Impact of phase noise on coherent BPSK homodyne systems in long-haul optical fiber communications

Abstract

The impact of phase noise induced by amplified spontaneous emission and nonlinear Kerr effect is analyzed in investigating the performance of BPSK homodyne systems based OPLL in long-haul optical fiber communications. Under the Gaussian probability density function assumption the equivalent power spectral density of linear and nonlinear phase noise are determined, respectively. Using the power spectral density function the expressions of phase error variance taking into account linear phase noise, nonlinear phase noise and shot noise of corresponding photodiodes are determined. The impact of the number of amplifiers, bit rate and signal power on the phase error variance is analyzed. Using the minimum phase error variance and corresponding BER expression the receiver sensitivity and BER curves are given, respectively. Under the required BER, it is shown that there is a limitation on the maximum transmission distance of the BPSK homodyne system based OPLL. The theory expressions and numerical results obtained in this paper are helpful for designing OPLL and evaluating the impact of phase noise on the receivers based OPLL in long-haul optical fiber communications.