System and Method for Enabling Coordinated Beam Switching and Scheduling

• US 20100075705A1
• Filed: 09/21/2009
• Published: 03/25/2010
• Est. Priority Date: 09/22/2008
• Status: Active Grant

• Current Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Inventors: van Rensburg, Cornelius, Hosein, Patrick Ahamad, Soong, Anthony C.K.
• Granted Patent: US 8,315,657 B2
• Time in Patent Office: Days
• US Class Current: 455/509
• 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 7/0617 for beam forming
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]

Abstract

A system and method for enabling coordinated beam switching and scheduling in a wireless communications system. A method for controller operation includes indicating that the controller is operating in a cooperative beam switching mode, transmitting a beam formed reference signal (BFRS), from each communications device being served by the controller, receiving a measurement of a communications channel between the controller and the communications device and an indicator indicating a transmission unit corresponding to the measurement of the communications channel, receiving a transmission intended for a communications device, and causing the transmission to be transmitted to the communications device. The BFRS is beam formed using a plurality of beam patterns, the beam pattern used in beam forming the BFRS changes once per transmission unit, and the transmission is transmitted using measurement of the communications channel and the indicator from the communications device.

Claims

1. A method for controller operation, the method comprising:

indicating that the controller is operating in a cooperative beam switching mode;

transmitting a beam formed reference signal (BFRS), wherein the BFRS is beam formed using a plurality of beam patterns, and wherein a beam pattern used in beam forming the BFRS changes once per transmission unit;

receiving a measurement of a communications channel between the controller and a communications device and an indicator indicating a transmission unit corresponding to the measurement of the communications channel from each communications device being served by the controller;

receiving a transmission intended for a communications device; and

causing the transmission to be transmitted to the communications device, wherein the transmission is transmitted using measurement of the communications channel and the indicator from the communications device.

2. The method of claim 1, further comprising, transmitting a period of the plurality of beam patterns.

3. The method of claim 2, wherein there are multiple controllers operating in a communications system, and wherein the period is equal for each controller.

4. The method of claim 2, wherein indicating that the controller is operating in a cooperative beam switching mode and transmitting a period each comprises transmitting a layer three message.

5. The method of claim 1, further comprising, transmitting a number of measurements of a communications channel and indicators that each communications device is to send to the controller.

6. The method of claim 1, wherein the measurement of a communications channel comprises a maximum signal plus noise to interference ratio measurement of the communications channel made during a period of the plurality of beam patterns.

7. The method of claim 1, wherein the measurement of a communications channel comprises N largest signal plus noise to interference ratio measurement of the communications channel made during a period of the plurality of beam patterns, where N is a positive integer value.

8. The method of claim 1, wherein causing the transmission to be transmitted comprises:

allocating a network resource during a transmission unit corresponding to the indicator; and

transmitting the transmission at the occurrence of the allocated network resource.

9. The method of claim 1, wherein a transmission unit corresponding to the indicator does not have sufficient network resources to transmit an entirety of the transmission, and wherein causing the transmission to be transmitted comprises:

allocating a first network resource during the transmission unit in a first period corresponding to the indicator to a first portion of the transmission;

transmitting the first portion of the transmission at the occurrence of the allocated first network resource;

allocating a second network resource during the transmission unit in a second period corresponding to the indicator to a second portion of the transmission; and

transmitting the second portion of the transmission at the occurrence of the allocated second network resource.

10. A method for communications device operation, the method comprising:

measuring a communications channel between the communications device and a controller using a beam formed reference signal (BFRS) transmitted by the controller, wherein the BFRS is beam formed using a plurality of beam patterns, and wherein a beam pattern used in beam forming the BFRS changes once per transmission unit;

selecting a communications channel measurement and an indicator indicating a transmission unit corresponding to the selected communications channel measurement; and

transmitting the communications channel measurement and the indicator to the controller.

11. The method of claim 10, further comprising, receiving a number of transmission units in a period of the plurality of beam patterns from the controller.

12. The method of claim 10, wherein the BFRS is cyclically beam formed using the plurality of beam patterns, and wherein measuring a communications channel comprises measuring the communications channel for multiple cycles.

13. The method of claim 12, wherein measuring a communications channel further comprises:

averaging a communications channel measurement made during a first transmission unit in a first cycle with a communications channel measurement made during a second transmission unit in a second cycle, wherein the first transmission unit and the second transmission unit occur at a same time in the first cycle and the second cycle; and

repeating the averaging for every transmission unit.

14. The method of claim 10, wherein selecting a communications channel measurement comprises, selecting a largest communications channel measurement.

15. The method of claim 14, wherein there are more than one communications channel measurement that are substantially equal, and wherein selecting a communications channel measurement comprises, selecting a communications channel measurement from the more than one communications channel measurement that are substantially equal with a history of larger communications channel measurements.

16. The method of claim 10, wherein selecting a communications channel measurement comprises selecting an N largest communications channel measurements, where N is a positive integer value.

17. The method of claim 10, wherein measuring a communications channel comprises, measuring a signal plus interference to noise ratio (SINR) of the communications channel over a transmission unit.

18. A communications system comprising:

a plurality of controllers, wherein an inuse subset of the controllers is wirelessly coupled to at least one communications device in a plurality of communications devices, wherein a subset of the plurality of controllers is operating in a cooperative beam switching mode (CBSM), wherein each of the controllers operating in the CBSM is configured to transmit a unique beam formed reference signal (BFRS), wherein the BFRS is beam formed using a plurality of beam patterns, and wherein a beam pattern used in beam forming the BFRS changes once per transmission unit, and to receive a measure of a communications channel between itself and communications devices it is serving; and

a central controller coupled the plurality of controllers, the central controller is configured to determine a period of the plurality of beam patterns for each controller.

19. The communications system of claim 18, wherein the communications system includes a plurality of communications devices, wherein a subset of the plurality of communications devices is operating in the CBSM, and wherein each communications device operating in the CBSM measures the communications channel once per transmission unit.

20. The communications system of claim 18, wherein the communications system includes a plurality of communications devices, wherein a subset of the plurality of communications devices is operating in the CBSM, and wherein each controller operating in the CBSM is further configured to receive a maximum measured communications channel and an indicator of a transmission unit corresponding to when the maximum measured communications channel was measured from the communications devices it is serving.

21. The communications system of claim 18, wherein each controller operating in the CBSM is further configured to transmit a mode indicator indicating that it is operating in the CBSM.

22. The communications system of claim 18, wherein the unique BFRS is unique to each controller operating in CBSM.