Sökresultat

Radio links in wireless mesh networks (WMN) can select one of several modulation and coding schemes (MCS). A MCS assignment influences links data rates and their mutual interference, and therefore should be optimized. We consider joint optimization of link rate assignment and transmission scheduling in order to maximize the minimal flow in a WMN. One of the main difficulties stems from the require

As new technologies emerge such as wearables, it opens up for new challenges, especially related to security and privacy. One such recent technology is smart glasses. The use of glasses introduces security and privacy concerns for the general public but also for the user itself. In this paper we present ongoing theoretical work which focus on privacy of the user during authentication. We propose a

We present property probes, a mechanism for helping a developer interactively explore partial program analysis results in terms of the source program, and as the program is edited. A node locator data structure is introduced that maps between source code spans and program representation nodes, and that helps identify probed nodes in a robust way, after modifications to the source code. We have dev

In this paper, we linear quadratic team decision problems, where a team of agents minimizes a convex quadratic cost function over T time steps subject to possibly distinct linear measurements of the state of nature. We assume that the state of nature is a Gaussian random variable and that the agents do not know the cost function nor the linear functions mapping the state of nature to their measure

Faults and errors are common in the execution of digital controllers on top of embedded hardware. Researchers from the embedded system domain devised models to understand and bound the occurrence of these faults. Using these models, control researchers have demonstrated robustness properties of control systems, and of their corresponding digital implementations. In this paper, we build a framework

System level synthesis is a promising approach that formulates structured optimal controller synthesis problems as convex problems. This work solves the distributed linear-quadratic regulator problem under communication constraints directly in infinite-dimensional space, without the finite-impulse response relaxation common in related work. Our method can also be used to construct optimal distribu

We present a new, scalable alternative to the structured singular value, which we call v, provide a convex upper bound, study their properties and compare them to l1 robust control. The analysis relies on a novel result on the relationship between robust control of dynamical systems and non-negative constant matrices.

Reliability in Ricean multiple-input-multiple-output (MIMO) channels is crucial for safety related vehicle-tovehicle (V2V) applications. Due to the time variability of vehicular communication channel, it is very significant to study the temporal evolution of channel characterization criteria. We present evaluation results of the temporal evolution of the spectral efficiency from channel sounder me

The COST2100 channel model is a reference channel model which provides dynamic multiple-input multiple-output channel responses for radio system simulations. In this paper, channels created by the COST2100 model were compared to channel measurements in order to understand behaviours of the model. Model parameters of the COST2100 model were derived by dynamic double-directional channel measurements

With the open and big data movement in full swing, data sharing becomes more ubiquitous and more often crosses sectoral boundaries. The promise of data to help address societal issues and foster innovation requires public organizations to work together with businesses and researchers. Data collaboratives whereby actors collaborate to share and use data for public good gain increasing interest. Mos

Random-walk and diffusion models for two-choice comparison of paired successive or simultaneous stimuli focus on response time (RT), modeled as the time needed to reach one or the other barrier, and its relation to the response probabilities. Logit P1 = ln[P1/(1-P1)], where P1 is the probability of responding ”first greater,” can be seen as a measure of subjective stimulus difference, d. Signed re

In this paper, multiple-input multiple-output (MIMO) channel measurements in an outdoor micro-cell environment are used to study the effect of base-station (BS) inter-element spacing on multi-user MIMO signal separation. Users with two dual-polarized patch antennas at the mobile station (MS), and four equally-spaced dual-polarized patch antennas at the BS are considered. At the BS, the inter-eleme

Measurements of a sub-threshold (sub-VT) decimation filter, composed of four half band digital (HBD) filters in 65 nm CMOS are presented. Different unfolded architectures are analyzed and implemented to combat speed degradation. The architectures are analyzed for throughput and energy efficiency over several threshold options. Reliability in the sub-VT domain is analyzed by Monte-Carlo simulations

A new architecture for Discrete Fourier Transform (DFT) based channel estimation has been analyzed, implemented and synthesized for ASIC. The core concept of the proposed esti- mation algorithm is to process the channel increments rather than the channel coefficients. With strong enough time correlation, we can reduce the wordlength of processing blocks compared to standard channel estimators and

Critical systems must comply with safety standards in many application domains. This involves gathering safety evidence in the form of artefacts such as safety analyses, system specifications, and testing results. These artefacts can evolve during a system’s lifecycle, and impact analysis might be necessary to guarantee that system safety and compliance are not jeopardised. Although extensive rese

In this paper we show a closed caption formula for the efficiency of the optimal sampling technique in the random S-box model. This formula is derived by analyzing the given model and sampling technique using statistical techniques. We further generalize the original random S-box model in two ways; allowing multiple-bit entries, xor of several random S-box outputs. For all cases we show the corres

This paper presents a double directional analysis of vehicle-to-vehicle channel measurements conducted in three different traffic scenarios. Using a high-resolution algorithm, we derive channel parameters like Angle-of-Arrival (AOA), Angle-of-Departure (AOD), propagation delay and Doppler shift and identify underlying propagation mechanisms by combining these estimates with maps of the measurement

This study is concerned with an original traffic restoration strategy for wide-area communication networks called Elastic Rerouting (ER). ER aims at alleviating the tradeoff between the network cost and traffic restoration complexity observed in existing solutions. We present the strategy, provide a mathematical formulation for the ER related optimization problem, and discuss an approach to its re