TY - JOUR
T1 - Degrees of freedom of wireless networks with relays, feedback, cooperation, and full duplex operation
AU - Cadambe, Viveck R.
AU - Jafar, Syed Ali
N1 - Funding Information:
Manuscript received February 05, 2008; revised September 20, 2008. Current version published April 22, 2009. This work was supported in part by the National Science Foundation under CAREER Grant 0546860 and by DARPA under ITMANET Grant UTA06-793. This work was presented in part at the IEEE International Symposium on Information Theory (ISIT), Toronto, ON, Canada, July 2008.
PY - 2009
Y1 - 2009
N2 - We find the degrees of freedom of a network with S source nodes, R relay nodes, and D destination nodes, with random time-varying/ frequency-selective channel coefficients and global channel knowledge at all nodes. We allow full-duplex operation at all nodes, as well as causal noise-free feedback of all received signals to all source and relay nodes. An outer bound to the capacity region of this network is obtained. Combining the outer bound with previous interference alignment based achievability results, we conclude that the techniques of relays, feedback, full-duplex operation and noisy cooperation do not increase the degrees of freedom of interference and X networks. As a second contribution, we show that for a network with emphasis K full-duplex nodes and K(K-1) independent messages with one message from every node to each of the other K-1 nodes, the total degrees of freedom are bounded above and below by K(K-1)/(2K-2) and K(K-1)/(2K-3), respectively.
AB - We find the degrees of freedom of a network with S source nodes, R relay nodes, and D destination nodes, with random time-varying/ frequency-selective channel coefficients and global channel knowledge at all nodes. We allow full-duplex operation at all nodes, as well as causal noise-free feedback of all received signals to all source and relay nodes. An outer bound to the capacity region of this network is obtained. Combining the outer bound with previous interference alignment based achievability results, we conclude that the techniques of relays, feedback, full-duplex operation and noisy cooperation do not increase the degrees of freedom of interference and X networks. As a second contribution, we show that for a network with emphasis K full-duplex nodes and K(K-1) independent messages with one message from every node to each of the other K-1 nodes, the total degrees of freedom are bounded above and below by K(K-1)/(2K-2) and K(K-1)/(2K-3), respectively.
UR - http://www.scopus.com/inward/record.url?scp=65749120701&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=65749120701&partnerID=8YFLogxK
U2 - 10.1109/TIT.2009.2016061
DO - 10.1109/TIT.2009.2016061
M3 - Article
AN - SCOPUS:65749120701
SN - 0018-9448
VL - 55
SP - 2334
EP - 2344
JO - IEEE Transactions on Information Theory
JF - IEEE Transactions on Information Theory
IS - 5
ER -