Filetype
Abstract in UndeterminedThe recent MPEG Reconfigurable Media Coding (RMC) standard aims at defining media processing specifications (e.g. video codecs) in a form that abstracts from the implementation platform, but at the same time is an appropriate starting point for implementation on specific targets. To this end, the RMC framework has standardized both an asynchronous dataflow model of computat
The Bidirectional Efficient Algorithm for Searching code Trees (BEAST), which is an algorithm to efficiently determine the free distance and spectral components of convolutional encoders, is implemented for the Cell Broadband Engine Architecture, efficiently utilizing the underlying hardware. Exhaustive and random searches are carried out, presenting new rate R=1/2 convolutional encoding matrices
We present a novel visibility algorithm for rendering motion blur with per-pixel anti-aliasing. Our algorithm uses a number of line samples over a rectangular group of pixels, and together with the time dimension, a two-dimensional spatio-temporal visibility problem needs to be solved per line sample. In a coarse culling step, our algorithm first uses a bounding volume hierarchy to rapidly remove
Massive MIMO can greatly increase both spectral and transmit-energy efficiency. This is achieved by allowing the number of antennas and RF chains to grow very large. However, the challenges include high system complexity and hardware energy consumption. Here we investigate the possibilities to reduce the required number of RF chains, by performing antenna selection. While this approach is not a ve
In this paper, we present a new approach to conservative bounding of displaced Bézier patches. These surfaces are expected to be a common use case for tessellation in interactive and real-time rendering. Our algorithm combines efficient normal bounding techniques, min-max mipmap hierarchies and oriented bounding boxes. This results in substantially faster convergence for the bounding volumes of di
Determining requirements process efficiency, and measuring the corresponding monetary impacts, is a challenging but necessary aspect of project management. In this paper, we perform an independent analysis of scoping decisions from a large industrial project with the goal of providing visualizations that facilitate investigations of process efficiency, agility, and the effects of scoping decisions
Software failures in medical devices can lead to catastrophic situations. Therefore is it crucial to handle software related risks when developing medical devices. This paper presents the experiences gained from an ongoing case study with a medical device development organisation. This part of the study focuses on the two first steps of the risk management process, i.e. risk identification and ris
A VCO is implemented in an RF 90 nm CMOS process and covers the frequency range 2.55-4.08 GHz. Drawing 19 mA from 1.2 V, the phase noise at 20 MHz frequency offset from a 3.7 GHz carrier is -156 dBc/Hz, meeting the phase noise requirement for GSM/EDGE and SAW-less WCDMA transmitter after frequency division by 2 or by 4. A second version of the VCO covers an additional 4.90-5.75 GHz range, at the e
Abstract in UndeterminedIn this paper, a number of channel estimation algorithms for iterative receivers are compared for the case of an up-link orthogonal frequency division multiplexing interleave division multiple access (OFDM-IDMA) system. Both pilot based algorithms, used to obtain an initial estimate, as well as semi-blind decision-directed algorithms working as a component of the iterative
Designing decorrelated MIMO antennas in small mobile terminals at frequencies below 1 GHz is challenging since more than one antenna tend to excite the single resonant mode available to a typical chassis structure. This challenge increases even further when multiple frequency bands are required from each antenna. Recently, a design framework to obtain efficient and decorrelated MIMO antennas based
The development of scientific software has similarities with processes that follow the software engineering "agile manifesto": responsiveness to change and collaboration are of utmost importance. But how well do current scientific software-development processes match the practices found in agile development methods, and what are the effects of using agile practices in such processes?
Vehicular communication channels are characterized by a non-stationary time- and frequency-selective fading process due to fast changes in the environment. We characterize the distribution of the envelope of the first delay bin in vehicle-to-vehicle channels by means of its Rician $K$-factor. We analyze the time–frequency variability of this channel parameter using vehicular channel measurements a
This paper presents a wireless receiver frontend intended for cellular applications implemented in a 65 nm CMOS technology. The circuit features a low noise amplifier (LNA), quadrature passive mixers, and a frequency divider generating 25 % duty cycle quadrature local oscillator (LO) signals. A complementary common-gate LNA is used, and to meet the stringent linearity requirements it employs posit
The present study deals with Elastic Flow Rerouting (EFR)-an original traffic restoration strategy for protecting traffic flows in communication networks (including wireless networks) against multiple link failures. EFR aims at alleviating the trade-off between practicability of traffic restoration and the cost of network resources observed in existing networking solutions. We present an extension
We present a method to compute, quickly and efficiently, the mutual information achieved by an independent identically distributed (IID) complex Gaussian signal on a block Rayleigh-faded channel without side information at the receiver. The method accommodates both scalar and multiple-input multiple-output (MIMO) settings. Operationally, this mutual information represents the highest spectral effi
A Digitally Controlled Oscillator (DCO) whose power consumption can be reconfigured while maintaining an almost constant phase-noise figure-of-merit (FoM). This is achieved by using either a single-switch-pair or a complementary (i.e., double-switch-pair) oscillator topology, without disturbing the optimized LC tank of the DCO. The optimal power consumption in the complementary (P-N) configuration
We present a new method for real-time render- ing of multiple recursions of reflections and refractions. The method uses the strengths of real-time ray tracing for objects close to the camera, by storing them in a per-frame constructed bounding volume hierarchy (BVH). For objects further from the camera, rasterization is used to create G-buffers which store an image-based representation of the sce
