Questions tagged [signal-synthesis]
The signal-synthesis tag has no usage guidance.
136 questions
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Arbitrary Waveform Synthesis
I am working on research project to generate a waveform of arbitrary shape given few parameters like Amplitude, Frequency, (if its a pulse then) pulse duration etc. Are there any signal processing ...
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how is a complex number converted to a form that can be played with pyaudio or sound device?
I have created some audio that I would like to play through a speaker using Ifft in python. It gives an array of complex numbers and as such no good to use with pyaudio or sound device.
I tried to get ...
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Don't we need both negative and positive discrete complex exponentials to make a real discrete time signal?
For a continuous time periodic signal , the Fourier spectrum has both negative and positive complex exponentials in equal numbers ,but I have seen for some discrete time periodic signals it is not the ...
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Maximum of the sum of different sinusoids
How to find the maximum sum of several (more than two) harmonic sinusoidal oscillations of the form $$y_n(t) = A_n\sin(2\pi f_nt+\phi_n)$$ with different amplitudes $A_n$, frequencies $f_n$ and phase ...
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Frequency doubling of a signal with noise and without
I've been given a task to simulate a real-world scenario, in which a system receives a signal with a carrier frequency of 3.75 MHz. To filter the signal, either a very sharp and resource-intensive ...
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Pulse signal to sine signal with the same frequency
I have a pulse signal with frequency f(t) And i want to generate from it a sine signal with frequency f(t) (f(t) doesn't vary a lot in time)
Is there a method to do it directly with a function ...
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Impulse response synthesis in the frequency domain
Background - Create context
I am trying to synthesise some impulse responses to simulate an active noise control system. I have already formulated the problem in the frequency domain so now I want to ...
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Generating new random phases for DFT of 2d uniform distributed noise image changes image distribution
My goal is to produce a new random noise image from two already existing noise images. For that I take the absolute values of one image and the angles (phases) from another image in Fourier Space and ...
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Relation between harmonics and quantization [closed]
I'd like to make digital samples that construct sine waves.
It's nothing but direct digital synthesis (DDS) before the digital-to-analog converter and filter.
I want to make a sinewave sample that ...
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Output spectrum of the direct digital synthesis (DDS)
I have a question about the output spectrum of DDS, which consists of a phase accumulator and look-up table.
Since the look-up table stores accurate information about sinusoidal waveform, I think ...
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Can someone explain me how the phase spectrum of trigonometric fourier series is related to phase spectrum of exponential fourier series of a signal?
Suppose we take a periodic signal and perform fourier analysis over it . Now we have two ways of representing the fourier series of this particular signal , one is trigonometric fourier series and ...
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How to simulate multiple targets in FMCW radar simulation in python?
I have simulated a FMCW radar for a single stationary target, now the next step in my project is to simulate multiple moving targets. For this I had thought of using doppler shift to show a difference ...
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How to generate square wave from sin and cos?
I have a signal that looks almost like a perfect square wave. When looking at its FFT, I see that the real part has components at the fundamental and third harmonic of almost equal magnitudes. When ...
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noise synthesis arbitrary PSD
I have noise measurements for a circuit, in units of noise power (measured in Watts against a known load), per frequency bin.
For simulation purposes, I wish to synthesize noise with the same spectral ...
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Build a shifted signal samples from the original samples
I have the original samples $\{x_1(nT)\}_{n=1}^N$ of a signal $x_1(t)$, where $T=\frac1{f_\mathrm{s}}$ is the sampling period. I want to find the samples $\{x_2(nT)\}_{n=1}^N$ of the signal $x_2(t)=...
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Synthetic Aperture Radar model: Ground reflected energy
My question is related to a theoretical part of the book: Digital Processing of Synthetic Aperture Radar Data, Algorithms and Implementation by I.G. Cumming et al. [Chapter 4. Equation 4.25 (for those ...
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Allpass Filter Gain Issue
Background
I am having issues implementing an allpass filter to model wave dispersion in a stiff string. In order to simulate wave propagation in a string, I am using a digital waveguide. I ...
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Consequences of variable sample rate in waveguide synthesis?
I'm making musical 'woodwind' type oscillators using digital delays with feedback, similar to these: A Meta-Wind-Instrument Physical Model, and a Meta-Controller for Real-Time Performance Control. I ...
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Stepped Frequency Modulated Waveform Continuity issues [duplicate]
I want to generate a stepped frequency modulated waveform (SFMW), similar to a linear frequency modulated chirp.
While approaching this, I wanted to consider the issue that there should be some ...
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Generating a random signal for an autocorrelation that is not square integrable
Suppose I have a function that is not square integrable such as the zeroth Bessel function of the first kind. How do I generate a random sequence, with mean zero of course, such that its ...
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How to figure out or estimate the level of noise in a given data distribution
I have been given a data distribution which was synthetically generated by geostatistical methods such as variogram analysis. Without having the source of the technique which generated the data, is ...
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Synthesizing piano
The sound of the piano is something very complex. There are various elements to consider such as action, hammer, soundboard, sympathetic resonance, tuning age and even room reverb.
Some companies (...
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Adding two sine waves results in a low buzz
I'm working on a little audio/embedded systems project, and I'm using synthesis to generate waveforms and feeding them into DAC and speakers. Currently, I am able to produce sine waves of individual ...
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Reconstructing Signal with Sinus-Waves
I want to create a real-time sampler for woodwind instruments.
Because it is possible to slide from one note to another without stopping the sound I decided to do it as a synthesizer. I want to ...
