Abstract: A signal recovery system for a phase modulated signal having a signal spectrum, wherein the phase modulated signal is passed along a communications system (1) having at least one filter (3) so as to define the frequency channel of the communication system. Losses result from the passage of the signal through the at least one filter (3) defining the transmission channel. The signal recovery system recovers at least some of the losses by introducing a relative frequency offset between the signal spectrum and the transmission spectrum of the at least one filter (3) in the communications system.