Ground based beam forming with clustering
A system and method for beamforming includes providing an antenna including feeds, a coverage area including service areas and data streams for each of the service areas; scheduling N data streams of the data streams, selecting a cluster of M feeds from the feeds; computing, with a GBBF processor (ground based beam former), M×N weights; generating M feed excitations by distributing the N data streams per the M×N weights; switching an array to transfer a respective one of the M feed excitations to a respective one of the M feeds; and beamforming, with the M feeds of the antenna, N beams. In the method, the N beams are each focused on a respective service area of each of the N data streams, the M×N weights improve the transmitting into the respective service area of each of the N data streams, and at least one of the N beams includes a portion of a plurality of the M feed excitations.
1. A method for beamforming comprising:
providing an antenna comprising feeds, a coverage area comprising service areas and data streams for each of the service areas;
scheduling N data streams of the data streams;
selecting a cluster of M feeds from the feeds;
computing, with a GBBF processor (ground based beam former), M×N weights;
generating M feed excitations by distributing the N data streams per the M×N weights;
switching an array to transfer a respective one of the M feed excitations to a respective one of the M feeds; and
beamforming, with the M feeds of the antenna, N beams,
wherein the N beams are each focused on a respective service area of each of the N data streams,
the M×N weights improve the transmitting into the respective service area of each of the N data streams, and
at least one of the N beams comprises a portion of a plurality of the M feed excitations.
2. The method of claim 1 , wherein the antenna comprises an array-fed reflector comprising the feeds, and a count of the feeds is greater than M.
3. The method of claim 1 , wherein M is greater than N.
4. The method of claim 1 , wherein the M×N weights are weighted to account for a predicted offered traffic demand based on a usage pattern for each of the N data streams.
5. The method of claim 1 , wherein the scheduling, the selecting, the generating, the switching and the beamforming are performed per an integral multiple of a transmission interval.
6. The method of claim 1 , wherein the scheduling moves the N beams over a breadth of the coverage area over a plurality of transmission intervals.
7. The method of claim 1 , wherein the selecting comprises a static mapping of clusters to a subset of service areas, wherein each subset comprises N service areas and each subset comprises uniformly spaced service areas.
8. The method of claim 1 , wherein the selecting selects feeds associated with a respective service area of one or more of the N data streams.
9. The method of claim 1 , further comprising forming the N data streams by encoding, modulating and framing each of the N data streams.
10. The method of claim 1 , further comprising sending the M feed excitations to a satellite, wherein the switching and the beamforming are performed in the satellite, and the beamforming comprises transmitting the N beams from the antenna.
11. The method of claim 1 , further comprising receiving the M feed excitations from a satellite, wherein the switching and the beamforming are performed in the satellite, and the beamforming comprises receiving the N beams from the antenna.
12. The method of claim 1 , wherein the M×N weights provide interference suppression so that a same frequency and polarization is used for the M feeds in the cluster.
13. A system to beamform comprising:
an antenna comprising feeds;
a coverage area comprising service areas and data streams for each of the service areas;
a scheduler to schedule N data streams of the data streams and to select a cluster of M feeds from the feeds;
a GBBF processor (ground based beam former), to compute M×N weights;
a Complex Weight Multiplier to generate M feed excitations that distribute the N data streams per the M×N weights; and
a switch to transfer a respective one of the M feed excitations to a respective one of the M feeds,
wherein N beams are beamformed with the M feeds of the antenna,
the N beams are each focused on a respective service area of each of the N data streams,
the M×N weights improve the transmitting into the respective service area of each of the N data streams, and
at least one of the N beams comprises a portion of a plurality of the M feed excitations.
14. The system of claim 13 , wherein the antenna comprises an array-fed reflector comprising more than the M feeds and M is greater than N.
15. The system of claim 13 , wherein the M×N weights are weighted to account for a predicted offered traffic demand based on usage patterns for each of the N data streams.
16. The system of claim 13 , wherein the Scheduler moves the N beams over a breadth of the coverage area over a plurality of transmission intervals.
17. The system of claim 13 , wherein the Scheduler comprises a static mapping of clusters to a subset of service areas, wherein each subset comprises N service areas and each subset comprises uniformly spaced service areas.
18. The system of claim 13 , wherein the Scheduler selects feeds associated with a respective service area of one or more of the N data streams.
19. The system of claim 13 , further comprising: a satellite; and a RF gateway to transmit the M feed excitations to the satellite, wherein the switch and the antenna are disposed in the satellite, and the beamformer transmits the N beams from the antenna.
20. The system of claim 13 , a satellite; and a RF gateway to receive the M feed excitations from the satellite, wherein the switch and the antenna are disposed in the satellite, and the beamformer receives the N beams from the antenna.