Method and apparatus for supporting multi-user and single-user MIMO in a wireless communication system

Patent metadata

Field	Value
Publication number	US-9755705-B2
Application number	US-53636609-A
Country	US
Kind code	B2
Filing date	Aug 5, 2009
Priority date	Aug 7, 2008
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

Techniques for supporting distributed multiple-input multiple-output (MIMO) transmissions are described. In one design, a user equipment (UE) determines channel estimates for multiple cells and reports the channel estimates. The UE thereafter receives a data transmission sent by the multiple cells to the UE based on the channel estimates. The data transmission may include at least one data stream, and each data stream may be sent by one cell or the multiple cells to the UE. In another design, a UE determines first and second channel estimates for first and second cells, respectively, and reports the channel estimates. The UE then receives a first data transmission sent by the first cell to the UE based on the first channel estimate. The UE also receives a second data transmission sent by the second cell to another UE and steered away from the UE based on the second channel estimate.

First claim

What is claimed is:

1. A method of receiving data in a wireless communication system, comprising:
determining a channel gain for each of multiple cells by a user equipment (UE) including a first channel gain from a serving cell and a second channel gain from a non-serving cell, wherein the channel gain comprises a gain from each transmit antenna of a cell to each receive antenna of the UE;
computing, by the UE, a receive filter using at least a set of vectors determined from the first channel gain;
generating a first virtual channel vector by applying the receive filter to at least a portion of a first channel matrix that includes the first channel gain;
generating a second virtual channel vector by applying the receive filter to at least a portion of a second channel matrix that includes the second channel gain;
sending, from the UE, the first virtual channel vector to the serving cell and the second virtual channel vector to the non-serving cell; and
receiving a data transmission sent by the serving cell based on the first virtual channel vector.

2. The method of claim 1 , wherein the data transmission comprises at least one data stream, each data stream being received by the UE from the multiple cells.

3. The method of claim 1 , wherein the data transmission comprises multiple data streams, each data stream being received by the UE from one of the multiple cells.

4. The method of claim 1 , wherein the data transmission is received from the multiple cells on resources utilized in common with a second UE.

5. The method of claim 1 , wherein the data transmission is received from the multiple cells on resources reserved for use by the UE.

6. The method of claim 1 , wherein the data transmission comprises at least one data stream, each data stream being sent with cell-specific precoding determined from a cell-specific component of the first virtual channel vector.

7. The method of claim 1 , further comprising:
reporting channel quality indicator (CQI) information for one or more of the multiple cells, wherein the data transmission is sent based further on the CQI information.

8. The method of claim 1 , wherein the multiple cells are each equipped with a single transmit antenna, wherein the UE is equipped with a single receive antenna, and wherein generating the first or second virtual channel vectors comprises determining an equivalent channel gain for each of the multiple cells.

9. The method of claim 8 , wherein the data transmission comprises a single data stream sent with precoding based on a precoding vector determined from the first virtual channel vector.

10. The method of claim 1 , wherein the multiple cells are each equipped with a single transmit antenna, wherein the UE is equipped with multiple receive antennas, and wherein generating the first or second virtual channel vectors comprises:
determining a channel vector for each of the multiple cells, wherein the determined channel gain is the channel vector, and
determining an equivalent channel gain for each cell based on the channel vector for the cell and the receive filter.

11. The method of claim 1 , wherein the multiple cells are each equipped with multiple transmit antennas, wherein the UE is equipped with a single receive antenna, and wherein generating the first or second virtual channel vectors comprises determining a channel vector for each of the multiple cells, wherein the determined channel gain is the channel vector.

12. The method of claim 1 , wherein the multiple cells are each equipped with multiple transmit antennas, wherein the UE is equipped with multiple receive antennas, and wherein generating the first or second virtual channel vectors comprises:
determining a channel matrix for each of the multiple cells, wherein the determined channel gain is the channel matrix, and
determining an equivalent channel gain for each cell based on the channel matrix for the cell and the receive filter.

13. The method of claim 1 , wherein the multiple cells belong to a single base station.

14. The method of claim 1 , wherein the multiple cells are associated with multiple antennas distributed at different locations.

15. An apparatus for receiving data in a wireless communication system, comprising:
means for determining a channel gain for each of multiple cells by a user equipment (UE) including a first channel gain from a serving cell and a second channel gain from a non-serving cell, wherein the channel gain comprises a gain from each transmit antenna of a cell to each receive antenna of the UE;
means for computing, by the UE, a receive filter using at least a set of vectors determined from the first channel gain;
means for generating a first virtual channel vector by applying the receive filter to at least a portion of a first channel matrix that includes the first channel gain;
means for generating a second virtual channel vector by applying the receive filter to at least a portion of a second channel matrix that includes the second channel gain;
means for sending, from the UE, the first virtual channel vector to the serving cell and the second virtual channel vector to the non-serving cell; and
means for receiving a data transmission sent by the serving cell based on the first virtual channel vector.

16. The apparatus of claim 15 , wherein the data transmission comprises at least one data stream, each data stream being received by the UE from the multiple cells.

17. The apparatus of claim 15 , wherein the data transmission comprises multiple data streams, each data stream being received by the UE from one of the multiple cells.

18. The apparatus of claim 15 , wherein the data transmission is received from the multiple cells on resources utilized in common with a second UE.

19. The apparatus of claim 15 , wherein the data transmission is received from the multiple cells on resources reserved for use by the UE.

20. The apparatus of claim 15 , wherein the data transmission comprises at least one data stream, each data stream being sent with cell-specific precoding determined from a cell-specific component of the first virtual channel vector.

21. An apparatus for wireless communication, comprising:
at least one processor;
memory in electronic communication with the processor; and
instructions stored in the memory and operable, when executed by the processor, to cause the apparatus to:
determine a channel gain for each of multiple cells by a user equipment (UE) including a first channel gain from a serving cell and a second channel gain from a non-serving cell, wherein the channel gain comprises a gain from each transmit antenna of a cell to each receive antenna of the UE,
compute a receive filter using at least a set of vectors determined from the first channel gain,
generate a first virtual channel vector by applying the receive filter to at least a portion of a first channel matrix that includes the first channel gain,
generate a second virtual channel vector by applying the receive filter to at least a portion of a second channel matrix that includes the second channel gain,
send, from the UE, the first virtual channel vector to the serving cell and the second virtual channel vector to the non-serving cell, and
receive a data transmission sent by the serving cell based on the first virtual channel vector.

22. The apparatus of claim 21 , wherein the data transmission comprises at least one data stream, each data stream being received by the UE from the multiple cells.

Assignees

• Hou Jilei
• Smee John E
• Malladi Durga Prasad
• Hassanpour Ghady Navid
• Mallik Siddhartha
• Qualcomm Inc

Inventors

• Hou Jilei
• Smee John E
• Malladi Durga Prasad
• Hassanpour Ghady Navid
• Mallik Siddhartha

Classifications

• H04B7/0639

  Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection · CPC title

• H04B7/0626

  Channel coefficients, e.g. channel state information [CSI] · CPC title

• H04B7/0452

  Multi-user MIMO systems · CPC title

• H04L25/0204

  of multiple channels · CPC title

• H04B7/024 Primary

  Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems · CPC title