Apparatus for generating precoding codebook for MIMO system and method using the apparatus

1. An apparatus for generating a precoding codebook, the apparatus comprising:

a clustering unit to collect a predetermined number of spatial beams into one cluster such that mutual interference is minimized, the predetermined number of spatial beams selected from among a plurality of spatial beams distributed to at least one user during a preceding process of a Multiple-Input Multiple-Output (MIMO) communication scheme;

a mapping table generator to generate a mapping table including a plurality of elements and one or more indexes generated based on information about a plurality of clusters of the clustering unit, wherein a value of each element of the mapping table is based on interference between the plurality of clusters and/or whether overlapping of the plurality of clusters is allowed; and

a codebook generator to select at least one cluster from the mapping table based on the value of each element of the mapping table, and generate a codebook from the selected at least one cluster.

2. The apparatus as claimed in claim 1 , wherein the interference between the plurality of clusters is determined based on feedback data that is received from a terminal with respect to a pilot signal.

3. The apparatus as claimed in claim 1 , further comprising:

a transmitter to select a transmitting cluster based on the mapping table and communication environment-based preferred cluster information that is received from a terminal, and to transmit data from a base station via the transmitting cluster,

wherein the transmitter selects the transmitting cluster to minimize interference with a neighboring terminal.

4. The apparatus as claimed in claim 1 , wherein the value of each element of the mapping table is based on interference between two corresponding clusters of the one or more indexes and/or whether overlapping of the two corresponding clusters is allowed.

5. The apparatus as claimed in claim 4 , wherein the mapping table comprises a first index of the plurality of clusters and a second index of the plurality of clusters, such that each element of the mapping table is generated based on an interference between a corresponding cluster of the first index and a corresponding cluster of the second index.

6. The apparatus as claimed in claim 1 , wherein a value of each element of the mapping table is a real number from 0 to 1 according to the interference between the plurality of clusters and/or whether overlapping of the plurality of clusters is allowed.

7. The apparatus as claimed in claim 1 , wherein overlapping is allowed only when the plurality of clusters are orthogonal or nearly orthogonal to each other.

8. The apparatus as claimed in claim 1 , wherein the mapping table only stores values of elements that are located in one of an upper portion and a lower portion of a diagonal line that crosses the mapping table, not including values of elements on the diagonal line.

9. The apparatus as claimed in claim 1 , wherein the one or more indexes comprise a plurality of cluster combinations.

10. The apparatus as claimed in claim 9 , wherein each cluster combination comprises:

a first preferred cluster that is preferred by a terminal due to a location of the terminal or a geographical characteristic in a cell coverage; and

a second preferred cluster that has a minimum interference with the first preferred cluster.

11. A method of generating a preceding codebook, the method comprising:

collecting a predetermined number of spatial beams into each of a plurality of clusters such that mutual interference is minimized, the predetermined number of spatial beams selected from among a plurality of spatial beams distributed to at least one user during a preceding process of a Multiple-input Multiple-Output (MIMO) communication scheme; generating a mapping table including a plurality of elements and one or more indexes generated based on information about the plurality of clusters, wherein a value of each element of the mapping table is based on interference between the plurality of clusters and/or whether overlapping of the plurality of clusters is allowed;

selecting at least one cluster from the mapping table based on the value of each element of the mapping table; and

generating a codebook from the selected at least one cluster.

12. The method as claimed in claim 11 , wherein the interference between the clusters is determined based on feedback data that is received from a terminal with respect to a pilot signal.

13. The method as claimed in claim 11 , further comprising:

selecting a transmitting cluster based on the mapping table and communication environment-based preferred cluster information that is received from a terminal such that interference with a neighboring terminal is minimized; and

transmitting data from a base station via the transmitting cluster.

14. The method as claimed in claim 11 , wherein the value of each element of the mapping table is based on interference between two corresponding clusters of the one or more indexes and/or whether overlapping of the two corresponding clusters is allowed.

15. The method as claimed in claim 14 , wherein the mapping table comprises a first index of the plurality of clusters and a second index of the plurality of clusters, such that each element of the mapping table is generated based on an interference between a corresponding cluster of the first index and a corresponding cluster of the second index.

16. The method as claimed in claim 11 , wherein a value of each element of the mapping table is a real number from 0 to 1 according to the interference between the plurality of clusters and/or whether overlapping of the plurality of clusters is allowed.

17. The method as claimed in claim 11 , wherein overlapping is allowed only when the plurality of clusters are orthogonal or nearly orthogonal to each other.

18. The method as claimed in claim 11 , wherein the mapping table only stores values of elements that are located in one of an upper portion and a lower portion of a diagonal line that crosses the mapping table, not including values of elements on the diagonal line.

