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17
Deterministic Analysis of Oversampled A/D Conversion and Sigma/Delta Modulation, and Decoding Improvements using Consistent Estimates
, 1993
"... Analogtodigital conversion (ADC) which consists in a double discretization of an analog signal in time and in amplitude is increasingly used in modern data acquisition. However, the conversion process always implies some loss of information due to amplitude quantization. Oversampling is the techni ..."
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Cited by 7 (0 self)
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Analogtodigital conversion (ADC) which consists in a double discretization of an analog signal in time and in amplitude is increasingly used in modern data acquisition. However, the conversion process always implies some loss of information due to amplitude quantization. Oversampling is the technique currently used to reduce this loss of accuracy. The error reduction can be performed by lowpass filtering the quantized signal, thus eliminating the high frequency components of the quantization error signal. This is the classical method used to reconstruct the analog signal from its oversampled and quantized version. This reconstruction scheme yields a mean squared error (MSE) inversely proportional to the oversampling ratio R. The fundamental question pursued in this thesis is the following: how much information is available in the oversampled and quantized version of a bandlimited signal for its reconstruction? In order to identify this information, it is essential to go back to the original description of quantization which is typically deterministic. We show that a reconstruction scheme fully takes this information into account
LowPower decimation filter design for multistandard transceiver applications
, 1997
"... Recent efforts in the design of wireless RF transceivers focus on high integration and multistandard operation. Higher integration can be obtained by using receiver architectures, such as wideband IF with double conversion (WIF), that perform channel select filtering onchip at baseband. Performin ..."
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Recent efforts in the design of wireless RF transceivers focus on high integration and multistandard operation. Higher integration can be obtained by using receiver architectures, such as wideband IF with double conversion (WIF), that perform channel select filtering onchip at baseband. Performing this baseband channel select filtering in the digital domain allows for the programmability necessary to adapt to the different channel bandwidths, sampling rates, and CNR requirements of multiple communication standards. At the back of a widedynamic range sigmadelta modulator, a decimation filter can select a desired channel in the presence of both strong adjacent channel interferers and quantization noise from the digitization process. A lowpower decimation filter that performs channel select filtering for the GSM (European cellular) and DECT (European cordless) standards is presented. Automatic gain control is used within the filter to reduce the dynamic range and power consumption. Since the two standards have different blocking profiles and CNR i
MLattice: A System For Signal Synthesis And Processing Based On ReactionDiffusion
 PROCESSING BASED ON REACTIONDIFFUSION. SCD THESIS, MIT
, 1994
"... This research begins with reactiondiffusion, first proposed by Alan Turing in 1952 to account for morphogenesis  the formation of hydranth tentacles, leopard spots, zebra stripes, etc. Reactiondiffusion systems have been researched primarily by biologists working on theories of natural pattern f ..."
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Cited by 5 (3 self)
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This research begins with reactiondiffusion, first proposed by Alan Turing in 1952 to account for morphogenesis  the formation of hydranth tentacles, leopard spots, zebra stripes, etc. Reactiondiffusion systems have been researched primarily by biologists working on theories of natural pattern formation and by chemists modeling dynamics of oscillating reactions. The past few years have seen a new interest in reactiondiffusion spring up within the computer graphics and image processing communities. However, reactiondiffusion systems are generally unbounded, making them impractical for many applications. In this thesis we introduce a bounded and more flexible nonlinear system, the "Mlattice", which preserves the natural patternformation properties of reactiondiffusion. On the theoretical front, we establish relationships between reactiondiffusion systems and paradigms in linear systems theory and certain types of artificial "neurallyinspired" systems. The Mlattice is closel...
AD Conversion And Channelization For MultiMode Terminals
 MTTS Euro. Wireless
, 1998
"... This paper presents an architecture for multimode terminals, strictly speaking multimode receivers, exploiting IF sampling with SigmaDelta ADCs. It is shown that SigmaDelta ADCs are not only an efficient means of digitizing signals but are a nearly perfect fit to the task of analogtodigital co ..."
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This paper presents an architecture for multimode terminals, strictly speaking multimode receivers, exploiting IF sampling with SigmaDelta ADCs. It is shown that SigmaDelta ADCs are not only an efficient means of digitizing signals but are a nearly perfect fit to the task of analogtodigital conversion in multimode terminals. For further processing the digitized signal, i.e. channel filtering for FDMA systems as well as decorrelation for spreadspectrum systems, a common hardware is presented.
An Architecture for LowPower Real Time Image Analysis Using 3D Silicon Technology
 In Proc. SPIE AeroSense Symp
, 1998
"... The technology to build highly integrated 3dimensional computational image sensors by stacking and interconnecting layers of 2dimensional silicon ICs is being developed. Unlike multichip module (MCMV) packaging, in which interconnect lines are brought to the periphery of a chip stack to achieve ..."
