Multi-antenna transmission for spatial division multiple access

Patent metadata

Field	Value
Publication number	US-9548851-B2
Application number	US-86954707-A
Country	US
Kind code	B2
Filing date	Oct 9, 2007
Priority date	Nov 21, 2003
Publication date	Jan 17, 2017
Grant date	Jan 17, 2017

Abstract

An uplink channel response matrix is obtained for each terminal and decomposed to obtain a steering vector used by the terminal to transmit on the uplink. An “effective” uplink channel response vector is formed for each terminal based on its steering vector and its channel response matrix. Multiple sets of terminals are evaluated based on their effective channel response vectors to determine the best set (e.g., with highest overall throughput) for uplink transmission. Each selected terminal performs spatial processing on its data symbol stream with its steering vector and transmits its spatially processed data symbol stream to an access point. The multiple selected terminals simultaneously transmit their data symbol streams via their respective MIMO channels to the access point. The access point performs receiver spatial processing on its received symbol streams in accordance with a receiver spatial processing technique to recover the data symbol streams transmitted by the selected terminals.

First claim

What is claimed is:

1. A method of receiving data in a multiple-input multiple-output (MIMO) communication system, comprising:
obtaining, from a plurality of receive antennas at a receiving entity, a plurality of received symbol streams for a plurality of data symbol streams sent by a plurality of transmitting entities, one data symbol stream for each transmitting entity;
evaluating each of a plurality of sets of transmitting entities for possible transmission based on a metric and steering vectors for the transmitting entities in the set; and
selecting a set of transmitting entities with a highest value of the metric for transmission, wherein the selected set of transmitting entities comprises the plurality of transmitting entities,
wherein the data symbol stream for each transmitting entity is spatially processed with a steering vector derived independently for the transmitting entity and is sent from a plurality of transmit antennas at the transmitting entity, and wherein the plurality of data symbol streams are transmitted simultaneously by the plurality of transmitting entities.

2. The method of claim 1 , further comprising:
processing the plurality of received symbol streams in accordance with a receiver spatial processing technique to obtain a plurality of recovered data symbol streams, which are estimates of the plurality of data symbol streams.

3. The method of claim 1 , wherein the steering vector for each transmitting entity is derived based on a channel estimate for a wireless channel for the transmitting entity.

4. The method of claim 1 , wherein the steering vector for each transmitting entity is derived by
decomposing a channel response matrix for the transmitting entity to obtain a plurality of eigenvectors and a plurality of singular values, and
forming the steering vector for the transmitting entity based on an eigenvector corresponding to a largest singular value among the plurality of singular values.

5. An apparatus at a receiving entity in a multiple-input multiple-output (MIMO) communication system, comprising:
a plurality of receiver units operative to obtain from a plurality of receive antennas a plurality of received symbol streams for a plurality of data symbol streams sent by a plurality of transmitting entities, one data symbol stream for each transmitting entity;
an evaluation unit operative to evaluate each of a plurality of sets of transmitting entities for possible transmission based on a metric and steering vectors for the transmitting entities in the set; and
a selection unit operative to select a set of transmitting entities with a highest value of the metric for transmission, wherein the selected set of transmitting entities comprises the plurality of transmitting entities;
wherein the data symbol stream for each transmitting entity is spatially processed with a steering vector derived independently for the transmitting entity and is sent from a plurality of transmit antennas at the transmitting entity, and wherein the plurality of data symbol streams are transmitted simultaneously by the plurality of transmitting entities.

6. The apparatus of claim 5 , further comprising:
a receive spatial processor operative to process the plurality of received symbol streams in accordance with a receiver spatial processing technique to obtain a plurality of recovered data symbol streams, which are estimates of the plurality of data symbol streams.

7. The apparatus of claim 5 , wherein the steering vector for each transmitting entity is derived based on a channel estimate for a wireless channel for the transmitting entity.

