Architecture to support network-wide multiple-in-multiple-out wireless communication over a downlink

• US 8,787,302 B2
• Filed: 09/18/2008
• Issued: 07/22/2014
• Est. Priority Date: 09/18/2008
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Balachandran, Krishna, Kadaba, Srinivas R., Karakayali, Kemal M., Rudrapatna, Ashok
• Primary Examiner(s): Sheikh, Ayaz
• Assistant Examiner(s): HAMPTON, TARELL A
• Application Number:
  US12/233,253
• Publication Number:
  US 20100067450A1
• Time in Patent Office: 2,133 Days
• Field of Search: 370/329, 370/330, 455/422.1, 455/446, 455/450, 455/452.1, 455/455.2, 455/509, 455/515, 455/517, 455/524
• US Class Current: 370/330
• 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 7/0413 MIMO systems
• CPC Class Codes: H04L 5/0035 Resource allocation in a cooperative multipoint environment
• CPC Class Codes: H04L 5/0082 at predetermined intervals
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others

Abstract

The present invention provides a method of coordinating the downlink transmissions from a plurality of base stations to at least one mobile unit. The method is implemented in a control plane entity and includes receiving, at the control plane entity and from each of the plurality of base stations, channel state information for a plurality of wireless communication channels between the plurality of base stations and one or more mobile units. The method also includes determining, at the control plane entity and based on the channel state information, transmission formats for downlink transmissions from the plurality of base stations to the mobile unit(s). The method further includes providing the transmission formats to the plurality of base stations.

Claims

1. A method of coordinating downlink transmissions from a plurality of base stations to at least one mobile unit, the method being implemented in a control plane entity and comprising:

receiving, at the control plane entity and from each of the plurality of base stations, channel state information for a plurality of wireless communication channels between the plurality of base stations and said at least one mobile unit and queue state information indicative of a status of queues for data to be transmitted over the downlink to said at least one mobile unit by each of the plurality of base stations;

determining, at the control plane entity and based on the channel state information and the queue state information, transmission formats for synchronized downlink transmissions from the plurality of base stations to said at least one mobile unit so that said synchronized downlink transmissions combine coherently and constructively at said at least one mobile unit; and

providing the transmission formats to the plurality of base stations.

2. The method of claim 1, wherein determining the transmission formats comprises determining at least one of a block size, an error control code, a code rate, a modulation order, an antenna beamforming weight, a transmit power, an orthogonal frequency division multiplexing tone, and an orthogonal frequency division multiplexing tile.

3. The method of claim 1, comprising determining, at the control plane entity, timing information for each of the plurality of base stations based upon the channel state information.

4. The method of claim 3, comprising providing, from the control plane entity to the plurality of base stations, the timing information, and wherein the plurality of base stations can transmit information over the downlink at times indicated by the provided timing information so that the transmitted information from the plurality of base stations combine coherently and constructively to amplify, at said at least one mobile unit, information transmitted over the downlink.

5. The method of claim 1, comprising scheduling, at the control plane entity, synchronized downlink transmissions from the plurality of base stations to said at least one mobile unit.

6. The method of claim 5, comprising jointly scheduling the synchronized downlink transmissions and determining transmission formats for the synchronized downlink transmissions.

7. The method of claim 1, wherein the synchronized downlink transmissions from the plurality of base stations to said at least one mobile unit are scheduled by the corresponding base stations and the control plane entity determines transmission formats for the scheduled synchronized downlink transmissions.

8. The method of claim 1, comprising selecting, at the control plane entity, the plurality of base stations that provide coordinated synchronized downlink transmission to said at least one mobile unit.

9. The method of claim 8, comprising providing, from the control plane entity to an Internet Protocol (IP) gateway, information indicating the selected plurality of base stations so that the IP gateway can provide parallel downlink data streams to each of the selected plurality of base stations.

19. The method of claim 1, comprising dynamically determining, at the control plane entity, relative time delays between legs of backhaul links between the control plane entity and antennas associated with the plurality of base stations, and wherein determining the transmission formats comprises determining the transmission formats based on the relative time delays.

10. A method of coordinated downlink transmission from a plurality of base stations to at least one mobile unit, the method being implemented in a first base station that is one of the plurality of base stations and comprising:

providing, to a control plane entity and from the first base station, channel state information for at least one wireless communication channel between at least one antenna associated with the first base station and at least one antenna associated with said at least one mobile unit and queue state information indicative of a status of queues for data to be transmitted over the downlink to said at least one mobile unit;

receiving, from the control plane entity and at the first base station, transmission formats for synchronized downlink transmissions from the first base station to said at least one mobile unit, the transmission formats being determined by the control plane entity for the plurality of base stations based on the channel state information and the queue state information transmitted to the control plane entity and additional channel state information and queue state information provided to the control plane entity by at least one second base station from the plurality of base stations; and

transmitting data over the downlink in coordination with the plurality of base stations using the received transmission formats so that synchronized downlink transmissions from the plurality of base stations combine coherently and constructively at said at least one mobile unit.

11. The method of claim 10, wherein receiving the transmission format comprises receiving at least one of a block size, an error control code, a code rate, a modulation order, an antenna beamforming weight, a transmit power, an orthogonal frequency division multiplexing tone, and an orthogonal frequency division multiplexing tile.

12. The method of claim 10, comprising receiving timing information determined by the control plane entity based upon the channel state information.

13. The method of claim 12, comprising transmitting, from the first base station, information over the downlink at times indicated by the provided timing information so that the transmitted information combines coherently and constructively at said at least one mobile unit with information transmitted over the downlink by the plurality of base stations to amplify the information transmitted over the downlink by the first base station.

14. The method of claim 10, wherein synchronized downlink transmissions from the first base station to said at least one mobile unit are scheduled at the control plane entity, and comprising receiving, from the control plane entity, scheduling information for said synchronized downlink transmissions from the first base station to said at least one mobile unit.

15. The method of claim 10, comprising scheduling, at the first base station, said at least one mobile unit for synchronized downlink transmissions and providing scheduling information to the control plane entity.

16. The method of claim 15, wherein receiving the transmission formats comprises receiving transmission formats determined by the control plane entity for the scheduled synchronized downlink transmissions in response to providing the scheduling information to the control plane entity.

17. The method of claim 10, comprising receiving information indicating that the control plane entity has selected the first base station to provide coordinated synchronized downlink transmission to said at least one mobile unit.

18. The method of claim 17, comprising receiving, from an Internet Protocol (IP) gateway and in response to being selected to provide coordinated synchronized downlink transmission, at least one downlink data stream concurrently with other downlink data streams provided to the plurality of base stations by the IP gateway.

20. A method of coordinating downlink transmissions from a plurality of base stations to at least one mobile unit, the method being implemented in a control plane entity and comprising:

receiving, at the control plane entity and from each of the plurality of base stations, channel state information for a plurality of wireless communication channels between the plurality of base stations and said at least one mobile unit;

dynamically determining, at the control plane entity, relative time delays between legs of backhaul links between the control plane entity and antennas associated with the plurality of base stations, wherein dynamically determining the relative time delays comprises transmitting a timing signal from the control plane entity to the plurality of antennas and receiving echoes of the timing signal at the control plane entity from the plurality of antennas;

determining, at the control plane entity and based on the channel state information, transmission formats for downlink transmissions from the plurality of base stations to said at least one mobile unit so that said downlink transmissions combine coherently and constructively at said at least one mobile unit, wherein determining the transmission formats comprises determining the transmission formats based on the relative time delays; and

providing the transmission formats to the plurality of base stations.