Performance Analysis of Interference-Limited AF
Relay Systems with Antenna Correlation
Jian Ouyang
1
, Min Lin
2,3
1. Institute of Signal Processing and Transmission
Nanjing University of Posts and Telecommunications,
Nanjing, 210003, P.R.China
2. PLA University of Science and Technology
Nanjing, 210007, P.R.China
Wei-Ping Zhu
1,4
and Jun Yan
1
3. National Mobile Communications Research Laboratory
Southeast University, Nanjing, 210096, P.R.China
4. Department of Electrical and Computer Engineering
Concordia University, Montreal, QC, Canada H3G1M8
Abstract—In this paper, we investigate the performance of a
dual-hop amplify-and-forward (AF) relay system with
beamforming (BF), where the source and destination are both
equipped with multi-antenna, which are correlated in space,
while the relay has a single antenna corrupted by multiple co-
channel interferences (CCIs). We first derive the closed-form
expression for the outage probability (OP) of the output signal-
to-interference-plus-noise ratio (SINR). Then, we present an
approximate yet accurate expression for the average symbol
error rate (ASER) of the AF relaying. Moreover, asymptotic
expressions of OP and ASER at high signal-to-noise ratio (SNR)
are also provided to reveal the diversity order and array gain of
the considered relay system. Finally, computer simulations are
given to validate the analytical results and demonstrate the
effects of antenna correlation and CCI on the dual-hop AF relay
network.
Keywords—amplify-and-forward relaying; antenna correlation;
beamforming; interference
I. INTRODUCTION
Due to the ability of enhancing the capacity, reliability and
coverage of wireless networks, multi-antenna amplify-and-
forward (AF) relay systems with beamforming (BF) have
received considerable attention from both industry and
academia (See [1]-[5] and the citations therein for example).
Specifically, by assuming that the perfect channel state
information (CSI) is available, the performance of dual-hop
relay network employing maximum ratio transmission (MRT)
at the transmitter and maximum ratio combining (MRC) at the
receiver has been well studied in [3]-[5]. More recently, note
that co-channel interference (CCI) due to frequency reuse
often exists in practical wireless systems [6], [7], the authors
of [8] and [9] have examined the effect of CCI on a dual-hop
AF relaying with BF in terms of the outage probability (OP),
and the authors of [10] have further derived the analytical
expressions of average symbol error rate (ASER). However, it
should be pointed that in [8]-[10], the authors have not taken
the antenna correlation into account, which is a restrictive
assumption in practice because of the insufficient antenna
spacing and/or the lack of local scatters. Although the authors
of [4] and [5] have investigated the effect of antenna
correlation on the dual-hop AF relay networks with BF in
Rayleigh fading channels, they have ignored the CCIs.
Therefore, to the best of our knowledge, the joint effects of
antenna correlation and interference on multi-antenna dual-
hop AF relay systems remain unknown by far. This
observation motivates the work presented in this paper.
In this paper, unlike the previous related works, by
assuming that both source-to-relay and relay-to-destination
links are subject to correlated Rayleigh fading while the
interferer-to-relay links undergo Rician fading, we derive the
analytical expressions of the OP and ASER for a multi-
antenna dual-hop AF relay network in the presence of CCIs.
To gain further insights, we also present asymptotic
expressions in high signal-to-noise ratio (SNR) regime.
Simulation results are given to verify the theoretical analysis
as well as the effects of antenna correlation and CCI on the
system performance.
Notations:
denotes the Hermitian transpose,
the transpose,
the Frobenius norm,
E
the expectation,
exp
the exponential function, and
,
C
the complex
Gaussian distribution with mean
and variance matrix
.
II. SYSTEM MODEL
Consider a dual-hop AF relay system, where a single
antenna relay R is employed to assist the signal transmission
from a source S with
antennas to a destination D with
antennas. Due to the heavy shadowing, the direct link between
S and D is assumed to be unavailable. The total transmission
takes place in two time slots. In the first time slot, S performs
transmit BF with
and sends signal
with the power
to
R. At the same time, R is also corrupted by
interferers
(
) with power
. Hence, the received signal at R
can be expressed as
This work is supported by the National Science Foundation of China (No.
61271255, 61372122 and 61302103
), the Natural Science Foundation of
Jiangsu Province (No. BK20131068), the
Jiangsu Planned Projects for
Postdoctoral Research Funds (No. 1402068B), the NUPTSF (No. NY214140
and NY213012) and
the Open Research Fund of National Mobile
Communications Research Laboratory in Southeast University (No. 2012D15).
978-1-4673-6305-1/15/$31.00 ©2015 IEEE
IEEE ICC 2015 - Workshop on Cooperative and Cognitive Networks (CoCoNet)
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