A discrete signal or discrete-time signal is a time series consisting of a sequence of quantities.

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How to obtain mean Power Spectrum from two audio channels?

I have a source of noise in a duct, on either side of the noise source I have a microphone, which register the pressure, so that I get two pressure signals: $p_1$ and $p_2$. I want to get the acoustic ...
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44 views

Difference Equation - Time Response analysis of Discrete Systems

We know that that the difference equation formula for computing an output sample at time $ n$ is based upon its past/present input samples and past output samples in time domain: $\displaystyle ...
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1answer
30 views

Natural, Forced and Total System Response - Time domain Analysis of DT

I am a self-learner of DSP by reading related books. While reading Time domain Analysis of DT (Discrete Time) system, I suddenly got introduced to difference equation representing a system. It then ...
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5answers
135 views

Why does the DFT assume the transformed signal is periodic?

In many signal processing books, it is claimed that the DFT assumes the transformed signal to be periodic (and that this is the reason why spectral leakage for example may occur). Now, if you look at ...
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48 views

Autocorrelation of a signal comprised of only the same number

In MATLAB I generated a signal and its autocorrealtion function using: signal = ones(1,500).*5; % a vector of the number 5 acf = autocorr(signal,numel(signal)-1)); To my suprise the ...
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29 views

minimum frequency in periodic components

Suppose we have the following signal model $y(t) = A_1\sin(\omega_1 t+\phi_1) + A_2\sin(\omega_2 t+\phi_2) + ... + A_p\sin(\omega_p t+\phi_p) + z(t)$ When we are sampling at sampling frequency ...
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0answers
34 views

Estimate the Discrete Fourier Series of a Signal with Missing Samples

Assuming we have a discrete signal $ { \left\{ x \left[ n \right] \right\}}_{n = 1}^{N} $. Which has a Discrete Fourier Series. Now, assume I'd like to estimate its Discrete Fourier Series ...
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26 views

How To Generate a Band Limited Sawtooth Wave Using Additive Synthesis using C++

I am trying to generate a continuous Band Limited Sawtooth wave using Additive Synthesis in C++. I understand that the harmonic structure of a sawtooth wave can be generated in this manor: ...
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1answer
34 views

Properties of Discrete-time Sinusoidal Signal

I was reading in a book that below stated are the Properties of Discrete-time Sinusoidal Signal: Property 1. The discrete time sinusoids whose frequency are separated by an integer multiple of ...
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1answer
28 views

Basics of waveform, how to define the zero point

Audio is a sequence of waveforms which have peaks, troughs, 0, just like below. How to define the x axis (y = 0) in the picture, how to choose the 0 point in the waveform since there are so many ...
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3answers
455 views

disadvantages of FFT, it can not extract enough frequencies without enough samples

Let's say sampling rate is $Fs = 44\mathtt{kHz}$, now I have $N = 2048$ samples, then I can get $N/2 + 1 = 1025$ frequencies. I'm confused by Matlab's FFT documentation that says the frequencies are ...
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0answers
26 views

How to draw discrete specturm of a signal

Before I begin this is not an assignment or a homework problem just something I'm practicing for my test next week. I need to draw discrete spectrum of a signal. How do I do that? Here is the actual ...
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0answers
25 views

DC offset removal from tetra signal

Hey I want to remove DC offset from tetra signal captured as inphase and quadrature phase samples(I and Q samples). I and and Q samples are 16 bit signed values. I tried averaging 2000 I and Q samples ...
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1answer
60 views

Understanding the windowing method in PSD calculation

I have some issues understanding the use of a window (it doesn't matter which one) to calculate the Power Spectral Density of a signal. For example say I want to use the hann window, with $N = ...
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0answers
22 views

Clustering of overlapping windows (K Means)

I'm attempting the clustering of some of my data using a K-means Euclidean square method. I've broken the data down into small windows, 200 samples in size, but with a 50% overlap. I've chosen to use ...
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2answers
58 views

Generating a high SNR sinusoide with lut on a DSP

I'm generating a sinus by using a lut method on a DSPic33f. My sample rate is 48 kHz, so I saved 12000 of the first value (unsigned int, 16 bits) and use trigonometric formulas to calculate the other ...
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1answer
55 views

