Transmit beamforming based on rotation weight and switched sub-codebook

In this study, we consider a scheduling algorithm for a limited feedback opportunistic beamforming (OBF). Our proposal is based on making Transmit OBF codebook vectors controlled by a rotation weight (RW)in order to obtain almost a zero correlation between the OBF codebook vectors used for the selected spatial channels. Accordingly, we meet the performance of OBF based on the feedback of the full channel state information while reducing the amount of data to be transmitted in the feedback link. The proposed limited feedback OBF - rotation weight increases the probability of the selection of the worst case user by applying a rotation on his best codevector to make zero the angle between his couple codevector and channel response. Then, if this user is selected he would be assigned the best possible symbol rate. To analyze and validate the proposed RW idea performance, simulations have been carried out.