System and method for supporting antenna beamforming in a cellular network
The present invention is a method and system for supporting a beamforming antenna system in a mobile broadband communication network with an improved beam pattern, beam sweep pattern, pilot channel design with feedback and reporting rules, and control signaling design. Specifically, the improved beam pattern includes a method of supporting wireless communications in a wireless network forming at least two spatial beams within a cell segment where the at least two spatial beams are associated with different power levels, and separately, where at least two spatial beams can be moved across the cell segment according to a unique sweep pattern. The pilot channel design improves network bandwidth performance and improve user mobility tracking. Feedback and reporting rules can be established using a particular field designator, CQI, in the preferred embodiment.
1. A method for selecting a best spatial beam for transmission from an access node to a receiver on a communication system that has at least two spatial beams providing coverage in a first coverage area in a cell segment, the method comprising:
transmitting a pilot channel indicator signal periodically from the access node over a plurality of spatial beam transmissions using the at least two spatial beams, wherein the at least two spatial beams use one of a plurality of spatial beam positions which change over time;
acquiring at the access node a feedback signal from the receiver, said feedback signal including:
two channel quality indicators determined from the pilot channel indicator signal transmitted from the access node; and
two beam index values having an indication of two spatial beam positions among the plurality of spatial beam positions where the receiver is located when the receiver is located in a position where spatial beams are overlapping; and
scheduling transmissions from the access node to the receiver based on an analysis of at least one of the two channel quality indicators and at least one of the two beam index values received in the feedback signal, said analysis determining a spatial beam that is best suited for the transmissions to the receiver without creating interference with other transmissions on other spatial beams.
2. The method of claim 1 , wherein the pilot channel indicator signal is transmitted on all beamformed transmissions in the first coverage area.
3. The method of claim 1 , wherein the pilot channel indicator signal is transmitted at high power to ensure receivers located on an edge of the first coverage area will receive the pilot channel indicator signal.
4. The method of claim 1 , wherein the access node determines the best spatial beam being transmitted at high power from the at least one of the two beam index values or the at least one of the channel quality indicators in the feedback signal.
5. The method of claim 1 , wherein the receiver determines the best spatial beam being transmitted at high power from the at least one of the two beam index values or the at least one of the channel quality indicators in the feedback signal.
6. The method of claim 1 , wherein data transmitted on the two spatial beams is processed through the same scrambling protocols.
7. The method of claim 1 , wherein a first spatial beam of the at least two spatial beams is transmitted at a higher power level than a second spatial beam of the at least two spatial beams.
8. A transmission system that selects a best spatial beam for transmission from an access node to a receiver on a communication system that has at least two spatial beams providing coverage in a cell sector, the transmission system comprising:
the access node configured to transmit a pilot channel indicator signal periodically over a plurality of spatial beam transmissions using the at least two spatial beams, wherein the at least two spatial beams use one of a plurality of spatial beam positions which change over time, said access node acquiring a feedback signal from the receiver, said feedback signal including:
two channel quality indicators determined from the pilot channel indicator signal transmitted from the access node; and
two beam index values having an indication of two spatial beam positions among the plurality of spatial beam positions where the receiver is located when the receiver is located in a position where spatial beams are overlapping; and
wherein said access node is further configured to schedule transmissions to the receiver based on an analysis of at least one of the two channel quality indicators and at least one of the two beam index values received in the feedback signal, said analysis determining a spatial beam that is best suited for the transmissions to the receiver without creating interference with other transmissions on other spatial beams.
9. The transmission system of claim 8 , wherein the access node is configured to transmit the pilot channel indicator signal on all beamformed transmissions in the cell sector.
10. The transmission system of claim 8 , wherein the access node is configured to transmit the pilot channel indicator signal at high power to ensure receivers located on an edge of the cell sector will receive the pilot channel indicator signal.
11. The transmission system of claim 8 , wherein the access node is configured to determine the best spatial beam being transmitted at high power from the at least one of the two beam index values or the at least one of the channel quality indicators in the feedback signal.
12. The transmission system of claim 8 , wherein the receiver is configured to determine the best spatial beam being transmitted at high power from the at least one of the two beam index values or the at least one of the channel quality indicators in the feedback signal.
13. The transmission system of claim 8 , wherein the access node is configured to process data transmitted on the two spatial beams through the same scrambling protocols.
14. The system of claim 8 , wherein a first spatial beam of the at least two spatial beams is transmitted at a higher power level than a second spatial beam of the at least two spatial beams.
15. A nontransitory memory medium for selecting a best spatial beam for transmission from an access node to a receiver on a communication system that has at least two spatial beams providing coverage in a first coverage area in a cell segment, wherein the memory medium stores program instructions, wherein the program instructions are executable by a processor to implement:
transmitting a pilot channel indicator signal periodically from the access node over a plurality of spatial beam transmissions using the at least two spatial beams, wherein the at least two spatial beams use one of a plurality of spatial beam positions which change over time;
acquiring at the access node a feedback signal from the receiver, said feedback signal including:
two channel quality indicators determined from the pilot channel indicator signal transmitted from the access node; and
two beam index values having an indication of two spatial beam positions among the plurality of spatial beam positions where the receiver is located when the receiver is located in a position where spatial beams are overlapping; and,
scheduling transmissions from the access node to the receiver based on an analysis of at least one of the two channel quality indicators and at least one of the two beam index values received in the feedback signal, said analysis determining a spatial beam that is best suited for the transmissions to the receiver without creating interference with other transmissions on other spatial beams.
16. The nontransitory memory medium of claim 15 , wherein the program instructions are executable by the processor to implement:
transmitting the pilot channel indicator signal on all beamformed transmissions in the first coverage area.
17. The nontransitory memory medium of claim 15 , wherein the program instructions are executable by the processor to implement:
transmitting the pilot channel indicator signal at high power to ensure receivers located on an edge of the first coverage area receive the pilot channel indicator signal.
18. The nontransitory memory medium of claim 15 , wherein the program instructions are executable by the processor to implement:
determining the best spatial beam being transmitted at high power from the at least one of the two beam index values or the at least one of the channel quality indicators in the feedback signal.
19. The nontransitory memory medium of claim 15 , wherein the receiver determines the best spatial beam being transmitted at high power from the at least one of the two beam index values or the at least one of the channel quality indicators in the feedback signal.
20. The nontransitory memory medium of claim 15 , wherein the program instructions are executable by a processor to implement:
processing data transmitted on the two spatial beams through the same scrambling protocols.
21. The nontransitory memory medium of claim 15 , wherein a first spatial beam of the at least two spatial beams is transmitted at a higher power level than a second spatial beam of the at least two spatial beams.