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A 24 GHz 2-path beamforming receiver front-end in 90 nm CMOS is presented. It consists of two direct conversion front-ends followed by a baseband block performing phase rotation and signal combination. The baseband phase rotation is performed by combining the quadrature phases using digitally controlled weights, achieving a phase resolution of 11 degrees. From each of the two inputs the front-end
Analytical Multiple-Input Multiple-Output (MIMO) models are often attractive due to their low complexity when analyzing possibilities and limitations in the system. In this paper we outline a a possible dual link extension of an analytical MIMO channel model and investigate its suitability based on measurements of a dual link MIMO scenario. The extension is based on the correlation matrix distance
In secure computing systems, isolation between different components is normally the basis for security. However, ab- solute isolation is seldom desired nor practical. Often for the system to function, a secure communication channel between otherwise isolated components is also needed. In this work, we consider implementation of the secure Remote Procedure Call (RPC) mechanism defined by the Global
Issue management in market-driven software projects is constantly under time pressure. A limited set of developers must share their time between developing features for the next release and resolving reported issues. Project managers need to find the appropriate balance between a high quality product and fast time to market. We study a telecom company in Sweden developing embedded systems for a co
Massive multiple-input multiple-output (MIMO) is one of the main candidates to be included in the fifth generation (5G) cellular systems. For further system development it is desirable to have real-time testbeds showing possibilities and limitations of the technology. In this paper we describe the Lund University Massive MIMO testbed – LuMaMi. It is a flexible testbed where the base station operat
The COST2100 channel model is a reference channel model which provides dynamic multiple-input multiple-output channel responses for radio system simulations. In this paper, channels created by the COST2100 model were compared to channel measurements in order to understand behaviours of the model. Model parameters of the COST2100 model were derived by dynamic double-directional channel measurements
A Vernier Gate-Ring-Oscillator (GRO) Time to Digital Converter (TDC) is proposed and implemented in 90-nm CMOS process technology. It utilizes two GRO chains as the delay lines. The time resolution is determined by the difference between two delays, so not limited by the process. Moreover, the quantization noise can be first-order shaped by the gated behavior in the oscillators, which further impr
The increase in demand for high-data rates on the move in the complex urbanenvironment requires either the allocation of new spectrum such as availablecontiguous spectrum in the mm-wave band or the use of novel configurationssuch as the application of massive multiple-input multiple-output (MIMO)technology. To enable the design of efficient wireless networks, an understandingof the propagation phe
This deliverable presents channel measurement results for the scenariosOpen exhibition and Crowded auditiorium. The measurement procedureand equipment are described. Massive MIMO (MaMi) channel characteristicsand key parameters are extracted and used in an extended COST 2100channel model for MaMi. The initial validation performed shows that themodel is capable of reproducing the statistics in term
Massive multiple input multiple output (MIMO) is a revolutionary communication technique, where large numbers of antennas are employed at the base stations to increase the spectral efficiency, reliability and data rate of the system. Moreover, in multi-user MIMO (MU-MIMO) multiple users can be served by the base stations on the same time-frequency resource. Distributed antenna system (DAS) is a fo
The second generation (2G) cellular networks are the current workhorse for machine-to-machine (M2M) communications. Diversity in 2G devices can be present both in form of multiple receive branches and blind repetitions. In presence of diversity, intersymbol interference (ISI) equalization and co-channel interference (CCI) suppression are usually very complex. In this paper, we consider the improve
The choice of channel propagation model used for the simulation-based study of Vehicular Ad hoc NETworks (VANETs) plays a key role in the accuracy of conclusions drawn about the performance of applications proposed for these networks. Relying on simplistic channel models, as frequently practised in previous works, leads either to pessimistic or optimistic conclusions. In the view of this, in this
Urban intersections constitute an important safety-critical scenario for vehicle-to-vehicle communication. Based on measurements, this paper presents detailed investigations of the radio wave propagation processes in a typical urban intersection. We focus on one time instance of the propagation process and set up hypothesis for locations of the scattering objects. Multipath components (MPCs) are i
We consider the problem of designing demodulators for channels with memory that use reduced-size trellis descriptions for the received signal. We assume an overall iterative receiver, and for the parts of the signal not covered by the trellis description, we use interference cancellation based on the soft information provided by the outer decoder. In order to reach a trellis description, a linear
