2 research outputs found
MIMO DF Relay Beamforming for Secrecy with Artificial Noise, Imperfect CSI, and Finite-Alphabet
In this paper, we consider decode-and-forward (DF) relay beamforming with
imperfect channel state information (CSI), cooperative artificial noise (AN)
injection, and finite-alphabet input in the presence of an user and
non-colluding eavesdroppers. The communication between the source and the user
is aided by a multiple-input-multiple-output (MIMO) DF relay. We use the fact
that a wiretap code consists of two parts: i) common message (non-secret), and
ii) secret message. The source transmits two independent messages: i) common
message (non-secret), and ii) secret message. The common message is transmitted
at a fixed rate , and it is intended for the user. The secret message is
also intended for the user but it should be kept secret from the
eavesdroppers. The source and the MIMO DF relay operate under individual power
constraints. In order to improve the secrecy rate, the MIMO relay also injects
artificial noise. The CSI on all the links are assumed to be imperfect and CSI
errors are assumed to be norm bounded. In order to maximize the worst case
secrecy rate, we maximize the worst case link information rate to the user
subject to: i) the individual power constraints on the source and the MIMO
relay, and ii) the best case link information rates to eavesdroppers be
less than or equal to in order to support a fixed common message rate
. Numerical results showing the effect of perfect/imperfect CSI,
presence/absence of AN with finite-alphabet input on the secrecy rate are
presented
A Survey on MIMO Transmission with Discrete Input Signals: Technical Challenges, Advances, and Future Trends
Multiple antennas have been exploited for spatial multiplexing and diversity
transmission in a wide range of communication applications. However, most of
the advances in the design of high speed wireless multiple-input multiple
output (MIMO) systems are based on information-theoretic principles that
demonstrate how to efficiently transmit signals conforming to Gaussian
distribution. Although the Gaussian signal is capacity-achieving, signals
conforming to discrete constellations are transmitted in practical
communication systems. As a result, this paper is motivated to provide a
comprehensive overview on MIMO transmission design with discrete input signals.
We first summarize the existing fundamental results for MIMO systems with
discrete input signals. Then, focusing on the basic point-to-point MIMO
systems, we examine transmission schemes based on three most important criteria
for communication systems: the mutual information driven designs, the mean
square error driven designs, and the diversity driven designs. Particularly, a
unified framework which designs low complexity transmission schemes applicable
to massive MIMO systems in upcoming 5G wireless networks is provided in the
first time. Moreover, adaptive transmission designs which switch among these
criteria based on the channel conditions to formulate the best transmission
strategy are discussed. Then, we provide a survey of the transmission designs
with discrete input signals for multiuser MIMO scenarios, including MIMO uplink
transmission, MIMO downlink transmission, MIMO interference channel, and MIMO
wiretap channel. Additionally, we discuss the transmission designs with
discrete input signals for other systems using MIMO technology. Finally,
technical challenges which remain unresolved at the time of writing are
summarized and the future trends of transmission designs with discrete input
signals are addressed.Comment: 110 pages, 512 references, submit to Proceedings of the IEE