Research Article
An Achievable Degree of Freedom for Multi-hop Wireless Networks under Layered TDD Constraint
@INPROCEEDINGS{10.1109/ChinaCom.2013.6694595, author={Feng Liu and Xiaofeng Wang and Chung Chan and Ying Jun Zhang}, title={An Achievable Degree of Freedom for Multi-hop Wireless Networks under Layered TDD Constraint}, proceedings={8th International Conference on Communications and Networking in China}, publisher={IEEE}, proceedings_a={CHINACOM}, year={2013}, month={11}, keywords={multi-hop networks degree of freedom (dof) layered tdd decode-and-forward fibonacci}, doi={10.1109/ChinaCom.2013.6694595} }- Feng Liu
Xiaofeng Wang
Chung Chan
Ying Jun Zhang
Year: 2013
An Achievable Degree of Freedom for Multi-hop Wireless Networks under Layered TDD Constraint
CHINACOM
IEEE
DOI: 10.1109/ChinaCom.2013.6694595
Abstract
We investigate the degrees of freedom (DoF) issue for multi-hop wireless networks with multiple-node layers under layered time-division-duplex (TDD) constraint. Our recent work about cascaded linear networks shows that the number of feasible network states is related to the famous Fibonacci sequence and the maximum achievable decode-and-forward (DF) rate is $r^*=\min \left{\frac{C1 C2}{C1 + C2},\frac{C2 C3}{C2 + C3},\cdots,\frac{C{K-1} C{K}}{C{K-1} + C{K}}\right}$ for $K$-hop networks, where $C_k, \forall k=1,2,\dots,K$, is the capacity of each hop. Based on these results, we studies the DoF aspect of multi-hop networks with multiple-node layers, mainly about achievable lower bound on the sum DoF, by viewing the network as cascaded $X$ channels (XC). Then we analyze the ultimate case where the number of antennas at each relay layer goes to infinity, from which we find that compared with two-hop networks, larger sum DoF can be obtained if the number of hops is no less than three.