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The telecommunication industry has been successful in turning the Internet into a mobile service and stimulating the creation of a new set of networked, remote services. Most of these services now run or are supported by cloud computing platforms. Embracing cloud computing solutions is fundamental for the telecommunication industry to remain competitive. However, there are many legal, regulatory,
Massive Multiple-Input Multiple-Output (MIMO) systems have been shown to improve both spectral and energy efficiency one or more orders of magnitude by efficiently exploiting the spatial domain. Low-cost RF chains can be employed to reduce the Base Station (BS) cost, however this may require additional baseband processing to handle induced distortions due to the hardware impairments. In this artic
In this paper, we study random puncturing of protograph-based spatially coupled low-density parity-check (SC- LDPC) code ensembles. We show that, with respect to iterative decoding threshold, the strength and suitability of an LDPC code ensemble for random puncturing over the binary erasure channel (BEC) is completely determined by a single constant that depends only on the rate and iterative deco
We consider an optimization problem of joint link rate assignment and transmission scheduling in wireless mesh networks. We assume that each radio link uses (when active) one selected link-dependent modulation and coding scheme. For finding an exact optimum, the problem requires a complicated branch-and-price algorithm that becomes excessively time consuming for networks of practical size. Therefo
The total transmission bandwidth and component carrier aggregation proposed by LTE-Advanced, sets a new challenge to the design of terminals. This article presents a way to assure terminals cope with the large bandwidth in an efficient manner. Various filtering methods are explored showing that an SDR architecture, such as ADRES (Architecture for Dynamically Reconfigurable Embedded Systems), is su
In this work we present a new low-power medium access scheme for sensor-type networks specifically with low traffic intensity. We call the proposed scheme DCW-MAC where ultra-low-power wake-up receivers are combined with optimal duty-cycled listening. First we introduce a framework for the analysis of energy consumption of the studied network type, then we use it to optimize the MAC scheme to achi
An increasing demand from e.g. real-time multimedia applications (IPTV, OTT) adds strains on especially DSL based access links. In this paper we argue why it is important to study DSL link impairments and their impact on QoS parameters on higher layers. We discuss the need for establishing methods for quality of service estimation with cross layer techniques and present some initial results.
Pattern reconfigurability is a desirable feature of mobile handset antennas, as it enables the antennas to adapt to non-stationary propagation environments. However, it is difficult to vary the radiation pattern of a handset antenna at frequencies below 1 GHz because the entire chassis commonly acts as the main radiator. Hence, designing pattern reconfigurability based on the antenna element (seco
The pervasive use and insatiable demand for high-performance wireless devices globally are driving the development of new communication technologies and standards. In this chapter, we present advancements in the area of terminal antenna systems and describe how they play a major role in enabling strict performance requirements to be met in future systems. As opposed to conventional systems that do
Context: The authors wanted to assess whether the quality of published human-centric software engineering experiments was improving. This required a reliable means of assessing the quality of such experiments. Aims: The aims of the study were to confirm the usability of a quality evaluation checklist, determine how many reviewers were needed per paper that reports an experiment, and specify an ap
Video content constitutes a large share of residential Internet traffic. The major source of video content as of today is YouTube. In this paper, we analyse the user demand patterns for YouTube in two metropolitan access networks with more than 1 million requests over three consecutive weeks in the first network and more than 600,000 requests over four consecutive weeks in the second network. In p
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 The Geometry of Meaning, Peter Gärdenfors proposes a theory of semantics that bridges cognitive science and linguistics and shows how theories of cognitive processes, in particular concept formation, can be exploited in a general semantic model. He argues that our minds organize the information involved in communicative acts in a format that can be modeled in geometric or topological terms—in w
