Beamforming coordination in heterogeneous networks

• US 8,977,307 B2
• Filed: 06/29/2012
• Issued: 03/10/2015
• Est. Priority Date: 11/04/2011
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Davydov, Alexei, Morozov, Gregory V., Maltsev, Alexander, Pudeyev, Andrey
• Primary Examiner(s): TRINH, TAN H
• Application Number:
  US13/538,784
• Publication Number:
  US 20130115985A1
• Time in Patent Office: 984 Days
• Field of Search: 455/501, 455/63.1, 455/67.13, 455/67.15, 455/522, 455/524, 455/69, 455/452.2, 455/88, 370/329, 370/331, 375/260, 375/148, 375/316, 375/267, 375/295, 375/224, 342/373
• US Class Current: 455/501
• CPC Class Codes: H04B 7/024 Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04B 7/0639 Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Technology for spatial domain beamforming coordination at a low power node (LPN) in a heterogeneous network (HetNet) is disclosed. One method can include the LPN collecting spatial feedback information of macro node interference from a plurality of wireless devices in a LPN cell. The LPN can compile the spatial feedback information into a spatial feedback report. The LPN can send the spatial feedback report from the LPN to a macro node for calculating a beamforming vector to reduce the macro node interference for the plurality of wireless devices in the LPN cell.

Claims

1. At least one non-transitory machine readable storage medium comprising a plurality of instructions adapted to be executed to implement the method for spatial domain beamforming coordination at a low power node (LPN) in a heterogeneous network (HetNet), comprising:

collecting at the LPN spatial feedback information of macro node interference from a plurality of wireless devices in a LPN cell;

compiling the spatial feedback information at the LPN into a spatial feedback report; and

sending the spatial feedback report from the LPN to a macro node for calculating a beamforming vector to reduce the macro node interference for the plurality of wireless devices in the LPN cell.

2. The non-transitory machine readable storage medium of claim 1, wherein the spatial feedback information is selected from the group consisting of a quantized principle eigen-vector, a precoding matrix indicator (PMI) of a codebook, a signal path gain, a reference signal received power (RSRP), a signal to interference and noise ratio (SINR), and combinations thereof.

3. The non-transitory machine readable storage medium of claim 1, wherein compiling the spatial feedback information further comprises:

categorizing the spatial feedback information of the plurality of wireless devices, wherein the spatial feedback information includes a precoding matrix indicator (PMI); and

selecting a most frequently reported category of the PMIs for the spatial feedback report.

4. The non-transitory machine readable storage medium of claim 1, wherein compiling the spatial feedback information further comprises:

quantizing a dominant principle eigen-vector corresponding to a matrix

5. The non-transitory machine readable storage medium of claim 1, wherein sending the spatial feedback report further comprises:

calculating a matrix

6. The non-transitory machine readable storage medium of claim 1, wherein the plurality of wireless devices include a majority of the wireless devices connected to the LPN.

7. The non-transitory machine readable storage medium of claim 1, further comprising:

transmitting a coordinated signal to a wireless device from a low power node (LPN) in a coordinated time-frequency resource partition, wherein the coordinated signal has reduced interference from a macro node transmission in the spatial direction of the wireless device using beamforming during the coordinated time-frequency resource partition;

receiving from the wireless device at the LPN a coordinated channel quality indicator (CQI) feedback, wherein the coordinated CQI feedback includes an estimation of a propagation channel and interference during the coordinated time-frequency resource partition at the wireless device;

modulating and coding the coordinated signal using a coordinated modulation and coding scheme (MCS) based on the coordinated CQI feedback;

transmitting a non-coordinated signal to the wireless device from the LPN in a non-coordinated time-frequency resource partition, wherein the non-coordinated signal includes interference from a macro node transmission during the non-coordinated time-frequency resource partition;

receiving from the wireless device at the LPN a non-coordinated CQI feedback, wherein the non-coordinated CQI feedback includes an estimation of a propagation channel and interference including a macro node interference channel during non-coordinated time-frequency resource partition at the wireless device; and

modulating and coding the non-coordinated signal using a non-coordinated MCS based on the non-coordinated CQI feedback, wherein the coordinated MCS differs from the non-coordinated MCS.

