Optimum power allocation for fading relay channels

Muhammad Mehboob Fareed, Murat Uysal

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Optimum power allocation is a key technique to realize the full potentials of relay-assisted transmission promised by the recent information-theoretic results. In this paper, we present a comprehensive framework for power allocation problem in a single-relay scenario taking into account the effect of relay location. In particular, we aim to answer the two fundamental questions: Q1) How should the overall transmit power be shared between broadcasting and relaying phases?; Q2) In the relaying phase, how much power should be allocated to relay-to-destination and source-to-destination links? The power allocation problem is formulated to minimize a union bound on the bit error rate (BER) performance assuming amplify-and-forward (AaF) relaying. We consider three TDMA-based cooperation protocols which correspond to distributed implementations of MIMO (multi-input-multi-output), SIMO (single-input-multi-output), and MISO (multi-input-single-output) schemes. Optimized protocols demonstrate significant performance gains over their original versions which assume equal sharing of overall transmit power between the source and relay terminals as well as between broadcasting and relaying phases. It is observed that optimized virtual (distributed) antenna configurations are able to demonstrate a BER performance as close as 0.4 dB within their counterpart co-located antenna configurations.

Original languageEnglish (US)
Title of host publication2007 IEEE 66th Vehicular Technology Conference, VTC 2007-Fall
Number of pages5
StatePublished - 2007
Event2007 IEEE 66th Vehicular Technology Conference, VTC 2007-Fall - Baltimore, MD, United States
Duration: Sep 30 2007Oct 3 2007

Publication series

NameIEEE Vehicular Technology Conference
ISSN (Print)1550-2252


Other2007 IEEE 66th Vehicular Technology Conference, VTC 2007-Fall
Country/TerritoryUnited States
CityBaltimore, MD

ASJC Scopus subject areas

  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Applied Mathematics


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