linear beat noise and nonlinear phase noise is proposed. The effectiveness of this two-step BER estimation method at all power levels has been established by comparison with direct error counting.