On power allocation for dual-hop amplify-and-forward OFDM relay systems

Masato Saito, Chandra R N Athaudage, Jamie Scott Evans

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-review

10 Citations (Scopus)


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 3(N) - 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 capacity (achievable rate) than conventional sub-optimal methods. As for the feasibility, the number of candidates to be evaluated is N in the proposed method.
Original languageEnglish
Title of host publicationIEEE Global Telecommunications Conference (Globecom)
EditorsKaminsky Bourgeois, Francis B Grosz
Place of PublicationNew York NY USA
PublisherIEEE, Institute of Electrical and Electronics Engineers
Pages4112 - 4117
Number of pages6
ISBN (Print)9781424423248
Publication statusPublished - 2008
Externally publishedYes
EventIEEE Global Telecommunications Conference 2008 - New Orleans, United States of America
Duration: 30 Nov 20084 Dec 2008
https://ieeexplore.ieee.org/xpl/conhome/4697774/proceeding (Proceedings)


ConferenceIEEE Global Telecommunications Conference 2008
Abbreviated titleIEEE GLOBECOM 2008
Country/TerritoryUnited States of America
CityNew Orleans
Internet address

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