8. The apparatus of claim 5 , wherein the steering vector for each transmitting entity is derived by
decomposing a channel response matrix for the transmitting entity to obtain a plurality of eigenvectors and a plurality of singular values, and
forming the steering vector for the transmitting entity based on an eigenvector corresponding to a largest singular value among the plurality of singular values.

9. An apparatus for receiving data in a multiple-input multiple-output (MIMO) communication system, comprising:
means for obtaining, from a plurality of receive antennas at a receiving entity, a plurality of received symbol streams for a plurality of data symbol streams sent by a plurality of transmitting entities, one data symbol stream for each transmitting entity;
means for evaluating each of a plurality of sets of transmitting entities for possible transmission based on a metric and steering vectors for the transmitting entities in the set; and
means for selecting a set of transmitting entities with a highest value of the metric for transmission, wherein the selected set of transmitting entities comprises the plurality of transmitting entities:
wherein the data symbol stream for each transmitting entity is spatially processed with a steering vector derived independently for the transmitting entity and is sent from a plurality of transmit antennas at the transmitting entity, and wherein the plurality of data symbol streams are transmitted simultaneously by the plurality of transmitting entities.

10. The apparatus of claim 9 , further comprising:
means for processing the plurality of received symbol streams in accordance with a receiver spatial processing technique to obtain a plurality of recovered data symbol streams, which are estimates of the plurality of data symbol streams.

11. The apparatus of claim 9 , wherein the steering vector for each transmitting entity is derived based on a channel estimate for a wireless channel for the transmitting entity.

12. The apparatus of claim 9 , wherein the steering vector for each transmitting entity is derived by
decomposing a channel response matrix for the transmitting entity to obtain a plurality of eigenvectors and a plurality of singular values, and
forming the steering vector for the transmitting entity based on an eigenvector corresponding

to a largest singular value among the plurality of singular values.

13. A non-transitory computer-program product for receiving data in a multiple-input multiple-output (MIMO) communication system comprising a computer readable medium having instructions thereon, the instructions comprising:
code for obtaining, from a plurality of receive antennas at a receiving entity, a plurality of received symbol streams for a plurality of data symbol streams sent by a plurality of transmitting entities, one data symbol stream for each transmitting entity;
code for evaluating each of a plurality of sets of transmitting entities for possible transmission based on a metric and steering vectors for the transmitting entities in the set; and
code for selecting a set of transmitting entities with a highest metric value for transmission, wherein the selected set of transmitting entities comprises the plurality of transmitting entities:
wherein the data symbol stream for each transmitting entity is spatially processed with a steering vector derived independently for the transmitting entity and is sent from a plurality of transmit antennas at the transmitting entity, and wherein the plurality of data symbol streams are transmitted simultaneously by the plurality of transmitting entities.

14. The non-transitory computer-program product of claim 13 , further comprising:
code for processing the plurality of received symbol streams in accordance with a receiver spatial processing technique to obtain a plurality of recovered data symbol streams, which are estimates of the plurality of data symbol streams.

15. The non-transitory computer-program product of claim 13 , wherein the st

Assignees

• Walton J Rodney
• Ketchum John W
• Smee John Edward
• Wallace Mark S
• Howard Steven J
• Qualcomm Inc

Inventors

• Walton J Rodney
• Ketchum John W
• Smee John Edward
• Wallace Mark S
• Howard Steven J

Classifications

• H04B7/0408

  using two or more beams, i.e. beam diversity · CPC title

• H04B7/0421

  utilizing implicit feedback, e.g. steered pilot signals · CPC title

• H04L5/023 Primary

  Multiplexing of multicarrier modulation signals, e.g. multi-user orthogonal frequency division multiple access [OFDMA] (multicarrier modulation H04L27/2601) · CPC title

• H04B1/71072 Primary

  Successive interference cancellation · CPC title

• H04B7/0678

  using different spreading codes between antennas (code allocation H04J13/16) · CPC title