| 摘要 |
<p>The present document relates to optical communication systems. In particular, the present document relates to coherent optical receivers using MLSE techniques. A detection unit to detect a symbol from a received digital signal is described, wherein the digital signal has been derived from an optical signal transmitted over an optical transmission channel and wherein the digital signal has been submitted to low pass filtering. The detection unit comprises a filter determination unit configured to determine a first plurality of filter coefficients of a digital filter based on the digital signal; a filter conversion unit configured to determine a second plurality of filter coefficients from the first plurality of filter coefficients such that a digital filter configured with the second plurality of filter coefficients is essentially an all pass filter; a filter unit configured to filter the digital signal using the digital filter configured with the second plurality of coefficients; and a maximum likelihood sequence detector, referred to as MLSE detector, configured to detect the symbol from the filtered digital signal at a given time instant, while taking into account one or more symbols of one or more previous time instants.</p> |
