Transmission and reception of channel state information

1. A method of transmitting channel state information in user equipment including a transceiver, the method comprising:

extracting one or more reference vectors having a high correlation with a channel state information vector associated with a downlink;

creating one or more compressed vectors by compressing the one or more reference vectors; and

transmitting, by the transceiver, the one or more compressed vectors,

wherein:

the correlation is calculated by multiplying a square matrix by the channel state information vector, where columns of the square matrix are orthogonal to each other; and

the reference vectors are column vectors having a high correlation in the square matrix.

2. The method of claim 1 , wherein:

the channel state information vector includes an l number of components indicating the channel state information, where l is a positive integer; and

the square matrix is a matrix having a size of l*l.

3. The method of claim 1 , wherein:

the channel state information vector includes (i) an l number of components indicating the channel state information, where l is a positive integer, and (ii) a 2 p (2 p +1)−l number of components not indicating the channel state information, where p is a prime number; and

the square matrix is a matrix having a size of 2 p (2 p +1)*(2 p +1).

4. The method of claim 1 , wherein:

the compressed vectors are calculated by multiplying a compression matrix by the reference vectors; and

the compression matrix is a matrix having a size of 2 p *l, where l is a positive integer satisfying l≦2 p (2 p +0.1) and p is a prime number, in a case that the reference vectors have an l number of components.

5. User equipment comprising:

a sparsity transform processor configured to extract one or more reference vectors having a high correlation with a channel state information vector associated with a downlink;

a compression processor configured to create one or more compressed vectors by compressing the one or more reference vectors; and

a transceiver configured to transmit the one or more compressed vectors,

wherein:

the correlation is calculated by multiplying a square matrix by the channel state information vector where columns of the square matrix are orthogonal to each other; and

the reference vectors are column vectors having a high correlation in the square matrix.

6. The user equipment of claim 5 , wherein:

the channel state information vector includes an l number of components indicating the channel state information, where l is a positive integer; and

the square matrix is a matrix having a size of l*l.

7. The user equipment of claim 5 , wherein:

the channel state information vector includes an l number of components indicating the channel state information, where l is a positive integer, and (ii) a 2 p (2 p +1)−l number of components not indicating the channel state information, where p is a prime number; and

the square matrix is a matrix having a size of 2 p (2 p +1)*2 p (2 p +1).

8. The user equipment of claim 5 , wherein:

the compressed vectors are calculated by multiplying a compression matrix by the reference vectors; and

the compression matrix is a matrix having a size of 2 p *l, where l is a positive integer satisfying l≦2 p (2 p +1) and p is a prime number, in a case that the reference vectors have an l number of components.

9. A method of receiving channel state information in a transmission point including a transceiver, the method comprising:

receiving, by the transceiver, one or more compressed vectors from user equipment;

creating one or more decompressed vectors by decompressing the one or more compressed vectors;

extracting one or more restoration vectors having a high correlation with the one or more decompressed vectors; and

creating a channel information vector by adding the one or more restoration vectors,

wherein:

the decompressed vectors are calculated by multiplying a Hermitian matrix of a reference matrix by the compressed vectors, and

the reference matrix has a low cross correlation between column vectors.

10. The method of claim 9 , wherein:

the compressed vectors have a 2 p number of components, where p is a prime number; and

the Hermitian matrix of the reference matrix is a matrix having a size of l*2 p , where ‘l’ represents the number of the channel state information, and is a positive integer satisfying l≦2 p (2 p +1).

11. The method of claim 9 , wherein:

the correlation is calculated by multiplying a square matrix by the decompressed vectors, where columns of the square matrix are orthogonal to each other; and

the restoration vectors are column vectors having a highest correlation in the square matrix.