1 research outputs found
Generalized Diversity-Multiplexing Tradeoff of Half-Duplex Relay Networks
Diversity-multiplexing trade-off has been studied extensively to quantify the
benefits of different relaying strategies in terms of error and rate
performance. However, even in the case of a single half-duplex relay, which
seems fully characterized, implications are not clear. When all channels in the
system are assumed to be independent and identically fading, a fixed schedule
where the relay listens half of the total duration for communication and
transmits the second half combined with quantize-map-and-forward relaying
(static QMF) is known to achieve the full-duplex performance [1]. However, when
there is no direct link between the source and the destination, a dynamic
decode-and-forward (DDF) strategy is needed [2]. It is not clear which one of
these two conclusions would carry to a less idealized setup, where the direct
link can be neither as strong as the other links nor fully non-existent.
In this paper, we provide a generalized diversity-multiplexing trade-off for
the half-duplex relay channel which accounts for different channel strengths
and recovers the two earlier results as two special cases. We show that these
two strategies are sufficient to achieve the diversity-multiplexing trade-off
across all channel configurations, by characterizing the best achievable
trade-off when channel state information (CSI) is only available at the
receivers (CSIR). However, for general relay networks we show that a
generalization of these two schemes through a dynamic QMF strategy is needed to
achieve optimal performance.Comment: to be presented at IEEE International Symposium on Information Theory
(ISIT) 201