Determine whether a signal is periodic or not and get fundamental period

Here is my signal Cos(n/2)*cos(pi*n/4) cos(n/2) has period 4pi and cos(pi*n/4) has period 8 Now, the question is will the signal be periodic for fundamental ...
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26 views

Time delay analysis in different binary sequences

I am extracting a property of a signal which I represent with either a 0 for absent or 1 for present. This property is extracted for each data point in a time series and in the end I am left with a ...
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3answers
68 views

Decimate/downsample a signal from 1920.93Hz to 1920Hz. Possible? [duplicate]

I've just learned that the A/D converter I am using is not sampling at my desired sampling rate. I request 20 seconds of data at 1920Hz and I receive 38400 points of data that were actually sampled ...
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1answer
55 views

Intertial navigation on android phone with Kalman filter

Ok, so suppose I've got a phone with gyroscope, compass and 3-d accelerometer. I wanted to track position of the moving phone for about 1 minute with let's say 50 mm accuracy. Actually let's say that ...
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2answers
103 views

Negative dB signal to noise ratio

Is it common to find systems having signal to noise ratio (SNR) less than 1 i.e. noise is more than signal? I am currently working with SNR of -5db to -20db. And how useful is it to work with sensor ...
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2answers
45 views

What is 'energy compaction' in simple terms?

This is my understanding of 'energy compaction' and want to know if it is right. Take a vector. The energy of the vector is the sum of the squares of its elements. If A is the transformation matrix ...
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2answers
43 views

shifting sequences using Matlab

I'm reading this book and I came across a function to shift sequences. Mathematically, $$ y(n) = \{x(n-k) \} $$ if $m = n-k$, then $$ y(m+k) = \{ x(m) \} $$ ...
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1answer
25 views

How to model the dispersion which is introduced by an electro-absorption modulator (EML)?

I need to model the dispersion which is introduced by an EML in Matlab. The parameters are: Lambda: 1310nm PAM4 power: Pmax = 1.09 mW Pmin = 0.13 mW Bandwidth = 56Gbps
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41 views

DSP - Understanding Formulas

I am a beginner in DSP but get confused when some formulas like below are referred: ...
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1answer
86 views

Detecting sound inside a sound

I was searching on the Internet hopelessly about some materials regarding detecting a sound in another sound. Say, I've got a recorded short sound (which may be anything, fragment of speech, fragment ...
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1answer
51 views

how to get the phasor(frequency domain) representation of a digitalized signal?

I know that we can get the phasor representation(frequency domain) of a signal through Fourier transform, but the picture above gives a method that can get the phasor representation of a signal in a ...
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1answer
58 views

Non-uniqueness of continuous time sinusoids?

I have read the DSP literature and I get why: $$e^{j(\omega+2 \pi m)n}=e^{j\omega n}$$ But can't we prove the same in continuous domain also in the following way: $$e^{j\omega t}$$ $$e^{j(\omega+2 ...
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1answer
50 views

Simulate a pulse of specific power

Suppose you produce a pulse x in discrete samples of duration dt each (e.g. in Matlab) according to a function. I was given some ...
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1answer
79 views

Digital Gaussian White noise signal generation in C++

I am trying to generate a band limited noise signal on a Raspberry Pi. I calculate samples at every 1/48000 sec on the Pi. If I generate normally distributed random numbers as data points at every ...
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1answer
34 views

Discrete signals notation underlined value

In a book i have there's an exercise that want to find the output of a system for a given signal system: $ 2y(n)=2x(n)+x(n+1)+x(n-1) $ input : $ Χ=[\underline1, -1, 2, 0, -2, 0, 1 ]$ $Χ1=Χ[0] $ ...
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89 views

When should we using moving average in algorithm design?

I'm new to signal processing. And I just read G.720.1. I find there is a lot of moving average used. And I can also recall there is a lot of moving average been used in other audio processing ...
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1answer
108 views

How can I load a wav file, split it in frames, apply different filters do different frames and then recombine the filtered frames into a single file?

