ELEMENT INDEPENDENT ROUTERLESS BEAMFORMING

• US 20100090898A1
• Filed: 10/15/2008
• Published: 04/15/2010
• Est. Priority Date: 10/15/2008
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Horn, William T., Gallagher, Timothy C.
• Granted Patent: US 7,973,713 B2
• Time in Patent Office: Days
• US Class Current: 342/373
• CPC Class Codes: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence

Abstract

Described herein are systems and methods that eliminate the need for costly and complex switching networks for routing channelized data between antenna elements and beamformers. In one aspect, a beamforming system comprises a beamformer for each antenna element of an antenna array, in which the beamformers for the different antenna elements are arranged in parallel. The beamforming system also comprises a combiner that combines the outputs of the beamformers into a single beam. In one aspect, the beamformers of antenna elements that do not contribute to a desired beam output zeros to the combiner, which when added to the subbeams of the other beamformers have no affect of the final beam. In another aspect, operations (e.g., multiplication, memory reads) of each beamformer that does not contribute to a desired beam may be turned off to conserve power.

Claims

1. A system for beamforming signals from a plurality of antenna elements, comprising:

for each antenna element;

a channelizer configured to channelize a signal received by the respective antenna element into a plurality of subchannels and output subchannel data for each of the plurality of subchannels; and

a beamformer configured to multiply subchannel data from the respective channelizer for one of the plurality of subchannels with a beam weight corresponding to the respective antenna element to form a subbeam; and

a combiner configured to combine subbeams from the beamformers into a beam.

2. The system of claim 1, wherein each beamformer comprises:

an input memory configured to store subchannel data from the respective channelizer into a subchannel table, the subchannel table comprising a plurality of subchannel bins, each subchannel bin corresponding to one of the plurality of subchannels;

a reader configured to read out subchannel data from the subchannel table based on a subchannel bin number; and

a multiplier configured to multiply the read subchannel data with the respective beam weight to form the respective subbeam.

3. The system of claim 2, wherein each beamformer comprises a controller configured to turn off the respective reader and multiplier when the respective beam weight is a zero weight.

4. The system of claim 2, wherein each beamformer comprises a controller configured to turn off the respective reader and multiplier when the respective beamformer does not contribute to the beam.

5. The system of claim 1, wherein each beamformer comprises:

a weight memory configured to store a weight table, the weight table comprising a plurality of beam weights; and

a reader configured to read one of the beam weights from the weight table based on a beam index number; and

a multiplier configured to multiply the read beam weight with the subchannel data from the respective channelizer to form the respective subbeam.

6. The system of claim 5, wherein each beamformer comprises a controller configured to turn off the respective multiplier when the read beam weight is a zero weight.

7. The system of claim 5, wherein each beamformer comprises a controller configured to turn off the respective multiplier when the respective beamformer does not contribute to the beam.

8. The system of claim 5, wherein each weight table is configured to store zero weights corresponding to beams for which the respective beamformer does not contribute.

9. The system of claim 1, wherein each beamformer comprises:

an input memory configured to store incoming subchannel data from the respective channelizer into a subchannel table, the subchannel table comprising a plurality of subchannel bins, each subchannel bin corresponding to one of the plurality of subchannels;

a first reader configured to read out subchannel data from the subchannel table in the input memory based on a subchannel bin number;

a weight memory configured to store a weight table, the weight table comprising a plurality of beam weights; and

a second reader configured to read one of the beam weights from the weight table based on a beam index number; and

a multiplier configured to multiply the read subchannel data with the read beam weight to form the respective subbeam.

10. The system of claim 9, wherein each beamformer comprises a controller configured to turn off the respective first reader and multiplier when the read beam weight is a zero weight.

11. The system of claim 9, wherein each beamformer comprises a controller configured to turn off the respective first reader and multiplier when the respective beamformer does not contribute to the beam.

12. The system of claim 9, wherein each weight table stores zero weights corresponding to beams for which the respective beamformer does not contribute.

13. The system of claim 9, further comprising:

an index memory configured to store an index table, the index table comprising a plurality of beam index numbers; and

for each beamformer, a controller configured to read out one of the beam index numbers from the index table, wherein the respective second reader is configured to read out the beam weight from the respective weight table according to the read beam index number.

14. The system of claim 11, wherein each controller is configured to sequentially read out the beam index numbers from the index table.

15. A system for beamforming signals for transmission on a plurality of antenna elements, comprising:

a channelizer configured to channelize an input signal into a plurality of subchannels and output subchannel data for each of the plurality of subchannels;

for each antenna element;

a beamformer configured to multiply subchannel data from the channelizer for one of the plurality of subchannels with a beam weight corresponding to the beamformer to form a subbeam; and

a reconstructor configured to process the respective subbeam into a reconstructed signal for transmission from the respective antenna element.

16. The system of claim 15, wherein each beamformer comprises:

an input memory configured to store subchannel data from the channelizer into a subchannel table, the subchannel table comprising a plurality of subchannel bins, each subchannel bin corresponding to one of the plurality of subchannels;

a reader configured to read out subchannel data from the subchannel table based on a subchannel bin number; and

a multiplier configured to multiply the read subchannel data with the respective beam weight to form the respective subbeam.

17. The system of claim 16, wherein each beamformer comprises a controller configured to turn off the respective reader and multiplier when the respective beam weight is a zero weight.

18. The system of claim 16, wherein each beamformer comprises a controller configured to turn off the respective reader and multiplier when the respective beamformer does not contribute to the beam.

19. The system of claim 15, wherein each beamformer comprises:

a weight memory configured to store a weight table, the weight table comprising a plurality of beam weights; and

a reader configured to read out one of the beam weights from the weight table based on a beam index number; and

a multiplier configured to multiply the read beam weight with the subchannel data from the channelizer to form the respective subbeam.

20. The system of claim 19, wherein each beamformer comprises a controller configured to turn off the respective multiplier when the read beam weight is a zero weight.

21. The system of claim 19, wherein each beamformer comprises a controller configured to turn off the respective multiplier when the respective beamformer does not contribute to the beam.

22. The system of claim 19, wherein each weight table stores zero weights corresponding to beams for which the respective beamformer does not contribute.

23. The system of claim 15, wherein each beamformer comprises:

an input memory configured to store incoming subchannel data from the channelizer into a subchannel table, the subchannel table comprising a plurality of subchannel bins, each subchannel bin corresponding to one of the plurality of subchannels;

a first reader configured to read out subchannel data from the subchannel table in the input memory based on a subchannel bin number;

a weight memory configured to store a weight table, the weight table comprising a plurality of beam weights; and

a second reader configured to read out one of the beam weights from the weight table based on a beam index number; and

a multiplier configured to multiply the read subchannel data with the read beam weight to form the respective subbeam.

24. The system of claim 23, wherein each beamformer comprises a controller configured to turn off the respective first reader and multiplier when the read beam weight is a zero weight.

25. The system of claim 23, wherein each beamformer comprises a controller configured to turn off the respective first reader and multiplier when the respective beamformer does not contribute to the beam.

26. The system of claim 23, wherein each weight table stores zero weights corresponding to beams for which the respective beamformer does not contribute.

27. The system of claim 23, further comprising:

an index memory that stores an index table, the index table comprising a plurality of beam index numbers; and

for each beamformer, a controller configured to read out one of the beam index numbers from the index table, wherein the respective second reader is configured to read out the beam weight from the respective weight table according to the read index beam number.

28. The system of claim 27, wherein each controller is configured to sequentially read out the beam index numbers from the index table.