Transmit Beamforming multi-user MISO systems based on switched sub-codebook

In this study, we consider Multi-user MISO systems based on Max-rate Limited Feedback Transmit Beamforming with B feedback bits. In the proposed idea, the Beamforming codebook {W
_i
}
_i=1

^N
(N=2
^B
) is divided into n
_D
sub codebooks, such as D1,D2,..,D
<sub>n

D</sub>
. At each channel use, the transmitter switches to a given sub-codebook adaptively to the user owning the worst case performance. Accordingly, the proposed scheme while minimizes the use of bandwidth of the feedback channel, enhances the fairness among users. Simulation results have been used to show the performance of the proposed scheme.