1,209 research outputs found
Performance Analysis of Optimal Single Stream Beamforming in MIMO Dual-Hop AF Systems
This paper investigates the performance of optimal single stream beamforming
schemes in multiple-input multiple-output (MIMO) dual-hop amplify-and-forward
(AF) systems. Assuming channel state information is not available at the source
and relay, the optimal transmit and receive beamforming vectors are computed at
the destination, and the transmit beamforming vector is sent to the transmitter
via a dedicated feedback link. Then, a set of new closed-form expressions for
the statistical properties of the maximum eigenvalue of the resultant channel
is derived, i.e., the cumulative density function (cdf), probability density
function (pdf) and general moments, as well as the first order asymptotic
expansion and asymptotic large dimension approximations. These analytical
expressions are then applied to study three important performance metrics of
the system, i.e., outage probability, average symbol error rate and ergodic
capacity. In addition, more detailed treatments are provided for some important
special cases, e.g., when the number of antennas at one of the nodes is one or
large, simple and insightful expressions for the key parameters such as
diversity order and array gain of the system are derived. With the analytical
results, the joint impact of source, relay and destination antenna numbers on
the system performance is addressed, and the performance of optimal beamforming
schemes and orthogonal space-time block-coding (OSTBC) schemes are compared.
Results reveal that the number of antennas at the relay has a great impact on
how the numbers of antennas at the source and destination contribute to the
system performance, and optimal beamforming not only achieves the same maximum
diversity order as OSTBC, but also provides significant power gains over OSTBC.Comment: to appear in IEEE Journal on Selected Areas in Communications special
issue on Theories and Methods for Advanced Wireless Relay
Ergodic Capacity Analysis of Amplify-and-Forward MIMO Dual-Hop Systems
This paper presents an analytical characterization of the ergodic capacity of
amplify-and-forward (AF) MIMO dual-hop relay channels, assuming that the
channel state information is available at the destination terminal only. In
contrast to prior results, our expressions apply for arbitrary numbers of
antennas and arbitrary relay configurations. We derive an expression for the
exact ergodic capacity, simplified closed-form expressions for the high SNR
regime, and tight closed-form upper and lower bounds. These results are made
possible to employing recent tools from finite-dimensional random matrix theory
to derive new closed-form expressions for various statistical properties of the
equivalent AF MIMO dual-hop relay channel, such as the distribution of an
unordered eigenvalue and certain random determinant properties. Based on the
analytical capacity expressions, we investigate the impact of the system and
channel characteristics, such as the antenna configuration and the relay power
gain. We also demonstrate a number of interesting relationships between the
dual-hop AF MIMO relay channel and conventional point-to-point MIMO channels in
various asymptotic regimes.Comment: 40 pages, 9 figures, Submitted to to IEEE Transactions on Information
Theor
Performance Analysis of Project-and-Forward Relaying in Mixed MIMO-Pinhole and Rayleigh Dual-Hop Channel
In this letter, we present an end-to-end performance analysis of dual-hop
project-and-forward relaying in a realistic scenario, where the source-relay
and the relay-destination links are experiencing MIMO-pinhole and Rayleigh
channel conditions, respectively. We derive the probability density function of
both the relay post-processing and the end-to-end signal-to-noise ratios, and
the obtained expressions are used to derive the outage probability of the
analyzed system as well as its end-to-end ergodic capacity in terms of
generalized functions. Applying then the residue theory to Mellin-Barnes
integrals, we infer the system asymptotic behavior for different channel
parameters. As the bivariate Meijer-G function is involved in the analysis, we
propose a new and fast MATLAB implementation enabling an automated definition
of the complex integration contour. Extensive Monte-Carlo simulations are
invoked to corroborate the analytical results.Comment: 4 pages, IEEE Communications Letters, 201
Impact of Transceiver Impairments on the Capacity of Dual-Hop Relay Massive MIMO Systems
Despite the deleterious effect of hardware impairments on communication
systems, most prior works have not investigated their impact on widely used
relay systems. Most importantly, the application of inexpensive transceivers,
being prone to hardware impairments, is the most cost-efficient way for the
implementation of massive multiple-input multiple-output (MIMO) systems.
Consequently, the direction of this paper is towards the investigation of the
impact of hardware impairments on MIMO relay networks with large number of
antennas. Specifically, we obtain the general expression for the ergodic
capacity of dual-hop (DH) amplify-and-forward (AF) relay systems. Next, given
the advantages of the free probability (FP) theory with comparison to other
known techniques in the area of large random matrix theory, we pursue a large
limit analysis in terms of number of antennas and users by shedding light to
the behavior of relay systems inflicted by hardware impairments.Comment: 6 pages, 4 figures, accepted in IEEE Global Communications Conference
(GLOBECOM 2015) - Workshop on Massive MIMO: From theory to practice, 201
Performance Analysis of Two-Hop Cooperative MIMO transmission with Relay Selection in Rayleigh Fading Channel
Wireless relaying is one of the promising solutions to overcome the channel
impairments and provide high data rate coverage that appears for beyond 3G
mobile communications. In this paper we present an end to end BER performance
analysis of dual hop wireless communication systems equipped with multiple
decode and forward relays over the Rayleigh fading channel with relay
selection. We select the best relay based on end to end channel conditions. We
apply orthogonal space time block coding (OSTBC) at source, and also present
how the multiple antennas at the source terminal affects the end to end BER
performance. This intermediate relay technique will cover long distance where
destination is out of reach from source.Comment: 5 figures, 4th International Conference on Wireless Communications,
Networking and Mobile Computing, 2008. WiCOM '0
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