Global ETD Search
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Showing 1 to 17 of 17 for “"DELTA MODULATION"”.
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Delta modulation techniques for low bit-rate digital speech encoding
Two new hybrid companding delta modulators for speech encoding are presented here. These modulators differ from the Hybrid Companding Delta Modulator (HCDM) proposed by Un et al in that the two new encoders employ Song Voice Adaptation as the basis of the instantaneous compandor, rather than …
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An optical-electrical sub-sampling down-conversion receiver with continuous-time [Sigma] [Delta] modulation
… down-conversion receiver that employs [Sigma] [Delta] modulation. Accurate sub-sampling of an electrical RF signal in the optical domain is achieved by using a low-jitter mode-locked-laser and a high-bandwidth interferometer. The sub-sampled information is then digitized by an optical-electrical …
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A fourth order [Sigma] [Delta] bandpass modulator
A fourth order bandpass [Sigma] [Delta] modulator is proposed to digitize signals from a MEMS gyroscope. The modulator samples the amplitude-modulated signal at eight times the carrier frequency and achieves an SNR of 82dB with a sampling frequency of 640kHz and a bandwidtn o 1.oKnz. ms document …
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Microprocessor simulation of speech-encoding
… real time speech processing. Linear and adaptive delta modulation systems for speech encoding and decoding are presented. The systems are based on the Signetics 8X300 microprocessor evaluation board. As this device operates under software control, this feature allows for making as much …
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Low-power amplifier chopper stabilization for a digital-to-analog converter
… CMOS design has allowed for oversampling sigma-delta modulation to achieve these goals. However, noise is typically limited by the kT/C noise in the switched capacitor filter following the digital modulation. These filters also require a large amount of on-chip capacitance. The goal of this …
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ΣΧΕΔΙΑΣΗ ΟΙΚΟΝΟΜΙΚΩΝ F.I.R. ΦΙΛΤΡΩΝ ΓΙΑ ΣΗΜΑΤΑ ΔΙΑΜΟΡΦΩΣΗΣ Δ
… IS THE DESIGN OF ECONOMICAL FIR FILTERS FOR DELTA MODULATION SIGNALS (D.M. FILTERS). THE MOTIVATION FOR THIS RESEARCH WAS THE OUT-COME OF THE FOLLOWING TWO CONSIDERATIONS A: THE IMPLEMENTATION OF FIR FILTER IN GENERAL REQUIRES ALOT OF HARDWARE, B. THE SIMPLICITY OF THE CIRCUITS PERFORMING THE …
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COMMON MODE VOLTAGE ELIMINATION IN THREE-PHASE FOUR-LEG INVERTERS UTILIZING PULSE DENSITY MODULATION
… by eliminating CM EMI using pulse density modulation (PDM) in conjunction with model predictive control (MPC) and delta modulation. A physics-based model of the equipment under test (EUT), utilizing state-space modeling, was analyzed using computer simulations and a laboratory prototype, …
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Digital pulse processing
… shown to be equivalent to the first-order sigma-delta modulation used in oversampled noise-shaping converters. The encoder circuits are well known and have simple construction using both current and next-generation technologies. Processing in the pulse-domain provides many benefits including: …
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A comparative analysis of dynamic vision sensors using 180 nm CMOS technology
… time-based image sensor)and ADMDVS (asynchronous delta modulation dynamic vision sensor). Among these architectures, only ATIS implements a light intensity encoding system, using time-based pulse-width modulation. In the design process, gm/ID methodology is used as a suitable tool for pixel …
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Advanced active rectifiers for electric vehicle battery charging
… in addition to digital current control using delta modulation. The final section builds upon a more advanced interleaved full-bridge topology by introducing more accurate inductor voltage and current equations while also applying gain scheduling based on system power to improve current …
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Low bit-rate speech encoding for digital mobile radio
… The two coders combine predictive coding with delta modulation, a property which enables them to achieve simultaneously the low bit-rate and good speech quality requirements. To enhance their efficiency, the predictor coefficients and the quantizer step size are updated periodically in each …
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MSE-based Linear Transceiver Designs for Multiuser MIMO Wireless Communications
… feedback rate is limited by employing adaptive delta modulation. Next, we consider the robust design of the sum-MSE and PMSE minimizing precoders with delay-free but imperfect estimates of the CSI. We extend the MSE duality to the case of imperfect CSI, and consider a new optimization problem …
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The Direct Torque Control of Induction Motors
… operation. A number of different pulse width modulation (p.w.m.) waveform generation strategies are simulated and discussed and their application to the above speed control systems fully investigated. A 3kW, three phase induction motor drive has been designed and experimental data obtained …
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Integration of energy storage components with cascaded H-bridge multilevel converters
… the regulation range when the staircase modulation method is employed. In order to extend the regulation range for the replacing capacitors, a new control scheme - phase shift modulation - is proposed. This method is more robust when compared to existing methods. In this method, the main …
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Design and Realization of a Single Stage Sigma-Delta ADC With Low Oversampling Ratio
… toward a high speed and high resolution sigma-delta A/D converter. This dissertation focuses on the design of a single-stage sigma-delta A/D converter with very low oversampling ratio for the wireless application. An architecture for a multibit single-stage delta-sigma A/D converter with …
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Acquisition systems and decoding algorithms of peripheral neural signals for prosthetic applications
… will be presented, based on the use of a sigma-delta architecture which is composed by two main parts: an analog front-end stage for neural signal acquisition, pre-filtering and sigma-delta modulation and a digital unit for sigma-delta decimation and system configuration. Hardware/software …
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ΜΕΘΟΔΟΙ ΜΕΤΑΤΡΟΠΩΝ ΚΩΔΙΚΑ ΔΙΑΜΟΡΦΩΣΗΣ ΔΕΛΤΑ ΓΙΑ ΤΗ ΒΕΛΤΙΩΣΗ ΚΑΙ ΑΠΛΟΥΣΤΕΥΣΗ ΤΗΣΕΠΕΞΕΡΓΑΣΙΑΣ ΣΗΜΑΤΩΝ
CONVERSION RATE AND CONVERSION CODE METHODS FOR DELTA MODULATED (DM) SEQUENCESARE PROPOSED IN THIS THESIS. WITH THE RATE CONVERSION METHOD A LINEAR DM (LDM) SEQUENCE CAN BE PROCESSED BY A DM SEQUENCES FILTER CLOCKED AT A HIGHER RATE THAN THAT OF THE INPUT SEQUENCE. THE FILTER OUTPUT IS A LDM …