Adaptive equalizer, step size derivation method and program
An adaptive equalizer includes an updating unit that updates a step size of a vector of a tap coefficient used for controlling an adaptive filter based on a time-series update vector in accordance with a time-series input and output of the adaptive filter that tracks a polarization state of an optical signal received by a coherent optical receiver. The updating unit updates the step size based on a DC gain of the update vector. The updating unit may update the step size for each update vector component based on a DC gain for each update vector component.
1 . An adaptive equalizer comprising:
a processor; and
a storage medium having computer program instructions stored thereon, wherein the computer program instructions, when executed by the processor, perform processing of:
updating a step size of a vector of a tap coefficient used for controlling an adaptive filter based on a time-series update vector in accordance with a time-series input and output of the adaptive filter that tracks a polarization state of an optical signal received by a coherent optical receiver,
wherein the computer program instructions further perform processing of updating the step size based on a DC gain of the update vector.
2 . The adaptive equalizer according to claim 1 , wherein the computer program instructions further perform processing of:
deriving a DC gain of the update vector based on any one of a sum of the update vector components, a Euclidean norm of the update vector components, and an L2 norm of the update vector components.
3 . The adaptive equalizer according to claim 1 , wherein the computer program instructions further perform processing of updating the step size for each update vector component based on a DC gain for each update vector component.
4 . A step size derivation method executed by an adaptive equalizer, the method comprising the step of:
updating a step size of a vector of a tap coefficient used for controlling an adaptive filter based on a time-series update vector in accordance with a time-series input and output of the adaptive filter that tracks a polarization state of an optical signal received by a coherent optical receiver,
wherein the step of updating includes updating the step size based on a DC gain of the update vector.
5 . A non-transitory computer readable medium which stores a program for causing a computer to function as the adaptive equalizer according to claim 1 .