Method and system for data detection in a global positioning system satellite receiver
View Patent ↗A data detection circuit within a global positioning system (GPS) satellite receiver operates to detect and decode data sent in a spread spectrum signal. The data detection circuit receives input from a radio receiver, the information containing data from a plurality of satellites. The data is supplied to a circular memory device, which determines which data corresponds to which satellite. The memory device sends the received signal to a matched filter, which decodes the signal received from each satellite. This signal is analyzed to determine whether a phase inversion due to data modulation on the received signal is present. The phase inversion can occur at boundaries, known as data epochs, in the received signal, and corresponds to data in the received signal. This data contains information relating to the position of each satellite and is collected by the data detection circuit for use by the GPS receiver.
1. A method of tracking a remote object comprising the steps of:
fitting a remote object with a positioning sensor configured to receive and store positioning information when the remote object is in a fix position;
positioning the remote object in a fix position such that the positioning sensor is capable of detecting an activation signal;
receiving and storing a predetermined amount of data in the positioning sensor, the data comprising positioning information;
processing the data to determine the location of the fix position;
decoding data encoded upon a signal using a matched filter, the data being demarcated into successive data epochs; and
decoding periodic phase shift-data encoded upon the signal by phase shifts of the data epochs using the matched filter.