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arXiv · 1103.6060

Interference, Cooperation and Connectivity - A Degrees of Freedom Perspective

Chenwei Wang·Syed A. Jafar·Shlomo Shamai·Michele Wigger
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Abstract

We explore the interplay between interference, cooperation and connectivity in heterogeneous wireless interference networks. Specifically, we consider a 4-user locally-connected interference network with pairwise clustered decoding and show that its degrees of freedom (DoF) are bounded above by 12/5. Interestingly, when compared to the corresponding fully connected setting which is known to have 8/3 DoF, the locally connected network is only missing interference-carrying links, but still has lower DoF, i.e., eliminating these interference-carrying links reduces the DoF. The 12/5 DoF outer bound is obtained through a novel approach that translates insights from interference alignment over linear vector spaces into corresponding sub-modularity relationships between entropy functions.

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Chenwei Wang, Syed A. Jafar, Shlomo Shamai, Michele Wigger. 2011-03-30. Interference, Cooperation and Connectivity - A Degrees of Freedom Perspective. https://doi.org/10.1109/isit.2011.6034162

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