MIMO system with multiple spatial multiplexing modes

• US 8,483,188 B2
• Filed: 05/05/2008
• Issued: 07/09/2013
• Est. Priority Date: 10/25/2002
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Walton, J. Rodney, Ketchum, John W., Wallace, Mark S., Howard, Steven J.
• Primary Examiner(s): Nguyen, Steven H
• Assistant Examiner(s): Waqas, Saad A
• Application Number:
  US12/115,523
• Publication Number:
  US 20080267138A1
• Time in Patent Office: 1,891 Days
• Field of Search: 370/336
• US Class Current: 370/336
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0421 utilizing implicit feedback, e.g. steered pilot signals
• CPC Class Codes: H04B 7/043 using best eigenmode, e.g. beam forming or beam steering
• CPC Class Codes: H04B 7/0434 using multiple eigenmodes
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0628 Diversity capabilities
• CPC Class Codes: H04B 7/0669 using different channel coding between antennas space-time coding H04L1/0618
• CPC Class Codes: H04B 7/0689 using different transmission schemes, at least one of them being a diversity transmission scheme
• CPC Class Codes: H04B 7/0697 using spatial multiplexing
• CPC Class Codes: H04B 7/0854 using error minimizing algorithms, e.g. minimum mean squared error [MMSE], "cross-correlation" or matrix inversion
• CPC Class Codes: H04B 7/0871 using different reception schemes, at least one of them being a diversity reception scheme
• CPC Class Codes: H04J 11/003 at the transmitter transmission to multiple receive units in multiple input multiple output [MIMO] H04B7/0452; transmit antenna weighting H04B7/0615
• CPC Class Codes: H04J 11/0053 using co-ordinated multipoint transmission/reception co-ordinated antenna or beam-forming aspects H04B7/022
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0017 where the mode-switching is based on Quality of Service requirement
• CPC Class Codes: H04L 1/06 using space diversity
• CPC Class Codes: H04L 25/0224 using sounding signals
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 25/0242 : using matrix methods
• CPC Class Codes: H04L 25/0248 : Eigen-space methods
• CPC Class Codes: H04L 25/03343 : Arrangements at the transmitter end
• CPC Class Codes: H04L 25/03891 : Spatial equalizers MIMO diversity systems H04B7/0413
• CPC Class Codes: H04L 27/2601 : Multicarrier modulation systems
• CPC Class Codes: H04L 27/261 : Details of reference signals
• CPC Class Codes: H04L 27/2647 : Arrangements specific to the receiver only equalisation H04L27/01
• CPC Class Codes: H04L 27/2675 : Pilot or known symbols
• 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 16/28 : using beam steering
• CPC Class Codes: H04W 52/50 : at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 72/046 : the resource being in the space domain, e.g. beams
• CPC Class Codes: H04W 74/04 : Scheduled access hybrid access H04W74/02

Abstract

A MIMO system supports multiple spatial multiplexing modes for improved performance and greater flexibility. These modes may include (1) a single-user steered mode that transmits multiple data streams on orthogonal spatial channels to a single receiver, (2) a single-user non-steered mode that transmits multiple data streams from multiple antennas to a single receiver without spatial processing at a transmitter, (3) a multi-user steered mode that transmits multiple data streams simultaneously to multiple receivers with spatial processing at a transmitter, and (4) a multi-user non-steered mode that transmits multiple data streams from multiple antennas (co-located or non co-located) without spatial processing at the transmitter(s) to receiver(s) having multiple antennas. For each set of user terminal(s) selected for data transmission on the downlink and/or uplink, a spatial multiplexing mode is selected for the user terminal set from among the multiple spatial multiplexing modes supported by the system.

Claims

1. A method of transmitting data in a wireless multiple-access multiple-input multiple-output (MIMO) communication system, comprising:

selecting a first user terminal for data transmission in a first transmission interval;

selecting a first spatial multiplexing mode to use for the first user terminal based on channel state information, the first spatial multiplexing mode being a steered spatial multiplexing mode;

selecting a second user terminal for data transmission in a second transmission interval;

selecting a second spatial multiplexing mode to use for the second user terminal based on channel state information, the second spatial multiplexing mode being a non-steered spatial multiplexing mode;

scheduling the first user terminal for data transmission in the first transmission interval with the first spatial multiplexing mode;

scheduling the second user terminal for data transmission in the second transmission interval with the second spatial multiplexing mode;

spatially processing a first plurality of data streams, having a selection of a first plurality of rates, with a plurality of steering vectors to transmit the first plurality of data streams on a first plurality of orthogonal spatial channels of a first MIMO channel for the first user terminal; and

spatially processing a second plurality of data streams, having a selection of a second plurality of rates, to transmit the second plurality of data streams on a second plurality of orthogonal spatial channels of a second MIMO channel for the second user terminal.

2. The method of claim 1, further comprising:

performing receiver spatial processing on a first plurality of received symbol streams with a plurality of eigenvectors to obtain estimates of a first plurality of data streams transmitted by the first user terminal; and

performing receiver spatial processing on a second plurality of received symbol streams in accordance with a spatial filter to obtain estimates of a second plurality of data streams transmitted by the second user terminal.