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Answered-Question About Radar Pulse Modulation
I am trying to simulate a radar-transmitted signal with a 4.5 Hz clock frequency and 1.8 GHz carrier frequency. I generated the carrier signal and a rectangle shape pulse signal, then multiplied in ...
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Pop sounds at intersection of overlapping envelopes
I am currently dabbeling with programming a real-time audio software and I already got a simple pipeline where notes can be played and released and each note has its own envelope so that the amplitude ...
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751
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Signal decomposition to even and odd components
I'm trying to decompose some signal to even and odd components, here's the Python code of it:
...
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Inverse DFT on the first half time domain ("DFT unpad property"?)
Assume to have c[] representing N DFT coefficients. The complex-valued signal of N samples in the time domain is computed by ...
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Why mixing two sines sounds like a triangle?
I'm not sure where to post this question that is related to audio synthesis through programmation.
More specifically, I'm using a library called synthplayer that implement basic synthesizer in Python.
...
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Generate complex signal with sinusoidal phase
I would like to syntethically generate a range of complex numbers whose phase (argument) over t will form a clean sine wave of frequency ...
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Weird crackling during audio playback - web audio api
I am using Web Audio API + extended Karplus-Strong algorithm to generate plucked string sound and play it.
The problem that I face is sometimes there's a weird crackling sound/thump when playing some ...
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The compensation for the output signal emission by using the digital non-recursive FIR filter
I have problem with how achieving the compensation (reduction) for the output signal emission that occurs when change abruptly the coefficients of the digital filters.
for the better compensation,Is ...
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Why is a feedback loop "appropriate" design for instruments that don't physically contain such loop?
Why is a feedback loop "appropriate" design for instruments that don't physically contain such loop? Or do they?
See e.g. paragraph 7.7, and Figure 7.9 (shown here):
https://www.cim.mcgill....
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What is the significance of the two-sided representation of a spectrum (frequency vs amplitude) when talking about analyzing a signal? [duplicate]
Doesn't the simple one sided representation give enough information about the signal?
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Synthesizing guitar sounds given a frequency
I'm trying to build a web app which plays a sequence of notes. The notes should have a timbre of different instruments. For now I only concentrate on a guitar synthesis. I'm using Web Audio API for ...
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Properties of the Frequency Domain to Ensure a Periodic Inverse Discrete Fourier Transform
I've been working on a project to send data via sound waves.
The way I've carried this out is by encoding the data in pulses in the frequency domain, and then creating a unique sound wave containing ...
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Compare two Fourier series to depict the signal smoothness
I have several signals, that I am trying to find a metric to compare the signal smoothness.
By signal smoothness I mean, the signal that the distance between the peak to trough become smaller (getting ...
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Can Goodness-of-fit increase while noise also increases?
I saw a tweet with a good slide. It has a Goodness-of-fit curve that goes up with Model Complexity. There is a Generalizability curve. Noise is cited as the difference between the GOF and ...
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Karplus-Strong with Jaffe-Smith sample rate-independent
I tried to implement the Karplus-Strong algorithm with some of the Jaffe-Smith extensions (improve pitch, dynamics, etc). Here is the code.
When I run it with a sampleRate of 48000Hz, I get very ...
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Phase Error Growth in Digital Mixer Signal
I am working on a code where digital mixing is to be performed for down-conversion of incoming signal. The mixer signal is created using the phase accumulation approach. However it was observed that ...
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filtering large wiggles in signals
I am trying to filter out large wiggles showing in a signal. Those wiggles are happening due to many signal processing layers and a final sine Fourier transform (no phase)
Here's the python code i am ...
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Does direct-digital RF signal generation have a "baseband?"
Semiconductor technology has advanced to the point that the digital representation of a modulated RF signal can be applied directly to a DAC for transmission. Is there, then, any distinction between a ...
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What is the algorithm to generate sine waves of arbitrary frequency in the STFT domain?
I'd like to write a DSP algorithm to do additive synthesis using arbitrary sine waves with inverse rectangular FFTs.
This requires two things:
The ability to generate phase/amplitude lists that cause ...
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Is it possible to add some kind of noise to a non stationary (having unit root) signals to make them stationary?
I am working on time-series signals for which I need to fit a model (like MVAR) that could describe the process satisfactorily. However, my signal has a unit root and is highly non-stationary because ...
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a neural network approach for FIR filter
I am trying to write a code for a neural network to do the digital filtering on some signals. Is there any neural network model for digital filtering?
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What equation predicts the amplitudes of harmonics from a square/triangle/sawtooth/pulse oscillator?
I have seen pictures like this which depict the shapes of amplitudes from the various common types of audio oscillators:
Similar pictures of spectra are shown here.
I am attempting recreating these ...
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Can cross correlation be used to see if filtering of a signal has changed it too much?
I am filtering a signal, and want to check if I am not over filtering it. I am doing a low pass filter, for a signal of input frequency of 512Hz, first with 250Hz pass band, then )I was intending to ...
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elementary one and multidimensional real examples of continuous/discrete LTI systems
By an LTI system, we mean a time-invariant linear map on continuous/discrete-time signals.
What (elementary one and multidimensional) real examples of continuous/discrete LTI systems do you suggest to ...
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How to make spectrogram smooth?
I am quite new in DSP and generating the spectrogram of an audio file. My spectrogram is not smooth and it is showing the quite raw image with pixel values, something like this
While I am looking for ...
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SNR of μ-law companding
I know the snr after μ-law compression is
$\text{SNR}\approx\frac{3L^2}{[\ln(1+ \mu)]^2}$
when $\mu \gg \frac{\max_t m(t)}{\text{rms}(m(t))}$,
where $m(t)$ is the message signal, and
$L$ the number ...
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