System and Method for Millimeter Wave Communications

• US 20170295502A1
• Filed: 04/06/2016
• Published: 10/12/2017
• Est. Priority Date: 04/06/2016
• Status: Active Grant

• Current Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Inventors: Stirling-Gallacher, Richard, Tenny, Nathan Edward, Liu, Bin, Zhang, Lili
• Granted Patent: US 10,057,787 B2
• Time in Patent Office: Days
• 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: H04W 16/28 using beam steering
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 56/001 Synchronization between nodes

Abstract

A method includes measuring beam-formed reference signals transmitted by a plurality of mmWave transmission points (TPs), sending a cloud cell formation request including indicators associated with best mmWave TPs determined in accordance with the measured beam-formed reference signals, receiving a cloud cell formation request response including indicators associated with a subset of the best mmWave TPs selected by a central controller in accordance with selection information, where the subset of the best mmWave TPs includes a first mmWave transmission point (TP) serving as a master TP and a second mmWave TP serving as a slave TP, and establishing a cloud cell with mmWave TPs of the subset of the best mmWave TPs selected by the central controller, where a data connection is established with the slave TP and at least a control connection is established with the master TP.

Claims

1. A method for operating a millimeter wave (mmWave) user equipment (UE), the method comprising:

measuring, by the mmWave UE, beam-formed reference signals transmitted by a plurality of mmWave transmission points (TPs);

sending, by the mmWave UE, a cloud cell formation request including a measurement report comprising indicators associated with best mmWave TPs determined in accordance with the measured beam-formed reference signals;

receiving, by the mmWave UE, a cloud cell formation request response including indicators associated with a subset of the best mmWave TPs selected by a central controller in accordance with selection information, where the subset of the best mmWave TPs includes a first mmWave transmission point (TP) serving as a master TP and a second mmWave TP serving as a slave TP; and

establishing, by the mmWave UE, a cloud cell with mmWave TPs of the subset of the best mmWave TPs selected by the central controller, where a data connection is established with the slave TP and at least a control connection is established with the master TP.

2. The method of claim 1, further comprising:

measuring, by the mmWave UE, TP specific signals transmitted by the plurality of mmWave TPs; and

establishing, by the mmWave UE, downlink synchronization with an mmWave TP associated with a strongest measured TP specific signal.

3. The method of claim 2, wherein the TP specific signals comprise at least one of broadcast control channels (BCCHs) or synchronization signals.

4. The method of claim 1, wherein the beam-formed reference signals comprise beam-formed channel state information reference signals (CSI-RSs).

5. The method of claim 1, wherein measuring the beam-formed reference signals comprises:

for each mmWave TP,

measuring, by the mmWave UE, a plurality of beam-formed reference signals using a plurality of receive beams; and

selecting, by the mmWave UE, a best beam-formed reference signal and a best receive beam for the mmWave TP.

6. The method of claim 1, wherein the selection information comprises the best beam-formed reference signals and the best received beams for the plurality of mmWave TPs, mmWave TP capabilities, mmWave TP loads, mmWave UE capabilities, and interference condition.

7. The method of claim 1, wherein establishing the cloud cell comprises:

sending, by the mmWave UE, a beam-formed random access channel (RACH) to the master TP;

receiving, by the mmWave UE, a beam-formed RACH response (RAR) from the master TP, thereby forming the control connection with the master TP;

receiving, by the mmWave UE, a beam-formed RAR from the slave TP;

sending, by the mmWave UE, an indicator of RARs received to the master TP; and

receiving, by the mmWave UE, an indicator of transmission parameters from the master TP.

8. The method of claim 7, wherein there are a plurality of slave TPs, and wherein establishing the cloud cell comprises receiving beam-formed RARs from each one of the plurality of slave TPs.

