JOURNAL OF COMMUNICATIONS (JCM)
ISSN : 1796-2021
Volume : 3    Issue : 2    Date : April 2008

Optimizing Time and Power Allocation for Cooperation Diversity in a Decode-and-Forward
Three-Node Relay Channel
Elsheikh M. A. Elsheikh and Kai-Kit Wong
Page(s): 43-52
Full Text:
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Abstract
Providing space diversity at mobile devices such as handsets, personal digital assistants (PDA),
etc is costly and problematic, due to their strict space limitation. Recent studies, however, have
revealed that extraordinary diversity gain, which results in the remarkable benefits of an increased
achievable transmission code-rate and a reduced information outage probability, can be obtained
from a relay node in the proximity, which forwards the decoded information from the source node to
the intended destination node via a diversity path. While previous works had shown the impressive
gains from simple fixed-relaying schemes over non-relaying, this paper takes an
information-theoretic viewpoint to study the optimal decode-and-forward (DF) single-hop relay
strategy for maximizing the mutual information between the source and destination nodes exploiting
the instantaneous channel state information at the nodes (CSIN), and for minimizing the outage
probability if only the statistical channel information is known at the nodes (SCIN). In particular, our
aim is to optimize the time and power distribution between the direct transmission and relaying
phases, for a cooperative three-node relay fading channel.

Index Terms
cooperation diversity, MANET, mutual information, power control, relay, outage probability