Cooperative Wireless Networks

• US 20140247895A1
• Filed: 05/13/2014
• Published: 09/04/2014
• Est. Priority Date: 05/14/2002
• Status: Active Grant

• Current Assignee: Genghiscomm Holdings, LLC
• Original Assignee: Genghiscomm Holdings, LLC
• Inventors: Shattil, Steve
• Granted Patent: US 9,048,897 B2
• Time in Patent Office: Days
• US Class Current: 375/267
• CPC Class Codes: H04B 1/0003 Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain digital baseband systems H04L25/00; digital modulation/demodulation H04L27/00; CDMA H04B1/707; TDMA H04B7/2643; image transmission H04N5/00
• 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 7/0697 using spatial multiplexing
• 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 27/01 Equalisers baseband equalizers at the transmitter end H04L25/03343; in analogue transmission systems H04B3/04, H04B7/005
• CPC Class Codes: H04L 27/148 using filters, including PLL-type filters
• 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 27/2636 with FFT or DFT modulators, e.g. standard single-carrier frequency-division multiple access [SC-FDMA] transmitter or DFT spread orthogonal frequency division multiplexing [DFT-SOFDM]
• CPC Class Codes: H04L 27/2646 using feedback from receiver for adjusting OFDM transmission parameters, e.g. transmission timing or guard interval length
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01
• CPC Class Codes: H04L 27/26526 with inverse FFT [IFFT] or inverse DFT [IDFT] demodulators, e.g. standard single-carrier frequency-division multiple access [SC-FDMA] receiver or DFT spread orthogonal frequency division multiplexing [DFT-SOFDM]
• CPC Class Codes: H04L 27/26534 Pulse-shaped multi-carrier, i.e. not using rectangular window
• CPC Class Codes: H04L 45/24 Multipath
• CPC Class Codes: H04L 47/10 : Flow control; Congestion control
• CPC Class Codes: H04L 5/0007 : the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0021 : in which codes are applied as a frequency-domain sequences, e.g. MC-CDMA
• CPC Class Codes: H04L 5/0023 : Time-frequency-space
• 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 72/046 : the resource being in the space domain, e.g. beams
• 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 spatially distributed network transceiver nodes for communicating with wireless client devices. A MIMO processor pre-codes data for transmission from the network transceiver nodes, wherein the pre-coding comprises subspace coding derived from channel measurements between the network transceiver nodes and the wireless client devices. A network controller coordinates the network transceiver nodes to transmit simultaneous non-interfering channels within a common frequency to the wireless client devices such that each client device receives a subspace-coded transmission from each of the network transceiver nodes. The client devices and/or the network transceiver nodes may be selected based on channel state information and/or measured channel quality.

Claims

1. A cooperative multi-user multiple input, multiple output (MIMO) system for communicating with a plurality of wireless client devices, comprising:

at least one network interface for communicating with a plurality of spatially distributed network transceiver nodes over a network, each of the network transceiver nodes identified by a unique network address and comprising at least one antenna;

at least one MIMO processor for pre-coding data for transmission from the plurality of network transceiver nodes to the plurality of wireless client devices, the pre-coding employing subspace codes derived from measurements of at least one channel between the plurality of network transceiver nodes and the plurality of wireless client devices; and

a network controller configured for coordinating the plurality of network transceiver nodes to transmit a simultaneous plurality of non-interfering subspace channels sharing a common frequency between the plurality of network transceiver nodes and the plurality of wireless client devices such that each of the plurality of wireless client devices receives a subspace coded transmission from each of the plurality of network transceiver nodes.

2. The system recited in claim 1, wherein at least one of the plurality of wireless client devices comprises an antenna array, and the pre-coding creates deliberate radio frequency interference comprising a controlled constructive and destructive interference of transmitted waveforms so as to enable data reception of a different data stream upon each of a plurality of receiving antennas of the antenna array.

3. The system recited in claim 1, wherein the network comprises at least one of a local area network and a backhaul network.

4. The system recited in claim 1, wherein at least one of the plurality of network transceiver nodes comprises an antenna array, and the pre-coding provides at least one of diversity transmission and spatial division multiple access for signals transmitted from the antenna array.

5. The system recited in claim 1, wherein at least one of the network controller and the at least one MIMO processor comprises at least one of the plurality of network transceiver nodes.

6. The system recited in claim 1, wherein the plurality of network transceiver nodes comprises at least one of a base transceiver station, a network access point, a network router, a gateway, a relay, and a client device.

7. The system recited in claim 1, wherein at least one of the network controller and the at least one MIMO processor is configured for employing at least one of antenna selection, selection of the plurality of network transceiver nodes, and selection of the plurality of wireless client devices to enhance channel spatial diversity.

