Patent ID: 7106807

Claim:
A method for estimating the frequency shift of a continuous phase-frequency-shift keying (CPFSK) signal, comprising the steps of: a) scanning the CPFSK signal; b) determining intermediate signal values for the CPFSK signal scanned in step a); and c) determining an estimated value (v) for the frequency shift of the CPFSK signal by assessing a predefined number of L 0 consecutive intermediate signal values obtained in step b), whereby an integer delay parameter D is specified, whereby in step b) the intermediate signal values for intervals k·T+τ are determined in each case from scanning values of the CPFSK signal obtained for intervals k·D·T+τ and [k−1]·D·T+τ, whereby T designates a scanning period, with which the CPFSK signal is scanned in step a), k is a scanning index and τ is a delay constant, and whereby in step c) the estimated value (ν) for the frequency shift is determined from the intermediate signal values thus obtained in step b) for intervals i·D·T+τ with i=0 . . . L 0 −1, wherein the integer delay parameter D is variable and is selected depending on the type of CPFSK modulation used for the CPFSK signal.