论文信息 - Multiple Unicast Capacity of 2-Source 2-Sink Networks

Multiple Unicast Capacity of 2-Source 2-Sink Networks

We study the sum capacity of multiple unicasts in wireless multihop networks. With 2 source nodes and 2 sink nodes, there are a total of 4 independent unicast sessions (messages), one from each source to each sink node (this setting is also known as an X network). We explore the degrees of freedom (DoF) of wireless multihop X networks with a layered structure, allowing arbitrary number of hops and arbitrary connectivity within each hop. For the case when there are no more than two relay nodes in each layer, the DoF can only take values 1, 4/3, 3/2 or 2, based on the connectivity of the network, for almost all values of channel coefficients. When there are arbitrary number of relays in each layer, the DoF can also take the value 5/3. Achievability schemes incorporate linear forwarding, interference alignment and aligned interference neutralization principles. Information theoretic converse arguments specialized for the connectivity of the network are constructed based on the intuition from linear dimension counting arguments.

Syed Ali Jafar | Chenwei Wang | Tiangao Gou

[1] Shlomo Shamai,et al. Degrees of Freedom Region of the MIMO $X$ Channel , 2008, IEEE Transactions on Information Theory.

[2] Amir K. Khandani,et al. Real Interference Alignment with Real Numbers , 2009, ArXiv.

[3] Syed Ali Jafar,et al. Interference Alignment and the Degrees of Freedom of Wireless $X$ Networks , 2009, IEEE Transactions on Information Theory.

[4] Ilan Shomorony,et al. Two-Unicast Wireless Networks: Characterizing the Degrees of Freedom , 2011, IEEE Transactions on Information Theory.

[5] Khaled Ben Letaief,et al. On the Solvability of 2-pair Unicast Networks --- A Cut-based Characterization , 2010, ArXiv.

[6] Mohammad Ali Maddah-Ali. On the degrees of freedom of the compound MISO broadcast channels with finite states , 2010, 2010 IEEE International Symposium on Information Theory.

[7] Amir K. Khandani,et al. Communication Over MIMO X Channels: Interference Alignment, Decomposition, and Performance Analysis , 2008, IEEE Transactions on Information Theory.

[8] Sae-Young Chung,et al. Aligned interference neutralization and the degrees of freedom of the 2 × 2 × 2 interference channel , 2010, 2011 IEEE International Symposium on Information Theory Proceedings.

[9] Erik Ordentlich,et al. The Degrees-of-Freedom of the $K$-User Gaussian Interference Channel Is Discontinuous at Rational Channel Coefficients , 2009, IEEE Transactions on Information Theory.