19 research outputs found

    Jitter reduction techniques for digital audio.

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    by Tsang Yick Man, Steven.Thesis (M.Phil.)--Chinese University of Hong Kong, 1997.Includes bibliographical references (leaves 94-99).ABSTRACT --- p.iACKNOWLEDGMENT --- p.iiLIST OF GLOSSARY --- p.iiiChapter 1 --- INTRODUCTION --- p.1Chapter 1.1 --- What is the jitter ? --- p.3Chapter 2 --- WHY DOES JITTER OCCUR IN DIGITAL AUDIO ? --- p.4Chapter 2.1 --- Poorly-designed Phase Locked Loop ( PLL ) --- p.4Chapter 2.1.1 --- Digital data problem --- p.7Chapter 2.2 --- Sampling jitter or clock jitter ( Δti) --- p.9Chapter 2.3 --- Waveform distortion --- p.12Chapter 2.4 --- Logic induced jitter --- p.17Chapter 2.4.1 --- Digital noise mechanisms --- p.20Chapter 2.4.2 --- Different types of D-type flop-flip chips are linked below for ease of comparison --- p.21Chapter 2.4.3 --- Ground bounce --- p.22Chapter 2.5 --- Power supply high frequency noise --- p.23Chapter 2.6 --- Interface Jitter --- p.25Chapter 2.7 --- Cross-talk --- p.28Chapter 2.8 --- Inter-Symbol-Interference (ISI) --- p.28Chapter 2.9 --- Baseline wander --- p.29Chapter 2.10 --- Noise jitter --- p.30Chapter 2.11 --- FIFO jitter reduction chips --- p.31Chapter 3 --- JITTER REDUCTION TECHNIQUES --- p.33Chapter 3.1 --- Why using two-stage phase-locked loop (PLL ) ?Chapter 3.1.1 --- The PLL circuit components --- p.35Chapter 3.1.2 --- The PLL timing specifications --- p.36Chapter 3.2 --- Analog phase-locked loop (APLL ) circuit usedin second stage --- p.38Chapter 3.3 --- All digital phase-locked loop (ADPLL ) circuit used in second stage --- p.40Chapter 3.4 --- ADPLL design --- p.42Chapter 3.4.1 --- "Different of K counter value of ADPLL are listed for comparison with M=512, N=256, Kd=2" --- p.46Chapter 3.4.2 --- Computer simulated results and experimental results of the ADPLL --- p.47Chapter 3.4.3 --- PLL design notes --- p.58Chapter 3.5 --- Different of the all digital Phase-Locked Loop (ADPLL ) and the analogue Phase-Locked Loop (APLL ) are listed for comparison --- p.65Chapter 3.6 --- Discrete transistor oscillator --- p.68Chapter 3.7 --- Discrete transistor oscillator circuit operation --- p.69Chapter 3.8 --- The advantage and disadvantage of using external discrete oscillator --- p.71Chapter 3.9 --- Background of using high-precision oscillators --- p.72Chapter 3.9.1 --- The temperature compensated crystal circuit operation --- p.73Chapter 3.9.2 --- The temperature compensated circuit design notes --- p.75Chapter 3.10 --- The discrete voltage reference circuit operation --- p.76Chapter 3.10.1 --- Comparing the different types of Op-amps that can be used as a voltage comparator --- p.79Chapter 3.10.2 --- Precaution of separate CMOS chips Vdd and Vcc --- p.80Chapter 3.11 --- Board level jitter reduction method --- p.81Chapter 3.12 --- Digital audio interface chips --- p.82Chapter 3.12.1 --- Different brand of the digital interface receiver (DIR) chips and clock modular are listed for comparison --- p.84Chapter 4. --- APPLICATION CIRCUIT BLOCK DIAGRAMS OF JITTER REDUCTION AND CLOCK RECOVERY --- p.85Chapter 5 --- CONCLUSIONS --- p.90Chapter 5.1 --- Summary of the research --- p.90Chapter 5.2 --- Suggestions for further development --- p.92Chapter 5.3 --- Instrument listing that used in this thesis --- p.93Chapter 6 --- REFERENCES --- p.94Chapter 7 --- APPENDICES --- p.100Chapter 7.1.1 --- Phase instability in frequency dividersChapter 7.1.2 --- The effect of clock tree on Tskew on ASIC chipChapter 7.1.3 --- Digital audio transmission----Why jitter is important?Chapter 7.1.4 --- Overview of digital audio interface data structuresChapter 7.1.5 --- Typical frequency Vs temperature variations curve of Quartz crystalsChapter 7.2 --- IC specification used in these research projec

