134 research outputs found
Noise Weighting in the Design of {\Delta}{\Sigma} Modulators (with a Psychoacoustic Coder as an Example)
A design flow for {\Delta}{\Sigma} modulators is illustrated, allowing
quantization noise to be shaped according to an arbitrary weighting profile.
Being based on FIR NTFs, possibly with high order, the flow is best suited for
digital architectures. The work builds on a recent proposal where the modulator
is matched to the reconstruction filter, showing that this type of optimization
can benefit a wide range of applications where noise (including in-band noise)
is known to have a different impact at different frequencies. The design of a
multiband modulator, a modulator avoiding DC noise, and an audio modulator
capable of distributing quantization artifacts according to a psychoacoustic
model are discussed as examples. A software toolbox is provided as a general
design aid and to replicate the proposed results.Comment: 5 pages, 18 figures, journal. Code accompanying the paper is
available at http://pydsm.googlecode.co
Output Filter Aware Optimization of the Noise Shaping Properties of {\Delta}{\Sigma} Modulators via Semi-Definite Programming
The Noise Transfer Function (NTF) of {\Delta}{\Sigma} modulators is typically
designed after the features of the input signal. We suggest that in many
applications, and notably those involving D/D and D/A conversion or actuation,
the NTF should instead be shaped after the properties of the
output/reconstruction filter. To this aim, we propose a framework for optimal
design based on the Kalman-Yakubovich-Popov (KYP) lemma and semi-definite
programming. Some examples illustrate how in practical cases the proposed
strategy can outperform more standard approaches.Comment: 14 pages, 18 figures, journal. Code accompanying the paper is
available at http://pydsm.googlecode.co
Aeronautical engineering: A continuing bibliography with indexes (supplement 255)
This bibliography lists 529 reports, articles, and other documents introduced into the NASA scientific and technical information system in June 1990. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics
Aeronautical engineering: A continuing bibliography with indexes (supplement 284)
This bibliography lists 974 reports, articles, and other documents introduced into the NASA scientific and technical information system in Oct. 1992. The coverage includes documents on design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles
Aeronautical engineering: A continuing bibliography with indexes (supplement 277)
This bibliography lists 467 reports, articles, and other documents introduced into the NASA scientific and technical information system in Mar. 1992. Subject coverage includes: the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines); and associated aircraft components, equipment, and systems. It also includes research and development in ground support systems, theoretical and applied aspects of aerodynamics, and general fluid dynamics
Aeronautical engineering: A continuing bibliography with indexes (supplement 295)
This bibliography lists 581 reports, articles, and other documents introduced into the NASA Scientific and Technical Information System in Sep. 1993. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment, and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics
Aeronautical engineering: A cumulative index to a continuing bibliography
This bibliography is a cumulative index to the abstracts contained in NASA SP-7037(210) through NASA SP-7037(221) of Aeronautical Engineering: A Continuing Bibliography. NASA SP-7037 and its supplements have been compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, foreign technology, contract number, report number, and accession number indexes
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