3. The method of claim 1, further comprising:

selecting a first plurality of rates for a first plurality of data streams to be transmitted via a first plurality of spatial channels of a first MIMO channel for the first user terminal; and

selecting a second plurality of rates for a second plurality of data streams to be transmitted via a second plurality of spatial channels of a second MIMO channel for the second user terminal, and

wherein the first user terminal is further scheduled with the first plurality of rates and the second user terminal is scheduled with the second plurality of rates.

4. An apparatus in a wireless multiple-access multiple-input multiple-output (MIMO) communication system, comprising:

a user selector operative to select a first user terminal for data transmission in a first transmission interval and to select a second user terminal for data transmission in a second transmission interval;

a mode selector operative to select, based on channel state information, a first spatial multiplexing mode to use for the first user terminal and to select a second spatial multiplexing mode to use for the second user terminal, wherein the first spatial multiplexing mode is a steered spatial multiplexing mode and the second spatial multiplexing mode is a non-steered spatial multiplexing mode; and

a scheduler operative to schedule the first user terminal for data transmission in the first transmission interval with the first spatial multiplexing mode and to schedule the second user terminal for data transmission in the second transmission interval with the second spatial multiplexing mode; and

a transmit spatial processor operative to spatially process;

(i) a first plurality of data streams, having a selection of a first plurality of rates, with a plurality of steering vectors to transmit the first plurality of data streams on a first plurality of orthogonal spatial channels of a first MIMO channel for the first user terminal, and (ii) a second plurality of data streams, having a selection of a second plurality of rates, to transmit the second plurality of data streams on a second plurality of orthogonal spatial channels of a second MIMO channel for the second user terminal.

5. The apparatus of claim 4, further comprising:

a receive spatial processor operative to

perform receiver spatial processing on a first plurality of received symbol streams with a plurality of eigenvectors to obtain estimates of a first plurality of data streams transmitted by the first user terminal, and

perform receiver spatial processing on a second plurality of received symbol streams in accordance with a spatial filter to obtain estimates of a second plurality of data streams transmitted by the second user terminal.

6. An apparatus in a wireless multiple-access multiple-input multiple-output (MIMO) communication system, comprising:

means for selecting a first user terminal for data transmission in a first transmission interval;

means for selecting a first spatial multiplexing mode to use for the first user terminal based on channel state information, the first spatial multiplexing mode being a steered spatial multiplexing mode;

means for selecting a second user terminal for data transmission in a second transmission interval;

means for selecting a second spatial multiplexing mode to use for the second user terminal based on channel state information, the second spatial multiplexing mode being a non-steered spatial multiplexing mode;

means for scheduling the first user terminal for data transmission in the first transmission interval with the first spatial multiplexing mode;

means for scheduling the second user terminal for data transmission in the second transmission interval with the second spatial multiplexing mode;

means for spatially processing a first plurality of data streams, having a selection of a first plurality of rates, with a plurality of steering vectors to transmit the first plurality of data streams on a first plurality of orthogonal spatial channels of a first MIMO channel for the first user terminal; and

means for spatially processing a second plurality of data streams, having a selection of a second plurality of rates, to transmit the second plurality of data streams on a second plurality of orthogonal spatial channels of a second MIMO channel for the second user terminal.

7. The apparatus of claim 6, further comprising:

means for performing receiver spatial processing on a first plurality of received symbol streams with a plurality of eigenvectors to obtain estimates of a first plurality of data streams transmitted by the first user terminal; and

means for performing receiver spatial processing on a second plurality of received symbol streams in accordance with a spatial filter to obtain estimates of a second plurality of data streams transmitted by the second user terminal.

8. A computer-program apparatus for use in a wireless multiple-input multiple-output (MIMO) communication system comprising a non-transitory computer readable medium having a set of instructions stored thereon, the set of instructions being executable by one or more processors and the set of instructions comprising:

instructions for selecting a first user terminal for data transmission in a first transmission interval;

instructions for selecting a first spatial multiplexing mode to use for the first user terminal based on channel state information, the first spatial multiplexing mode being a steered spatial multiplexing mode;

instructions for selecting a second user terminal for data transmission in a second transmission interval;

instructions for selecting a second spatial multiplexing mode to use for the second user terminal based on channel state information, the second spatial multiplexing mode being a non-steered spatial multiplexing mode;

instructions for scheduling the first user terminal for data transmission in the first transmission interval with the first spatial multiplexing mode;

instructions for scheduling the second user terminal for data transmission in the second transmission interval with the second spatial multiplexing mode;

instructions for spatially processing a first plurality of data streams, having a selection of a first plurality of rates, with a plurality of steering vectors to transmit the first plurality of data streams on a first plurality of orthogonal spatial channels of a first MIMO channel for the first user terminal; and

instructions spatially processing a second plurality of data streams, having a selection of a second plurality of rates, to transmit the second plurality of data streams on a second plurality of orthogonal spatial channels of a second MIMO channel for the second user terminal.

9. The computer-program apparatus of claim 8, further comprising:

instructions for performing receiver spatial processing on a first plurality of received symbol streams with a plurality of eigenvectors to obtain estimates of a first plurality of data streams transmitted by the first user terminal; and

instructions for performing receiver spatial processing on a second plurality of received symbol streams in accordance with a spatial filter to obtain estimates of a second plurality of data streams transmitted by the second user terminal.