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The technology to build highly integrated 3dimensional computational image sensors by stacking and interconnecting layers of 2dimensional silicon ICs is being developed. Unlike multichip module (MCMV) packaging, in which interconnect lines are brought to the periphery of a chip stack to achieve vertical integration, this new technology allows virtually unrestricted placement of vertical vias within the interior of the chip. The goal of this development is to enable high speed, high resolution image processing in compact low power wearable systems that would be coupled with a headmounted display (HMD). Potential applications for these systems include target tracking and image stabilization. In this talk we focus on the architecture of the 3D image sensor, which includes pixelparallel analogtodigital conversion and programmable digital processors for pixel and block operations. We show that 3D technology will allow at least an order of magnitude decrease in power dissipation over...
Convex coders and oversampled A/D conversion: theory and algorithms
, 1991
"... Signal reconstruction in oversampled A/D conversion (ADC) is classically performed by lowpass filtering the quantized signal. This leads to a mean squared error (MSE) inversely proportional to R 2n+1 where R is the oversampling rate and n is the order of the converter. However, while the estimate ..."
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Signal reconstruction in oversampled A/D conversion (ADC) is classically performed by lowpass filtering the quantized signal. This leads to a mean squared error (MSE) inversely proportional to R 2n+1 where R is the oversampling rate and n is the order of the converter. However, while the estimate given by this reconstruction has the same bandwidth as that of the original analog signal, we show that it does not necessarily lead to the same digital sequence when fed into the same A/D converter. Moreover, under some assumptions, we show analytically that an estimate having the same bandwidth and giving the same digital sequence as those of the original signal should yield an MSE with an upper bound inversely proportional to R 2n+2 , instead of R 2n+1 ; that is an improvement of 3 dB per octave of oversampling, regardless of the order of the converter. We propose a structural analysis covering most currently known configurations of oversampled ADC, which enables us to identify sets o...
Theory and Applications of Incremental 16 Converters
"... c○2004 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other w ..."
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c○2004 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.
Analysis and Design of MultipleBit HighOrder \Sigma\Delta Modulator
 566 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS—II: ANALOG AND DIGITAL SIGNAL PROCESSING, VOL. 50, NO. 9, SEPTEMBER 2003 [13
, 1997
"... The highorder \Sigma\Delta modulator is an appropriate approach for highbandwidth, highresolution A/D conversion. However, nonideal effects such as the finite opamp gain and the capacitor mismatch have great impacts on its performance at a low oversampling ratio. To achieve greater performance ..."
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The highorder \Sigma\Delta modulator is an appropriate approach for highbandwidth, highresolution A/D conversion. However, nonideal effects such as the finite opamp gain and the capacitor mismatch have great impacts on its performance at a low oversampling ratio. To achieve greater performance under the inevitable nonideal effects, we explore several multiplebit schemes, based on our CIQE highorder \Sigma\Delta architecture, to remove the nonideal deterioration. Design rules of these multiplebit schemes are developed and verified by extensive simulations. I. Introduction The A/D converter is an important element for digitalsignal processing systems. The cruxes of an A/D converter are high resolution for precise representation of the original signal and high bandwidth for fast processing. Conventional A/D architectures, e.g., flash, 2step flash, and successive approximation, are not suitable for highresolution applications because of the need of nearideal analog component...
CHARGEDOMAIN SAMPLING OF HIGHFREQUENCY SIGNALS WITH EMBEDDED FILTERING
"... Academic Dissertation to be presented with the assent of ..."
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Academic Dissertation to be presented with the assent of
TimeVariant CicFilters For Sample Rate Conversion With Arbitrary Rational Factors
, 1999
"... Sample rate conversion (SRC) with rational factors can be realized by interpolation followed by decimation, where CICFilters [1] can be chosen for either. However, the necessary increase of the sample rate that goes with the interpolation is not feasible in most RFapplications. Therefore a timeva ..."
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Sample rate conversion (SRC) with rational factors can be realized by interpolation followed by decimation, where CICFilters [1] can be chosen for either. However, the necessary increase of the sample rate that goes with the interpolation is not feasible in most RFapplications. Therefore a timevariant implementation of CICfilters is presented which circumvents the high intermediate sample rate. This timevariant implementation results in a linear periodically timevariant system (LPTV) which is completely equivalent to its original linear timeinvariant system (LTI) consisting of the interpolator and the decimator. Thus wellknown methods of system analysis can be used by analysing the LTI system, while implementing the system as an LPTV system, avoiding the high intermediate sample rates of the LTI system. The advantage of CICfilters not having stored the coefficients of the impulse response but rather the description of the impulse response, enabling an implementation which is independent of the interpolation as well as the decimationfactor, is preserved with the LPTV system. In contrast to Lagrange interpolators cancelling only the image components of the interpolated signal, timevariant CICfilters also cancel the aliasing components, which is important in applications, where antialiasing is more important than antiimaging.