An arrangement and a method for carrier signal recovery

Patent, 2014

The present invention relates to a carrier recovery arrangement (100) for recovering an input modulated signal (R(t)), down- converted by a local oscillator with a frequency different from the carrier frequency of the input modulated signal (R(t)) such that a distorted down-converted signal (RQ(t)) is provided. It comprises a delay means (14) for introducing a time delay into the distorted signal (RQ (t)), a mixer (4) adapted to multiply the received distorted signal (RQ(t)) with the delayed distorted signal and to provide an adjusted output signal, (Radj(t)), with a distortion term, a low pass filter (5) adapted to extract a signal comprising the second harmonic of the distortion term from the adjusted output signal (R adj (t)) related to twice the frequency difference (2Δω) between the local oscillator and the carrier frequency of the input modulated signal (R(t)), and means for removing modulated data from said signal to provide a recovery signal free from modulated data that can be used to eliminate the distortion.