9. The method of claim 1, wherein establishing the cloud cell comprises:

sending, by the mmWave UE, a beam-formed random access channel (RACH) to the master TP;

sending, by the mmWave UE, a no RAR received message when no RAR is received from the master TP;

receiving, by the mmWave UE, a response including indicators associated with a set of new mmWave TPs selected by a central controller, where the set of new mmWave TPs includes a third mmWave TP serving as a new master TP and a fourth mmWave TP serving as a new slave TP; and

establishing, by the mmWave UE, a cloud cell with mmWave TPs of the set of new mmWave TPs selected by the central controller, where a data connection is established with the new slave TP and at least a control connection is established with the new master TP.

10. The method of claim 1, wherein sending the cloud cell formation request including the measurement report comprises:

sending, by the mmWave UE, the cloud cell formation request to a legacy evolved NodeB (eNB) to trigger a forwarding of the cloud cell formation request to the central controller.

11. The method of claim 1, wherein the mmWave UE is simultaneously connected to a legacy eNB and to the master TP.

12. A method for operating a central controller, the method comprising:

receiving, by the central controller, a cloud cell formation request including a measurement report comprising best beam-formed reference signals for best millimeter wave (mmWave) transmission points (TPs) determined in accordance with measured beam-formed reference signals transmitted by the mmWave TPs and indicators associated with the best mmWave TPs;

selecting, by the central controller, a subset of the best mmWave TPs in accordance with the best beam-formed reference signals, where the subset of the best mmWave TPs includes a mmWave transmission point (TP) serving as a master TP and a mmWave TP serving as a slave TP; and

sending, by the central controller, a cloud cell formation response including indicators associated with the subset of the best mmWave TPs.

13. The method of claim 12, wherein selecting the subset of the best mmWave TPs further comprises selecting the subset of the best mmWave TPs in accordance with mmWave TP capabilities, mmWave TP loads, mmWave UE capabilities, and interference condition.

14. The method of claim 12, further comprising updating a central database in accordance with the subset of the best mmWave TPs and the best beam-formed reference signals. .

15. The method of claim 12, wherein sending the cloud cell formation response comprises:

sending, by the central controller, the cloud cell formation response to a legacy evolved NodeB (eNB) to trigger a forwarding of the cloud cell formation response to a mmWave user equipment (UE).

16. The method of claim 12, further comprising:

sending, by the central controller, indicators of best receive beams determined in accordance with the best beam-formed reference signals to the mmWave TPs of the subset of the best mmWave TPs.

17. A method for operating a first millimeter wave (mmWave) transmission point (TP), the method comprising:

performing, by the first mmWave TP, an uplink synchronization with a mmWave user equipment (UE);

initiating, by the first mmWave TP, acknowledgements from second mmWave TPs to the mmWave UE to trigger beam-formed random access channel responses (RARs) to the mmWave UE;

receiving, by the first mmWave TP, an indicator of a number of RARs received by the mmWave UE; and

sending, by the first mmWave TP, an indicator of selected transmission parameters to the mmWave UE.

18. The method of claim 17, wherein performing the uplink synchronization comprises:

receiving, by the first mmWave TP, a beam-formed random access channel (RACH) from the mmWave UE; and

sending, by the mmWave TP, a beam-formed RAR to the mmWave UE.

19. The method of claim 18, wherein the beam-formed RAR includes timing advance information.

20. The method of claim 18, further comprising:

sending, by the first mmWave TP, an indicator of the number of RARs received by the mmWave UE to a central controller; and

sending, by the first mmWave TP, indicators of the number of RARs received by the mmWave UE to the second mmWave TPs.

21. A millimeter wave (mmWave) user equipment (UE) adapted to perform digital communications, the mmWave UE comprising:

a processor; and

a computer readable storage medium storing programming for execution by the processor, the programming including instructions to configure the mmWave UE to;

measure beam-formed reference signals transmitted by a plurality of mmWave transmission points (TPs),

send a cloud cell formation request including a measurement report comprising indicators associated with best mmWave TPs determined in accordance with the measured beam-formed reference signals,

receive a cloud cell formation request response including indicators associated with a subset of the best mmWave TPs selected by a central controller in accordance with selection information, where the subset of the best mmWave TPs includes a first mmWave transmission point (TP) serving as a master TP and a second mmWave TP serving as a slave TP, and

establish a cloud cell with mmWave TPs of the subset of the best mmWave TPs selected by the central controller, where a data connection is established with the slave TP and at least a control connection is established with the master TP.

