SYSTEMS AND METHODS FOR PRIORITIZING BEAMS TO ENABLE EFFICIENT DETERMINATION OF SUITABLE COMMUNICATION LINKS

• US 20110110453A1
• Filed: 11/08/2010
• Published: 05/12/2011
• Est. Priority Date: 11/06/2009
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Laboratories America Inc (NEC Corporation)
• Inventors: Rangarajan, Sampath, Prasad, Narayan, Ramachandran, Kishore
• Granted Patent: US 8,660,598 B2
• Time in Patent Office: Days
• US Class Current: 375/285
• CPC Class Codes: H04B 1/1027 assessing signal quality or detecting noise/interference for the received signal
• CPC Class Codes: H04B 7/0408 using two or more beams, i.e. beam diversity
• CPC Class Codes: H04B 7/063 Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection
• CPC Class Codes: H04B 7/0695 using beam selection
• CPC Class Codes: H04B 7/088 using beam selection

Abstract

Methods and systems for enabling the rectification of deteriorated channel conditions on a communication link are described. In particular, the methods and systems can employ mechanisms that prioritize beams in accordance with signal quality measures, direction of departures of transmission beams and/or direction of arrivals of reception beams to address variable channel conditions.

Claims

1. A beamforming transmission method comprising:

transmitting signals on different beams to enable a receiver to determine a respective signal quality for each of the beams;

prioritizing a plurality of the different beams in accordance with a metric that depends upon the signal quality for each of the plurality of the different beams measured at the receiver and a direction of departure for each of the plurality of the different beams;

selecting a particular beam from the plurality of the different beams; and

transmitting data signals to the receiver on the particular beam.

2. The method of claim 1, wherein the prioritizing further comprises selecting beams with a signal quality exceeding a threshold for inclusion in the plurality of different beams and ordering the beams included in the plurality of different beams in accordance with the direction of departure with respect to the beam resulting in the largest signal quality.

3. The method of claim 2, wherein a beam having a direction of departure that is larger than direction of departures of other beams is prioritized over the other beams.

4. The method of claim 2, wherein a beam having a direction of departure that is smaller than direction of departures of other beams is prioritized over the other beams.

5. The method of claim 1, wherein the method further comprises:

iteratively transmitting signals on each beam in a subset of transmission beams to enable the receiver to determine the direction of arrivals of a set of reception beams by scanning through the set of reception beams for each of the transmission beams in the subset.

6. The method of claim 1, wherein the selecting further comprises prioritizing a plurality of given beams based on the metric for evaluation during a subsequent transmission sector level sweep or during a beam combination stage in which each given beam is iteratively transmitted for each reception beam in a set of reception beams applied by the receiver.

7. The method of claim 6, wherein the method further comprises:

ordering combinations of transmission beams and reception beams based on a signal quality for the combinations measured at the receiver, direction of departures of the transmission beams in the combinations and direction of arrivals of the reception beams in the combinations.

8. A beamforming reception method comprising:

applying different reception beams to receive a transmission signal;

determining a respective signal quality for each of the reception beams;

prioritizing a plurality of the different beams in accordance with a metric that depends upon the respective signal quality for each of the plurality of the different beams and a direction of arrival of each of the plurality of the different beams; and

receiving data signals on a particular beam that is selected from the plurality of the different beams.

9. The method of claim 8, wherein the applying different reception beams further comprises receiving a set of transmission beams chosen in accordance with a respective signal quality measured during a transmission sector level sweep and with a direction of departure for each of the transmission beams.

10. The method of claim 8, wherein the prioritizing comprises selecting beams with a signal quality exceeding a threshold for inclusion in the plurality of different beams and ordering the beams included in the plurality of different beams in accordance with the direction of arrival with respect to the beam resulting in the largest signal quality.

11. The method of claim 10, wherein a beam having a direction of arrival that is larger than direction of arrivals of other beams is prioritized over the other beams.

12. The method of claim 10, wherein a beam having a direction of arrival that is smaller than direction of arrivals of other beams is prioritized over the other beams.

13. The method of claim 8, wherein the prioritizing further comprises selecting a plurality of given reception beams based on the metric for evaluation during a subsequent receiver sector level sweep or during a beam combination stage in which each given reception beam is iteratively applied for each transmission beam in a set of transmission beams transmitted by the transmitter.

14. The method of claim 13, wherein the method further comprises:

ordering combinations of transmission beams and reception beams based on signal qualities for the combinations measured at a receiver, directions of departures of the transmission beams in the combinations and direction of arrivals of the reception beams in the combinations.

15. A beamforming method comprising:

determining a signal quality for each combination of a transmission beam and a reception beam from candidate sets of transmission and reception beams,

prioritizing the combinations in accordance with a metric that is based upon a signal quality for a given combination measured at a receiver and at least one of;

a direction of departure of the transmission beam in the given combination and a direction of arrival of the reception beam in the given combination;

selecting a particular combination in accordance with the priority of the particular combination; and

transmitting or receiving data signals on the beams in the particular combination.

16. The method of claim 15, wherein the prioritizing comprises ordering the combinations in accordance with an angular disparity with respect to a combination resulting in the largest signal quality, wherein a combination having an angular disparity that is larger than angular disparities of other combinations is prioritized over the other combinations.

17. The method of claim 16, wherein the selecting is performed in response to detecting a blockage of a communication link between a transmitter and a receiver and wherein the transmitting or receiving data signals on the beams in the particular combination is performed in response to determining a sufficiency of a signal quality for the particular combination subsequent to said detecting.

18. The method of claim 15, wherein the prioritizing comprises ordering the combinations in accordance with an angular disparity with respect to a combination resulting in the largest signal quality, wherein a combination having an angular disparity that is lower than angular disparities of other combinations is prioritized over the other combinations.

19. The method of claim 18, wherein the selecting is performed in response to detecting a deterioration of a communication link between a transmitter and a receiver and wherein the transmitting or receiving data signals on the beams in the particular combination is performed in response to determining a sufficiency of a signal quality for the particular combination subsequent to said detecting.

20. The method of claim 15, wherein the signal quality is at least one of:

a signal to noise ratio (SNR), a bit error rate (BER), a packet error rate (PER) and a frame error rate (FER).