19. The method as claimed in claim 11 , wherein the one or more indexes comprise a plurality of cluster combinations.

20. The method as claimed in claim 19 , wherein each cluster combination comprises:

a first preferred cluster that is preferred by a terminal due to a location of the terminal or a geographical characteristic in a cell coverage; and

a second preferred cluster that has a minimum interference with the first preferred cluster.

21. The method as claimed in claim 13 , further comprising:

downloading the generated precoding codebook from the base station to the terminal.

22. The method as claimed in claim 21 , wherein the downloading of the generated precoding codebook comprises:

transmitting a correlation value of an interference channel from the base station to the terminal.

23. A computer readable recording medium encoded with the method of claim 11 and implemented by a computer.

24. A system for generating and transmitting a precoding codebook, the system comprising:

a base station to generate the preceding codebook, the base station comprising:

a clustering unit to collect a predetermined number of spatial beams into one cluster such that mutual interference is minimized, the predetermined number of spatial beams selected from among a plurality of spatial beams distributed to at least one user during a preceding process of a Multiple-Input Multiple-Output (MIMO) communication scheme,

a mapping table generator to generate a mapping table including a plurality of elements and one or more indexes generated based on information about a plurality of clusters of the clustering unit, wherein a value of each element of the mapping table is based on interference between the plurality of clusters and/or whether overlapping of the plurality of clusters is allowed, and

a transmitter to select a transmitting cluster based on the mapping table and communication environment-based preferred cluster information, and to transmit data from via the transmitting cluster; and

a terminal to download the preceding codebook from the base station, to receive the transmitted data from the base station via the transmitting cluster, and to transmit the communication environment-based preferred cluster information to the base station,

wherein the transmitter selects the transmitting cluster to minimize interference with a neighboring terminal of the terminal.

25. The system as claimed in claim 24 , wherein the interference between the plurality of clusters is determined based on feedback data that is received from the terminal with respect to a pilot signal.

26. The system as claimed in claim 24 , wherein the value of each element of the mapping table is based on interference between two corresponding clusters of the one or more indexes and/or whether overlapping of the two corresponding clusters is allowed.

27. The system as claimed in claim 26 , wherein the mapping table comprises a first index of the plurality of clusters and a second index of the plurality of clusters, such that each element of the mapping table is generated based on an interference between a corresponding cluster of the first index and a corresponding cluster of the second index.

28. The system as claimed in claim 24 , wherein overlapping is allowed only when the plurality of clusters are orthogonal or nearly orthogonal to each other.

29. The system as claimed in claim 24 , wherein the mapping table only stores values of elements that are located in one of an upper portion and a lower portion of a diagonal line that crosses the mapping table, not including values of elements on the diagonal line.

30. The system as claimed in claim 24 , wherein the transmitter transmits a correlation value of an interference channel from the base station to the terminal.

31. A method of generating and transmitting a preceding codebook, the method comprising:

collecting a predetermined number of spatial beams into each of a plurality of clusters such that mutual interference is minimized, the predetermined number of spatial beams selected from among a plurality of spatial beams distributed to at least one user during a preceding process of a Multiple-Input Multiple-Output (MIMO) communication scheme;

generating a mapping table including a plurality of elements and one or more indexes generated based on information about the plurality of clusters, wherein a value of each element of the mapping table is based on interference between the plurality of clusters and/or whether overlapping of the plurality of clusters is allowed;

selecting a transmitting cluster based on the mapping table and communication environment-based preferred cluster information that is received from a terminal such that interference with a neighboring terminal is minimized; and

transmitting data from a base station via the transmitting cluster.

32. The method as claimed in claim 31 , wherein the value of each element of the mapping table is based on interference between two corresponding clusters of the one or more indexes and/or whether overlapping of the two corresponding clusters is allowed.

33. The method as claimed in claim 32 , wherein the mapping table comprises a first index of the plurality of clusters and a second index of the plurality of clusters, such that each element of the mapping table is generated based on an interference between a corresponding cluster of the first index and a corresponding cluster of the second index.

34. The method as claimed in claim 31 , wherein overlapping is allowed only when the plurality of clusters are orthogonal or nearly orthogonal to each other.

35. The method as claimed in claim 31 , further comprising:

downloading the generated preceding codebook from the base station to the terminal.

36. The method as claimed in claim 35 , wherein the downloading of the generated preceding codebook comprises:

transmitting a correlation value of an interference channel from the base station to the terminal.

37. A computer readable recording medium encoded with the method of claim 31 and implemented by a computer.