The impact of in-band crosstalk on the transmission performance of optical cross-connects, incorporating (de)multiplexers and space switches, is studied. A statistical description of the receiver decision variable that yields a performance analysis in good agreement with experiment is given. Bit error rate and power penalties are calculated using the so-called saddlepoint approximation which is numerically simple and gives accurate results.
Tafur Monroy, I., & Tangdiongga, E. (1998). Performance evaluation of optical cross-connects by saddlepoint approximation. IEEE Journal of Lightwave Technology, 16(3), 317-323. https://doi.org/10.1109/50.661356