Receiver Sensitivity and Equivalent Noise Bandwidth Receiver Sensitivity and Equivalent Noise Bandwidth
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Autoencoding Neural Networks As Musical Audio Synthesizers
Proceedings of the 21st International Conference on Digital Audio Effects (DAFx-18), Aveiro, Portugal, September 4–8, 2018 AUTOENCODING NEURAL NETWORKS AS MUSICAL AUDIO SYNTHESIZERS Joseph Colonel Christopher Curro Sam Keene The Cooper Union for the Advancement of The Cooper Union for the Advancement of The Cooper Union for the Advancement of Science and Art Science and Art Science and Art NYC, New York, USA NYC, New York, USA NYC, New York, USA [email protected] [email protected] [email protected] ABSTRACT This training corpus consists of five-octave C Major scales on var- ious synthesizer patches. Once training is complete, we bypass A method for musical audio synthesis using autoencoding neural the encoder and directly activate the smallest hidden layer of the networks is proposed. The autoencoder is trained to compress and autoencoder. This activation produces a magnitude STFT frame reconstruct magnitude short-time Fourier transform frames. The at the output. Once several frames are produced, phase gradient autoencoder produces a spectrogram by activating its smallest hid- integration is used to construct a phase response for the magnitude den layer, and a phase response is calculated using real-time phase STFT. Finally, an inverse STFT is performed to synthesize audio. gradient heap integration. Taking an inverse short-time Fourier This model is easy to train when compared to other state-of-the-art transform produces the audio signal. Our algorithm is light-weight methods, allowing for musicians to have full control over the tool. when compared to current state-of-the-art audio-producing ma- This paper presents improvements over the methods outlined chine learning algorithms. -
Application Note Template
correction. of TOI measurements with noise performance the improved show examples Measurement presented. is correction a noise of means by improvements range Dynamic explained. are analyzer spectrum of a factors the limiting correction. The basic requirements and noise with measurements spectral about This application note provides information | | | Products: Note Application Correction Noise with Range Dynamic Improved R&S R&S R&S FSQ FSU FSG Application Note Kay-Uwe Sander Nov. 2010-1EF76_0E Table of Contents Table of Contents 1 Overview ................................................................................. 3 2 Dynamic Range Limitations .................................................. 3 3 Signal Processing - Noise Correction .................................. 4 3.1 Evaluation of the noise level.......................................................................4 3.2 Details of the noise correction....................................................................5 4 Measurement Examples ........................................................ 7 4.1 Extended dynamic range with noise correction .......................................7 4.2 Low level measurements on noise-like signals ........................................8 4.3 Measurements at the theoretical limits....................................................10 5 Literature............................................................................... 11 6 Ordering Information ........................................................... 11 1EF76_0E Rohde & Schwarz -
All You Need to Know About SINAD Measurements Using the 2023
applicationapplication notenote All you need to know about SINAD and its measurement using 2023 signal generators The 2023A, 2023B and 2025 can be supplied with an optional SINAD measuring capability. This article explains what SINAD measurements are, when they are used and how the SINAD option on 2023A, 2023B and 2025 performs this important task. www.ifrsys.com SINAD and its measurements using the 2023 What is SINAD? C-MESSAGE filter used in North America SINAD is a parameter which provides a quantitative Psophometric filter specified in ITU-T Recommendation measurement of the quality of an audio signal from a O.41, more commonly known from its original description as a communication device. For the purpose of this article the CCITT filter (also often referred to as a P53 filter) device is a radio receiver. The definition of SINAD is very simple A third type of filter is also sometimes used which is - its the ratio of the total signal power level (wanted Signal + unweighted (i.e. flat) over a broader bandwidth. Noise + Distortion or SND) to unwanted signal power (Noise + The telephony filter responses are tabulated in Figure 2. The Distortion or ND). It follows that the higher the figure the better differences in frequency response result in different SINAD the quality of the audio signal. The ratio is expressed as a values for the same signal. The C-MES signal uses a reference logarithmic value (in dB) from the formulae 10Log (SND/ND). frequency of 1 kHz while the CCITT filter uses a reference of Remember that this a power ratio, not a voltage ratio, so a 800 Hz, which results in the filter having "gain" at 1 kHz. -
Noise Tutorial Part IV ~ Noise Factor
