6,324 research outputs found
Exploiting Trust Degree for Multiple-Antenna User Cooperation
For a user cooperation system with multiple antennas, we consider a trust
degree based cooperation techniques to explore the influence of the
trustworthiness between users on the communication systems. For the system with
two communication pairs, when one communication pair achieves its quality of
service (QoS) requirement, they can help the transmission of the other
communication pair according to the trust degree, which quantifies the
trustworthiness between users in the cooperation. For given trust degree, we
investigate the user cooperation strategies, which include the power allocation
and precoder design for various antenna configurations. For SISO and MISO
cases, we provide the optimal power allocation and beamformer design that
maximize the expected achievable rates while guaranteeing the QoS requirement.
For a SIMO case, we resort to semidefinite relaxation (SDR) technique and block
coordinate update (BCU) method to solve the corresponding problem, and
guarantee the rank-one solutions at each step. For a MIMO case, as MIMO is the
generalization of MISO and SIMO, the similarities among their problem
structures inspire us to combine the methods from MISO and SIMO together to
efficiently tackle MIMO case. Simulation results show that the trust degree
information has a great effect on the performance of the user cooperation in
terms of the expected achievable rate, and the proposed user cooperation
strategies achieve high achievable rates for given trust degree.Comment: 15 pages,9 figures, to appear in IEEE Transactions on Wireless
communication
5G Wireless Network Slicing for eMBB, URLLC, and mMTC: A Communication-Theoretic View
The grand objective of 5G wireless technology is to support three generic
services with vastly heterogeneous requirements: enhanced mobile broadband
(eMBB), massive machine-type communications (mMTC), and ultra-reliable
low-latency communications (URLLC). Service heterogeneity can be accommodated
by network slicing, through which each service is allocated resources to
provide performance guarantees and isolation from the other services. Slicing
of the Radio Access Network (RAN) is typically done by means of orthogonal
resource allocation among the services. This work studies the potential
advantages of allowing for non-orthogonal sharing of RAN resources in uplink
communications from a set of eMBB, mMTC and URLLC devices to a common base
station. The approach is referred to as Heterogeneous Non-Orthogonal Multiple
Access (H-NOMA), in contrast to the conventional NOMA techniques that involve
users with homogeneous requirements and hence can be investigated through a
standard multiple access channel. The study devises a communication-theoretic
model that accounts for the heterogeneous requirements and characteristics of
the three services. The concept of reliability diversity is introduced as a
design principle that leverages the different reliability requirements across
the services in order to ensure performance guarantees with non-orthogonal RAN
slicing. This study reveals that H-NOMA can lead, in some regimes, to
significant gains in terms of performance trade-offs among the three generic
services as compared to orthogonal slicing.Comment: Submitted to IEE
Asymptotic amplitudes and cauchy gains: A small-gain principle and an application to inhibitory biological feedback
The notions of asymptotic amplitude for signals, and Cauchy gain for
input/output systems, and an associated small-gain principle, are introduced.
These concepts allow the consideration of systems with multiple, and possibly
feedback-dependent, steady states. A Lyapunov-like characterization allows the
computation of gains for state-space systems, and the formulation of sufficient
conditions insuring the lack of oscillations and chaotic behaviors in a wide
variety of cascades and feedback loops. An application in biology (MAPK
signaling) is worked out in detail.Comment: Updates and replaces math.OC/0112021 See
http://www.math.rutgers.edu/~sontag/ for related wor
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Robust H2/H∞-state estimation for systems with error variance constraints: the continuous-time case
Copyright [1999] IEEE. This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.The paper is concerned with the state estimator design problem for perturbed linear continuous-time systems with H∞ norm and variance constraints. The perturbation is assumed to be time-invariant and norm-bounded and enters into both the state and measurement matrices. The problem we address is to design a linear state estimator such that, for all admissible measurable perturbations, the variance of the estimation error of each state is not more than the individual prespecified value, and the transfer function from disturbances to error state outputs satisfies the prespecified H∞ norm upper bound constraint, simultaneously. Existence conditions of the desired estimators are derived in terms of Riccati-type matrix inequalities, and the analytical expression of these estimators is also presented. A numerical example is provided to show the directness and effectiveness of the proposed design approac
A Repeated Game Formulation of Energy-Efficient Decentralized Power Control
Decentralized multiple access channels where each transmitter wants to
selfishly maximize his transmission energy-efficiency are considered.
Transmitters are assumed to choose freely their power control policy and
interact (through multiuser interference) several times. It is shown that the
corresponding conflict of interest can have a predictable outcome, namely a
finitely or discounted repeated game equilibrium. Remarkably, it is shown that
this equilibrium is Pareto-efficient under reasonable sufficient conditions and
the corresponding decentralized power control policies can be implemented under
realistic information assumptions: only individual channel state information
and a public signal are required to implement the equilibrium strategies.
Explicit equilibrium conditions are derived in terms of minimum number of game
stages or maximum discount factor. Both analytical and simulation results are
provided to compare the performance of the proposed power control policies with
those already existing and exploiting the same information assumptions namely,
those derived for the one-shot and Stackelberg games.Comment: 25 pages, 5 figures, accepted for publication in IEEE Transaction on
Wireless Communicatio
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