Abstract: A digitized quasi-phase synchronous phase detecting signal of the PSK signal is used to generate digitized quasi-synchronous phase detecting signal phase-corrected by phase correcting data and a first phase display data indicating the phase of the carrier of the PSK signal is generated from the phase-corrected digitized quasi-synchronous phase detecting signal. Alternatively, the digitized quasi-synchronous phase detecting signal of the PSK signal is used to generate second phase display data indicating the phase of the carrier of the PSK signal and third phase-corrected phase display data is generated from the second phase display data. The first or third phase display data is used to generate fourth phase display data indicating the phase assigned to the code of the PSK signal and a decoded digitized code is generated from the fourth phase display data.