On the Degrees-of-Freedom of Two-Unicast Wireless Networks With Delayed CSIT
On the Degrees-of-Freedom of Two-Unicast Wireless Networks With Delayed CSIT
复制标题
具有时延CSIT的两单播无线网络的自由度
DOI：
10.1109/tit.2019.2913996
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发表时间：
2018
影响因子：
2.5
通讯作者：
Alireza Vahid
中科院分区：
文献类型：
--
作者：
Alireza Vahid
在发射端具有延迟信道状态信息的假设下，我们刻画了一类两单播无线网络的自由度(DoF)区域。我们考虑了具有任意连通性的分层拓扑，并通过瓶颈节点的图论概念在这类网络的DoF域上引入了新的外界。这样的节点仅在延迟的信道状态信息的假设下充当信息瓶颈。我们还提出了实现外界的新的传输方案。我们证明了与瞬时信道状态信息模型不同，具有延迟信道知识的两个单播网络的和DOF可以取无穷多个值。在这篇文章中，我们将我们的结果与以前已知的最好的外界进行了比较，我们证明了差距可以是任意大的有利的。
We characterize the degrees-of-freedom (DoF) region of a class of two-unicast wireless networks under the assumption of delayed channel state information at the transmitters. We consider a layered topology with arbitrary connectivity, and we introduce new outer-bounds on the DoF region of such networks through the graph-theoretic notion of bottleneck nodes. Such nodes act as informational bottlenecks only under the assumption of delayed channel state information. We also present new transmission schemes that achieve the outer-bounds. We show that unlike the instantaneous channel state information model, the sum DoF of two-unicast networks with delayed channel knowledge can take an infinite set of values. In this paper, we compare our results to the best previously known outer-bounds, and we show that the gap can be arbitrary large in favor.