8. A method comprising:

selecting a plurality of spatially distributed network transceiver nodes for serving a plurality of wireless client devices in a multi-user multiple input, multiple output (MIMO) system, each node identified by a unique network address and comprising at least one antenna;

measuring channels between the plurality of network transceiver nodes and the plurality of wireless client devices for generating channel state information;

employing subspace codes generated from the channel state information for pre-coding data to be transmitted from the plurality of network transceiver nodes to the plurality of wireless client devices; and

transmitting subspace-coded data signals from the plurality of network transceiver nodes to each of the plurality of wireless client devices, the subspace codes providing a plurality of simultaneous non-interfering subspace channels within a common frequency between the plurality of network transceiver nodes and the plurality of wireless client devices.

9. The method recited in claim 8, wherein selecting comprises at least one of selecting the plurality of network transceiver nodes and selecting the plurality of wireless client devices;

wherein selecting the plurality of network transceiver nodes comprises, for each wireless client device, selecting each network transceiver node based on at least one of the channel state information and measured channel quality between the each wireless client device and the each network transceiver node; and

wherein selecting the plurality of wireless client devices comprises selecting each of the plurality of wireless client devices to share a common frequency with at least one other of the plurality of wireless client devices based on at least one of the channel state information and the measured channel quality.

10. The method recited in claim 8, wherein measuring the channels is performed by at least one of a set of devices, the set comprising the plurality of wireless client devices and the plurality of network transceiver nodes.

11. The method recited in claim 8, wherein the subspace codes comprise at least one of eigen-directions of a channel covariance matrix, singular value decomposition pre-coding, and pre-coding configured for cancelling known interference, including interference from a source other than the plurality of network transceiver nodes.

12. The method recited in claim 8, wherein measuring channels comprises receiving feedback from the plurality of wireless client devices, wherein the feedback comprises at least one of a performance indication of received signals, channel estimates, and a training sequence used to evaluate the channel.

13. The method recited in claim 8, further comprising, for at least one subspace channel, selecting at least one of modulation, coding, transmit power, OFDM subcarriers, network transceiver nodes, an antenna on a network transceiver node, and a client device antenna based on at least one of the channel state information and measured channel quality of the at least one subspace channel.

14. The method recited in claim 8, wherein pre-coding provides for at least one of diversity transmission from a plurality of antennas of the plurality of network transceiver nodes and antenna selection in at least one network transceiver node antenna array.

15. A non-transitory computer readable storage medium having computer readable code thereon, the medium comprising instructions for:

providing independent subspace weightings to a plurality of data streams to be transmitted from a plurality of spatially distributed network transceiver nodes in a multiuser multiple input, multiple output (MIMO) system, each data stream intended for a different client device, wherein the subspace weightings are calculated from known channel properties between the network transceiver nodes and a plurality of wireless client devices and configured to cancel co-channel interference at each of the plurality of wireless client devices; and

coordinating the plurality of network transceiver nodes for simultaneously transmitting a plurality of subspace-weighted data streams over wireless links to each of the plurality of wireless client devices.

16. The medium recited in claim 15, further comprising at least one of selecting the plurality of network transceiver nodes and selecting the plurality of wireless client devices;

wherein selecting the plurality of network transceiver nodes comprises, for each wireless client device, selecting each network transceiver node based on at least one of channel state information and channel quality between the each wireless client device and the each network transceiver node; and

wherein selecting the plurality of wireless client devices comprises selecting each of the plurality of wireless client devices to share a common frequency with at least one other of the plurality of wireless client devices based on at least one of the channel state information and the measured channel quality.

17. The medium recited in claim 15, further comprising measuring the channel properties, wherein measuring is performed by at least one of a set of devices, the set comprising the plurality of wireless client devices and the plurality of network transceiver nodes.

18. The medium recited in claim 17, wherein measuring the channel properties comprises receiving feedback from the plurality of wireless client devices, wherein the feedback comprises at least one of a performance indication of received signals, channel estimates, and a training sequence to be used for evaluating the channel.

19. The medium recited in claim 15, wherein providing independent subspace weightings comprises performing at least one of antenna selection and diversity transmission in at least one network transceiver node antenna array.

20. The medium recited in claim 15, wherein the subspace codes comprise at least one of eigen-directions of a channel covariance matrix, singular value decomposition pre-coding, and pre-coding configured for cancelling known interference, including interference from a source other than the plurality of network transceiver nodes.

21. The medium recited in claim 15, further comprising, for at least one subspace channel, selecting at least one of modulation, coding, transmit power, OFDM subcarriers, network transceiver nodes, an antenna on a network transceiver node, and a client device antenna based on at least one of channel state information and measured channel quality of the at least one subspace channel.