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A two-stage mm-wave power amplifier (PA) is presented. Designed in a 65 nm CMOS process, the PA employs capacitive neutralization in each stage for increased differential isolation and gain. Baluns are used for single-ended input/output signal to balanced signal conversion, and the interstage matching consists of a 2:1 transformer. With a 1.2 V supply, at 67 GHz, measurements show a gain of 16.8 d
The increasing number of mobile devices and high-speed services accelerate the growth of traffic in cellular backhaul networks. The traditional technologies used in the backhaul, copper, radio links and optical fibers, either cannot offer high data-rate, or are expensive. In this paper, we propose mixed integer programming models to facilitate upgrading the cellular backhaul using the free space o
Large-scale software development is a complex undertaking and generates an ever-increasing amount of information. To be able to work efficiently under such circumstances, navigation in all available data needs support. Maintaining traceability links between software artefacts is one approach to structure the information space and support this challenge. Several researchers have proposed traceabili
Abstract in UndeterminedThis study investigates the impact of user on the multiplexing efficiency of a pentaband two-element MIMO terminal antenna. At the 750MHz band, the results show that the antenna total efficiency decreases by 4 dB in the presence of the user hand. However, this negative effect is partly compensated by the de-correlation effect of the hand. As a result, the multiplexing effic
We introduce the problem of reoptimizing the network after a link failure has been repaired as an effective way for reducing capacity usage and improving network performance. Numerical results show gains higher than 42%.
Max-min fairness (MMF) is a general objective of multi-criteria optimization with important and natural applications in communication network design. The notion of MMF and optimization models involving MMF seem not to be commonly known to network designers and therefore they are not used to an extent they deserve. Moreover, the MMF approaches are sometimes “reinvented”, in some cases not correctly
In this paper we consider time-division-duplex (TDD) reciprocity calibration of a massive MIMO system. The calibration of a massive MIMO system can be done entirely at the base station (BS) side by sounding the BS antennas one-by-one while receiving with the other BS antennas. With an M antenna BS, this generates M(M - 1) signals that can be used for calibration purposes. In this paper we study se
In this paper, we propose a telco cloud meta-model that can be used to simulate different infrastructure con- figurations and explore their consequences on the system performance and costs. To achieve this, we analyse current telecommunication and data centre infrastructure paradigms, describe the architecture of the telco cloud and detail the benefits of merging both infrastructures in a unified
In 2001, a paper published in Nature by Andrews et al postulated the use of six co-located antennas, namely three electric and three magnetic dipoles, to achieve up to a six-fold capacity increase in wireless channels, relative to that of a single antenna. In other words, six degrees of freedom (DOFs) can be supported in a wireless channel with co-located six-port transmit and receive antenna arra
A new version of the stream cipher Grain-128 is proposed. The new version, Grain-128a, is strengthened against all known attacks and observations on the original Grain-128, and has built-in support for authentication. The changes are modest, keeping the basic structure of Grain-128. This gives a high confidence in Grain-128a and allows for easy updating of existing implementations.
This paper presents a directional analysis of the on-body propagation channels using the high resolution space alternating generalized expectation (SAGE) maximization algorithm. The analysis has been done on data obtained through FDTD simulations, on a male and a female numerical phantom. For estimating the angle of arrival (AoA) at a four element square array located at the chest, two different p
Wireless communication using very-large multiple-input multiple-output (MIMO) antennas is a new research field, where base stations are equipped with a very large number of antennas as compared to previously considered systems. Unlike the conventional small and compact antenna arrays, the very-large arrays may span many wavelengths in space, thus they can experience large-scale fading over the arr
