Mutual Coupling Calibration for Smart Antennas in CDMA Communication Systems

A novel mutual coupling calibration method is presented for smart antennas in CDMA communication systems. The proposed method first uses the measured smaller mutual coupling coefficients as a prior knowledge and relies on processing the covariance matrix of the signal vector after pseudo noise (PN) despreading to estimate the other coupling coefficients and direction-of-arrivals (DOAs) of the desired users simultaneously. Then mutual coupling effect can easily be eliminated with matrix compensation technique. Compared with previous blind calibration methods, the proposed method shows less computation time and higher calibration accuracy. Computer simulation results demonstrate that the new method is correct and effective.