A new adaptive beamforming using pilot and traffic channel

We propose a new adaptive beamforming algorithm using the pilot and traffic channel in mobile communication systems. This algorithm updates the weight vector by applying the constant modulus algorithm to traffic channel and the least mean square algorithm to pilot channel. The performance of adaptive beamforming algorithm using pilot channel that is suitable for the cdma2000 reverse link is evaluated by Lim, Yoo and Seongdo Kim (see VTC2001 Spring, May 2000). It updates the weight vector by the complex normalized least mean square algorithm through the pilot channel and applies the weight vector to the traffic channel with the traffic symbol rate. However, it is degraded by the channel estimation error according the change of pilot to traffic power ratio especially in fading channel. Also, since it utilizes only the pilot channel information for weight vector calculation, the information obtained through the traffic channel is discarded. Therefore, we propose a new algorithm using the pilot and traffic channel, which calculates the weight vector more precisely. In addition, the proposed beamforming algorithm has a robust characteristic against channel estimation error.