Carrier recovery method for mobile communications

Claim 1

A carrier regenerating device for regenerating a regenerated carrier signal from a modulated overall signal having a frame period and comprising a modulated data signal and modulated unique words which are periodically interspersed in said modulated data signal, said carrier regenerating device comprising: demodulating means for quadrature demodulating, by the use of said regenerated carrier signal, said modulated overall signal to produce a demodulated overall signal comprising a demodulated data signal and demodulated unique words; carrier reproducing means for reproducing a reproduced carrier signal from said demodulated overall signal; producing means for producing, by the use of said demodulated overall signal, an aperture signal which defines an aperture interval determined on the basis of said frame period when said demodulated overall signal has a level which is lower than a predetermined threshold level; cross-correlating means responsive to said aperture signal for calculating a cross-correlation coefficient between said demodulated overall signal and a locally known unique word; phase error calculating means for calculating, by the use of said cross-correlation coefficient, a phase error which said reproduced carrier signal has relative to said regenerated carrier signal; frequency error calculating means for calculating, by the use of said cross-correlation coefficient and said demodulated overall signal, a frequency error which said reproduced carrier signal has relative to said regenerated carrier signal; first correction setting means for setting said phase error at said aperture interval in said carrier reproducing means to make said reproduced carrier signal become said regenerated carrier signal; and second correction setting means for setting said frequency error at said aperture interval in said carrier reproducing means to make said reproduced carrier signal become said regenerated carrier signal.