Steps

Activities

Input

SR channel matrices and noise variance at the relay terminal ( H k and σ r l 2 )

1.

Calculation ofthe summation of covariance matrices S ˜ 1 and S ˜ 2 .

2.

Computation of the transform factor P from singular value decomposition of S

3.

For l = 1 , , N k relay receive antennas

4.

For k = 1 , , K number of relays

Using the FKT factor, transform the lth receive antennas covariance matrix S ˜ 1 from (21)

Transformation of P to S ˜ 1 and selection of the first eigenvector v l of matrix S ˜ 1

b k l = P v l is the relay receive beamforming vector for lth antennasand k relay receive antennas

5.

Multiplication of B k l with F j

6.

End

Output

F = B k l × F j the relay precoding matrix