This paper presents a new on-off beamforming algorithm to provide an optimal weight vector. The proposed algorithm is based on the eigen-space on-off algorithm for exploiting a diversity gain that is available in the signal environments of wide angle spread. The proposed technique utilizes the primary and secondary eigenvectors to form the optimal weight vector, which is robust to the angle spread. It is confirmed in this paper that the proposed algorithm shows excellent performance compared to some typical beamforming methods which degrade the receiving performance as the angle spread increases. It is also shown that the proposed algorithm has a reasonable computational complexity of O(14N) and fast convergent speed, where N is the number of antenna elements.

A new beamforming technique based on the power method is proposed in this paper. We show that the new technique is quite robust to the angular spread in the received signals making it particularly useful for smart antennas in WCDMA systems. The proposed technique utilizes two primary eigenvectors of the autocovariance matrix of the received data to form the weight vector of a smart antenna. An efficient adaptive procedure combining the power method and deflation method is given to compute the first and second largest eigenvalues with a reasonable complexity and accuracy. To demonstrate the proposed technique, it has been applied to WCDMA signal environment showing its robust and improved performance.