8. The non-transitory machine readable storage medium of claim 7, wherein the coordinated time-frequency resource partitions and the non-coordinated time-frequency resource partitions are selected from the group consisting of a radio frame, a radio subframe, a slot, a frequency carrier, a frequency subcarrier, a physical resource block (PRB), a subband, and combinations thereof.

9. The non-transitory machine readable storage medium of claim 1, further comprising:

semi-statically configuring, at the LPN, coordinated time-frequency resource partitions and non-coordinated time-frequency resource partitions via upper layer signaling with the macro node, wherein a coordinated signal transmitted to a wireless device has reduced interference from a macro node transmission in the spatial direction of the wireless device using beamforming during the coordinated time-frequency resource partition, and a non-coordinated signal to the wireless device includes interference from a macro node transmission during the non-coordinated time-frequency resource partition.

10. At least one non-transitory machine readable storage medium comprising a plurality of instructions adapted to be executed to implement the method for spatial domain beamforming coordination at a macro node in a heterogeneous network (HetNet), comprising:

receiving at the macro node a plurality of spatial feedback reports, wherein a spatial feedback report is received from each low power node (LPN) in a coordination set of the HetNet, and each spatial feedback report provides information about interference from the macro node at a reporting LPN; and

calculating a beamforming vector for the time-frequency resource partition using at least one spatial feedback report from the LPNs associated with the time-frequency resource partition, wherein the time-frequency resource partition provides a time-frequency resource for transmission coordination between the macro node and LPNs associated with the time-frequency resource partition, and the beamforming vector is configured to suppress interference in the spatial direction of the LPNs associated with a time-frequency resource partition.

11. The non-transitory machine readable storage medium of claim 10, further comprising:

grouping of LPNs with similar spatial characteristics into a same time-frequency resource partition as determined by the spatial feedback reports of the LPNs.

12. The non-transitory machine readable storage medium of claim 10, wherein the spatial feedback report is selected from the group consisting of a most frequently reported category of precoding matrix indicator (PMI) of codebook by wireless devices served by a reporting LPN, a quantized dominant principle eigen-vector of the wireless devices served by the reporting LPN, a matrix G generated by the reporting LPN from the wireless devices served by the reporting LPN, and combinations thereof, wherein the quantized dominant principle eigen-vector corresponds to a matrix

13. The non-transitory machine readable storage medium of claim 10, further comprising:

transmitting a channel from the macro node using the beamforming vector during the time-frequency resource partition.

14. The non-transitory machine readable storage medium of claim 10, wherein calculating the beamforming vector further comprises using a zero-forcing process for interference mitigation.

15. The non-transitory machine readable storage medium of claim 10, further comprising:

semi-statically configuring at the macro node coordinated time-frequency resource partitions and non-coordinated time-frequency resource partitions via upper layer signaling with each LPN, wherein a coordinated signal transmitted to a wireless device in a specified LPN cell has reduced interference from a macro node transmission in the spatial direction of the wireless device using beamforming during the coordinated time-frequency resource partition, and a non-coordinated signal to the wireless device in the specified LPN cell includes interference from a macro node transmission during the non-coordinated time-frequency resource partition.

16. The non-transitory machine readable storage medium of claim 15, wherein the coordinated time-frequency resource partitions and the non-coordinated time-frequency resource partitions are selected from the group consisting of a radio frame, a radio subframe, a slot, a frequency carrier, a frequency subcarrier, a physical resource block (PRB), a subband, and combinations thereof.

17. The non-transitory machine readable storage medium of claims 10, wherein receiving at the macro node the plurality of spatial feedback reports includes X2 signaling or backhaul link signaling with the LPNs via a wired connection, a wireless connection, or an optical fiber connection.

