Interference Alignment Using a MIMO Relay and Partially-Adapted Transmit/Receive Filters
Interference alignment is proposed for achieving the maximum degrees of freedom in interference channels. In the present paper, a scenario consisting of several pairs of multiple antenna nodes and a single MIMO relay helping the interference alignment is considered. The interference alignment is performed in two subsequent transmission phases assuming a time-invariant channel during the two transmission phases. Firstly, the relay and the destination nodes receive the signals from all the source nodes, i.e., also the direct links between the communicating node pairs are exploited. In the second transmission phase, both the source nodes and the relay retransmit the signals to the destination nodes.