Impact of unknown time-varying fading on the information rates of amplify and forward cooperative systems

Date

2013

Authors

Mohammadi, Mohammadali
Sadeghi, Parastoo
Lamahewa, Tharaka
Ardebilipour, Mehrdad

Journal Title

Journal ISSN

Volume Title

Publisher

Institute of Electrical and Electronics Engineers (IEEE Inc)

Abstract

We study information rate penalties for single-relay amplify and forward (AF) cooperative communication in the presence of unknown and time-varying fading. The penalty is defined as the gap between the information rate with perfect channel state information and that when the source-destination, source-relay and relay-destination channels are unknown at the receiving nodes. We prove that this gap in the cooperative system is the sum of gaps in the source-destination (single-hop) and source-relay-destination (dual-hop) channels. Under the assumption that the source and destination are mobile and the relay is stationary, we derive a closed-form accurate approximation for the asymptotic penalty of the mobile-to-mobile single-hop channel, which can also be used in computing asymptotic penalties for the mobile-fixed-mobile dual-hop channel. AF relaying induces non-Gaussian noise at the destination and hence, the penalty of the dual-hop channel is computed semi-analytically. We discuss a numerical technique for evaluation of destination noise entropy. One main observation of this paper is that non-negligible amplified relay noise can increase the cooperation information rate penalty of up to 1.5 times, as compared to non-relayed transmission. We provide extensive simulation results that characterize the behavior of penalty and include other mobility models for the source, relay and destination.

Description

Keywords

Keywords: Amplify-and-forward; Amplify-and-forward relaying; Closed form; Cooperative systems; dual-hop channel; Extensive simulations; Information rates; Mobility model; Non-Gaussian noise; Numerical techniques; Perfect channel state information; Receiving nodes; Amplify and forward relaying; channel state information; dual-hop channel; information rate penalty

Citation

Source

IEEE Transactions on Wireless Communications

Type

Journal article

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2037-12-31