English

Informational Bottlenecks in Two-Unicast Wireless Networks with Delayed CSIT

Information Theory 2015-10-06 v2 math.IT

Abstract

We study the impact of delayed channel state information at the transmitters (CSIT) in two-unicast wireless networks with a layered topology and arbitrary connectivity. We introduce a technique to obtain outer bounds to the degrees-of-freedom (DoF) region through the new graph-theoretic notion of bottleneck nodes. Such nodes act as informational bottlenecks only under the assumption of delayed CSIT, and imply asymmetric DoF bounds of the form mD1+D2mmD_1 + D_2 \leq m. Combining this outer-bound technique with new achievability schemes, we characterize the sum DoF of a class of two-unicast wireless networks, which shows that, unlike in the case of instantaneous CSIT, the DoF of two-unicast networks with delayed CSIT can take an infinite set of values.

Keywords

Cite

@article{arxiv.1508.04359,
  title  = {Informational Bottlenecks in Two-Unicast Wireless Networks with Delayed CSIT},
  author = {Alireza Vahid and Ilan Shomorony and Robert Calderbank},
  journal= {arXiv preprint arXiv:1508.04359},
  year   = {2015}
}

Comments

In proceedings of the 53rd Annual Allerton Conference on Communication, Control, and Computing

R2 v1 2026-06-22T10:36:09.896Z