Performance of multihop decode-and-forward and amplify-and-forward relay networks with channel estimation

Gillian Huang, Yue Wang, Justin Coon

Research output: Chapter in Book/Report/Conference proceedingConference Contribution (Conference Proceeding)

22 Citations (Scopus)


This paper investigates the performance of three types of multihop relay systems with a single relay path from the source to the destination, using the relaying strategies: decode-and-forward (DF), fixed gain amplify-and-forward (AF), and variable gain AF, respectively. It is shown that, as the number of hops increases, the performance degradation of DF relay systems is due to error propagation, while that of AF relay systems comes from 1) noise propagation from each relay node, and 2) the statistical fading property of the AF compound channel. Although the performance degradation of a variable gain AF relay system mainly comes from noise propagation and its performance is robust in a cascaded AF fading channel, it is shown that a fixed gain AF relay system suffers from a large performance loss since the cascaded fixed gain AF fading channel gives more severe fading. As a result, the variable gain AF significantly outperforms the fixed gain AF and achieves comparable performance as the DF scheme. Furthermore, we study channel estimation techniques, such as the least squares (LS) and linear minimum mean square error (LMMSE) channel estimation in multihop, single path AF relay systems, where the mean squared error (MSE) of both channel estimators in a fixed gain AF relay system is derived, and the performance of the aforementioned three systems with channel estimation errors are simulated.

Original languageEnglish
Title of host publicationIEEE Pacific Rim Conference on Communications, Computers and Signal Processing, 2011. PacRim 2011.
Place of PublicationNEW YORK
PublisherInstitute of Electrical and Electronics Engineers (IEEE)
Number of pages6
ISBN (Print)978-1-4577-0251-8
Publication statusPublished - Aug 2011
EventIEEE Pacific Rim Conference on Communications, Computers and Signal Processing (PACRIM) - Victoria, Canada
Duration: 23 Aug 201126 Aug 2011


ConferenceIEEE Pacific Rim Conference on Communications, Computers and Signal Processing (PACRIM)

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