Aiding beam identification in a satellite system
First Claim
1. A method to determine timing offset errors in a satellite system, comprising:
- (a) determining in a user terminal a first timing offset associated with a first satellite beam from a first satellite;
(b) determining in the user terminal a second timing offset associated with a second satellite beam from a second satellite based upon the first timing offset;
(c) estimating a first range from the user terminal to the first satellite;
(d) estimating a second range from the user terminal to the second satellite; and
(e) determining an error in the second timing offset based upon a difference between the estimated first and second ranges.
0 Assignments
0 Petitions
Accused Products
Abstract
A system and method for determining timing offset errors in a low earth orbit satellite system based upon Doppler and Doppler rate of change is provided. A user terminal determines first and second timing offsets respectively associated with first and second satellite beams from respective first and second satellites. Next, the user terminal determines the Doppler and Doppler rate of change associated with the first and second satellite beams. A timing offset is estimated from the measured Doppler and Doppler rate of change and is then compared with the user terminal'"'"'s own determined timing offset. If the comparison does not produce a value within a predetermined threshold, a beam identification error is declared.
17 Citations
11 Claims
-
1. A method to determine timing offset errors in a satellite system, comprising:
-
(a) determining in a user terminal a first timing offset associated with a first satellite beam from a first satellite; (b) determining in the user terminal a second timing offset associated with a second satellite beam from a second satellite based upon the first timing offset; (c) estimating a first range from the user terminal to the first satellite; (d) estimating a second range from the user terminal to the second satellite; and (e) determining an error in the second timing offset based upon a difference between the estimated first and second ranges. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A method to perform beam identification in a user terminal configured to communicate using a low earth orbit satellite system, the user terminal including a processor configured to (i) receive a first satellite beam including a first timing offset from a servicing satellite, and (ii) facilitate a handoff from the first satellite beam to a second satellite beam, the second satellite beam being radiated from a destination satellite, the method comprising:
-
(a) acquiring the second satellite beam in the user terminal; (b) determining a second timing offset of the second satellite beam based upon the first timing offset; (c) identifying the second satellite beam based upon the second timing offset; (d) estimating a first range from the user terminal to the servicing satellite; (e) estimating a second range from the user terminal to the destination satellite; (f) determining a timing difference based upon a difference between the estimated first range and the estimated second range; (g) calculating a difference between the second timing offset and the timing difference; and (h) confirming identification of the second satellite beam when the difference between the second timing offset and the timing difference is greater than a predetermined value. - View Dependent Claims (8, 9)
-
-
10. A method to determine timing offset errors in a communications system, comprising:
-
(a) determining in a user terminal a first timing offset associated with a first transmitter signal from a first transmitter; (b) determining in the user terminal a second timing offset associated with a second transmitter signal from a second transmitter based upon the first timing offset; (c) estimating a first range from the user terminal to the first transmitter; (d) estimating a second range from the user terminal to the second transmitter; and (e) determining an error in the second timing offset based upon a difference between the estimated first and second ranges. - View Dependent Claims (11)
-
Specification