On the performance of multi-relay cooperation over correlated
nakagami-m fading
Haixia Cui
1
, Yongcong Yu
2
1.
School of Physics and Telecommunication Engineering South China Normal University
Guangzhou, China
2.
School of Electronic and Information Engineering South China University of Technology
Guangzhou, China
cuicuihang0715@gmail.com
a
;yyc@gpdi.com
b
Keywords: cooperative communication; multi-relay cooperation; performance analysis; correlated
channels
Abstract. The analytical expression in terms of symbol error rate (SER) for distributed multi-relay
cooperative networks is derived over correlated Nakagami-m fading environments. Specifically, the
proposed expression can be used to evaluate the impact of channel correlation on spectral access
schemes through the statistical characteristic of complex channels. Furthermore, the overall
performance analyses are illustrated through representative numerical results.
Introduction
It is well known that the deployment of relays in cellular networks could extend the coverage and
capacity near to the cell edges or even beyond. In fact, multi-relay diversity is also a kind of spatial
diversity achieved by mutual cooperation in a distributed way. As one of the most popular
cooperative protocols, decode-and-forward (DF) relaying has been extensively evaluated in the
performance behavior [1-7]. However, the classical proposed performance analysis suffers from one
disadvantage-a loss in spectral efficiency as multiple orthogonal time slots which only fit for cellular
networks. In this letter, a more attractive network is the distributed multi-relay cooperative way over
correlated Nakagami-m fading channels with the multi-branch maximal ratio combing (MRC). In
order to improve the diversity gains, decrease the interference between relay channels and fully
exploit spatial correlations among cooperative links, the analytical expression for distributed multi-
relay cooperation in terms of SER is necessary to investigated. Especially, the impact of the
correlation coefficient between the relay channels on the overall system performance is discussed.
This paper is organized as follows. Section II describes the system model for the wireless relay
channel. Section III presents a mathematical performance analysis for the multi-relay cooperation
over correlated Nakagami-m fading channels. Finally, Section IV and Section V provide the
simulation results and conclusions, respectively. Furthermore, we also discuss the future work by our
team in the numerical part.
system and channel models
Let
k
=
denote the decoding relay subset to participate in the so-called cooperative
retransmit phase. In this case, the multiple relay-to-destination channels are correlated, i.e., there
may have interferences between multi-branch links which is indicated in Fig. 1. The correlation
coefficient between
and
is defined as
with equal correlation model presented in [3],
here
. Let
denotes the instantaneous received symbol-to-noise (SNR) ratio and
denotes the
SNR expectation of per relay channel. With the output of a MRC, the probability density function
(PDF) of the received SNR at destination can be presented as
Applied Mechanics and Materials Vols 380-384 (2013) pp 3653-3656 Online: 2013-08-30
© (2013) Trans Tech Publications, Switzerland
doi:10.4028/www.scientific.net/AMM.380-384.3653
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