    LISA Metrology System - Final Report

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    Gravitational Waves will open an entirely new window to the Universe, different from all other astronomy in that the gravitational waves will tell us about large-scale mass motions even in regions and at distances totally obscured to electromagnetic radiation. The most interesting sources are at low frequencies (mHz to Hz) inaccessible on ground due to seismic and other unavoidable disturbances. For these sources observation from space is the only option, and has been studied in detail for more than 20 years as the LISA concept. Consequently, The Gravitational Universe has been chosen as science theme for the L3 mission in ESA's Cosmic Vision program. The primary measurement in LISA and derived concepts is the observation of tiny (picometer) pathlength fluctuations between remote spacecraft using heterodyne laser interferometry. The interference of two laser beams, with MHz frequency difference, produces a MHz beat note that is converted to a photocurrent by a photodiode on the optical bench. The gravitational wave signal is encoded in the phase of this beat note. The next, and crucial, step is therefore to measure that phase with µcycle resolution in the presence of noise and other signals. This measurement is the purpose of the LISA metrology system and the subject of this report

    Phase readout for satellite interferometry

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    Recent Trends in Communication Networks

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    In recent years there has been many developments in communication technology. This has greatly enhanced the computing power of small handheld resource-constrained mobile devices. Different generations of communication technology have evolved. This had led to new research for communication of large volumes of data in different transmission media and the design of different communication protocols. Another direction of research concerns the secure and error-free communication between the sender and receiver despite the risk of the presence of an eavesdropper. For the communication requirement of a huge amount of multimedia streaming data, a lot of research has been carried out in the design of proper overlay networks. The book addresses new research techniques that have evolved to handle these challenges

    Radiation Tolerant Electronics, Volume II

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    Research on radiation tolerant electronics has increased rapidly over the last few years, resulting in many interesting approaches to model radiation effects and design radiation hardened integrated circuits and embedded systems. This research is strongly driven by the growing need for radiation hardened electronics for space applications, high-energy physics experiments such as those on the large hadron collider at CERN, and many terrestrial nuclear applications, including nuclear energy and safety management. With the progressive scaling of integrated circuit technologies and the growing complexity of electronic systems, their ionizing radiation susceptibility has raised many exciting challenges, which are expected to drive research in the coming decade.After the success of the first Special Issue on Radiation Tolerant Electronics, the current Special Issue features thirteen articles highlighting recent breakthroughs in radiation tolerant integrated circuit design, fault tolerance in FPGAs, radiation effects in semiconductor materials and advanced IC technologies and modelling of radiation effects

    DESIGN AND CHARACTERIZATION OF LOW-POWER LOW-NOISE ALLDIGITAL SERIAL LINK FOR POINT-TO-POINT COMMUNICATION IN SOC

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    The fully-digital implementation of serial links has recently emerged as a viable alternative to their classical analogue counterpart. Indeed, reducing the analogue content in favour of expanding the digital content becomes more attractive due to the ability to achieve less power consumption, less sensitivity to the noise and better scalability across multiple technologies and platforms with inconsiderable modifications. In addition, describing the circuit in hardware description languages gives it a high flexibility to program all design parameters in a very short time compared with the analogue designs which need to be re-designed at transistor level for any parameter change. This can radically reduce cost and time-to-market by saving a significant amount of development time. However, beside these considerable advantages, the fully-digital architecture poses several design challenges

    Optimised soft-core processor architecture for noise jamming

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    M.Ing. (Electrical & Electronic Engineering)Abstract: Noise jamming is a traditional electronic counter measure (ECM) that existed since the establishment of electronic warfare (EW). Traditional noise jamming techniques have been shown to be failing when interacting with intelligent Radar systems such as pulse Doppler radar. Hence there is a need to introduce new noise jamming techniques with digital architecture that will provide improved performance against smart pulse Doppler radar. The work is undertaken to investigate the feasibility of digitizing noise jamming. It focuses on analog-to-digital conversion optimization towards noise jamming architecture, as a result digitization will allow for an opportunity for adaptation of intelligent processing that previously didn’t exist. In this dissertation, certain contributions to the field of noise jamming were made by introducing state of the art odd/even order sampling architecture by proving four case studies. Case study 1 experimentally investigates sample frequency behaviour. Case study 2 uses simulation to investigate step-size and dynamic range behaviour. Case study 3 uses FPGA implementation and SNR to investigate quantization error behaviour. Case study 3 also uses SNR to investigate superiority of proposed odd/even order sampling. Lastly case study 4 uses field measurements, FPGA implementation and SNR to investigate practical implementation of digitized noise jamming. The main contribution is concerned with an architecture that digitizes, reduces sample frequency, optimizes digital resource utilization while reducing noise jamming signal-to-noise ratio. The approach evaluates and empirically compares three sampling techniques from lecture Mod-Δ, Mod-Δ (Gaussian) and Mod-Δ (Sinusoidal) with proposed novel odd/even order sampling. Sampling techniques are evaluated in terms of quantization error, mean square error and signal-to-noise ratio. It was found that the proposed novel odd/even order sampling achieved most case SNR performance of 6 dB in comparison to 18 dB for Mod-Δ. Sampling frequency findings indicated that the proposed novel odd/even order sampling had achieved sampling frequency of 2 kHz in comparison to 8 kHz from traditional 1st order sigma-delta. Dynamic range findings indicated that the proposed odd/even order sampling achieved a dynamic range of 1.088 volts/ms in comparison to 1.185 volts/ms from traditional 1st order sigma-delta. Findings have indicated that the proposed odd/even order sampling has superior SNR and sampling frequency..
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