Filetype
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
Test and evaluation of wireless communication performance with cars can be done in many ways. One approach, for both vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) tests, is to use a multipath propagation simulator to achieve realistic signal environments for the different communication systems under test. Multipath propagation simulators have previously been shown to be useful for t
In this paper, we provide an efficient way to predict iterative belief propagation (BP) decoding thresholds of randomly punctured low-density parity-check (LDPC) code ensembles on the binary-input additive white Gaussian noise channel (AWGNC), given only the BP threshold of the mother code ensemble on the binary erasure channel (BEC) and the code design rate. We show that the predictions are accur
The possibility of using the channel reciprocity between the uplink and downlink channels in Frequency Division Duplex (FDD) systems to improve the efficiency has been deeply investigated. Previous studies have come to different conclusions for the characterization of the dissimilarity in uplink and downlink channel properties. This paper analyzes the mismatch in directional properties of the upli
Cooperative content replication and request routing (C2R3) has emerged as a promising technique to enhance the efficiency of content delivery networks (CDN). Most existing approaches to C2R3 focus on efficient bandwidth usage and assume a hierarchical CDN architecture targeted towards the delivery of specific content types (e.g., video). Therefore, C2R3 problem of covering the broad range of conte
The design of a digital baseband for a low power wireless receiver in 65 nm CMOS is presented. It consists of decimation filtering, matched filters for data detection, and preamble based synchronization. The circuit was designed using low threshold devices in both low power (LP-LVT) and general-purpose (GP-LVT) domains. The fabricated circuits were functionally verified, and silicon measurements s
A order 3-bit continuous-time (CT) ΔΣ ADC is presented in this paper. The design equations starting from a discrete-time reference modulator to the circuit implementation are given. The non-return to zero (NRZ) DAC pulses have a half clock cycle loopdelay which is corrected by the feedforward (also known as PI) loop delay compensation, and nonlinearities in the DACs are suppressed by data-weighted
This paper presents a detailed description of a propagation channel measurement campaign performed in a warehouse environment and provide a comprehensive channel model for this environment. Using a vector network analyzer (VNA), we explored both Line-of-sight(LOS) and Non-Line-of-sight (NLOS) scenarios over a 2-8 GHz frequency range. We extracted both small-scale and large-scale channel parameters
In this paper we present an analysis of the effects of antenna placement on the radio channel properties for Vehicle-to-Vehicle communications based on measurements performed in three different propagation scenarios; highway, urban and rural. Four omni-directional antennas were mounted at four different positions: roof, bumper, left-side mirror and inside windscreen of two standard station wagons
The ambitious goal of the upcoming IEEE 802.11ax (HEW) standard for wireless LANs (WLANs) to enhance throughput by four times (and beyond), compared with IEEE 802.11ac, demands a radical improvement of present medium access control (MAC) functionality. To this end, a promising paradigm would be a graceful migration towards new MAC protocols which incorporate higher certainty in their decisions. Ho
The findings from a user study regarding particular ob- servable “interaction patterns” in the interaction during a “guided tour” are summarized in this paper.
There has been extensive research about single link multiple-input multiple-output (MIMO) channels, both simulated and measured, but only few studies have targeted multilink analysis with measured channel data. Hence, in this paper, we analyze the influence of spatial separation of user terminals and the human shadowing effect on the MIMO capacity and to the signal to interference ratio (SIR) in a
Software development organizations are continuously looking for better ways to manage their projects. An emerging approach to achieve this is Inner Source, which refers to the adoption of Open Source development practices within the confines of an organization. With an Inner Source approach, individuals, teams, and departments within an organization can start software projects, very similar to the
