Patent ID: 8548322

Claim:
A channel power estimator for estimating the power of each channel in a wavelength division multiplexed (WDM) signal, comprising: a filter adapted to select and output a sub-band having a sub-set of the channels of an incoming WDM signal; a function application device adapted to apply a weighting function to the output from the filter; a reconstruction processor arranged to receive the weighted signal and adapted to control the function application device to apply the weighting function a predetermined number of times to the selected sub-band, and to modify the weighting function for each said application; and a storage memory arranged to store optical characteristic data on at least the function application device; wherein the reconstruction processor is arranged to calculate an estimation of the power distribution of the incoming WDM signal using the weighted signal and the optical characteristic data, wherein the predetermined number of times is M times wherein M is greater or equal to the number of channels N contained in the sub-band.