An Improved Robust Beamforming Design for Cognitive Multiantenna Relay Networks

Algorithm 1

The proposed algorithm.

(1) solve the SDP problem to obtain the optimal solution ;

(2) if    then

(3)  Decompose ;

(4) else

(5)  Set , solve the SDP problem to obtain the optimal solution ;

(6)  Decomposed , set ;

(7) end if

(8) Calculate the optimal/near-optimal beamforming matrix .