We consider the secrecy rate maximization for multiple-input-multiple-output (MIMO) wiretap channels in the presence of a multiple-antenna eavesdropper. We propose an efficient algorithm based on minorization-maximization (MM) technique. The proposed algorithm constructs a simple surrogate function and has a closed-form solution at each iteration. In addition, we prove that the proposed algorithm has guaranteed convergence of the sequence of objective values. Moreover, an acceleration scheme, called squared iterative method (SQUAREM), is used to enhance the convergence rate of the proposed algorithm. Then, we extend the proposed algorithm to handle the transmission power minimization problem. Results show that the proposed algorithm have the same secrecy rate performance as the state-of-art algorithm but is much more computationally efficient.
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