Degrees of freedom of wireless X networks

Abstract — We study the degrees of freedom characteriza-tion of wireless X networks, i.e. networks of M distributed single antenna transmitters and N distributed single an-tenna receivers where every transmitter has an independent message to every receiver. We provide an outerbound on the capacity region of X networks within o(log(SNR)). If the channel co-efficients are time-varying/frequency selective, we show that the total number of degrees of freedom is equal to MN M+N−1 using a coding scheme based on the idea of interference alignment. I