Enabling distributed access points on high bandwidth cables for band and antenna splitting

• US 10,601,475 B2
• Filed: 04/15/2019
• Issued: 03/24/2020
• Est. Priority Date: 07/27/2016
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Hart, Brian D., Stager, Paul J., Kloper, David, Jiang, Jie Cheng
• Primary Examiner(s): Ohri, Romani
• Application Number:
  US16/383,915
• Publication Number:
  US 20190245593A1
• Time in Patent Office: 344 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 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A wireless access point device wirelessly communicates with a plurality of wireless client devices. The wireless access point includes a central processor subsystem and a plurality of transceiver devices each including a plurality of antennas, and a plurality of radio transceivers, each of the plurality of transceiver devices configured for deployment throughout a coverage area, each transceiver device being connected to the central processor subsystem via a respective cable. The central processor subsystem distributes in-phase and quadrature baseband samples across the plurality of transceiver devices associated with traffic to be transmitted and received via the plurality of transceiver devices in one or more frequency bands so as to synthesize a wideband multiple-input multiple-output transmission channel and a wideband multiple-input multiple-output reception channel. The access point transmit and receive functions are “split” or partitioned across the plurality of transceivers devices.

Claims

1. A method performed at a wireless access point device that wirelessly communicates with a plurality of wireless client devices, the wireless access point device including a central processor subsystem and a plurality of transceiver devices each including a plurality of antennas and a plurality of radio transceivers, each of the plurality of transceiver devices for deployment throughout a coverage area and being connected to the central processor subsystem via a corresponding cable of a plurality of cables, the method comprising:

the central processor subsystem distributing in-phase and quadrature samples, in time domain or frequency domain, across the plurality of transceiver devices associated with traffic to be transmitted and received via the plurality of transceiver devices in one or more frequency bands so as to synthesize a wideband multiple-input multiple-output (MIMO) transmission channel and a wideband MIMO reception channel; and

coupling respective ones of in-phase and quadrature transmit samples from the central processor subsystem to each corresponding cable to be sent to a corresponding one of the plurality of transceiver devices for wireless transmission via the plurality of antennas of each of the plurality of transceiver devices, and respective ones of in-phase and quadrature receive samples from a respective one of the plurality of transceiver devices to the corresponding cable to be sent to the central processor subsystem.

2. The method of claim 1, where distributing is achieved by one of:

selecting which samples go through which cable, or selecting which subset of a sample stream goes through which cable.

3. The method of claim 1, wherein distributing comprises dividing the in-phase and quadrature samples based on at least one of:

frequency band, transceiver chains of the respective transceiver devices and subbands within a frequency band, across the plurality of transceiver devices.

4. The method of claim 3, wherein distributing comprises dividing the in-phase and quadrature samples for at least a first frequency band and a second frequency band to produce first transmit and receive signals associated with traffic for the first frequency band and second transmit and receive signals associated with traffic for the second frequency band, and wherein coupling comprises coupling the first transmit and receive signals for the first frequency band to a first cable that is connected between the central processor subsystem and a first transceiver device of the plurality of transceiver devices and coupling the second transmit and receive signals for the second frequency band to a second cable that is connected between the central processor subsystem a second transceiver device of the plurality of transceiver devices.

5. The method of claim 3, wherein distributing comprises dividing the in-phase and quadrature transmit samples by transceiver chains across the plurality of transceiver devices to produce transceiver chain-specific transmit signals, and wherein coupling comprises coupling respective transceiver chain-specific transmit signals to a corresponding cable for a corresponding transceiver chain.

6. The method of claim 3, wherein distributing comprises dividing the in-phase and quadrature transmit samples by subbands of a frequency band to produce a plurality subband-specific transmit signals, and coupling comprises coupling respective subband-specific transmit signals to a corresponding cable for a respective one of the plurality of transceiver devices.

7. The method of claim 6, wherein distributing comprises dividing the in-phase and quadrature transmit samples using one of:

dividing by subcarriers, filtering in a linear domain, and filtering in a power domain.

8. The method of claim 7, wherein the wideband MIMO transmission channel and the wideband MIMO reception channel comprise a 160 MHz and 80+80 MHz transmission channel and reception channel using two transceiver devices each having four antennas and handling 4*80 MHz of traffic.

9. The method of claim 3, further comprising using selection diversity across the plurality of transceiver devices to determine on which transceiver chain to transmit for a given subband.

