Determination of electronic beam steering angles
In an embodiment, a method includes determining a first beam pointing vector associated with an antenna assembly by searching for a satellite from a plurality of satellites. The method includes maintaining a communication link with the satellite by determining a plurality of beam pointing vectors that converge to a signal quality value. The method includes obtaining, from the satellite, satellite ephemeris information of the satellite and one or more of remaining satellites of the plurality of satellites. The method includes determining an estimated orientation of the antenna assembly based on one or more of the satellite ephemeris information and the plurality of beam pointing vector. The method includes determining a second beam pointing vector based on the estimated orientation, the satellite ephemeris information, and an approximate position information of the antenna assembly.
1. An end terminal in a communication system, the end terminal comprising:
an antenna assembly configured to transmit and receive beams in time-varying directions; and
a beam steering controller electrically coupled to the antenna assembly, wherein:
the beam steering controller is configured to determine a first beam pointing vector associated with the antenna assembly by searching for a satellite from a plurality of satellites included in the communication system;
the antenna assembly maintains a communication link with the satellite of the plurality of satellites by determining a plurality of beam pointing vectors that converge to a signal quality value;
the beam steering controller is configured to obtain, from the satellite, satellite ephemeris information of the satellite and one or more of remaining satellites of the plurality of satellites;
the beam steering controller is configured to determine an estimated orientation of the antenna assembly based on the satellite ephemeris information and the plurality of beam pointing vectors; and
the beam steering controller is configured to determine a second beam pointing vector based on the estimated orientation, the satellite ephemeris information, and an approximate position information of the end terminal from a positioning system.
2. The end terminal of claim 1 , wherein the beam steering controller is capable of one or both of switching the communication link with the satellite to a second satellite of the plurality of satellites or maintaining the communication link with the satellite, based on the second beam pointing vector.
3. The end terminal of claim 1 , wherein prior to searching for the satellite, a radiating side plane of the antenna assembly has a tilt angle error within ±5 degrees relative to an ideal tilt angle to a sky.
4. The end terminal of claim 1 , wherein the communication system comprises a non-geostationary orbit (NGO) satellite communication system, a low earth orbiting (LEO) communication system, or a satellite communication system.
5. The end terminal of claim 1 , wherein the end terminal comprises a user terminal configured to intermediate communications between the plurality of satellites and one or more user devices, and wherein the antenna assembly comprises a phased array antenna assembly.
6. The end terminal of claim 1 , wherein the signal quality value is a maximum RSSI value.
7. The end terminal of claim 1 , wherein the signal quality value increases or decreases over time.
8. A method comprising:
determining a first beam pointing vector associated with an antenna assembly by searching for a satellite from a plurality of satellites;
maintaining a communication link with the satellite by determining a plurality of beam pointing vectors that converge to a signal quality value;
obtaining, from the satellite, satellite ephemeris information of the satellite and one or more of remaining satellites of the plurality of satellites;
determining an estimated orientation of the antenna assembly based on one or more of the satellite ephemeris information and the plurality of beam pointing vectors; and
determining a second beam pointing vector based on the estimated orientation, the satellite ephemeris information, and an approximate position information of the antenna assembly.
9. The method of claim 8 , further comprising determining, based on the second beam pointing vector, whether to switch the communication link with the satellite to a second satellite of the plurality of satellites or maintain the communication link with the satellite.
10. The method of claim 8 , further comprising:
performing a coarse scan of a sky from zero degrees of a broadside of the antenna assembly to a pre-determined maximum angle from the broadside;
if a downlink signal is detected during the coarse scan performing a fine scan of the sky around one or more degrees from the broadside at which the downlink signal is detected; and
measuring a RSSI at each search point of a plurality of search points of the fine scan.
11. The method of claim 10 , wherein one or both of the coarse scan or the fine scan comprises a spiral pattern scan.
12. The method of claim 8 , wherein an initial beam pointing vector used to obtain the plurality of beam pointing vectors comprises a beam pointing vector having a highest RSSI measurement from a pointing search performed prior to establishing the communication link with the satellite.
13. The method of claim 12 , wherein at least a subset of the plurality of beam pointing vectors comprises one or more of a first perturbation added to the initial beam pointing vector, a second perturbation added to the initial beam pointing vector, and a third perturbation added to the initial beam pointing vector, and wherein the first, second, and third perturbations are different from each other.
14. The method of claim 8 , wherein the signal quality value is a maximum RSSI value.
15. The method of claim 8 , wherein the signal quality value increases or decreases over time.