Abstract: A dual adaptive importance-sampling system and method is provided that can estimate the probability of events by combining dual complementary importance-sampling simulations. The present invention exploits the ability to determine an optimal biased pdf using an iterative procedure that requires relatively little a priori knowledge of how to bias. Hence, the present invention is particularly suited for evaluating the BERs and/or WERs of coded communication and storage systems, and is generally applicable to arbitrarily chosen codes. When applied to coded communication and storage systems, the present invention provides a versatile technique for the fast and accurate estimation of BERs and WERs of FEC codes down to values of 10?20 or lower.

Abstract: A method for generating a polarization-multiplexed optical clock signal for an optical communication system is described. The method includes splitting a polarized input optical clock signal having a clock rate into a first and a second polarized optical signal. The first polarized optical signal includes a first polarization state and the second polarized optical signal includes a second polarization state. The first polarized optical signal is delayed relative to the second polarized optical signal. The first and the second polarized optical signals are combined to generate the polarization-multiplexed optical clock signal for the optical communication system.