Patent ID: 7456785
Filing Date: 2008-11-25
Classification: G01S

Abstract:
1. A method of acquiring signals from satellites in a Global Positioning System (GPS), the method comprising: receiving navigation signals from the satellites of the GPS; down-converting to complex baseband the received navigation signals to form a first signal; digitizing samples of the first signal; nonlinear processing of the digitized samples of the first signal to form a second signal, where the nonlinear processing comprises forming a weighted sum of products of pairs of the digitized samples at different relative delays, in which one of each of the pairs has been complex conjugated; coherent averaging the second signal over integer multiples or submultiples of a spreading sequence period of the navigation signals to form a third signal; performing circular correlation processing of the third signal with a representation of each navigation signal of the navigation signals; and determining a timing offset at which a correlated output energy is maximized, based on the circular correlation processing.