22. The mmWave UE of claim 21, wherein the programming further includes instructions to measure TP specific signals transmitted by the plurality of mmWave TPs, and establish downlink synchronization with an mmWave TP associated with a strongest measured TP specific signal.

23. The mmWave UE of claim 21, wherein the programming further includes instructions to, for each mmWave TP, measure a plurality of beam-formed reference signals using a plurality of receive beams, and select a best beam-formed reference signal and a best receive beam for the mmWave TP.

24. The mmWave UE of claim 21, wherein the programming further includes instructions to send a beam-formed random access channel (RACH) to the master TP, receive a beam-formed RACH response (RAR) from the master TP, thereby forming the control connection with the master TP, receive a beam-formed RAR from the slave TP, send an indicator of RARs received to the master TP, and receive an indicator of transmission parameters from the master TP.

25. The mmWave UE of claim 21, wherein the programming further includes instructions to send a beam-formed random access channel (RACH) to the master TP, send a no RAR received message when no RAR is received from the master TP, receive a response including indicators associated with a set of new mmWave TPs selected by a central controller, where the set of new mmWave TPs includes a third mmWave TP serving as a new master TP and a fourth mmWave TP serving as a new slave TP, and establish a cloud cell with mmWave TPs of the set of new mmWave TPs selected by the central controller, where a data connection is established with the new slave TP and at least a control connection is established with the new master TP.

26. The mmWave UE of claim 21, wherein the programming further includes instructions to send the cloud cell formation request to a legacy evolved NodeB (eNB) to trigger a forwarding of the cloud cell formation request to the central controller.

27. A central controller adapted to perform digital communications, the central controller comprising:

a processor; and

a computer readable storage medium storing programming for execution by the processor, the programming including instructions to configure the central controller to;

receive a cloud cell formation request including a measurement report comprising best beam-formed reference signals for best millimeter wave (mmWave) transmission points (TPs) determined in accordance with measured beam-formed reference signals transmitted by the mmWave TPs and indicators associated with the best mmWave TPs,

select a subset of the best mmWave TPs in accordance with the best beam-formed reference signals, where the subset of the best mmWave TPs includes a mmWave transmission point (TP) serving as a master TP and a mmWave TP serving as a slave TP, and

send a cloud cell formation response including indicators associated with the subset of the best mmWave TPs.

28. The central controller of claim 27, wherein the programming further includes instructions to select the subset of the best mmWave TPs in accordance with mmWave TP capabilities, mmWave TP loads, mmWave UE capabilities, and interference condition.

29. The central controller of claim 27, wherein the programming further includes instructions to send the cloud cell formation response to a legacy evolved NodeB (eNB) to trigger a forwarding of the cloud cell formation response to a mmWave user equipment (UE).

30. The central controller of claim 27, wherein the programming further includes instructions to send indicators of best received beams determined in accordance with the best beam-formed reference signals to the mmWave TPs of the subset of the best mmWave TPs.

31. A first millimeter wave (mmWave) transmission point (TP) adapted to perform digital communications, the first mmWave TP comprising:

a processor; and

a computer readable storage medium storing programming for execution by the processor, the programming including instructions to configure the first mmWave TP to;

perform an uplink synchronization with a mmWave user equipment (UE),

initiate acknowledgements from second mmWave TPs to the mmWave UE to trigger beam-formed random access channel responses (RARs) to the mmWave UE,

receive an indicator of a number of RARs received by the mmWave UE, and

send an indicator of selected transmission parameters to the mmWave UE.

32. The first mmWave TP of claim 31, wherein the programming further includes instructions to receive a beam-formed random access channel (RACH) from the mmWave UE, and send a beam-formed RAR to the mmWave UE.

33. The first mmWave TP of claim 31, wherein the programming further includes instructions to send an indicator of the number of RARs received by the mmWave UE to a central controller, and send indicators of the number of RARs received by the mmWave UE to the second mmWave TPs.