Date Added: Jul 2009
In recent years, smart antenna technologies are of ever-increasing interest to boost the capacity of existing and future wireless systems. Several standards support these techniques such as the wireless metropolitan area network IEEE 802.16 (WiMAX) and IMT-Advanced candidates. In applying smart antenna beam-forming and Space Division Multiple Access (SDMA) techniques, adaptive antennas are able to increase cell capacity by reducing inter-cell interference and by allowing concurrent transmissions. As a downside, an SDMA enabled cell generates less predictable interference than a conventional cell, because a changing number of Mobile Stations (MS) are sending uplink data in parallel and downlink streams with changing direction are transmitted by the Base Station (BS). Thereby the SINR estimation becomes less precise and the link adaptation sub optimal.