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Questions tagged [signal-synthesis]

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1
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0answers
29 views

Generate time domain signal from frequency domain filter

I am familiar with using the Fourier transform to take a signal from the time domain to the frequency domain. What I would like to do is the reverse: describe a signal in the frequency domain and then ...
0
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2answers
35 views

How to make sure that a sinusoid wave with different subsequent frequencies matches up?

A very basic formula to transform a sequence of notes into a signal would be: $$ x(t) = A\cos( 2 \pi (2^{current\_note}/12) t) $$ where $current\_note$ is $notes[\lfloor t / period\_per\_note\...
0
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1answer
44 views

Glitches in certain frequencies

I am trying to produce some simple audio waves using WASAPI (Windows Audio Session API). If I skip all the abstractions, my program basically receives a buffer from the API, then writes results of a ...
1
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1answer
52 views

Separating two frequency component

How can we separate two frequency component when they get mixed means when signal get mixed with noise how receiver can judge which part is signal and which is noise ?
0
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3answers
136 views

What is the algorithm to do frequency modulation?

I'm familiar with audio synthesis, oscillators etc. I'm now trying to implement my own software algorithm to do FM as described by https://en.wikipedia.org/wiki/Frequency_modulation. What I have ...
2
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1answer
41 views

How is the energy conservation principle preserved in the case mentioned below?

Suppose there are 2 sinusoidal signals $\cos(\omega t)$ and $\cos(\omega t)$, which implies that their individual power is $1/2$ unit and total power is $1$ unit. When added, the signal $2\cos(\omega ...
15
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4answers
2k views

Finding polynomial approximations of a sine wave

I want to approximate the sine wave given by $\sin\left(\pi x\right)$ by applying a polynomial waveshaper to a simple triangle wave, generated by the function $$T\left(x\right)=1-4\left|\tfrac{1}{2}-...
1
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0answers
46 views

Band Limited Impulse Train - DC offset correction

I am trying to get band limited saw-tooth wave. I have found this paper: Alias-Free Digital Synthesis of Classic Analog Waveforms. I am prototyping this code in common LISP, here is snippet of what I ...
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1answer
287 views

relationship of column of spectrogram to original signal

We can get the spectrograms of a signal which is a 2D matrix. How do I get back from the columns of the spectrogram to the time stamps in original signal? For example, what time stamp does the columns ...
1
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0answers
48 views

Bandwidth enhanced sinusoidal model with oscillators banks

i am currently implementing the bandwidth enhanced sinusoidal model for an additive synthesizer, this model allow to accurately produce noisy sounds by adding a noise component to each sinusoids. But ...
0
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0answers
81 views

How can I use signal processing techniques in modelling noise, which doesnt follow a specific pattern

I want to take your guidance in modelling noise which is truly random. Please see below the following 2 images. First one shows my development. The background curve is the amount of solar ...
0
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2answers
109 views

Controlling a signals amplitude in the frequency domain [closed]

I want to control the amplitude of a signal I'm creating from a user drawn spectrum by scaling the magnitude values in the frequency domain. Here is my scenario. Sample rate $F_s= 44100\textrm{ Hz}$...
12
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2answers
6k views

What are advantages of having higher sampling rate of a signal?

Being a non signal processing science student I have limited understanding of the concepts. I have a continuous periodic bearing faulty signal (with time amplitudes) which are sampled at $12\textrm{ ...
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1answer
212 views
0
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0answers
324 views

Best way to synthesize signal from Power Spectral Density (PSD)

I am looking for methods of synthesizing a random time history signal from a PSD. To me it seems that the simplest method is to take the square root, randomize the phase and then take inverse FFT. ...
0
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2answers
156 views

How should you decide on the number of sweeps to be used in FMCW radar?

