| US 7,579,987 B2 | ||
| Low earth orbit satellite providing navigation signals | ||
| Clark E. Cohen, Washington, D.C. (US); David A. Whelan, Newport Coast, Calif. (US); Robert W. Brumley, Narberth, Pa. (US); Gregory M. Gutt, Ashburn, Va. (US); and Barton G. Ferrell, Troy, Ill. (US) | ||
| Assigned to The Boeing Company, Chicago, Ill. (US) | ||
| Filed on May 16, 2007, as Appl. No. 11/749,627. | ||
| Claims priority of provisional application 60/801764, filed on May 18, 2006. | ||
| Prior Publication US 2008/0001818 A1, Jan. 03, 2008 | ||
| Int. Cl. G01S 1/00 (2006.01) | ||
| U.S. Cl. 342—357.15 | 29 Claims |
| 1. A method of providing a low earth orbit (LEO) signal from a LEO satellite, the method comprising:
providing a plurality of transmit channels over a plurality of transmit slots, wherein the transmit channels comprise a set
of communication channels associated with a first set of the transmit slots and a set of navigation channels corresponding
to unused communication capacity associated with a second set of the transmit slots;
generating a pseudo random noise (PRN) ranging overlay comprising a first navigation signal and a second navigation signal;
applying the PRN ranging overlay to the navigation channels to distribute the first navigation signal over a first set of
the navigation channels and to distribute the second navigation signal over a second set of the navigation channels;
combining the communication channels and the first and second sets of navigation channels into a LEO signal; and
broadcasting the LEO signal from the LEO satellite, wherein the LEO signal is a composite LEO signal comprising the communication
channels and the first and second sets of navigation channels.
|