Patent ID: 6940927
Filing Date: 2005-09-06
Classification: H04L

Abstract:
1. A method for establishing a symbol timing epoch reference for demodulating a CPM input data signal received from a CPM transmitter modulated onto a carrier, comprising the steps of: trellis demodulating the received CPM input data signal by computing trellis branch metric signals using estimates of the phase of the transmitter phase clock relative to the CPM input data signal and a transmitter symbol timing reference signal; using the computed branch metric signals to select a path signal through the trellis having the highest probability of representing the CPM input data signal; using the selected path signal to obtain an estimate of the transmitter frequency signal; using the selected path signal to obtain an estimate of a product of the phase shifted transmitter signal and the CPM input data signal; calculating the product of the transmitter frequency signal and the product of the phase shifted transmitter signal and the CPM data signal to obtain a timing epoch estimation error signal; using the timing epoch estimation error signal to adjust the symbol timing epoch reference.