PRE-CODING METHOD FOR SPATIAL MULTIPLEXING IN MULTIPLE INPUT AND OUTPUT SYSTEM

• US 20110280188A1
• Filed: 11/02/2009
• Published: 11/17/2011
• Est. Priority Date: 11/02/2008
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Tiraspolsky, Sergey, Flaksman, Alexander, Kim, Joong Heon, Jeon, Beom Jin, Rubtsov, Alexey
• Granted Patent: US 8,842,640 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/063 Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection
• CPC Class Codes: H04B 7/0691 using subgroups of transmit antennas
• CPC Class Codes: H04B 7/0697 using spatial multiplexing

Abstract

The present invention relates to a pre-coding method for spatial multiplexing, comprising the steps of: performing a beam search for beam forming with a receiver device equipped with multiple antennas to perform pre-coding for spatial multiplexing in a transmitter device equipped with multiple antennas; transmitting a first packet including at least one or more training sequences to the receiver device after completion of said beam search; receiving, from the receiver device, a second packet including feedback information for pre-coding, determined in the receiver device by using the training sequences; and performing pre-coding for spatial multiplexing, onto the data stream to be transmitted to the receiver device, by using the pre-coding matrix calculated on the basis of the feedback information.

Claims

1. A method for performing spatial multiplexing precoding in a transmitting device that includes a plurality of antennas, the method comprising:

performing a beam searching process for beamforming with a receiving device that includes a plurality of antennas;

transmitting a first packet comprising at least one training sequence to the receiving device after performing the beam searching process;

receiving a second packet comprising feedback information for precoding from the receiving device, wherein the feedback information is determined using the training sequence; and

performing spatial multiplexing precoding for data streams to be transmitted to the receiving device, by using a precoding matrix obtained based on the feedback information.

2. The method according to claim 1, wherein the first packet is transmitted if the number of ranks of a channel matrix determined by the beam searching process is greater than 1.

3. The method according to claim 1, wherein the at least one training sequence is a training sequence for each spatial multiplexing port and the at least one training sequence includes different training sequences for different spatial multiplexing ports.

5. The method according to claim 1, wherein the feedback information is related to precoding angles for obtaining the precoding matrix.

6. The method according to claim 5, wherein the number and order of the precoding angles are determined depending on a number of data streams and a number of spatial multiplexing ports.

4. (canceled)

7. A transmitting device for transmitting data to a receiving device by using a plurality of antennas, the transmitting device comprising:

the plurality of antennas;

a beamforming module;

a transmitting module;

a receiving module; and

a spatial multiplexing precoder;

wherein the beamforming module performs a beam searching process for beamforming with the receiving device that includes a plurality of antennas;

the transmitting module transmits a first packet comprising at least one training sequence to the receiving device after performing the beam searching process;

the receiving module receives a second packet comprising feedback information for precoding from the receiving device, wherein the feedback information is determined using the training sequence; and

the spatial multiplexing precoder performs spatial multiplexing precoding for data streams to be transmitted to the receiving device, by using a precoding matrix obtained based on the feedback information.

8. The transmitting device according to claim 7, wherein the at least one training sequence is a training sequence for each spatial multiplexing port, and the at least one training sequence includes different training sequences for different spatial multiplexing ports.

10. The transmitting device according to claim 7, wherein the feedback information is related to precoding angles for obtaining the precoding matrix.

11. The transmitting device according to claim 10, wherein the number and order of the precoding angles are determined depending on a number of data streams and a number of spatial multiplexing ports.

22. The transmitting device according to claim 7, wherein the first packet is transmitted if the number of ranks of a channel matrix determined by the beam searching process is greater than 1.

9. (canceled)

12. A method for transmitting feedback information for spatial multiplexing precoding from a receiving device that includes a plurality of antennas, the method comprising the steps of:

performing a beam searching process for beamforming with a transmitting device that includes a plurality of antennas;

receiving a first packet comprising at least one training sequence from the transmitting device after performing the beam searching process;

determining feedback information for precoding in the receiving device by using the training sequence;

transmitting a second packet comprising the feedback information to the transmitting device; and

receiving data subjected to spatial multiplexing precoding, from the transmitting device by using a precoding matrix obtained based on the feedback information.

13. The method according to claim 12, wherein the at least one training sequence is a training sequence for each spatial multiplexing port, the at least one training sequence includes different training sequences for different spatial multiplexing ports.

15. The method according to claim 12, wherein the feedback information is related to precoding angles for obtaining the precoding matrix.

16. The method according to claim 15, wherein the number and order of the precoding angles are determined depending on a number of data streams and a number of spatial multiplexing ports.

23. The method according to claim 12, wherein the first packet is transmitted if the number of ranks of a channel matrix determined by the beam searching process is greater than 1.

14. (canceled)

17. A receiving device for transmitting feedback information for spatial multiplexing precoding to a transmitting device by using a plurality of antennas, the receiving device comprising:

the plurality of antennas;

a beamforming module;

a transmitting module;

a receiving module; and

a control module;

wherein the beamforming module performs a beam searching process for beamforming with a transmitting device that includes a plurality of antennas;

the receiving module receives a first packet comprising at least one training sequence from the transmitting device after performing the beam searching process;

the control module determines feedback information for precoding in the apparatus by using the training sequence;

the transmitting module transmits a second packet comprising the feedback information to the transmitting device; and

the receiving module further receives data subjected to spatial multiplexing precoding, from the transmitting device by using a precoding matrix obtained based on the feedback information.

18. The receiving device according to claim 17, wherein the first packet is transmitted if the number of ranks of a channel matrix determined by the beam searching process is greater than 1.

19. The receiving device according to claim 17, wherein the at least one training sequence is a training sequence for each spatial multiplexing port, and the at least one training sequence includes different training sequences for different spatial multiplexing ports.

20. The receiving device according to claim 17, wherein the feedback information is related to precoding angles for obtaining the precoding matrix.

21. The receiving device according to claim 20, wherein the number and order of the precoding angles are determined depending on a number of data streams and a number of spatial multiplexing ports.