Noise Tutorial Part IV ~ Noise Factor Whitham D. Reeve Anchorage, Alaska USA See last page for document information Noise Tutorial IV ~ Noise Factor Abstract: With the exception of some solar radio bursts, the extraterrestrial emissions received on Earth’s surface are very weak. Noise places a limit on the minimum detection capabilities of a radio telescope and may mask or corrupt these weak emissions. An understanding of noise and its measurement will help observers minimize its effects. This paper is a tutorial and includes six parts. Table of Contents Page Part I ~ Noise Concepts 1-1 Introduction 1-2 Basic noise sources 1-3 Noise amplitude 1-4 References Part II ~ Additional Noise Concepts 2-1 Noise spectrum 2-2 Noise bandwidth 2-3 Noise temperature 2-4 Noise power 2-5 Combinations of noisy resistors 2-6 References Part III ~ Attenuator and Amplifier Noise 3-1 Attenuation effects on noise temperature 3-2 Amplifier noise 3-3 Cascaded amplifiers 3-4 References Part IV ~ Noise Factor 4-1 Noise factor and noise figure 4-1 4-2 Noise factor of cascaded devices 4-7 4-3 References 4-11 Part V ~ Noise Measurements Concepts 5-1 General considerations for noise factor measurements 5-2 Noise factor measurements with the Y-factor method 5-3 References Part VI ~ Noise Measurements with a Spectrum Analyzer 6-1 Noise factor measurements with a spectrum analyzer 6-2 References See last page for document information Noise Tutorial IV ~ Noise Factor Part IV ~ Noise Factor 4-1. Noise factor and noise figure Noise factor and noise figure indicates the noisiness of a radio frequency device by comparing it to a reference noise source. -
Measurement of In-Band Optical Noise Spectral Density 1
Measurement of In-Band Optical Noise Spectral Density 1 Measurement of In-Band Optical Noise Spectral Density Sylvain Almonacil, Matteo Lonardi, Philippe Jennevé and Nicolas Dubreuil We present a method to measure the spectral density of in-band optical transmission impairments without coherent electrical reception and digital signal processing at the receiver. We determine the method’s accuracy by numerical simulations and show experimentally its feasibility, including the measure of in-band nonlinear distortions power densities. I. INTRODUCTION UBIQUITUS and accurate measurement of the noise power, and its spectral characteristics, as well as the determination and quantification of the different noise sources are required to design future dynamic, low-margin, and intelligent optical networks, especially in open cable design, where the optical line must be intrinsically characterized. In optical communications, performance is degraded by a plurality of impairments, such as the amplified spontaneous emission (ASE) due to Erbium doped-fiber amplifiers (EDFAs), the transmitter-receiver (TX-RX) imperfection noise, and the power-dependent Kerr-induced nonlinear impairments (NLI) [1]. Optical spectrum-based measurement techniques are routinely used to measure the out-of-band optical signal-to-noise ratio (OSNR) [2]. However, they fail in providing a correct assessment of the signal-to-noise ratio (SNR) and in-band noise statistical properties. Whereas the ASE noise is uniformly distributed in the whole EDFA spectral band, TX-RX noise and NLI mainly occur within the signal band [3]. Once the latter impairments dominate, optical spectrum-based OSNR monitoring fails to predict the system performance [4]. Lately, the scientific community has significantly worked on assessing the noise spectral characteristics and their impact on the SNR, trying to exploit the information in the digital domain by digital signal processing (DSP) or machine learning. -
Next Topic: NOISE
ECE145A/ECE218A Performance Limitations of Amplifiers 1. Distortion in Nonlinear Systems The upper limit of useful operation is limited by distortion. All analog systems and components of systems (amplifiers and mixers for example) become nonlinear when driven at large signal levels. The nonlinearity distorts the desired signal. This distortion exhibits itself in several ways: 1. Gain compression or expansion (sometimes called AM – AM distortion) 2. Phase distortion (sometimes called AM – PM distortion) 3. Unwanted frequencies (spurious outputs or spurs) in the output spectrum. For a single input, this appears at harmonic frequencies, creating harmonic distortion or HD. With multiple input signals, in-band distortion is created, called intermodulation distortion or IMD. When these spurs interfere with the desired signal, the S/N ratio or SINAD (Signal to noise plus distortion ratio) is degraded. Gain Compression. The nonlinear transfer characteristic of the component shows up in the grossest sense when the gain is no longer constant with input power. That is, if Pout is no longer linearly related to Pin, then the device is clearly nonlinear and distortion can be expected. Pout Pin P1dB, the input power required to compress the gain by 1 dB, is often used as a simple to measure index of gain compression. An amplifier with 1 dB of gain compression will generate severe distortion. Distortion generation in amplifiers can be understood by modeling the amplifier’s transfer characteristic with a simple power series function: 3 VaVaVout=−13 in in Of course, in a real amplifier, there may be terms of all orders present, but this simple cubic nonlinearity is easy to visualize. -
