Patent ID: 6208201
Filing Date: 2001-03-27
Classification: H04L

Abstract:
A method of recovering a carrier phase from a higher order M-PSK modulated input signal in a channel with low signal-to-noise ratio, the method comprising the steps of:employing a voltage controlled oscillator to generate first and second oscillations in phase quadrature with respect to each other;mixing the modulated input signal with the first oscillation to derive a first demodulated signal, (I);mixing the modulated input signal with the second oscillation to derive a second demodulated signal, (Q);deriving, from the first and second demodulated signals (I) and (Q), a control signal representing the phase difference between the input signal carrier and the voltage controlled oscillator according to the relationship: ##EQU5##where `a` is the control signal, `k` is an odd integer between 1 and M, and C.sub.m.sup.k represent binominal coefficients; andcontrolling the frequency of the voltage controlled oscillator by means of the control signal to recover the carrier phase.