Method for transmitting/receiving data in a multiple-input multiple-output system using multi-carrier

1. A data transmission method for a Multiple-Input Multiple-Output (MIMO) wireless access system using a plurality of sub-carriers, the method comprising:

determining, by a base station, a precoding matrix [W], the precoding matrix [W] being a part of a phase-shift-based precoding matrix [P];

determining, by the base station, a first diagonal matrix [D 1 ] for phase shift, the first diagonal matrix [D 1 ] being a part of the phase-shift-based precoding matrix [P];

determining, by the base station, a unitary matrix [U], the unitary matrix [U] being a part of the phase-shift-based precoding matrix [P];

precoding, by the base station, a transmission symbol per resource using the phase-shift-based precoding matrix [P] to generate precoded data; and

transmitting, by the base station, the precoded data to a mobile station,

wherein the phase-shift-based precoding matrix [P] is determined by a product of the precoding matrix [W], a Hermitian matrix of the unitary matrix [U H ], the first diagonal matrix [D 1 ], and the unitary matrix [U] in sequence as follows:

[P]=[W][U H ][D1][U].

2. The method according to claim 1 , further comprising:

determining a second diagonal matrix [D 2 ] for phase shift, the second diagonal matrix [D 2 ] being a part of the phase-shift-based precoding matrix [P],

wherein the phase-shift-based precoding matrix [P] is determined by a product of the second diagonal matrix [D 2 ], the precoding matrix [W], the Hermitian matrix of the unitary matrix [U H ], the first diagonal matrix [D 1 ], and the unitary matrix [U] in sequence as follows:

[P]=[D2][W][U H ][D1][U].

3. The method according to claim 2 , wherein the first diagonal matrix [D 1 ] and the second diagonal matrix [D 2 ] use phase values for phase-shift independent of each other.

4. The method according to claim 3 , further comprising:

controlling whether to use each of the first diagonal matrix [D 1 ] and the second diagonal matrix [D 2 ] using the phase values for phase-shift.

5. The method according to claim 1 or 2 , wherein the product of the Hermitian matrix of the unitary matrix [U H ], the first diagonal matrix [D 1 ], and the unitary matrix [U] is a rotation matrix determined according to a spatial multiplexing rate (R).

6. The method according to claim 5 , wherein the rotation matrix is configured to be changed according to resource index (k).

7. The method according to claim 5 , wherein the rotation matrix is configured to be changed according to resource index (k), and the same rotation matrix is used for a predetermined ‘I’ number of consecutive resources.

8. The method according to claim 5 , wherein whether to use the rotation matrix or not is determined by configuration.

9. A data reception method for a Multiple-Input Multiple-Output (MIMO) wireless access system using a plurality of sub-carriers, the method comprising:

determining, by a mobile station, a precoding matrix [W], the precoding matrix [W] being a part of a phase-shift-based precoding matrix [P];

determining, by the mobile station, a first diagonal matrix [D 1 ] for phase shift, the first diagonal matrix [D 1 ] being a part of the phase-shift-based precoding matrix [P];

determining, by the mobile station, a unitary matrix [U], the unitary matrix [U] being a part of the phase-shift-based precoding matrix [P];

receiving, by the mobile station, precoded data from a base station, the precoded data being generated according to the phase-shift-based precoding matrix [P]; and

decoding, by the mobile station, a corresponding sub-carrier symbol of the precoded data on a basis of the phase-shift-based precoding matrix [P],

wherein the phase-shift-based precoding matrix [P] is determined by a product of the precoding matrix [W], a Hermitian matrix of the unitary matrix [U H ], the first diagonal matrix [D 1 ], and the unitary matrix [U] in sequence as follows:

[P]=[W][U H ][D1][U].

10. The method according to claim 9 , further comprising:

determining a second diagonal matrix [D 2 ] for phase shift, the second diagonal matrix [D 2 ] being a part of the phase-shift-based precoding matrix [P],

wherein the phase-shift-based precoding matrix [P] is determined by a product of the second diagonal matrix [D 2 ], the precoding matrix [W], the Hermitian matrix of the unitary matrix [U H ], the first diagonal matrix [D 1 ], and the unitary matrix [U] in sequence as follows:

[P]=[D2][W][U H ][D1][U].

11. The method according to claim 10 , wherein the first diagonal matrix [D 1 ] and the second diagonal matrix [D 2 ] use phase values for phase-shift independent of each other.

12. The method according to claim 11 , further comprising:

controlling whether to use each of the first diagonal matrix [D 1 ] and the second diagonal matrix [D 2 ] using the phase values for phase-shift.

13. The method according to claim 9 or 10 , wherein a product of the Hermitian matrix of the unitary matrix [U H ], the first diagonal matrix [D 1 ], and the unitary matrix [U] is determined according to a spatial multiplexing rate.

14. The method according to claim 13 , wherein the rotation matrix is configured to be changed according to resource index (k).

15. The method according to claim 13 , wherein the rotation matrix is configured to be changed according to resource index (k), and the same rotation matrix is used for a predetermined ‘I’ number of consecutive resources.

16. The method according to claim 13 , wherein whether to use the rotation matrix or not is determined by configuration.