1 research outputs found
Retrospective Interference Alignment for Two-Cell Uplink MIMO Cellular Networks with Delayed CSIT
In this paper, we propose a new retrospective interference alignment for
two-cell multiple-input multiple-output (MIMO) interfering multiple access
channels (IMAC) with the delayed channel state information at the transmitters
(CSIT). It is shown that having delayed CSIT can strictly increase the sum-DoF
compared to the case of no CSIT. The key idea is to align multiple interfering
signals from adjacent cells onto a small dimensional subspace over time by
fully exploiting the previously received signals as side information with
outdated CSIT in a distributed manner. Remarkably, we show that the
retrospective interference alignment can achieve the optimal sum-DoF in the
context of two-cell two-user scenario by providing a new outer bound.Comment: 7 pages, 2 figures, to appear in IEEE ICC 201