I am designing an FMCW radar in MATLAB and I would like to know on how should I decide on the number of linear sweeps in FMCW .Does the number of sweeps affect the performance?
4
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1answer
161 views

Overlapping power-of-cosine windows with constant weight

I would like to refer you to a relevant question I posed on the Math StackExchange: A generalisation of the Pythagorean trigonometric identity. As can be seen from the question and the answer, what ...
0
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1answer
74 views

Convert image of an irregular surface to it's signal equivalent

I want to take the image of an irregular object , say and then I want to convert the elevation of the points into a spatial signal. To make my point clear: the signal would be 'height of the ...
0
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1answer
357 views

Generate loopable sine wave cycle for given frequencies

I am somewhat new to DSP so bare with me. I am working on a simple wavetable oscillator. What I am trying to do is generate one cycle of a wave form for each note (frequency) and store it in an array ...
1
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3answers
499 views

Effect of noise on high and low frequency components

It is given that noise is present in the noisy image in the form of high frequency components. Can any one please explain this concept. Also please tell me that whether it is correct to say that "...
1
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0answers
262 views

What's wrong with my minBLEP Hard Sync Sawtooth code?

I implemented a Sawtooth Oscillator which uses minBLEP - Eli Brandt's original paper The minBLEP approach works very well for a normal Sawtooth but I specifically want to implement Hard Sync and ...
8
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1answer
985 views

How can I decompose a signal into square waves?

I am dealing with signals that are a superposition of different square waves with different amplitudes and phases. Normally, one would decompose a signal into sine waves with help of the Fourier ...
0
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0answers
273 views

Flattening out a power spectral density

The situation is as follows. I am generating a white noise voltage signal with a certain power spectral density amplitude of choice, from 0 to some cutoff frequency, for example 200 MHz. This proceeds ...
0
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0answers
42 views

Is my approach for Splitting a magnitude across multiple bins correct?

I'm trying to synthesise a sine wave whose frequency is between bin centre frequencies per this post: Splitting a magnitude across multiple bins in an IFFT I'm trying to split my sine's magnitude ...
1
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1answer
300 views

Splitting a magnitude across multiple bins in an IFFT

By Georg-Johann own work, CC BY-SA 3.0. I’m trying to synthesise a sine wave using an IFFT at a frequency between bin centre frequencies. Here are the details ...
0
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2answers
510 views

Sine Wave Aliasing during IFFT

I’’m synthesising a simple sine wave using the IFFT. I’m controlling the pitch of the sine wave by controlling the bin number and the phase for that bin number. I’ve synthesised an F whose ...
0
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1answer
69 views

Cascading FM synthesis operations

I'm trying to understand how to program cascading FM synthesis operations. I can find a good deal of information out there on how to do it on various pieces of hardware, but unfortunately, there isn'...
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0answers
112 views

Calculating amplitudes of FM Sidebands

How are the amplitudes of FM sidebands calculated? E.g. when negative frequencies are reflected back and their amplitudes added to any existing positive frequencies at that band, how are the ...
0
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1answer
140 views

Bandlimited PWM

Trying to figure out how to synthesize a Bandlimited PWM in my audio code in C. I have already figured out a bandlimited pulse wave but I can't really figure out how to translate that to PWM. I have ...
1
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1answer
102 views

How can I realize a complex communication system in a real time application?

So I am working on a project where I have to model a communication system in MATLAB, then implement it on an FBGA. My transmitter goes something like that: ...
0
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1answer
443 views

Daubechies wavelet transform

i have N samples obtained by sampling a signal with lot of frequency contents. How will i apply daubechies wavelet transform to obtain the frequency and its location? i need to write a program which ...
1
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2answers
619 views

Additive synthesis vs. “just draw the waveform”

I've been experimenting with PYO recently, a Python module for sound synthesis and audio processing. This is really my first foray into this topic, so I have what is probably a very basic question. ...
0
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0answers
298 views

Multidimensional EMD - Problem Plotting Spectogram

I'm having difficulty plotting the famous Time vs Frequency plot of the Amplitude. What I did so far is  1. Simulated a three dimensional signal using ...
1
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3answers
461 views

