Analysis and simulation of the CLTD feedback from the Multiflow assisting cell

The latest 3GPP Rel-11 is characterized by a number of new features, where a few of them specifically address UE performance at the cell edge. In particular, uplink CLTD aims at reducing the UE transmission power, and/or improving the received SINR, by steering a transmission beam towards the base station based by sending appropriate feedback information. At the same time, the downlink Multiflow improves noticeably the cell edge performance as a UE receives simultaneously data from two neighboring cells. What remains unclear and is still under study, is the overall system behavior when these features are combined together. Furthermore, there is a special interest in providing the CLTD feedback from the so-called Multiflow assisting cell, which can mitigate the link imbalance and enable Multiflow operation for larger handover areas.