Performance of a Simple Downlink Beam Switching Scheme for Umts Fdd

We present a simple beam switching scheme to increase the downlink capacity of the UMTS FDD-mode. At the base station this method only needs an additional transceiver chain, i.e. a separate one for each beam, a beamforming network and a uniform linear array. The mobiles need no changes at all. We analyze the performance of our method by means of system level simulations. We found an increase in downlink capacity of up to 73% over a conventional 3-sectored system if uniform linear arrays with four antenna elements are used for beamforming. Using uniform linear arrays with six elements we obtain a capacity increase of up to 90%.