I'm working on a wav audio file using MATLAB. What i would like to do is: load a wav file and divide it into frames of the same dimension filter these frames (with a different filter for each ...
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1answer
60 views

Inverse DTFT of $e^{-j\omega}$

I've been trying to solve the following problem, but I noticed that I get two different answers by means of two different techniques: Find the impulse response, $h(n)$, of the following system, ...
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0answers
42 views

Noisy Signal auto/cross-correlation

I am trying to understand the basics of the cross/auto-correlation if the noisy signal $y(t)$ which is received from the channel at the receiver. Here at receiver we want to estimate the noise in the ...
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0answers
83 views

Least Angle without matrix inversion?

Sorry if this is too damned long. I did what I could to abbreviate it. I'm new to numerical work with matrices. I believe I have a way to compute Least Angle without explicit matrix inversion. I'm ...
3
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1answer
118 views

Under what condition is the available bandwidth $f_s$ instead of $\frac{f_s}{2}$?

Can someone help me with this interview question? It is about the sampling frequency rate. Under what condition the available bandwidth is $f_s$ instead of $\frac{f_s}{2}$?
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1answer
91 views

Implementations of Low-Pass Filter

I should say which of the filters from the following image implements an ideal low-pass filter with cutoff frequency $\frac{\pi}{4}$. In the picture, Sa is a zero insertion filter, which inserts a ...
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2answers
105 views

Causality of Linear Phase Filter

If a digital LTI filter has phase response on the form $arg[H(e^{jw})] = -\alpha\omega$, what could one say about it's causality (and consequently, the causality of it's impulse response)? Also is ...
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1answer
44 views

How to represent the following system function in a block diagram?

I am aware that this a simple question, but I haven't been able to find a single reference that explains this situation. The system function is: $$\frac{1}{1-(0.3)(1+j)D}$$ How can one draw a block ...
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1answer
989 views

Difference between discrete time fourier transform and discrete fourier transform

I have read many articles about DTFT and DFT but am not able to discern the difference between the two except for a few visible things like DTFT goes till infinity while DFT is only till N-1. Can ...
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1answer
139 views

how to apply Short-time fourier transform to code in matlab

Please Help, I have a white noise signal that I created and need help to apply the Short-time fourier transform to my code so that it can do the bandpass filtering. I am trying to put it in the code ...
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1answer
52 views

How to perform a Stockwell Transform on a 2D matrix

I was looking at performing a Stockwell transform on a matrix (or an image as it has two directions - the matrix I am interested in has a spatial dimension and a time dimension, but this should make ...
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1answer
72 views

How moving part pixel intensity values of video frames becomes dominant compared to stationary part intensities in reconstructed frames?

Hello everyone i want to do dynamic texture video sementation using the Fourier transform in MATLAB. I am applying 3-D fft on dynamic texture video frames (using matlab function 'fftn') and ...
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2answers
99 views

I have a mix signals (2 signals with different dc offset). How to recover another dc value which has been buried by the stronger dc value?

Let say I have a time-varying signal which is a mixture of two signals with different dc offsets. If I apply the fft on that signal, I will only get the dc value (at f=0hz) with stronger energy. How ...
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1answer
62 views

Finding linear convolution of two time series

PROBLEM Two real, causal time series $$f_k = a^k \quad \text{and} \quad g_k = b^k$$ where $a \neq b$, $|a| < 1$, and $|b| < 1$, are given for $k = 0,1,2,...$ Find the linear convolution ...
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65 views

Before the birth of computers how people calculated the bandwidths?

In these days we can able to easily calculate the bandwidths with the help of technology, but in olden days where people used the analog phones, how did they calculated the bandwidths?
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1answer
42 views

Can a discrete sinusoidal signal represent only limited number of frequencies?

If $\omega$ is the frequency of a continuous time sinusoidal signal, $-\infty < \omega < \infty $. But when it comes to discrete time sinusoidal signals, the range becomes limited : $-\pi \le ...
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1answer
60 views

Playing/Recording acoustic signal in matlab to tell difference between 2 sounds

I will be using one central node/latop to play a tone and will have a second node/laptop to record and read the sound and be able to say this node is on the left or right. So trying to figure out the ...
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29 views

Data Processing Question

I'm curious if there is a method to separate the signal from the noise in this kind of data set, other than manually do it by indexing. the top plot is the data, the bottom plot is the zoom in of the ...