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

• US 10,312,979 B2
• Filed: 07/27/2016
• Issued: 06/04/2019
• 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:
  US15/220,701
• Publication Number:
  US 20180034517A1
• Time in Patent Office: 1,042 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 connected to the central processor subsystem via a respective plurality of cables for deployment throughout a coverage area, each of the plurality of transceiver devices including a plurality of antennas and a plurality of radio transceivers, the method comprising:

the central processor subsystem dividing in-phase and quadrature baseband transmit and receive 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 (MIMO) transmission channel and a wideband MIMO reception channel;

transmitting respective ones of in-phase and quadrature baseband transmit samples from the central processor subsystem to each of a number of the plurality of transceiver devices via corresponding ones of the respective plurality of cables, wherein the in-phase and quadrature baseband transmit samples are each to be sent to a corresponding one of the number of the plurality of transceiver devices for wireless transmission via the plurality of antennas of each of the number of the plurality of transceiver devices; and

receiving at least one in-phase and quadrature baseband receive sample from a respective one of the plurality of transceiver devices via a corresponding one of the respective plurality of cables connecting the respective one of the plurality of transceiver devices to the central processor subsystem.

2. The method of claim 1, further comprising the central processor subsystem compressing the in-phase and quadrature baseband transmit samples prior to transmitting via the corresponding ones of the respective plurality of cables.

3. The method of claim 1, wherein dividing comprises dividing the in-phase and quadrature baseband 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 dividing comprises dividing the in-phase and quadrature baseband samples for at least a first frequency band and a second frequency band to produce first baseband transmit and receive signals associated with traffic for the first frequency band and second baseband transmit and receive signals associated with traffic for the second frequency band, and wherein transmitting comprises transmitting the first baseband transmit and receive signals for the first frequency band to a first transceiver device of the plurality of transceiver devices via a first cable of the respective plurality of cables that is connected between the central processor subsystem and the first transceiver device of the plurality of transceiver devices and transmitting the second baseband transmit and receive signals for the second frequency band to a second transceiver device of the plurality of transceiver devices via a second cable of the respective plurality of cables that is connected between the central processor subsystem and the second transceiver device of the plurality of transceiver devices.

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

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

7. The method of claim 6, wherein dividing comprises dividing the in-phase and quadrature baseband 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 even if a current received packet is being decoded using a subset of all the transceiver chains.

12. The method of claim 3, wherein dividing 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 transmitting comprises transmitting via a respective cable of the respective plurality of cables transceiver chain-specific signals for one or more transceiver chains for a particular frequency band.

13. The method of claim 3, wherein dividing 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 transmitting comprises transmitting via a respective cable of the respective plurality of cables 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; and

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

divide in-phase and quadrature baseband transmit and receive 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;

transmit respective ones of in-phase and quadrature baseband transmit samples from the central processor subsystem to each of a number of the plurality of transceiver devices via corresponding ones of the respective plurality of cables, wherein the in-phase and quadrature baseband transmit samples are each to be sent to a corresponding one of the number of the plurality of transceiver devices for wireless transmission via the plurality of antennas of each of the number of the plurality of transceiver devices; and

receive at least one in-phase and quadrature baseband receive sample from a respective one of the plurality of transceiver devices via a corresponding one of the respective plurality of cables.

15. The system of claim 14, wherein the central processor subsystem is configured to compress the in-phase and quadrature baseband transmit samples prior to transmitting via the corresponding ones of the respective plurality of cables.

16. The system of claim 14, wherein the central processor subsystem is configured to divide the in-phase and quadrature baseband 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 baseband signals.

17. The system of claim 16, wherein the central processor subsystem is configured to use selection diversity across the plurality of transceiver devices to determine on which transceiver chain to transmit for a given subband.

18. An apparatus comprising:

a plurality of baseband modulators;

a plurality of baseband demodulators;

a communication interface configured to enable communication with a plurality of transceiver devices each including a plurality of antennas and a plurality of radio transceivers, wherein the communication interface is configured to connect to the plurality of transceiver devices via a respective plurality of cables;

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

divide in-phase and quadrature baseband transmit and receive 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;

transmit sage respective ones of in-phase and quadrature baseband transmit samples from the central processor subsystem to each of a number of the plurality of transceiver devices via corresponding ones of the respective plurality of cables, wherein the in-phase and quadrature baseband transmit samples are each to be sent to a corresponding one of the number of the plurality of transceiver devices for wireless transmission via the plurality of antennas of each of the number of the plurality of transceiver devices; and

receive at least one in-phase and quadrature baseband receive sample from a respective one of the plurality of transceiver devices via a corresponding one of the respective plurality of cables.

19. The apparatus of claim 18, wherein the control processor is configured to cause the in-phase and quadrature baseband transmit samples to be compressed prior to transmitting via the corresponding ones of the respective plurality of cables.

20. The apparatus of claim 18, wherein the control processor is configured to divide the in-phase and quadrature baseband 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 baseband signals.