Patent ID: 7308055

Claim:
A transmission method with compensation for fading distortion or frequency offset distortion in digital communications using pilot signals, comprising: receiving radiofrequency signals modulated by one of amplitude modulation, frequency modulation, phase modulation, and polarization modulation; demodulating digital signals carried by said received modulated radiofrequency signals; oversampling said demodulated digital signals at a predetermined frequency; finding a spectrum of the oversampled signals using the oversampled signals as periodic pilot symbols; finding fading components or frequency-offset components from said spectrum using an averaging means in a closed loop scheme in which frequency offset is estimated in a unit of delay of frames and compensated by changing a base frequency of demodulation by the estimated delay of frames wherein, at a time of finding the fading components or frequency-offset components, performing an evaluation of a bandwidth of a spectrum of the fading components by a predetermined method, and depending on these results, changing the method of finding the fading components or frequency-offset components; and using one of said fading components or frequency-offset components to compensate said received modulated radiofrequency signals or estimate the original digital signal from the demodulated digital signals.