In this paper, we consider the problem of data transmission for K-user interference channel (IC) with no channel state information (CSI) at transmitters. Each pair of transceivers with the aid of a particular precoder and a switching pattern structure tries to place its desired signal in a subspace which is linearly independent of interference signals. We show that if the channel values are known only to the receivers, the sum degrees-of-freedom (DoF) of the linear interference alignment (IA) with reconfigurable antenna at receivers is Kr/r 2 -r+K, where r = [√1+4K-1/2]. For previous methods when 3 ≤ K ≤ 10 4 , the number of solvable problems to achieve maximum sum DoF is less than 2% of different cases while in our work there is not any limitation on the number of users. In comparison with the previous related works in our proposed method, there is no limit on the number of users and the reception modes. The result indicates that the maximum sum DoF for the K-user IC with asymptotically large values of K is √K/2. Thus, the sum DoF of such networks using the reconfigurable antenna at receivers grows sublinearly with the number of users, whereas it grows linearly in the case where transmitters have access to CSI.
