In band noise dection in short distance optical communication systems based on the sub-space method

In this work, a novel estimation method is proposed for in-band noise monitoring in short distance optical communication systems based on the sub-space method. In the polarization multiplexing systems, when only one data tributary is transmitted, one may use the other polarization state for noise detection. Although random rotation occurs during the transmission, sub-space analysis based on the correlation matrix of the received tributaries will recover the noise term perfectly. Numerical simulations demonstrate the effectiveness of the proposed method.