Patent ID: 7031405
Filing Date: 2006-04-18
Classification: H04L

Abstract:
1. A method of carrier phase detection in a demodulated signal formed from a data-modulated carrier, the method comprising: a) generating, from the signal, an estimate of an angle between the carrier and a locally generated reference based on a stochastic gradient of a single-axis (SA) cost function, the cost function being a Bussgang-class cost function; and b) adjusting at least one of the frequency and phase of the demodulated signal based on the angle such that the magnitude of the angle is driven toward a predetermined value, wherein: step a) generates the estimate by: for step a3), the phase error is the stochastic gradient of the single-axis constant modulus criterion J where e SA-CM is the SA cost function error term defined by (Re{y n (θ)} 2 −ρ 2 )Re{y n (θ)}, y n (θ) is input data based on the demodulated signal, and DT[n] approximates a derivative of the demodulated signal with respect to the angle θ (d(y n (θ))/dθ).