Smart Innovation, Systems and Technologies
Smart Innovation, Systems and Technologies Volume 235 Series Editors Robert J. Howlett, Bournemouth University and KES International, Shoreham-by-Sea, UK Lakhmi C. Jain, KES International, Shoreham-by-Sea, UK The Smart Innovation, Systems and Technologies book series encompasses the topics of knowledge, intelligence, innovation and sustainability. The aim of the series is to make available a platform for the publication of books on all aspects of single and multi-disciplinary research on these themes in order to make the latest results available in a readily-accessible form. Volumes on interdisciplinary research combining two or more of these areas is particularly sought. The series covers systems and paradigms that employ knowledge and intelligence in a broad sense. Its scope is systems having embedded knowledge and intelligence, which may be applied to the solution of world problems in industry, the environment and the community. It also focusses on the knowledge-transfer methodologies and innovation strategies employed to make this happen effectively. The combination of intelligent systems tools and a broad range of applications introduces a need for a synergy of disciplines from science, technology, business and the humanities. The series will include conference proceedings, edited collections, monographs, hand- books, reference books, and other relevant types of book in areas of science and technology where smart systems and technologies can offer innovative solutions. High quality content is an essential feature for all book proposals accepted for the series. It is expected that editors of all accepted volumes will ensure that contributions are subjected to an appropriate level of reviewing process and adhere to KES quality principles. -
AN10062 Phase Noise Measurement Guide for Oscillators
Phase Noise Measurement Guide for Oscillators Contents 1 Introduction ............................................................................................................................................. 1 2 What is phase noise ................................................................................................................................. 2 3 Methods of phase noise measurement ................................................................................................... 3 4 Connecting the signal to a phase noise analyzer ..................................................................................... 4 4.1 Signal level and thermal noise ......................................................................................................... 4 4.2 Active amplifiers and probes ........................................................................................................... 4 4.3 Oscillator output signal types .......................................................................................................... 5 4.3.1 Single ended LVCMOS ........................................................................................................... 5 4.3.2 Single ended Clipped Sine ..................................................................................................... 5 4.3.3 Differential outputs ............................................................................................................... 6 5 Setting up a phase noise analyzer ........................................................................................................... -
Preview Only
AES-6id-2006 (r2011) AES information document for digital audio - Personal computer audio quality measurements Published by Audio Engineering Society, Inc. Copyright © 2006 by the Audio Engineering Society Preview only Abstract This document focuses on the measurement of audio quality specifications in a PC environment. Each specification listed has a definition and an example measurement technique. Also included is a detailed description of example test setups to measure each specification. An AES standard implies a consensus of those directly and materially affected by its scope and provisions and is intended as a guide to aid the manufacturer, the consumer, and the general public. An AES information document is a form of standard containing a summary of scientific and technical information; originated by a technically competent writing group; important to the preparation and justification of an AES standard or to the understanding and application of such information to a specific technical subject. An AES information document implies the same consensus as an AES standard. However, dissenting comments may be published with the document. The existence of an AES standard or AES information document does not in any respect preclude anyone, whether or not he or she has approved the document, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the standard. Attention is drawn to the possibility that some of the elements of this AES standard or information document may be the subject of patent rights. AES shall not be held responsible for identifying any or all such patents. This document is subject to periodicwww.aes.org/standards review and users are cautioned to obtain the latest edition and printing. -