18. At least one non-transitory machine readable storage medium comprising a plurality of instructions adapted to be executed to implement the method for spatial domain beamforming coordination at a wireless device in a heterogeneous network (HetNet), comprising:

receiving at the wireless device a coordinated signal from a low power node (LPN) in a coordinated time-frequency resource partition, wherein the coordinated signal has reduced interference from a macro node transmission in the spatial direction of the wireless device using beamforming during the coordinated time-frequency resource partition;

calculating a coordinated channel quality indicator (CQI) from an estimation of a propagation channel and interference during the coordinated time-frequency resource partition;

receiving at the wireless device a non-coordinated signal from the LPN in a non-coordinated time-frequency resource partition, wherein the non-coordinated signal includes interference from a macro node transmission during the non-coordinated time-frequency resource partition; and

calculating a non-coordinated CQI from an estimation of a propagation channel and interference including a macro node interference channel during the non-coordinated time-frequency resource partition.

19. The non-transitory machine readable storage medium of claim 18, further comprising:

transmitting the coordinated CQI from the wireless device to the LPN to enable transmission with coordinated modulation and coding scheme (MCS) for the coordinated signal; and

transmitting the non-coordinated CQI from the wireless device to the LPN to enable transmission with non-coordinated MCS for the non-coordinated signal to be determined the LPN.

20. The non-transitory machine readable storage medium of claim 18, further comprising:

transmitting spatial feedback information of macro node interference channel from the wireless device to the LPN, wherein the spatial feedback information is selected from the group consisting of a quantized principle eigen-vector, a preceding matrix indicator (PMI) of a code book, a signal path gain, a reference signal received power (RSRP), a signal to interference and noise ratio (SINR), and combinations thereof.

21. The non-transitory machine readable storage medium of claim 18, wherein the coordinated time-frequency resource partitions and the non-coordinated time-frequency resource partitions are selected from the group consisting of a radio frame, a radio subframe, a slot, a frequency carrier, a frequency subcarrier, a physical resource block (PRB), a subband, and combinations thereof.

22. The non-transitory machine readable storage medium of claim 18, wherein the wireless device is selected from the group consisting of a user equipment (UE) and a mobile station (MS), wherein the wireless device is configured to connect to at least one of a wireless local area network (WLAN), a wireless personal area network (WPAN), and a wireless wide area network (WWAN), wherein the wireless device includes an antenna, a touch sensitive display screen, a speaker, a microphone, a graphics processor, an application processor, internal memory, a non-volatile memory port, or combinations thereof.

23. A beamforming coordination device for a macro node in a heterogeneous network (HetNet) for spatial domain beamforming coordination, comprising:

a receiving module configured to receive a plurality of spatial feedback reports, wherein a spatial feedback report is received from each low power node (LPN) in a coordination set of the HetNet, and each spatial feedback report provides information about interference from the macro node at a reporting LPN; and

a processing module configured to calculate a beamforming vector for a time-frequency resource partition using at least one spatial feedback report from the LPNs associated with a time-frequency resource partition, wherein the time-frequency resource partition provides a time-frequency resource for transmission coordination between the macro node and LPNs associated with the time-frequency resource partition, and the beamforming vector is configured to suppress interference in the spatial direction of the LPNs associated with the time-frequency resource partition.

24. The beamforming coordination device of claim 23, further comprising:

a scheduler configured to group LPNs with similar spatial characteristics into a same time-frequency resource partition as determined by the spatial feedback reports of the LPNs.

25. The beamforming coordination device of claim 23, wherein the spatial feedback report is selected from the group consisting of a most frequently reported category of precoding matrix indicator (PMI) by wireless devices served by a reporting LPN, a quantized dominant principle eigen-vector of the wireless devices served by the reporting LPN, a matrix G generated by the reporting LPN from the wireless devices served by the reporting LPN, and combinations thereof, wherein the quantized dominant principle eigen-vector corresponds to a matrix

26. The beamforming coordination device of claim 23, further comprising:

a transceiver module configured to transmit a channel using the beamforming vector during the time-frequency resource partition.

27. The beamforming coordination device of claim 23, wherein the macro node includes a macro evolved Node B (macro-eNB) or a macro Node B (macro-NB).