Patent ID: 6459888
Filing Date: 2002-10-01
Classification: H04L

Abstract:
In a mobile communication system having at least one base station and at least one mobile unit where information is transmitted there-between as digitally encoded bursts modulated on an analog radio carrier signal, a method for demodulating said bursts comprising the steps of:receiving said radio carrier signal transmitted by said base station; digitizing said radio carrier signal; storing said digitized radio carrier signal; and performing a multiple-hypothesis frequency detection analysis on said stored digitized radio carrier signal to estimate a frequency offset of said radio carrier signal, wherein said multiple-hypothesis frequency detection analysis step comprises the following substeps: demodulating said digitized radio carrier signal in accordance with a plurality of phase rotation or frequency offset hypotheses to recover, for each hypothesis, the encoded information transmitted with said radio carrier signal; performing error detection on the encoded information for each hypothesis to determine an error parameter for each of the hypotheses; and determining the frequency offset of the radio carrier signal responsive to a comparison of the error parameters for each of the hypotheses.