Topological Interference Management with Alternating Connectivity: The Wyner-Type Three User Interference Channel

Interference management in a three-user interference channel with alternating connectivity with only topological knowledge at the transmitters is considered. The network has a Wyner-type channel flavor, i.e., for each connectivity state the receivers observe at most one interference signal in addition to their desired signal. Degrees of freedom (DoF) upper bounds and lower bounds are derived. The lower bounds are obtained from a scheme based on joint encoding across the alternating states. Given a uniform distribution among the connectivity states, it is shown that the channel has 2+ 1/9 DoF. This provides an increase in the DoF as compared to encoding over each state separately, which achieves 2 DoF only.Comment: 4 pages, 3 figure

On the Symmetric Capacity of the K-user Symmetric Cyclic Gaussian Interference Channel

Abstract—The capacity region of Gaussian interference channel in the weak interference regime is an open problem. Recently, Etkin, Tse and Wang derived an outer bound for the two-user Gaussian interference channel and proved that a simple Han-Kobayashi signaling scheme can achieve within one bit of the capacity region for all values of channel parameters. In this paper, we extend their result to the K-user symmetric cyclic Gaussian interference channel. Our result shows that both the Etkin, Tse and Wang’s upper bound and their one-bit achievability result on the symmetric rate continue to hold for the symmetric rate of the K-user symmetric cyclic channel using the same Han-Kobayashi strategy. I