Cooperative wireless networks

• US 9,136,931 B2
• Filed: 10/10/2014
• Issued: 09/15/2015
• Est. Priority Date: 05/14/2002
• Status: Expired due to Fees

• Current Assignee: Genghiscomm Holdings, LLC
• Original Assignee: Genghiscomm Holdings, LLC
• Inventors: Shattil, Steve
• Primary Examiner(s): SEFCHECK, GREGORY B
• Application Number:
  US14/511,585
• Publication Number:
  US 20150023202A1
• Time in Patent Office: 340 Days
• US Class Current: 1/1
• 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 7/026 Co-operative diversity, e.g. using fixed or mobile stations as relays
• CPC Class Codes: H04B 7/0452 Multi-user 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 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04J 13/0003 Code application, i.e. aspects relating to how codes are applied to form multiplexed channels
• CPC Class Codes: H04J 13/004 Orthogonal
• CPC Class Codes: H04J 13/12 Generation of orthogonal codes
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/2614 Peak power aspects
• CPC Class Codes: H04L 45/24 Multipath
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 5/0021 in which codes are applied as a frequency-domain sequences, e.g. MC-CDMA
• CPC Class Codes: H04L 5/0035 Resource allocation in a cooperative multipoint environment
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0073 Allocation arrangements that take into account other cell interferences for intercell interference mitigation or co-ordination in orthogonal multiplex systems H04J11/005
• CPC Class Codes: H04W 52/267 taking into account the information rate
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/046 : the resource being in the space domain, e.g. beams
• CPC Class Codes: H04W 72/541 : using the level of interference
• CPC Class Codes: H04W 84/18 : Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A cooperative multi-user multiple input, multiple output (MIMO) system coordinates wireless client devices to provide cooperative uplink transmissions. A group of wireless client devices is selected based on their channel state information such that their uplink transmissions are uncorrelated. All of the client devices in the group transmit data on the same set of OFDM subcarriers. Channel state information is also communicated to at least one base transceiver along with the data. The channel state information may be measured by the wireless client devices, or the channel state information may be determined from pilot tones transmitted by the wireless client devices and received by at least one base transceiver. A cooperative-MIMO processing system communicatively coupled to at least one base transceiver processes the received uplink transmissions and the channel state information to separate received interfering signals via subspace de-multiplexing.

Claims

1. A multiplex communication method, comprising:

selecting a group of wireless client devices to provide cooperative uplink transmissions, wireless client devices in the group being selected to produce uncorrelated uplink transmissions to a plurality of spatially distributed base transceivers configured to have overlapping coverage areas;

assigning at least one common Orthogonal Frequency Division Multiplexed (OFDM) subcarrier to each of the wireless client devices such that the at least one common OFDM subcarrier for each wireless client device is the same and is concurrently used for uplink transmission; and

in a central processor communicatively coupled to the plurality of spatially distributed base transceivers, subspace demultiplexing a virtual multiple input multiple output (MIMO) uplink transmission from signals cooperatively received by multiple ones of the spatially distributed base transceivers, and calculating pre-coding weights for downlink signals to be transmitted by the plurality of spatially distributed base transceivers, wherein at least one of subspace demultiplexing and calculating the pre-coding weights comprises performing distributed computing.

2. The method recited in claim 1, wherein selecting comprises measuring channel state information for each of a plurality of wireless client devices to produce measured channel state information, and selecting the group of wireless client devices from the plurality of wireless client devices based on the measured channel state information.

3. The method recited in claim 1, further comprising communicating channel state information to the central processor, wherein communicating the channel state information comprises at least one of transmitting a known training signal from the each of the wireless client devices to enable channel estimation from the known training signal received by the plurality of spatially distributed base transceivers, and communicating channel state information estimated by each wireless client device to the plurality of spatially distributed base transceivers.

4. The method recited in claim 1, wherein the plurality of spatially distributed base transceivers are coupled to the central processor by at least one of a wireless network and an optical fiber network.

5. The method recited in claim 1, wherein selecting is performed by at least one of a wireless client device, a base transceiver, and a central processor.

