Title :
Performance of electrical equalizers in optically amplified OOK and DPSK systems
Author :
Wang, Jin ; Kahn, Joseph M.
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Univ. of California, Berkeley, CA, USA
fDate :
5/1/2004 12:00:00 AM
Abstract :
We study the performance of feed-forward equalizers (FFEs) and decision-feedback equalizers (DFEs) in compensating chromatic dispersion and first-order polarization-mode dispersion (PMD) in optically amplified nonreturn-to-zero on-off keying (NRZ-OOK) and NRZ differential phase-shift-keying (DPSK) systems at 10 Gb/s. We use Monte Carlo simulation of the least-mean-square algorithm to estimate equalizer tap weights. Once stationary tap weights are obtained, we compute the bit-error ratio using an analytical method whose accuracy has been verified by simulation. We find that FFE and DFE offer the greatest improvement when combating first-order PMD with NRZ-OOK, reducing power penalties by about 45%. With NRZ-DPSK, the equalizers offer quite limited improvement.
Keywords :
Monte Carlo methods; amplitude shift keying; decision feedback equalisers; differential phase shift keying; error statistics; least mean squares methods; optical fibre communication; optical fibre dispersion; optical fibre polarisation; DFE; FFE; Monte Carlo simulation; NRZ differential phase-shift-keying; NRZ-OOK; bit-error ratio; compensating chromatic dispersion; decision-feedback equalizers; equalizer tap weights; feed-forward equalizers; first-order polarization-mode dispersion; least-mean-square algorithm; nonreturn-to-zero on-off keying; optically amplified DPSK; optically amplified OOK; Analytical models; Chromatic dispersion; Computational modeling; Decision feedback equalizers; Differential quadrature phase shift keying; Feedforward systems; Optical signal processing; Phase shift keying; Polarization mode dispersion; Stimulated emission;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2004.826222
