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This paper presents a 1MHz bandwidth, ΔƩ fractional-N PLL as the frequency synthesizer for LTE. A noise cancellation path composed of a novel hybrid ΔƩ DAC with 9 output bits is incorporated into the PLL in order to cancel the out-of-band phase noise caused by the quantization error. Further, a re-timing circuit is proposed to reduce the nonlinearity in the Charge Pump and provide pulse shaping si

Weak alignment of requirements engineering (RE) with verification and validation (VV) may lead to problems in delivering the required products in time with the right quality. For example, weak communication of requirements changes to testers may result in lack of verification of new requirements and incorrect verification of old invalid requirements, leading to software quality problems, wasted ef

Pathloss is typically modeled using a log-distance power law with a large-scale fading term that is log-normal. However, the received signal is affected by the dynamic range and noise floor of the measurement system used to sound the channel, which can cause measurement samples to be truncated or censored. If the information about the censored samples is not included in the estimation method, as i

Families of generalized spatially-coupled low-density parity-check (GSC-LDPC) code ensembles can be formed by terminating protograph-based generalized LDPC convolutional (GLDPCC) codes. It has previously been shown that ensembles of GSC-LDPC codes constructed from a protograph have better iterative decoding thresholds than their block code counterparts, and that, for large termination lengths, the

The Theory of Characteristic Modes provides a convenient tool for designing multi-antennas for MIMO applications, as it enables orthogonal radiation patterns to be excited in a given antenna structure. Moreover, the frequency behavior of the modes reveals interesting wideband properties of the structure. However, the tracking of characteristic modes over frequency remains a challenge, especially w

This paper presents an energy-efficient sorted QR decomposition (SQRD) processor for 3GPP LTE-Advanced (LTE-A) systems. The processor adopts a hybrid decomposition scheme to reduce computational complexity and provides a wide-range of performance complexity trade-offs. Based on the energy distribution of spatial channels, it switches between the brute-force SQRD and a low-complexity group-sort QR-

The 14th edition of International Telecommunications Network Strategy and Planning Symposium (shortly: Networks 2010) held in Warsaw, Poland. Networks 2010 was a four-day professional and scientific event organized by Warsaw University of Technology in co-operation with Polish Association of Telecommunication Engineers (SIT). The conference was focused on network design and planning methods includ

In this paper a frequency compensation method for operational transconductance amplifiers is proposed, which poses no power overhead compared to Miller compensation, while improving the 3dB bandwidth, the unity gain frequency and the slew rate. The technique employees positive feedback to introduce an extra left half plane zero to cancel a pole.The phase margin shows good robustness against proces

This paper presents a multi-bit, continuous time delta-sigma modulator with 20 MHz bandwidth implemented in 65nm CMOS for cellular communication. The modulator features a third order, single loop filter and a 4-bit internal quantizer operating at 640 MHz. The DACs are resistive for lower thermal noise compared to the current-steering DACs and nonreturn-to-zero DAC pulse is used to reduce the clock

A large ensemble of regional climate model projections was investigated regarding if and when they show an emergence of significant climate change signals in seasonal temperature and precipitation within Europe. The influence of the North Atlantic Oscillation (NAO), as simulated in the projections, was investigated. In most parts of Europe, the projections indicate robust emergence of temperature

Finding optimal routes and spectrum allocation in flexgrid optical networks, known as the RSA problem, is an important design problem in transport communication networks. The problem is NP -hard, and its intractability becomes profound when network instances with several tens of nodes and several hundreds of demands are to be solved to optimum. In order to deal with such instances, large-scale opt

With the densification of nodes in cellular networks, free space optic (FSO) connections are becoming an appealing low cost and high rate alternative to copper and fiber backhaul solutions for wireless communication systems. To ensure a reliable cellular backhaul, provisions for redundant disjoint paths between the nodes must be made in the design phase. This paper aims at finding a cost-effective

[Context & motivation] For market-driven software product developing organizations operating on a competitive open market, it is important to plan the product’s releases so that they can reach the market as early as possible with a competitive level of quality compared to its competitors' products. Hence, quality requirements can be seen as a key competitive advantage. The QUPER model was deve

In vehicular ad-hoc networks (VANETs) the impact of vehicles as obstacles has largely been neglected in the past. Recent studies have reported that the vehicles that obstruct the line-of-sight (LOS) path may introduce 10-20 dB additional loss, and as a result reduce the communication range. Most of the traffic mobility models (TMMs) today do not treat other vehicles as obstacles and thus can not m

The ability to detect a virtualized environment has both malicious and non-malicious uses. This paper reveals a new exploit and technique that can be used to remotely detect VMware Workstation, VMware Player and VirtualBox. The detection based on this technique can be done completely passively in that there is no need to have access to the remote machine and no network connections are initiated by

Future mobile terminals are expected to support an ever increasing number of Radio Access Technologies (RAT) concurrently. This imposes a challenge to terminal designers already today. Software Defined Radio (SDR) solutions are a compelling alternative to address this issue in the digital baseband, given its high flexibility and low Non-Recurring Engineering (NRE) cost. However, the challenge stil

Despite recent attempts to relax the phase-noise demands on voltage-controlled oscillators (VCOs) for cellular communications [1], mainstream radios require harmonic VCOs capable of a very low phase noise with moderate power consumption, associated to a large tuning range (TR) and a high insensitivity to interfering signals. Ideally, the TR should be in excess of one octave, since this allows the

We perform a minimum distance analysis of a class of two-dimensional intersymbol interference (ISI) channels applicable to multitrack magnetic recording and orthogonal frequency division multiplex transmission systems. Exact minimum distance for a wide class of ISI responses is derived. The fundamental analytical technique is to transform the channel into an equivalent minimum phase channel. The r

The popularity of Open Source Software (OSS) has increased the interest in using it in safety critical applications. The aim of this study is to review research carried out on usage of open source code in development of safety-critical software and systems. We conducted a systematic mapping study through searches in library databases and manual identification of articles from open source conferenc