TY - GEN
T1 - Can feedback, cooperation, relays and full duplex operation increase the degrees of freedom of wireless networks?
AU - Cadambe, Viveck R.
AU - Jafar, Syed A.
PY - 2008
Y1 - 2008
N2 - We consider a fully connected network with S full duplex source nodes, D full duplex destination nodes and R relay nodes, perfect feedback to source and relay nodes, and noisy cooperation between all source, relay and destination nodes. We show that this network has SD/S+D-1 degrees of freedom if the channel gains are time-varying/frequency selective. The implication of the result is that, the techniques mentioned in the title (i.e relays etc.) can affect the capacity of a network only upto a o(log(SNR,)) term and therefore cannot improve the degrees of freedom of a network. Certain communication scenarios excluded by our system model where these techniques improve the degrees of freedom are also identified. Bounds on the degrees of freedom of a fully connected K node network emerge as a by-product of our study.
AB - We consider a fully connected network with S full duplex source nodes, D full duplex destination nodes and R relay nodes, perfect feedback to source and relay nodes, and noisy cooperation between all source, relay and destination nodes. We show that this network has SD/S+D-1 degrees of freedom if the channel gains are time-varying/frequency selective. The implication of the result is that, the techniques mentioned in the title (i.e relays etc.) can affect the capacity of a network only upto a o(log(SNR,)) term and therefore cannot improve the degrees of freedom of a network. Certain communication scenarios excluded by our system model where these techniques improve the degrees of freedom are also identified. Bounds on the degrees of freedom of a fully connected K node network emerge as a by-product of our study.
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U2 - 10.1109/ISIT.2008.4595190
DO - 10.1109/ISIT.2008.4595190
M3 - Conference contribution
AN - SCOPUS:52349089602
SN - 9781424422579
T3 - IEEE International Symposium on Information Theory - Proceedings
SP - 1263
EP - 1267
BT - Proceedings - 2008 IEEE International Symposium on Information Theory, ISIT 2008
T2 - 2008 IEEE International Symposium on Information Theory, ISIT 2008
Y2 - 6 July 2008 through 11 July 2008
ER -