Date Added: Oct 2012
The authors study the sum Degrees of Freedom (DoF) of a class of multi-layer relay-aided MIMO broadcast networks with delayed Channel State Information at Transmitters (CSIT). In the assumed network a K-antenna source intends to communicate to K single-antenna destinations, with the help of N-2 layers of K full-duplex single-antenna relays. With the increasing interest in deploying relays in 4th generation mobile networks, multiuser multi-hop systems have drawn substantial research attention. In spite of the rapid advances in the understanding of single-hop networks, their knowledge on how to deal with inter-user interference and design efficient transmission schemes in multi-hop systems is relatively limited.