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The development of MIMO over-the-air (OTA) test methodology is an ongoing activity in 3GPP RAN4, CTIA and EU COST Action 2100. In this paper, the focus is on the anechoic chamber approach, which uses a uniform circular array of probe antennas to replicate directional channels for the device under test (DUT) at the array center. In particular, we study in simulation the complexity requirements of i
Coordination is an important success factor for a development project. Communication gaps, e.g. between product owners shaping the requirements and testers verifying the developed software can result in wasted effort and unsuccessful products. We propose improving the communication between project members with recommendations of whom to interact with and what to discuss based on link prediction in
We consider a class of weak feedback polynomials for LFSRs in the nonlinear combiner. When feedback taps are located in small groups, a distinguishing attack can sometimes be improved considerably, compared to the common attack that uses low weight multiples. This class of weak polynomials was introduced in 2004 and the main property of the attack is that the noise variables are represented as vec
Shadowing from vehicles can degrade the performance of vehicle-to-vehicle (V2V) communication systems significantly. It is thus important to characterize and model the influence of common shadowing objects like cars properly. For multilink systems it is essential to model the joint effects on the different links. However, the multilink shadowing effects in V2V channels are not yet well understood.
This paper presents a new Hardware (HW) im- plementation proposal for Discrete Fourier Transform (DFT) based channel estimators. The presented algorithm uses the high time correlation property of the channel estimates to reduce the complexity and the power consumption by utilizing a lower number of bits for the FFT in the channel estimator, compared to a traditional approach. The idea is that the
Attribute grammars are useful in integrated editing environments for obtaining automatic incremental compilation features. However, traditional attribute grammars use aggregated values during name resolution, resulting in large sets of affected attribute instances after edits. In this paper, we show how reference attribute grammars (RAGs) can significantly reduce the number of affected attributes.
The friction stir welding procedure to seal copper canisters requires variable power input throughout the 45 minute long weld cycle to keep the welding temperature within the process window. This is due to variable thermal boundary conditions throughout the weld cycle which, together with fast disturbances in the spindle torque, requires control of both the power input and the welding temperature
The state-of-the-art in development tools today provides users with a large number of both syntactic and semantic services, such as syntax highlighting, name completions and refactorings. Preferably, every language should have sophisticated tool support, but unfortunately, the manual task of tool development is both time-consuming and error-prone, making it too costly for small language communitie
This paper presents a high throughput, low latency soft-output signal detector for a 4×4 64-QAM MIMO system. To achieve high data-level parallelism and accurate soft information, the detector adopts a node perturbation technique to generate a list of candidate vectors around Zero Forcing, ZF, result. Additionally a fast and hardware friendly node enumeration scheme is developed to significantly re
Successful coordination of Requirements Engineering and Testing (RET) is crucial in large-scale software engineering. If the activities involved in RET are not aligned, effort is inevitably wasted, and the probability of delivering high quality software products in time decreases. Previous work has identified sixteen challenges in aligning RET in a case study of six companies. However, all six cas
This paper presents a QVCO and divider for a 28 GHz SiGe PLL. It was designed in a SiGe process with fT= 200 GHz. The PLL is intended to be used for beam steering in an 81-86 GHz E-band transmitter. Phase control is implemented by programmable current injection into the loop filter. The simulations in Spectre use a layout extracted view with parasitics for the QVCO and the frequency divider and an
Next generation wireless systems have to be able to efficiently deal with fast fading environments in order to achieve high spectral efficiency. Using multiple-input multiple-output (MIMO) systems and exploiting receive diversity, their spectral efficiency can be greatly increased. Commonly, the channel is estimated via training symbols, before the data detection is carried out based on the previo
As massive MIMO is currently considered a leading 5G technology candidate, channel models that capture important massive MIMO channel characteristics are urgently needed. In this paper we present an attempt for massive MIMO channel modeling based on measurement campaigns at 2.6 GHz in both outdoor and indoor environments, using physically-large arrays and with closely-spaced users. The COST 2100 M
This paper presents low power hardware generation, based on a CAL actor language dataflow implementation. The CAL language gives a higher level of abstraction and generate both hardware and software description. The original CAL flow is targeted for hardware-software co-design of complex systems on FPGA. Modifications are done to the original CAL flow to facilitate low power ASIC implementations.
Antenna systems are provided including a chassi (115) and first and second radiating (110, 120) elements coupled to the chassi. The first radiating element is configured to amplify excitation of the chassi and the second radiating element is configured to reduce excitation of the chassi so as to reduce mutual coupling in the antenna system. Related co- located antennas and methods of controlling m
In this paper, we present a thin single-arm Archimedean spiral antenna designed to be used in underground soil measurements to characterize the dielectric properties of soil during freezing and thawing processes. The designed antenna works in low permittivity, low-loss frozen soil as well as in high permittivity, high-loss marshy soil and operates over the frequency range 1–3 GHz. The antennas has
