Summary: Optimal Relay-Subset Selection and
Time-Allocation in Decode-and-Forward
Elzbieta Beres and Raviraj Adve
Dept. of Elec. and Comp. Eng. , University of Toronto
10 King's College Road, Toronto, ON M5S 3G4, Canada
email: email@example.com, firstname.lastname@example.org
Abstract--We present the optimal relay-subset selection and
transmission-time for a decode-and-forward, half-duplex coop-
erative network of arbitrary size. The resource allocation is
obtained by maximizing over the rates obtained for each possible
subset of active relays, and the unique time allocation for each
set can be obtained by solving a linear system of equations.
We also give a recursive algorithm which reduces the number
of operations as well as the computational load of finding the
required matrix inverses. Our results, in terms of outage rate,
confirm the benefit of adding potential relays to a small network
and the diminishing marginal returns for a larger network.
Furthermore, optimizing over the channel resources ensures that
more relays are active over a larger SNR range.