Johnson Noise Thermometry Measurement of the Boltzmann Constant with a 200 Ω Sense Resistor Alessio Pollarolo, Taehee Jeong, Samuel P
1512 IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, VOL. 62, NO. 6, JUNE 2013 Johnson Noise Thermometry Measurement of the Boltzmann Constant With a 200 Ω Sense Resistor Alessio Pollarolo, Taehee Jeong, Samuel P. Benz, Senior Member, IEEE, and Horst Rogalla, Member, IEEE Abstract—In 2010, the National Institute of Standards and Technology measured the Boltzmann constant k with an electronic technique that measured the Johnson noise of a 100 Ω resistor at the triple point of water and used a voltage waveform synthesized with a quantized voltage noise source (QVNS) as a reference. In this paper, we present measurements of k using a 200 Ω sense re- sistor and an appropriately modified QVNS circuit and waveform. Preliminary results show agreement with the previous value within the statistical uncertainty. An analysis is presented, where the largest source of uncertainty is identified, which is the frequency dependence in the constant term a0 of the two-parameter fit. Index Terms—Boltzmann equation, Josephson junction, mea- surement units, noise measurement, standards, temperature. Fig. 1. Schematic diagram of the Johnson-noise two-channel cross-correlator. I. INTRODUCTION HE Johnson–Nyquist equation (1) defines the thermal measurement electronics are calibrated by using a pseudonoise T noise power (Johnson noise) V 2 of a resistor in a voltage waveform synthesized with the quantized voltage noise bandwidth Δf through its resistance R and its thermodynamic source (QVNS) that acts as a spectral-density reference [8], [9]. temperature T [1], [2]: Fig. 1 shows the experimental schematic. The two chan- nels of the cross-correlator simultaneously amplify, filter, and 2 VR =4kTRΔf. -
Noise Reduction by Cross-Correlation
Application Note Noise reduction by parallel Zurich cross-correlation measurements Instruments Applications: Nanoelectronics, Materials Characterization, Low-Temperature Physics, Transport Measurements, DC SQUID Products: MFLI, MFLI-DIG, MDS Release date: May 2019 Introduction 4 10 Studying noise processes can reveal fundamental infor- mation about a physical system; for example, its tem- perature [1, 2, 3],the quantization of charge carriers [4], 3 10 or the nature of many-body behavior [5]. Noise mea- surements are also critical for applications such as sensing, where the intrinsic noise of a detector defines its ultimate sensitivity. In this note, we will describe 100 a generic method for measuring the electronic noise of a device when the spectral density of its intrinsic noise is less than that of the measurement apparatus. 10 We implement the method using a pair of MFLI Lock-in Amplifiers, both with the Digitizer option MF-DIG. To demonstrate the measurement, we measure the 1 noise of a Superconducting Quantum Interference De- 100 101 102 103 104 105 106 vice (SQUID) magnetometer. Typically, SQUIDs are op- erated by supplying a DC bias current and measuring Figure 1. The voltage noise density at the Voltage Input of an MFLI a voltage and, as such, the limiting factor in the mea- Lock-in Amplifier plotted for available Input ranges [6]. surement is usually the noise floor of the voltage pre- amplifier. For a SQUID with gain (transfer function)p VΦ = 1 mV/Φ0 and targetp sensitivity of S = 1 μΦ0/ Hz, larly at low frequencies. One way of resolving signals a noise floor of 1 nV/ Hz is required. -
Quantum Noise and Quantum Measurement
Quantum noise and quantum measurement Aashish A. Clerk Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8 1 Contents 1 Introduction 1 2 Quantum noise spectral densities: some essential features 2 2.1 Classical noise basics 2 2.2 Quantum noise spectral densities 3 2.3 Brief example: current noise of a quantum point contact 9 2.4 Heisenberg inequality on detector quantum noise 10 3 Quantum limit on QND qubit detection 16 3.1 Measurement rate and dephasing rate 16 3.2 Efficiency ratio 18 3.3 Example: QPC detector 20 3.4 Significance of the quantum limit on QND qubit detection 23 3.5 QND quantum limit beyond linear response 23 4 Quantum limit on linear amplification: the op-amp mode 24 4.1 Weak continuous position detection 24 4.2 A possible correlation-based loophole? 26 4.3 Power gain 27 4.4 Simplifications for a detector with ideal quantum noise and large power gain 30 4.5 Derivation of the quantum limit 30 4.6 Noise temperature 33 4.7 Quantum limit on an \op-amp" style voltage amplifier 33 5 Quantum limit on a linear-amplifier: scattering mode 38 5.1 Caves-Haus formulation of the scattering-mode quantum limit 38 5.2 Bosonic Scattering Description of a Two-Port Amplifier 41 References 50 1 Introduction The fact that quantum mechanics can place restrictions on our ability to make measurements is something we all encounter in our first quantum mechanics class. One is typically presented with the example of the Heisenberg microscope (Heisenberg, 1930), where the position of a particle is measured by scattering light off it.