Calibration techniques of multi-channel transceiver using noninterfering calibration signals for CDMA smart antenna systems

A new calibration algorithm has been proposed to correct multi-channel RF transceiver gain/phase errors for CDMA smart antenna systems. We present the structure of a multi-channel RF transceiver with digital calibration apparatus and calibration techniques. The proposed RF transceiver calibration scheme is to minimize interference of the calibration signal to the user signals using weighted and noninterfering calibration signals. The calibration signal is injected into the multi-channel transceiver through a calibration signal injector whose array response vector is controlled to have a low correlation with the antenna response vector of the received signals. The results of computer simulation verify the calibration algorithms. Also, the simulation results describe the effect of the bit error rate of the received signal, including the proposed calibration signals, in a WCDMA FDD reverse link.