Extrapolation after taking inverse Fourier transform

Suppose I have 2000 point(time series) signal and I take 512 point FFT, after this some operation is done in frequency domain. Now if I take IFFT to get 512 points in time domain, Is there a way to ...
0
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1answer
497 views

adding u(t) and r(t) to create a signal

I previously asked this question in the maths community not realising that this stack exchange community existed. I have searched online extensively and haven't been able to find an explanation to how ...
3
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1answer
103 views

Mysterious notation used in “BLIT” CCRMA paper

I'm working on a project involving synthesizing audio, which led me to a promising Stanford CCRMA paper on band-limited synthesis. However, this double-arrow notation keeps popping up throughout some ...
0
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1answer
98 views

Adding sine waves

I need to play thousands of simple sounds (generated tones) at the same time. If I am understand correctly there should be a way to add them together in complex wave but i really can't see the light ...
2
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2answers
796 views

Integration of square wave

trying to program an integrator. My input is a square wave and my expected output should be a triangle wave. However, whenever I pass it through my low pass filter algorithm (just a 2nd order ...
1
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2answers
87 views

How to represent half of equilateral triangle signal?

How to represent the signal in above image ? I know a ramp signal can be represented by $$x(t) = t\cdot u(t)$$ but here amplitude of that signal is not same with $t$
-1
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3answers
913 views

Extracting a varying DC from a signal

I have a signal that has both AC and DC components and both a re varying with time. How can I extract the varying DC wave from the signal? eg: A PPG (Photopletysmography) signal extracted from a ...
0
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1answer
226 views

IFFT Synthesis from an empty spectrum

I'm trying to generate a sawtooth wave using the IFFT. I can do this successfully by first performing an FFT and then putting that analysed spectrum into the IFFT, however I would really like to be ...
3
votes
1answer
135 views

Controlling one signal with another one (Rocket engine effect - Subtractive synthesis of sound)

I am programming some sound effects in Java and exporting them into .wav files. Currently, I am trying to program a rocket engine sound effect. I want to do it in the following way: The sound of a ...
0
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2answers
6k views

How sine wave is generated using lookup tables

From this document I am quoting P2,L7 So what is the incremental distance if we are using a 64 element look-up table instead of a sine function based on 2π? incremental distance = 2k*64/48k = 8/3. ...
0
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2answers
319 views

How do I zero pad time samples if I only have frequency samples?

Related to this question: Convolution in frequency space with fft and ifft -> num output samples? When doing convolution in time domain by doing multiplication in frequency domain, you apparently ...
0
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2answers
145 views

Phase Offtset Bandlimited Saw Wave

I'm able to make a standard band limited saw wave, but at some point in the past, I remember reading that if you phase offset the sinusoids, you get a different looking wave form that sounds the same. ...
1
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1answer
263 views

What interesting audio can be synthesized with ifft

I'm working on a presentation on audio synthesis for some fellow software engineers. I want to include some "fourier synthesis" creating time domain samples from frequency domain samples using ifft. ...
0
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2answers
251 views

Fourier Synthesis With Varying Frequencies Over Time

I'm doing some fourier synthesis by making bins of complex numbers, filling them out with the amplitude and phase information and using IFFT to turn that into time domain samples. I'm able to make ...
0
votes
1answer
43 views

How to prove: high-slope/more change is high freq part of signal

Generally, everyone knows that "the part of signal with high-slope is the high frequency part." What is the definition or theory behind it? How to prove this well-known thing? perhaps, I miss ...
2
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2answers
1k views

How can noise be added to a signal to obtain a specific SNR?

How can I add noise to a recording to obtain a SNR value provided by the user? I am tryin to test the effects of noise on my algorithm. Is there any function or app for doing that kind of task? Thank ...
0
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0answers
422 views

Combine multiple FFT

I have been acquiring data through ADC and into memory, the input signal are square waves that step down in frequency as time goes by. Due to memory, I have a fixed maximum number of samples per FFT. ...