Patent ID: 7564926

Claim:
A method for calculating zero-crossing reference sequences ({t i }) for the data detection of a sequence of zero crossings ({{circumflex over (t)} i }), determined in a receiver, of a received signal that is based on a data symbol sequence ({d k }) angle-modulated at a transmitter and transmitted to the receiver, wherein the relationship between the data symbol sequence ({dk}) and the zero crossings of the signal generated at the transmitter is non-linear, comprising: calculating the zero-crossing reference sequences ({t i }) according to a linear equation specifying an output of a finite state machine, wherein the linear equation results from a linearization of the non-linear relationship between the data symbol sequence and the zero crossings of the signal generated at the transmitter; and performing a demodulation by determining a transmitted data sequence ({{circumflex over (d)} k }) by comparing the calculated zero-crossing reference sequences ({t i }) with a detected sequence of zero crossings ({{circumflex over (t)} i }) at the receiver, wherein determining the transmitted data symbol sequence ({d k }) is performed in accordance with the Viterbi algorithm by processing a trellis diagram that describes a state diagram of the finite state machine, for each time increment, wherein transition metric values between a precursor state and a target state in the trellis diagram are calculated by comparing the state-dependent zero-crossing reference sequences with the sequence of zero crossings detected for the time increment considered.