Patent ID: 8320441

Claim:
A method for demodulating a Gaussian Filtered Minimum Shift Keyed (GMSK) signal, comprising: receiving a Complex Data Signal (CDS) which can be represented as a Laurent expansion in which said CDS is approximated as a sum of linearly modulated pulses; filtering the CDS using a first matched filter having a filter shape corresponding to a first pulse used in a first term of said Laurent expansion; performing a phase rotation on data samples representing a first filtered complex output signal from said first matched filter to produce a −90 degree phase rotation for each complex data sample relative to a previous complex data sample; subsequent to the phase rotation, performing a scaling and delaying function exclusively on a real number portion of at least one of said complex data samples to obtain an approximation of at least a second filtered complex output signal that would be produced by a second matched filter having a filter shape corresponding to a second pulse used in a second term of said Laurent expansion.