Interference alignment in TDD-cognitive network

Interference alignment is a new technology which is used to solve the problem of sending and receiving multi-information flows simultaneously in wireless interference networks. It can be applied to a variety of wireless interference networks. In the X-type cognitive interference network, we propose cognitive sending and cognitive receiving interference alignment algorithm respectively. This algorithm can achieve the upper limit of DoF (degrees of freedom). In this paper, we also present the basic idea of interference alignment technology and the conditions for implementing it in TDD cognitive interference network. Finally, our simulation results show the effectiveness of the proposed algorithm.