Interference alignment for peer-to-peer underlay MIMO cognitive radio network

In this work, interference alignment is designed for peer-to-peer underlay MIMO cognitive radio network in which single primary user (PU) coexists with multiple secondary users (SUs). The proposed scheme chooses the transmit precoding and receiver interference subspace to minimize the total interference leakage while limiting the interference level to the PU. With perfect knowledge of local channel information, the optimization problem is solved iteratively, in which the transmitter and receivers take turns to update the precoding and interference receiving matrices, respectively. It is proven that the algorithm converges monotonically, and simulation results reveal the effectiveness of the proposed interference alignment scheme for cognitive radio network.