Massive MIMO (M-MIMO) Support for Heterogeneous Networks (HETNETS)

• US 20140307702A1
• Filed: 03/21/2014
• Published: 10/16/2014
• Est. Priority Date: 04/12/2013
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: JINDAL, Nihar, JALLOUL, Louay, PAULRAJ, Arogyaswami, BENNETT, James, ALEX, Sam, MESE, Murat, WANG, Yan, MOBASHER, Amin, ARIYAVISITAKUL, Sirikiat
• Granted Patent: US 9,768,843 B2
• Time in Patent Office: Days
• US Class Current: 370/330
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0691 using subgroups of transmit antennas

Abstract

Systems and methods for enabling a wireless backhaul network between access points (APs) in a wireless network are provided. In an embodiment, the wireless backhaul network is enabled using a Massive Multiple Input Multiple Output (MIMO) radio access technology (RAT). In another embodiment, the wireless backhaul network is established using the same RAT as used by the APs to serve user devices, and can utilize the same time and frequency resources used for user communication.

Claims

1. An Access Point (AP), comprising:

a Massive Multiple Input Multiple Output (M-MIMO) antenna array;

a processor configured to;

generate a first symbol stream comprising user data for a user device;

generate a second symbol stream comprising backhaul information for another AP;

determine a transmit precoder matrix;

pre-code the first symbol stream and the second symbol stream using the transmit precoder matrix to generate a plurality of signals; and

couple the plurality of signals to the M-MIMO antenna array for transmission.

2. The AP of claim 1, wherein the processor is configured to determine the transmit precoder matrix based on one or more of:

a first channel estimate of a first channel from the AP to the user device, and a second channel estimate of a second channel from the AP to the other AP.

3. The AP of claim 1, wherein the processor is configured to determine the transmit precoder matrix such that transmission of the plurality of signals by the M-MIMO antenna array results in the first symbol stream being beamformed to the user device and the second symbol stream being beamformed to the other AP.

4. The AP of claim 1, further comprising:

a switching module, coupled between the processor and the M-MIMO antenna array,

wherein the processor is further configured to select a subset of the M-MIMO antenna array, and to control the switching module to couple the plurality of signals to respective antenna elements of the subset of the M-MIMO antenna array.

5. The AP of claim 4, wherein the subset of the M-MIMO antenna array is configured to transmit the plurality of signals on same time and frequency physical resources.

6. The AP of claim 5, further comprising:

a multi-carrier modulator,

wherein the processor is configured to control the multi-carrier modulator to modulate the plurality of signals onto the same time and frequency physical resources.

7. The AP of claim 6, wherein the same time and frequency physical resources correspond to one or more symbols of a multi-carrier frame.

8. The AP of claim 6, wherein the same time and frequency physical resources correspond to one or more subcarriers of a multi-carrier frame.

9. A method performed by an Access Point (AP) having a Massive Multiple Input Multiple Output (M-MIMO) antenna array, the method comprising:

generating a first symbol stream comprising user data for a user device;

generating a second symbol stream comprising backhaul information for another AP;

determining a transmit precoder matrix;

pre-coding the first symbol stream and the second symbol stream using the transmit precoder matrix to generate a plurality of signals; and

transmitting the plurality of signals using the M-MIMO antenna array.

10. The method of claim 9, further comprising:

determining the transmit precoder matrix based on one or more of;

a first channel estimate of a first channel from the AP to the user device, and a second channel estimate of a second channel from the AP to the other AP.

11. The method of claim 9, wherein determining the transmit precoder matrix comprises determining the transmit precoder matrix such that transmission of the plurality of signals by the M-MIMO antenna array results in the first symbol stream being beamformed to the user device and the second symbol stream being beamformed to the other AP.

12. The method of claim 9, further comprising:

selecting a subset of the M-MIMO antenna array; and

coupling the plurality of signals to respective antenna elements of the subset of the M-MIMO antenna array.

13. The method of claim 12, wherein transmitting the plurality of signals using the M-MIMO antenna array comprises transmitting the plurality of signals on same time and frequency physical resources using the subset of the M-MIMO antenna array.

14. The method of claim 13, further comprising:

modulating the plurality of signals onto the same time and frequency physical resources.

15. The method of claim 14, wherein the same time and frequency physical resources correspond to one or more symbols of a multi-carrier frame.

16. The method of claim 14, wherein the same time and frequency physical resources correspond to one or more subcarriers of a multi-carrier frame.

17. An Access Point (AP), comprising:

a Massive Multiple Input Multiple Output (M-MIMO) antenna array; and

a processor configured to;

inspect outgoing backhaul traffic to determine whether the outgoing backhaul traffic belongs to a first category or a second category;

if the outgoing backhaul traffic belongs to the first category, transmit the outgoing backhaul traffic, using a first subset of the M-MIMO antenna array and a first radio access technology (RAT), over a first wireless backhaul channel; and

if the outgoing backhaul traffic belongs to the second category, transmit the outgoing backhaul traffic, using a second subset of the M-MIMO antenna array and a second RAT, over a second wireless backhaul channel.

18. The AP of claim 17, wherein the first category and the second category correspond respectively to one or more of:

first and second traffic types, first and second Quality of Service (QoS) levels, and first and second classes of service.

19. The AP of claim 17, wherein the first RAT is a M-MIMO based RAT and the second RAT is a non-M-MIMO RAT.

20. The AP of claim 17, wherein the first RAT and the second RAT are M-MIMO based RATs, and wherein the first subset of the M-MIMO antenna array is larger than the second subset of the M-MIMO antenna array.

21. An Access Point (AP) comprising:

a first transceiver circuit configured to support, via a Massive Multiple Input Multiple Output (M-MIMO) antenna array, both a beam formed backhaul pathway and a wireless access pathway to a user device;

a second transceiver circuit configured to support an additional backhaul pathway;

a memory that stores instructions; and

a processing circuit configured, by executing the instructions, to;

select the beam formed backhaul pathway over the additional backhaul pathway to support a first data flow originating from the user device; and

manage sharing of the M-MIMO antenna array via the first transceiver to support the first data flow from the user device through both the wireless access pathway and the beam formed backhaul pathway.

22. The AP of claim 21, wherein the processing circuit adapts by selecting the additional backhaul pathway to support the first data flow.

23. The AP of claim 21, wherein the processing circuit selects the additional backhaul pathway to support a second data flow originating from the user device.

24. The AP of claim 21, further comprising a third transceiver circuit configured to support an additional access pathway to the user device, and the processing circuit selects between the first wireless access pathway and the second access pathway.

25. The AP of claim 21, wherein the processing circuit makes the selection based on coordination related communication exchanges via a backhaul pathway.

26. The AP of claim 25, wherein the coordination related communication exchanges comprise exchanges involving a neighboring AP.

27. The AP of claim 25, wherein the coordination related communication exchanges comprise exchanges involving a backhaul node.

28. The AP of claim 21, wherein the processing circuit makes the selection based at least in part on a characteristic associated with the first data flow.

29. The AP of claim 22, wherein the processing circuit makes the adaptation based at least in part on identifying a change in a communication related status.