Zirwas, Wolfgang; Khan, Aneeq (Nokia Siemens Networks, CEF CTO R RS, Werinherstr. 91, 81541 München, Germany)
A novel very advanced interference mitigation framework (IFM-A) for celluar mobile radio systems has been developed, including several means like enlarged and overlapping cooperation areas performing a joint precoding over e.g. 3 sites. Assuming 3 sectors per site and 4 Tx-antennas per sector cooperation areas will comprise 36 antenna ports (AP). IMF-A promises for cellular mobile radio systems and under ideal conditions large spectral efficencies of 6 or even more bit/s/Hz. The details can be found in the ARTIST4G delverable D1.4 . For realistic channel estimation the user equipments (UE) will have to estimate few to more than 20 relevant channel components with high accuracy. The quality of the estimated channel state information (CSI) is very important as it defines how much of the performance gains of the IMF-A framework can be maintained in reality. Here we propose a suitable channel estimation concept for the IMF-A framework having a small to moderate overhead for reference signals of about 5 to 10%. It allows an accurate estimation of weak channel components (CC), being typically neglected in less advanced interference mitigation schemes. Index terms — channel estimation, JP CoMP, reference signals.