Method and apparatus for transmitting CSI-RS and data using partial muting of CSI-RS

1. A method for transmitting, by a base station, a Channel State Information Reference Signal (CSI-RS) and data, the method comprising:

determining a CSI-RS pattern to be used among CSI-RS pattern candidates;

determining a muting pattern for muting one or more resource elements constituting CSI-RS pattern candidates;

mapping data symbols and CSI-RS to resource elements in a resource grid with rate matching in consideration of the CSI-RS pattern and muting pattern; and

transmitting the data symbols and CSI-RS to a terminal,

wherein the muting pattern is selected from at least one part of the CSI-RS pattern candidates, and data symbols are mapped to resource elements corresponding to non-selected part of the CSI-RS pattern candidates in the resource grid.

2. The method of claim 1 , further comprising signaling a transmission cycle of the CSI-RS and an application cycle of the muting pattern to the terminal.

3. The method of claim 2 , wherein the transmission cycle of the CSI-RS and the application cycle of the muting pattern are determined individually.

4. The method of claim 1 , further comprising, after the determining of the muting pattern, signaling the CSI-RS pattern and the muting pattern to the terminal.

5. The method of claim 4 , wherein the muting pattern is determined according to a transmission time point of a subframe.

6. A base station for transmitting Channel State Information Reference Signals (CSI-RS) and data, the base station comprising:

a controller for determining a CSI-RS pattern to be used among CSI-RS pattern candidates and a muting pattern for muting one or more resource elements constituting CSI-RS pattern candidates;

a resource element mapper for mapping data symbols and CSI-RS to resource elements in a resource grid with rate matching in consideration of the CSI-RS pattern and muting pattern;

an Orthogonal Frequency Division Multiplexing (OFDM) signal generator for modulating the mapped data symbols and CSI-RS; and

an antenna for transmitting the modulated data symbols and CSI-RS to a terminal,

wherein the muting pattern is selected from at least one part of the CSI-RS pattern candidates, and data symbols are mapped to resource elements corresponding to non-selected part of the CSI-RS pattern candidates in the resource grid.

7. The base station of claim 6 , wherein the controller signals a transmission cycle of the CSI-RS to the terminal and an application cycle of the muting pattern.

8. The base station of claim 7 , wherein the transmission cycle of the CSI-RS and the application cycle of the muting pattern are determined individually.

9. The base station of claim 6 , wherein the controller transmits the determined CSI-RS pattern and the muting pattern to the terminal.

10. The base station of claim 9 , wherein the muting pattern is determined according to a transmission time point of a subframe.

11. A method for receiving, by a terminal, Channel State Information Reference Signals (CSI-RS) and data, the method comprising:

receiving a CSI-RS pattern and a muting pattern transmitted by a base station;

receiving a downlink signal from the base station;

estimating a channel with the CSI-RS extracted at positions constituting the CSI-RS pattern in the received downlink signal;

extracting data symbols from the received downlink signal by referencing the CSI-RS pattern and the muting pattern; and

decoding the extracted data symbols,

wherein the muting pattern is selected from at least one part of the CSI-RS pattern candidates, and data symbols are mapped to resource elements corresponding to non-selected part of the CSI-RS pattern candidates in the resource grid.

12. The method of claim 11 , further comprising receiving a transmission cycle of the CSI-RS and an application cycle of the muting pattern from the base station.

13. The method of claim 12 , wherein the transmission cycle of the CSI-RS and the application cycle of the muting pattern are determined individually.

14. The method of claim 13 , wherein the CSI-RS pattern to be used among CSI-RS pattern candidates and the muting pattern for muting some of resource elements constituting CSI-RS pattern candidates except the determined CSI-RS pattern are determined according to a transmission time point of a subframe.

15. The method of claim 11 , wherein the receiving of the CSI-RS pattern and the muting pattern comprises:

receiving a CSI-RS pattern indicator indicating the CSI-RS pattern and a muting pattern indicator indicating the muting pattern used by the base station;

extracting the CSI-RS pattern indicated by the CSI-RS pattern indicator; and

extracting the muting pattern indicated by the muting pattern indicator.

16. A terminal for receiving Channel State Information Reference Signals (CSI-RS) and data, the terminal comprising:

an antenna for receiving a downlink signal from a base station;

a controller for extracting a CSI-RS pattern and a muting pattern from a signal transmitted by the base station;

a channel estimator for estimating a channel with the CSI-RS extracted at positions constituting the CSI-RS pattern in the received downlink signal;

a symbol extractor for extracting data symbols from the received downlink signal by referencing the CSI-RS pattern and the muting pattern; and

a decoder for decoding the extracted data symbols,

wherein the muting pattern is selected from at least one part of the CSI-RS pattern candidates, and data symbols are mapped to resource elements corresponding to non-selected part of the CSI-RS pattern candidates in the resource grid.

17. The terminal of claim 16 , wherein the controller receives a transmission cycle of the CSI-RS and an application cycle of the muting pattern from the base station.

18. The terminal of claim 17 , wherein the transmission cycle of the CSI-RS and the application cycle of the muting pattern are determined individually.

19. The terminal of claim 18 , wherein the CSI-RS pattern to be used among CSI-RS pattern candidates and the muting pattern for muting some of resource elements constituting CSI-RS pattern candidates except the determined CSI-RS pattern are determined according to a transmission time point of a subframe.

20. The terminal of claim 16 , wherein the controller receives a CSI-RS pattern indicator indicating the CSI-RS pattern and a muting pattern indicator indicating the muting pattern used by the base station and extracts the CSI-RS pattern indicated by the CSI-RS pattern indicator and the muting pattern indicated by the muting pattern indicator.