Ultrareliable communication over vulnerable optical networks via lightpath diversity: receiver architectures and performance

We develop a class of structured receivers for a lightpath diversity scheme, which was introduced to provide ultrareliable communication with low delay in vulnerable all-optical networks. We explore the trade-off between implementation complexity and error probability to achieve optimum and near-optimum performance within a class of structured receivers. Using a doubly-stochastic point process model, we develop receiver architectures for both the optimal receiver with respect to error performance, and the equal-gain-combining receiver with suboptimum error performance but simpler receiver architecture. Closed-form error bounds for both receivers are obtained and compared with the ´Genie-aided´ limit of the lightpath diversity transmission scheme. The comparison shows that the error performance of both receivers approaches the ´Genie-aided´ limit when the signal is strong. Numerical results also demonstrate that additional power over what is required for the optimum receiver is needed to be transmitted in order for the equal-gain-combining receiver to achieve the same target error probability, and the power penalty decreases with decreasing noise level. These results suggest that the simpler equal-gain-combing receiver provides similar performance as the optimal receiver in the high signal-to-noise ratio (SNR) regime, but the optimal receiver should be used in the low SNR regime for significantly better performance.