On Power Allocation for Dual-Hop Amplify-and-Forward OFDM Relay Systems
Masato Saito, Chandra RN Athaudage, Jamie Evans
GLOBECOM 2008 - 2008 IEEE GLOBAL TELECOMMUNICATIONS CONFERENCE | IEEE | Published : 2008
The solutions to an optimal power allocation problem in dual-hop amplify-and-forward (non-regenerative) OFDM relay systems over given channel gains are provided with a joint transmit power constraint. We analytically derive the allocated power to each hop/subcarrier that satisfies the Karush-Kuhn-Tucker (KKT) conditions by solving simultaneous equations. The solutions imply that at most 3N - 1 possible power allocation candidates could exist on both source and relay nodes satisfying KKT conditions when N is the number of subcarriers. Based on the solution, a sub-optimal power allocation method that selects only significant allocated power in strong subcarriers is proposed and achieves higher..View full abstract
This study was supported by the ARC Special Research Centre for Ultra-Broadband Information Networks (CUBIN). The first author would like to thank the Telecommunications Advancement Foundation (TAF) for financial support.