# All Questions

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41 views

### PSD from autocorrelation in MATLAB

I am trying to simulate a simple stochastic process defined by the equation: $$\frac{1}{v}\frac{db}{dt} +\Gamma_0 b= \sqrt{\sigma}R(t),$$ where $R(t)$ is a zero-mean white ...
16 views

### splitting real voice based on words using python or other program

Recently, I have a research project that need me to cut a large number of wav files containing the voice from movies, youtube videos or songs based on words for statistical analysis. The sounds are ...
22 views

### Autocorrelation of an AR model

When I plot the autocorrelation function of an autoregressive signal, I get this instead of a damping sinusoid. I am having trouble understanding why this is happening. My signal is an generated ...
42 views

### Estimation / Reconstruction of an Image from Its Missing Data 2D DFT

Given the 2D DFT of an image i.e. a NxM matrix of complex numbers, with some missing lines (or even partial lines), considering we have zeros in the missing positions. Any suggestions for an ...
27 views

### What factors affect the propagation delay at wireless communication?

Generally, the signal propagation delay is d/c. d is a distance between a transmitting antenna and a receiving antenna. c is light speed. However in NS-3, there is Random Propagation Delay Model ...
46 views

### Ripples in filter

What are the uses of ripples in the filter design. We try to design a filter with least ripples but sometimes we design a filter to have 2 or 3 ripples. Why is it so?
37 views

### Correlation between a signal segment and its stretched replica

In my application the measurements are affected by temperature and the signal is stretched over time, though preserving relatively similar structure. I want to find incremental stretching between ...
20 views

### How to calculate this energy for a given signal?

So the question Im asking can be seen in the picture below.The d at the end of the question stands for the minimum euclidian distance. Mostly I just want to know how to calculate the energy for each ...
125 views

### How would you interpret the pattern in this picture? (generated by re-sorting pixels based on their RGB value)

Was playing with some pictures and ran the ruby code below. The code reads an input image using the ImageMagick library, gets an array of pixels, re-sorts the pixels and then writes out an image with ...
85 views

### Old style signal processing?

I am wondering if "an array of overlapping band-pass ﬁlters" it is 'mostly' equivalent to a Short-Time Fourier transform. See this (figure down), where $s(t)$ is the signal; LPF a second-order low-...
87 views

### Reverse engineering a digital filter

I have 2 simultaneous signals that both are designed to measure eye movements. They are sampled at 250 Hz. We have 12 subject recordings. For 3 stable periods in each subject, we choose 256 points and ...
29 views

### Simulating polar pattern for custom radiator (custom speaker design)

I'm interested in performing a speaker simulation to extract an approximate polar pattern for two custom speaker designs. First design: A half wave pipe (transmission line) subwoofer 24 hz to 56 hz ...
14 views

### How can I analyse, recognise some part of audio files?

I have 1000+ programmes recorded from a radio channel. There are about 6 kind of programmes among them. I would like to discard one of the six types of programmes: about 1/6 of the programmes, ~...
14 views

### how to calculate rmse and mse using codes in matlab?

i am new to matlab. for predicting energy data in ann tool, im little bit confused about calculating rmse and mse in matlab. i had tried many codes for calculating rmse but errors are arriving. can ...
32 views

### Implementing MVDR beamformer in the STFT domain

I am trying to implement an MVDR beamformer for the first time. I was reading a couple of papers and books with many different notations and I am a bit confused. In my case, without loss of ...
55 views

### Finding impulse response of an RC circuit from its step response

I have to find the impulse response of an RC circuit (c up ). I have to find it from the step response $g(t)$. I found that $V_i - V_c - V_r = 0$ , with $V_r = V_u$ So $V_u = V_r = R I_r$ , with ...
18 views

### Linear prediction and filter stability

I am currently trying to implement an iterative block-wise algorithm in which AR coefficients are computed for each block. There is a issue with my code where values get too large, and I was ...
11 views

### Convolutional coding that payload length does not change

This is the question about Sigfox radio specification. The stack: Specifically, in Section 3.10 of the specification, we have a convolutional coding (after CRC) with three possible polynominals. I ...
29 views

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60 views

### Is spectral leakage normal for FFT?

I record a sample of 2000 data points, with a sampling rate of 40khz, so freq. resolution is 20hz. I multiplied the chunk of data with a Hanning window prior to doing the FFT. I recorded a 1khz test ...
27 views

### Stereo triangulation similar triangle derivation

I understand that the similar triangles are the red and blue triangles. I'm trying to understand where $T + x_r - x_l$ comes from. I understand we are trying to compute the length of the base of the ...
13 views

### Computing differences between dynamic power spectrums to identify transient features

I have a few minutes of magnetic field data with a lot of noise and unwanted frequencies, and I'd like to be able to identify any transient waves that may appear in my data. To do this, I'm dividing ...
32 views

### The frequency-domain spectrum obtained using MATLAB's FFT function seems inaccurate

I am using MATLAB R2018b on a Windows 10 PC. In order to obtain the frequency domain information of a signal, I'm applying MATLAB's FFT function. The signal of interest is obtained from an experiment ...
76 views

### Help me understand this filter

I'm a trader, so I'm interested in filtering data with minimum lag. I found a post on Forexfactory of a user who posted 3 pictures of a filter he got and participated to create at TSD (an old trading ...
29 views

### Is the whole data needed for the fast fourier transform with an ongoing signal?

I sample an signal with around 840k values a second, to check the spectrum around <400kHz. But i can't save the whole data as it is just to much for my microcontroller. I know that for the ...
89 views

### Intermittent Harmonics, Is there a physical explanation?

I am doing some frequency analysis of a vibration signal from a spinning rotor, I am expecting to see peaks corresponding to the rotational frequency of the rotor. So the fundamental frequency ...
129 views

### How can I know if these two signal are orthogonal to each other

So the question is to determine if this statement is true or false. The question can be seen below. I know that two signals are orthogonal if their inner product is equal to 0. I know how this ...
85 views

### Which Noise Reduction Algorithms Are Used in Commercial RAW Image Processors?

I'm trying to guess what noise reduction algorithms are used in commercial processors for raw images from digital cameras. I find this fairly easy to do for the sharpening algorithms (most use unsharp ...
20 views

### If a AM modulation have large carrier is a asincronous modulation? and if that is correct why?

When I use DSB-LC (Double Side Band-Large Carrier) trasmission the receiver just use a envelope detector instead a mixer that fact means a asincronuos trasmission? Because I understand that in DSC-...
26 views

### Granular synthesis of a periodic waveform - How to derive grain start and end point

I understand to find the length of the grain I need to perform an FFT over the source to find the fundamental harmonic, I can do that and find an accurate grain length, but now I need to find a start ...