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In this paper, we survey Faster-than-Nyquist (FTN) signaling, an extension of ordinary linear modulation in which the usual data bearing pulses are simply sent faster, and consequently are no longer orthogonal. Far from a disadvantage, this innovation can transmit up to twice the bits as ordinary modulation at the same bit energy, spectrum, and error rate. The method is directly applicable to orth
Abstract in UndeterminedAn efficient technique is introduced to reduce mutual coupling between two closely spaced PIFAs for MIMO mobile terminals. The proposed mutual coupling reduction method is based on a T-shape slot impedance transformer and can be applied to both single-band and dual-band PIFAs. For the proposed single-band dual PIFAs, the 10 dB impedance bandwidth covers the 2.4 GHz WLAN ban
Multi-antenna enabled terminal devices are required to comply with the standards for limiting human exposure to electric fields. However, when compared to traditional single-antenna terminals, a comprehensive evaluation of specific absorption rate (SAR) for multi-antenna terminals is impractical. This is because both the power allocation and phase of the electric fields from different antennas are
We study the potential benefits of cooperative multiple-input multiple-output signaling from multiple coherent base stations with one or more mobile stations in an urban macrocellular environment at 2.66 GHz. The analysis uses fully-coherent measurements of the channel from three base stations to a single mobile station equipped with four antennas. The observed channels are used to explore the gai
We design of an efficient channel shortener for nonlinear satellite channels. When the memory of the channel is too large to be taken into account by a full complexity detector, excellent performance can be achieved by properly filtering the received signal followed by a reduced-state detector. This letter derives closed-form expressions for the front-end filter and the target response of the redu
Compact arrays such as multiple antennas on a mobile terminal suffer from low efficiency and high correlation between antenna signals. In the present paper, a simple and rigorous procedure for decoupling two closely coupled antennas with a parasitic scatterer is proposed. The parasitic scatterer, which can be an additional antenna, acts as a shield between two active antenna elements. In contrast
This article discusses opportunities and challenges of physical layer security integration in MaMIMO systems. Specifically, we first show that MaMIMO itself is robust against passive eavesdropping attacks. We then review a pilot contamination scheme that actively attacks the channel estimation process. This pilot contamination attack not only dramatically reduces the achievable secrecy capacity bu
Geometry-based stochastic channel models (GSCMs) are extended to support multi-link simulations by applying the concept of common clusters. This novel approach aims to control the correlation between different links, inter-link correlation, by adjusting the amount of power simultaneously propagating via the same clusters in the different links. The behavior of common clusters is analyzed based on
This paper presents two class-C CMOS VCOs with a dynamic bias of the core transistors, which maximizes the oscillation amplitude without compromising the robustness of the oscillation start-up, thereby breaking the most severe trade-off in the original class-C topology. An analysis of several different oscillators, starting with the common class-B architecture and arriving to the proposed class-C
The COST 2100 channel model has introduced the concept of common clusters to model multi-link MIMO characteristics. In this paper, a ray launching tool is used to analyze multi-ink propagation properties in an outdoor scenario at 300 MHz. It is shown that in a multi-link propagation scenario there are shared scatterers among the different links, which reflects the physical existence of common clus
This paper presents a low band antenna impedance tuner in 130nm CMOS-SOI technology. It consists of three digitally controlled switched capacitor banks and two off-chip inductors and is intended for use in terminals supporting modern cellular standards like WCDMA and LTE. By using a negative gate bias in the off state, linearity can be improved and maintained. Measurements show an OIP3 exceeding +
This paper presents the co-design of a class-D digitally-controlled oscillator (DCO) and a low-dropout voltage regulator (LDO) generating the supply voltage for the DCO. Despite the high intrinsic supply pushing of the class-D oscillator topology, the LDO noise has only a very marginal impact on the DCO phase noise. The class-D DCO and LDO have been integrated in a 65nm CMOS process without any th
Popular Abstract in Swedish Made in China - På hur många av dina barns leksaker står det? Produktionen inom många sektorer flyttas från Europa till länder där arbetskraften är billigare. Forskningen i avhandlingen "Modeling and Control of Stiff Robots for Flexible Manufacturing" ska hjälpa europeiska småföretag att bli mer konkurrenskraftiga och samtidigt underlätta för arbetarna. Högt ljud frånTo survive on a global market, small and medium size enterprises (SMEs) require affordable and competitive industrial automation for high quality flexible manufacturing. This thesis contributes to the development of robot concepts that fit the needs of SMEs. A major part of the thesis deals with the modeling of the three degree-of-freedom (DOF) Gantry-Tau parallel kinematic robot, which has the po
Human beings make errors and that is nothing that we can avoid completely. We can however lower the risk of people doing wrong in situations where, for example, medical devices are used. The overall objective of the research presented in this paper is to investigate how usability testing can contribute to software risk management process in the medical device domain. Experience has been collected
In radio communications, a set of links that can transmit in parallel with a tolerable interference is called a compatible set. Finding a compatible set with maximum weighted revenue of the parallel transmissions is an important subproblem in wireless network management. For the subproblem, there are two basic approaches to express the signal to interference plus noise ratio (SINR) within integer
Multi-antenna design in compact mobile handsets at frequency bands below 1 GHz is very challenging, since severe mutual coupling is commonly induced by simultaneous excitation of the chassis’ fundamental dipole mode by more than one antenna element. To address this problem, a novel multi-antenna design approach is proposed herein to obtain efficient and uncorrelated antennas. By manipulating the c
