BEAM COMBINATION METHODS AND SYSTEMS FOR ADAPTING COMMUNICATION LINKS TO VARYING CHANNEL CONDITIONS

• US 20110113137A1
• 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: Prasad, Narayan, Ramachandran, Kishore, Rangarajan, Sampath
• Granted Patent: US 8,510,433 B2
• Time in Patent Office: Days
• US Class Current: 709/224
• 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 rectifying deteriorated channel conditions on a communication link are described. In response to the detection of a link deterioration event, a cluster of beams about a currently utilized beam pair can be trialed to determine a suitable, alternate pair of beams on which to establish a communication link. In turn, in the case of a link blockage event, a set of beams having a relatively large azimuthal angle with respect to a currently utilized beam pair can be trialed to determine a suitable beam pair for further communication.

Claims

1. A beamforming method comprising:

detecting a deterioration of a first communication link between a transmitter and a receiver;

in response to the detecting, obtaining candidate sets of transmission beams and reception beams, wherein at least one of the candidate sets is composed of a respective cluster of beams about a transmission beam or a reception beam on which the first communication link is implemented;

determining a signal quality for each transmission beam and reception beam pair from the candidate sets by transmitting or receiving signals on the respective transmission beam or reception beam in each pair; and

establishing a new communication link with one of the pairs from the candidate sets that is selected based on the determined signal quality for the selected pair.

2. The method of claim 1, wherein the candidate set of reception beams is prioritized in accordance with a direction of arrival with respect to the reception beam on which the first communication link is implemented.

3. The method of claim 1, wherein the candidate set of transmission beams is prioritized in accordance with a direction of departure with respect to the transmission beam on which the first communication link is implemented.

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

ordering beam pairs from the candidate sets in accordance with an angular disparity with respect to the beam pair on which the new communication link is established.

5. The method of claim 4, wherein a pair having an angular disparity that is larger than angular disparities of other pairs is prioritized over the other pairs.

6. The method of claim 4, wherein a pair having an angular disparity that is lower than angular disparities of other pairs is prioritized over the other pairs.

7. The method of claim 1, wherein the signal quality is dependent on at least one of:

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

8. A beamforming method comprising:

detecting a blockage of a first communication link between a transmitter and a receiver;

in response to the detecting, obtaining candidate sets of transmission beams and reception beams, wherein at least one of the candidate sets is composed of respective beams having azimuthal angles that exceed pre-determined thresholds with regard to a transmission beam or a reception beam on which the communication link is implemented;

determining a signal quality for each transmission beam and reception beam pair from the candidate sets by transmitting or receiving signals on the respective transmission beam or reception beam in each pair; and

establishing a new communication link with one of the pairs from the candidate sets that is selected based on the determined signal quality for the selected pair.

9. The method of claim 8, wherein the candidate set of reception beams is prioritized in accordance with a direction of arrival with respect to the reception beam on which the first communication link is established, wherein the threshold with regard to the reception beam is variable and corresponds to the azimuthal angle of the reception beam having the lowest disparity with respect to the azimuthal angle of the reception beam on which the first communication link is established.

10. The method of claim 8, wherein the candidate set of transmission beams is prioritized in accordance with a direction of departure with respect to the transmission beam on which the first communication link is established, wherein the threshold with regard to the transmission beam is variable and corresponds to the azimuthal angle of the transmission beam having the lowest disparity with respect to the azimuthal angle of the transmission beam on which the first communication link is established.

11. The method of claim 8, wherein the method further comprises:

ordering beam pairs from the candidate sets in accordance with an angular disparity with respect to the beam pair on which the new communication link is established.

12. The method of claim 11, wherein a pair having an angular disparity that is larger than angular disparities of other pairs is prioritized over the other pairs.

13. The method of claim 11, wherein a pair having an angular disparity that is lower than angular disparities of other pairs is prioritized over the other pairs.

14. The method of claim 8, wherein the signal quality is dependent on at least one of:

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

15. A beamforming system comprising:

a transmitter device configured to separately transmit signals on transmission beams in a candidate set of transmission beams; and

a receiver device configured to separately apply reception beams from a candidate set of reception beams to receive the signals on the transmission beams and to determine a received signal quality for each transmission beam and reception beam pair from the candidate sets,

wherein at least one of the devices is further configured to perform at least one of;

a) detection of a deterioration or a blockage of a first communication link between the devices, and b) determination of at least one of the candidate sets by selecting a respective cluster of beams about a transmission beam or a reception beam on which the first communication link is implemented or by selecting beams for inclusion in the respective candidate set that have azimuthal angles exceeding azimuthal angles of beams in the cluster with respect to the transmission beam or the reception beam on which the first communication link is implemented,

wherein the transmitter and receiver devices are further configured to establish a new communication link on one of the pairs from the candidate sets that is selected based on the received signal quality for the selected pair.

16. The system of claim 15, wherein the candidate set of reception beams is prioritized in accordance with a direction of arrival with respect to the reception beam on which the first communication link is implemented.

17. The system of claim 15, wherein the candidate set of transmission beams is prioritized in accordance with a direction of departure with respect to the transmission beam on which the first communication link is implemented.

18. The system of claim 15, wherein at least one of the devices is further configured to order beam pairs from the candidate sets in accordance with an angular disparity with respect to the beam pair on which the new communication link is established.

19. The system of claim 18, wherein a pair having an angular disparity that is larger than angular disparities of other pairs is prioritized over the other pairs.

20. The system of claim 18, wherein a pair having an angular disparity that is lower than angular disparities of other pairs is prioritized over the other pairs.