MIMO system with multiple spatial multiplexing modes

• US 9,048,892 B2
• Filed: 04/04/2013
• Issued: 06/02/2015
• 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): Hamza, Faruk
• Assistant Examiner(s): OH, ANDREW CHUNG SUK
• Application Number:
  US13/857,025
• Publication Number:
  US 20130235825A1
• Time in Patent Office: 789 Days
• Field of Search: None
• US Class Current: 1/1
• 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 processing data in a multiple-input multiple-output (MIMO) communication system, comprising:

generating, at an apparatus, an uplink channel response matrix for each of a plurality of transmitting entities;

deriving a steering vector for each of the transmitting entities by decomposing the channel response matrix to obtain a plurality of eigenvectors and a plurality of singular values, and forming the steering vector for each transmitting entity based on an eigenvector corresponding to a largest singular value among the plurality of singular values;

evaluating different sets of the transmitting entities and selecting a best set for transmission and reception;

sending, to each transmitting entity in the selected best set, a rate selected based on the steering vector and the channel response matrix; and

sending the steering vector to each transmitting entity in the selected best set for use in spatially processing data symbol streams to be transmitted to the apparatus from a plurality of transmit antennas at the transmitting entity.

2. The method of claim 1, further comprising:

obtaining received symbol streams for the data symbol streams transmitted from the at least some of the transmitting entities; and

processing the received symbol streams in accordance with a receiver spatial processing technique to obtain recovered data symbol streams, which are estimates of the data symbol streams.

3. The method of claim 2, wherein the receiver spatial processing technique is a channel correlation matrix inversion (CCMI) technique or a minimum mean square error (MMSE) technique.

4. The method of claim 2, wherein the receiver spatial processing technique is a successive interference cancellation (SIC) technique.

5. The method of claim 1, wherein the steering vector for the transmitting entity is equal to the eigenvector corresponding to the largest singular value.

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

at least one processor configured to;

generate an uplink channel response matrix for each of a plurality of transmitting entities;

derive a steering vector for each of the transmitting entities by decomposing the channel response matrix to obtain a plurality of eigenvectors and a plurality of singular values, and forming the steering vector for each transmitting entity based on an eigenvector corresponding to a largest singular value among the plurality of singular values;

evaluate different sets of the transmitting entities and select a best set for transmission and reception;

send a rate to each of the transmitting entities in the selected best set, the rate selected based on the steering vector and the channel response matrix; and

send the steering vector to each of the transmitting entities for use in spatially processing data symbol streams to be transmitted to the apparatus from a plurality of transmit antennas at the transmitting entity.

7. The apparatus of claim 6, wherein the at least one processor is further to obtain received symbol streams for the data symbol streams transmitted from at least some of the transmitting entities and process the received symbol streams in accordance with a receiver spatial processing technique to obtain recovered data symbol streams, which are estimates of the data symbol streams.

8. The apparatus of claim 7, wherein the receiver spatial processing technique is a channel correlation matrix inversion (CCMT) technique or a minimum mean square error (MMSE) technique.

9. The apparatus of claim 7, wherein the receiver spatial processing technique is a successive interference cancellation (SIC) technique.

10. The apparatus of claim 6, wherein the steering vector for the transmitting entity is equal to the eigenvector corresponding to the largest singular value.

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

means for generating an uplink channel response matrix for each of a plurality of transmitting entities;

means for deriving a steering vector for each of the transmitting entities by decomposing the channel response matrix to obtain a plurality of eigenvectors and a plurality of singular values, and forming the steering vector for each transmitting entity based on an eigenvector corresponding to a largest singular value among the plurality of singular values;

means for evaluating different sets of the transmitting entities and selecting a best set for transmission and reception;

means for sending, to each transmitting entity in the selected best set, a rate selected based on the steering vector and the channel response matrix; and

means for sending the steering vector to each transmitting entity in the selected best set for use in spatially processing data symbol streams to be transmitted to the apparatus from a plurality of transmit antennas at the transmitting entity.

12. The apparatus of claim 11, further comprising:

means for obtaining received symbol streams for the data symbol streams transmitted from at least some of the transmitting entities; and

means for processing the received symbol streams in accordance with a receiver spatial processing technique to obtain recovered data symbol streams, which are estimates of the data symbol streams.

13. The apparatus of claim 12, wherein the receiver spatial processing technique is a channel correlation matrix inversion (CCMI) technique or a minimum mean square error (MMSE) technique.

14. The apparatus of claim 12, wherein the receiver spatial processing technique is a successive interference cancellation (SIC) technique.

15. The apparatus of claim 11, wherein the steering vector for the transmitting entity is equal to the eigenvector corresponding to the largest singular value.

16. A computer-program product in a multiple-input multiple-output (MIMO) communication system comprising a non-transitory computer readable medium having instructions thereon, the instructions comprising:

code for generating, at an apparatus, an uplink channel response matrix for each of a plurality of transmitting entities;

code for deriving a steering vector for each of the transmitting entities by decomposing the channel response matrix to obtain a plurality of eigenvectors and a plurality of singular values, and forming the steering vector for each transmitting entity based on an eigenvector corresponding to a largest singular value among the plurality of singular values;

code for evaluating different sets of the transmitting entities and selecting a best set for transmission and reception;

code for sending, to each transmitting entity in the selected best set, a rate selected based on the steering vector and the channel response matrix; and

code for sending the steering vector to each transmitting entity in the selected best set for use in spatially processing data symbol streams to be transmitted to the apparatus from a plurality of transmit antennas at the transmitting entity.

17. The computer-program product of claim 16, further comprising:

code for obtaining received symbol streams for the data symbol streams transmitted from at least some of the transmitting entities; and

code for processing the received symbol streams in accordance with a receiver spatial processing technique to obtain recovered data symbol streams, which are estimates of the data symbol streams.

18. The computer-program product of claim 17, wherein the receiver spatial processing technique is a channel correlation matrix inversion (CCMI) technique or a minimum mean square error (MMSE) technique.

19. The computer-program product of claim 17, wherein the receiver spatial processing technique is a successive interference cancellation (SIC) technique.

20. The computer-program product of claim 16, wherein the steering vector for the transmitting entity is equal to the eigenvector corresponding to the largest singular value.