Use of minimum-variance beamforming algorithms for a smart antenna applied to a repeater

In this paper, we study the possibility of applying the smart antenna technology to repeater design. The difficulties of using an array antenna in a repeater have to do with the coherence of the desired signal and the interfering signal as well as the sensitivity to the array calibration. To cope with the difficulties, we propose a robust beamforming algorithm which uses a interference projection matrix in Generalized Sidelobe Canceller (GSC). The matrix is designed to prevent the desired signal cancellation caused by array error. To verify the algorithm, we use the data generated by computer simulation and the field data measured through a custom-built W-CDMA test-bed.