Homodyne PSK receivers with a Costas loop for high-speed long-haul communications

In this paper a realistic model for the performance determination of a homodyne PSK receiver with a Costas loop for long-haul communication is proposed. The paper reports the receiver sensitivity, linewidth requirements and power penalties taking into account the laser phase noise, ASE noise and shot noise of corresponding photodiodes. Expressions for the phase error variance and receiver bit-error rate are determined precisely and these expressions are used in power penalty determination. Contrary to present papers, the sources of power penalty creation are considered simultaneously, due to their mutual dependency, instead of considering them separately. The optimum power splitting ratio to minimize the receiver error probability is used in the power penalty determination