Distributed processing in a centralized radio access network

• US 10,244,507 B2
• Filed: 09/23/2014
• Issued: 03/26/2019
• Est. Priority Date: 09/24/2013
• Status: Active Grant

• Current Assignee: Andrew Wireless Systems GmbH (CommScope Holding Company, Inc.)
• Original Assignee: Andrew Wireless Systems GmbH (CommScope Holding Company, Inc.)
• Inventors: Tarlazzi, Luigi, Brighenti, Samuele
• Primary Examiner(s): Chery, Dady
• Application Number:
  US15/024,548
• Publication Number:
  US 20160242147A1
• Time in Patent Office: 1,645 Days
• Field of Search: 370229-236, 370254, 370255, 370280, 370311, 370314, 370328, 370330, 370331, 370338, 370410, 370426, 370437, 370469
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

Certain features relate to a centralized radio access network (C-RAN) that can flexibly and dynamically allocate protocol layer processing among baseband processing units and remote units. A C-RAN can be configured to include a media access control (“MAC”) scheduler and a fronthaul physical layer coordinator. The fronthaul physical layer coordinator can include a fronthaul physical layer scheduler, which can allocate spatial resources by determining the specific remote unit(s) that should serve a given mobile device. The MAC scheduler can allocate time/frequency resources to user devices communicating with the remote units. The fronthaul physical layer coordinator or the MAC scheduler can also determine the optimal transmission modes remote units can use to serve the user devices.

Claims

1. A centralized radio access network (C-RAN), comprising:

a media access control (MAC) scheduler; and

a fronthaul physical layer coordinator positioned between the MAC scheduler and a plurality of remote units, the fronthaul physical layer coordinator including a fronthaul physical layer scheduler for determining at least one remote unit of the plurality of remote units to serve a mobile device, wherein the fronthaul physical layer coordinator is configured for formulating an allocation of physical layer processing between the plurality of remote units and a baseband processing unit based on resources selected by the fronthaul physical layer scheduler and the MAC scheduler for serving the mobile device.

2. The C-RAN of claim 1, wherein the MAC scheduler is configured for allocating time resources, frequency resources, modulation and coding scheme, and transmission mode for serving the mobile device.

3. The C-RAN of claim 1, wherein the fronthaul physical layer coordinator is configured for implementing a different allocation plan in the C-RAN based on a policy from a system administrator.

4. The C-RAN of claim 1, wherein the fronthaul physical layer coordinator is configured for formulating the allocation of physical layer processing between the plurality of remote units and the baseband processing unit based on a traffic condition detected in the C-RAN.

5. The C-RAN of claim 1, wherein the fronthaul physical layer coordinator is configured for implementing the allocation by outputting signals that configure the plurality of remote units and the baseband processing unit.

6. The C-RAN of claim 1, wherein the physical layer processing includes scrambling, descrambling, modulation, demodulation, layer to antenna mapping, layer to antenna demapping, resource elements mapping, resource elements demapping, inverse fast Fourier transport and cyclic prefix insertion, fast Fourier transport and cyclic prefix extraction, and baseband processing.

7. The C-RAN of claim 1, further comprising the plurality of remote units, at least one of the plurality of remote units being configured for implementing full physical layer processing, partial physical layer processing, and no physical layer processing in transceiving signals wirelessly with the mobile device located in a coverage area.

8. The C-RAN of claim 7, wherein the at least one of the plurality of remote units is a remote radio head that is automatically switchable between a small cell mode and a C-RAN mode.

9. The C-RAN of claim 7, wherein the C-RAN is configured for supporting an intra-cell Coordinate Multi-Point (CoMP) transmission mode and an inter-cell CoMP transmission mode, wherein the intra-cell CoMP transmission mode involves communication between multiple remote units of the plurality of remote units that relay the same sector of signals, wherein the inter-cell CoMP transmission mode involves communication between the multiple remote units of the plurality of remote units that relay different sectors of signals.

10. The C-RAN of claim 1, wherein the fronthaul physical layer coordinator is configured for conducting real time analysis of power received in an uplink physical resource block by the plurality of remote units providing coverage to a common cell identifier and using channel estimation indexes in obtaining a maximum gain when jointly processing fast Fourier transform bins of physical resource blocks from the plurality of remote units.

11. A wireless distribution system, comprising:

a baseband pool for transceiving signals with a backhaul network, the baseband pool including a media access control (MAC) scheduler;

remote units configured for providing wireless signal coverage for mobile devices in a coverage area; and

a fronthaul physical layer coordinator positioned in a fronthaul network between the baseband pool and the remote units, the fronthaul physical layer coordinator including a fronthaul physical layer scheduler for determining at least one remote unit of the plurality of remote units to serve a mobile device, the fronthaul physical layer coordinator being configured for forming an allocation plan for allocating physical layer processing between the plurality of remote units and a baseband processing unit based on resources selected by the fronthaul physical layer scheduler and the MAC scheduler for serving the mobile device.

12. The wireless distribution system of claim 11, wherein the wireless distribution system is a centralized radio access network (C-RAN).

13. The wireless distribution system of claim 11, wherein the physical layer processing includes scrambling, descrambling, modulation, demodulation, layer to antenna mapping, layer to antenna demapping, resource elements mapping, resource elements demapping, inverse fast Fourier transport and cyclic prefix insertion, fast Fourier transport and cyclic prefix extraction, and baseband processing.

14. The wireless distribution system of claim 11, wherein the fronthaul physical layer coordinator includes a fronthaul physical layer scheduler that is configured to determine which remote unit of a plurality of remote units is to serve a selected mobile device and output signals for configuring the wireless distribution system such that the remote unit determined to serve the selected mobile device serves the selected mobile device.

15. The wireless distribution system of claim 11, wherein the wireless distribution system is configured for supporting an intra-cell Coordinate Multi-Point (CoMP) transmission mode and an inter-cell CoMP transmission mode, wherein the intra-cell CoMP transmission mode involves communication between multiple remote units that relay the same sector of signals, wherein the inter-cell CoMP transmission mode involves communication between the multiple remote units that relay different sectors of signals.

16. The wireless distribution system of claim 11, wherein the MAC scheduler is configured for allocating time resources, frequency resources, modulation and coding scheme, and transmission mode for serving a mobile device.

17. The wireless distribution system of claim 11, wherein the fronthaul physical layer coordinator is configured for conducting real time analysis of power received in an uplink physical resource block by the remote units providing coverage to a common cell identifier and using channel estimation indexes in obtaining a maximum gain when jointly processing fast Fourier transform bins of physical resource blocks from the remote units.

18. A method, comprising:

detecting a traffic condition of a centralized radio access network (C-RAN) by a fronthaul physical layer coordinator between a media access control (MAC) scheduler and a plurality of remote radio heads;

formulating a physical layer processing allocation plan between the remote radio heads and a baseband processing unit by the fronthaul physical layer coordinator based on resources selected by the fronthaul physical layer coordinator and the MAC scheduler for serving a mobile device; and

determining at least one remote radio head of the plurality of remote radio heads to serve the mobile device by the fronthaul physical layer coordinator.

19. The method of claim 18, wherein the physical layer processing includes scrambling, descrambling, modulation, demodulation, layer to antenna mapping, layer to antenna demapping, resource elements mapping, resource elements demapping, inverse fast Fourier transport and cyclic prefix insertion, fast Fourier transport and cyclic prefix extraction, and baseband processing, the method further comprising:

subsequently re-allocating the physical layer processing dynamically among a baseband processing unit and the plurality of remote radio heads based on a changed traffic condition.