METHOD FOR PRECODING BASED ON ANTENNA GROUPING

• US 20110085588A1
• Filed: 10/06/2010
• Published: 04/14/2011
• Est. Priority Date: 10/09/2009
• Status: Abandoned Application

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola Mobility, Inc. (Lenovo Group Ltd.)
• Inventors: Brown, Tyler A., Zhuang, Xiangyang
• Application Number:
  US12/899,211
• Publication Number:
  US 20110085588A1
• Time in Patent Office: Days
• US Class Current: 375/219
• CPC Class Codes: H04B 7/0408 using two or more beams, i.e. beam diversity
• CPC Class Codes: H04B 7/0691 using subgroups of transmit antennas
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end

Abstract

A method an apparatus for performing uplink transmission in a user device with a plurality of transmit antennas, including transmitting a first data stream from a first subset of the antennas according to a first precoding vector wherein the first precoding vector may be any vector in a precoding codebook, and transmitting a second data stream from a second subset of the antennas according to a second precoding vector wherein any vector in the precoding codebook may be used for the second precoding vector when the second precoding vector is the same as the first precoding vector to within a scaling factor.

Claims

1. A method for performing uplink transmission in a user device with a plurality of transmit antennas, the method comprising:

transmitting a first data stream from a first subset of the plurality of transmit antennas according to a first precoding vector, wherein the first precoding vector may be any vector in a precoding codebook;

transmitting a second data stream from a second subset of the plurality of transmit antennas according to a second precoding vector,

wherein any vector in the precoding codebook may be used for the second precoding vector when the second precoding vector is the same as the first precoding vector to a scaling factor.

2. The method of claim 1, wherein any vector in the precoding codebook may be used when the first precoding vector is different than the second precoding vector.

3. The method according to claim 1, wherein the first subset of the plurality of transmit antennas and the second subset of the plurality of the transmit antennas are non-overlapping and are of the same size.

4. The method according to claim 1,

wherein transmitting the first data stream from the first subset of antennas according to the first precoding vector is by weighting the first data stream with the entries of the first precoding vector on each corresponding antenna in the first subset, and

wherein transmitting the second data stream from the second subset of antennas according to the second precoding vector is by weighting the second data stream with the entries of the second precoding vector on each corresponding antenna in the second subset.

5. The method according to claim 1, wherein the scaling factor is any complex number of magnitude one, including the value of one.

6. The method according to claim 1, wherein any vector in the precoding codebook may be used for the second precoding vector regardless of the precoding vector in the precoding codebook used for the first precoding vector.

7. The method according to claim 1, wherein at least a vector in the precoding codebook cannot be used for the second precoding vector when a certain precoding vector in the precoding codebook is used for the first precoding vector.

8. The method according to claim 1 further comprising the user device receiving an indication from a base station of the first precoding vector and the second precoding vector.

9. The method according to claim 1, wherein the precoding codebook is defined for a number of antennas in the first subset and the precoding codebook is known to the user device.

10. The method according to claim 1, wherein there are only two data streams to be sent from the user device.

12. The method according to claim 10, wherein the first set of precodings vectors in a precoding codebook includes all vectors in the precoding codebook.

11. A method for performing uplink transmission in a user device with a plurality of transmit antennas, the method comprising:

transmitting a first data stream from a first subset of the plurality of transmit antennas according to a first precoding vector, wherein at any time instant the first precoding vector is one of a first set of precoding vectors in a precoding codebook;

transmitting a second data stream from a second subset of the plurality of transmit antennas according to a second precoding vector, wherein at a plurality of time instants the second precoding vector is one of a second set of precoding vectors in the precoding codebook,

wherein at each of the plurality of time instants the second precoding vector is the same as the first precoding vector to a scaling factor and at each of the plurality of time instants the first set of precoding vectors is the same as the second set of precoding vectors to a scaling factor.

13. A method in a base station, the method comprising:

indicating to a user device a first precoding vector selected from a precoding codebook, wherein the first precoding vector is for a first subset of a plurality transmit antennas of the user device;

indicating to the user device a second precoding vector, wherein the second precoding vector is for a second subset of a plurality transmit antennas of the user device,

wherein any vector in the precoding codebook may be used for the second precoding vector when the second precoding vector is the same as the first precoding vector to a scaling factor.

14. The method according to claim 13, wherein the first subset of the plurality of antennas and the second subset of the plurality of the antennas are non-overlapping and have a common size.

15. The method according to claim 13, wherein the scaling factor is any complex number of one, including the value one itself.

16. The method according to claim 13, wherein any vector in the precoding codebook may be used for the second precoding vector regardless of the first precoding vector selected from the precoding codebook.

17. The method according to claim 13, wherein at least a vector in the precoding codebook cannot be used for the second precoding vector when a certain precoding vector in the precoding codebook is used for the first precoding vector.

19. The wireless terminal according to claim 17, wherein the first subset of the plurality of antennas and the second subset of the plurality of the antennas are non-overlapping and have a common size.

21. The wireless terminal according to claim 17, wherein any vector in the precoding codebook may be used for the second precoding vector regardless of the precoding vector in the precoding codebook being used for the first precoding vector.

22. The wireless terminal according to claim 17, wherein at least a vector in the precoding codebook cannot be used for the second precoding vector when a certain precoding vector in the precoding codebook is used for the first precoding vector.

18. A wireless terminal comprising:

a plurality of transmit antennas;

a plurality of transceivers coupled to the plurality of transmit antennas;

a precoding module coupled to the plurality of transceivers,

the precoding module weights a first data stream according to a first precoding vector, wherein the first data stream is transmitted from a first subset of transmit antennas and the first precoding vector may be any vector in a precoding codebook,

the precoding module weights a second data stream according to a second precoding vector, wherein the second data stream is transmitted from a second subset of transmit antennas and wherein any vector in the precoding codebook may be used for the second precoding vector when the second precoding vector is the same as the first precoding vector to a scaling factor.

20. The wireless terminal according to claim 18, wherein the scaling factor is any complex number of magnitude one, including the value one itself.