10. The method of claim 9, further comprising selecting one or more transceiver chains for an entire frequency band and using selection diversity on all other transceiver chains so that a full bandwidth of a frequency band is used for at least one transceiver chain for at least one transceiver device.

11. The method of claim 3, further comprising sending channel state information for all or a subset of all antennas of a given transceiver device or all or a subset of all transceiver chains to the central processor subsystem;

and selecting a subband for each antenna for a given wireless client device of the plurality of wireless client devices.

12. The method of claim 3, wherein distributing comprises dividing the in-phase and quadrature baseband samples based on a combination of frequency band and transceiver chains across the plurality of transceiver devices to produce transceiver chain-specific signals for each frequency band, and coupling comprises coupling via a respective transceiver chain-specific signals for one or more transceiver chains for a particular frequency band.

13. The method of claim 3, wherein distributing comprises dividing the in-phase and quadrature baseband samples based on a combination of frequency band, transceiver chains and subbands within a frequency band, to produce transceiver chain-specific signals for one or more particular subbands of each of one or more frequency bands, and coupling comprises coupling via a respective cable transceiver chain-specific signals for one or more transceiver chains for each of one or more subbands for each frequency band.

14. A system comprising:

a plurality of transceiver devices each including a plurality of antennas and a plurality of radio transceivers, each of the plurality of transceiver devices for deployment throughout a coverage area to wirelessly communicate with a plurality of wireless client devices; and

a central processor subsystem configured to be connected to the plurality of transceiver devices via a corresponding plurality of cables, the central processor subsystem configured to;

distribute in-phase and quadrature in-phase and quadrature samples, in time domain or frequency domain, across the plurality of transceiver devices associated with traffic to be transmitted and received via the plurality of transceiver devices in one or more frequency bands so as to synthesize a wideband multiple-input multiple-output (MIMO) transmission channel and a wideband MIMO reception channel; and

couple respective ones of in-phase and quadrature transmit samples to each corresponding cable to be sent to a corresponding one of the plurality of transceiver devices for wireless transmission via the plurality of antennas of each of the plurality of transceiver devices, and couple respective ones of in-phase and quadrature receive samples from a respective one of the plurality of transceiver devices to the corresponding cable for processing by the central processor subsystem.

15. The system of claim 14, wherein the central processor subsystem is configured to select which samples go through which cable, or select which subset of a sample stream goes through which cable.

16. The system of claim 14, wherein the central processor subsystem is configured to divide the in-phase and quadrature samples based on at least one of:

frequency band, antenna paths of the respective transceiver devices and subbands within a frequency band, across the plurality of transceiver devices, to produce a plurality of partitioned signals.

17. The system of claim 14, wherein the central processor subsystem is configured to:

receive channel state information for all or a subset of all antennas of a given transceiver device or all or a subset of all transceiver chains; and

select a subband for each antenna for a given wireless client device of the plurality of wireless client devices.

18. An apparatus comprising:

a plurality of modulators;

a plurality of demodulators;

a communication interface configured to enable communication, by a plurality of cables, with a corresponding plurality of transceiver devices each including a plurality of antennas and a plurality of radio transceivers to wirelessly communicate with a plurality of wireless client devices;

a control processor coupled to the plurality of modulators, the plurality of demodulators and the communication interface, wherein the control processor is configured to;

distribute in-phase and quadrature in-phase and quadrature samples, in time domain or frequency domain, across the plurality of transceiver devices associated with traffic to be transmitted and received via the plurality of transceiver devices in one or more frequency bands so as to synthesize a wideband multiple-input multiple-output (MIMO) transmission channel and a wideband MIMO reception channel; and

couple respective ones of in-phase and quadrature transmit samples to each corresponding cable to be sent to a corresponding one of the plurality of transceiver devices for wireless transmission via the plurality of antennas of each of the plurality of transceiver devices, and couple respective ones of in-phase and quadrature receive samples from a respective one of the plurality of transceiver devices to the corresponding cable for processing.

19. The apparatus of claim 18, wherein the control processor is configured to select which samples go through which cable, or select which subset of a sample stream goes through which cable.

20. The apparatus of claim 18, wherein the control processor is configured to:

receive channel state information for all or a subset of all antennas of a given transceiver device or all or a subset of all transceiver chains; and

select a subband for each antenna for a given wireless client device of the plurality of wireless client devices.