6. The method recited in claim 1, wherein calculating pre-coding weights for the downlink signals comprises employing downlink channel state information derived from uplink channel state information.

7. A digital computer processor residing in at least one of the plurality of spatially distributed base transceivers and the central processor, the digital computer processor comprising a cooperative-MIMO processor and a network management operator, the digital computer processor being programmed to perform the method recited in claim 1.

8. A non-transitory computer readable storage medium having computer readable code thereon, the medium comprising instructions for performing the method recited in claim 1.

9. A multiplex communication method, comprising:

determining channel transfer functions for a plurality of subcarriers for each of a plurality of wireless client devices served by multiple ones of a plurality of spatially distributed base transceivers having overlapping coverage areas;

assigning at least one multicarrier channel comprising ones of the plurality of sub-carriers to the plurality of wireless client devices to be simultaneously used by each wireless client device to produce a virtual multiple input multiple output (MIMO) uplink transmission;

receiving uplink transmissions from each wireless client device at multiple ones of the plurality of spatially distributed base transceivers;

coupling the uplink transmissions to a central processor; and

at the central processor, employing distributed computing for subspace de-multiplexing the uplink transmissions and pre-coding downlink transmissions, wherein each subspace channel employs antennas from multiple ones of the plurality of spatially distributed base transceivers.

10. The method recited in claim 9, wherein each of the plurality of wireless client devices is served by a selected plurality of the spatially distributed base transceivers.

11. The method recited in claim 9, wherein the plurality of spatially distributed base transceivers is coupled to the central processor by at least one of a wireless network and an optical fiber network.

12. The method recited in claim 9, wherein determining the channel transfer functions comprises at least one of communicating from the plurality of wireless client devices to at least one base transceiver channel state information determined by the plurality of wireless client devices, and determining the channel transfer functions from pilot signals transmitted by the each of the plurality of wireless client devices to the plurality of spatially distributed base transceivers.

13. The method recited in claim 9, wherein pre-coding the downlink transmissions comprises determining downlink channel transfer functions from uplink channel transfer functions.

14. The method recited in claim 9, wherein assigning is performed by at least one of a wireless client device, at least one base transceiver, and the central processor.

15. A digital computer processor residing in at least one of a base transceiver and the central processor, the digital computer processor comprising a cooperative-MIMO processor and a network management operator, the digital computer processor programmed to perform the method recited in claim 9.

16. A non-transitory computer readable storage medium having computer readable code thereon, the medium comprising instructions for performing the method recited in claim 9.

17. A system configured for coordinating multiplex communications, comprising:

a central processor communicatively coupled to a plurality of spatially distributed base transceivers having overlapping coverage areas, the central processor comprising a cooperative multiple-input multiple-output (MIMO) processor configured for determining channel state information for each of a plurality of wireless client devices served by multiple ones of the plurality of spatially distributed base transceivers; and

a network management operator configured for assigning at least one Orthogonal Frequency Division Multiplex (OFDM) channel comprising ones of a plurality of subcarriers to be simultaneously used by each wireless client device for the uplink transmissions, wherein the cooperative-MIMO processor is configured to employ distributed computing for subspace de-multiplexing the uplink transmissions received by multiple ones of the plurality of spatially distributed base transceivers and pre-coding downlink signals to be transmitted by multiple ones of the plurality of spatially distributed base transceivers.

18. The system recited in claim 17, wherein the network management operator resides in the central processor.

19. The system recited in claim 17, wherein the central processor is coupled to the plurality of spatially distributed base transceivers via at least one of an optical fiber network and a wireless network.

20. The system recited in claim 17, wherein determining the channel state information comprises at least one of communicating channel state information determined by the plurality of wireless client devices to the plurality of spatially distributed base transceivers, and determining the channel state information from pilot signals transmitted by the plurality of wireless client devices to the plurality of spatially distributed base transceivers.

21. The system recited in claim 17, wherein the cooperative-MIMO processor is further configured for at least one of providing pre-coding to the wireless client devices, performing subspace decoding of signals received by the plurality of spatially distributed base transceivers, and determining downlink channel state information from uplink channel state information for pre-coding the downlink transmissions.