# All Questions

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26 views

### Simulate BER curves for OFDM with convolutional coding

I am tasked with generating performance curves for an OFDM transmitter/receiver, and I am unsure how to calculate the appropriate AWGN power, and where exactly the apply it. The transmitted packets ...
3 views

### Puzzled by CIC filters

I have been trying to wrap my head around CIC filters. Say that I want to do filtered decimation by a factor D. Option#1: boxcar filter. Each output sample is formed by taking the sum of D input ...
236 views

### Change pitch of mp3 audio on a microcontroller

I have an MP3 decoder running on a ESP32, and I'd like to change the pitch of the streaming audio in real time. I plan to build a little toy that streams Amazon Alexa and changes her voice so that it ...
61 views

146 views

### Algorithm/Code for finding surface shape of an image?

Is it possible to find the surface shape of an image as mentioned in the reference question ? If I find the unknowns of the equation , then what should be my next step in determining the shape of the ...
252 views

### What is the normalization factor for the quincunx lattice wavelet transform, and how do you find it?

On pages 57-60 (preview was available last I checked, images here in case), there is a quincunx lattice transform described. Lattice: ...
25 views

### how to understand the MIMO zero forcing as a bank of decorrelators?

I am studying the zero forcing as a simple linear receiver for MIMO detection. according to following notes: http://www.ee.ic.ac.uk/bruno.clerckx/All.pdf. The zero forcing can be understood as the ...
19 views

### Smoothing a discrete function with point wise variances

In Stark's Introduction to numerical methods [1970] it suggests fitting local polynomials to smooth discrete data before the Fourier transform using least squares minimisation. This gives the ...
784 views

### How do I find the peak frequency of a wav file in python?

I am fairly new to python and signal processing and I was given a task to record audio for 'x' seconds and then find the peak frequency in the audio file. So far I have successfully implemented the ...
20 views

### Flicker Frequency for taking snapshot of monitor

When a snapshot of a monitor with refresh rate 60 Hz is taken with a camera with rolling shutter config operating at 30 FPS, what is the expected flicker frequency in the resultant image? I took ...
14 views

### Advantage of applying a Window Function in Analysis and Synthesis of STFT?

I'm studying Short-time Fourier Transform and I learned that if you apply a windowing other than rectangular, you need to overlap the frames---for example, 50% overlap for Hamming family---to ...
10 views

### EEG signal dataset info

So I wanted to use pre processing on EEG data obtained from BCI competition 2005 dataset iiia which is a multiclass dataset. This data has lots of info on it but i cant seem to obtain/get data other ...
40 views

### Whether y(t) = x(t/3) is a memoryless system?

I am a newbie in signal and system, and feeling confused about the memoryless property, it says at the definition, if a system gives output only depends on present input, then its memoryless. So if at ...
177 views

### Significance of sequency ordering in Walsh-Hadamard matrices

So I've been doing some reading into Hadamard and related matrices (Slant, Walsh, , and have observed that there are three typical "orderings" of the rows based on various criterion. E.g. "Natural", "...
18 views

### Math.Net and alglib returning different FFT outputs by default

I am developing an application in C# with spectrogram drawing functionality. For my fist try, I used MathNet.Numerics, and now I am continuing to develop with alglib. When I changed from one to the ...
52 views

### Problem in verifying zero blocking property of a zero of a multiple input multiple output system

I have a multiple input multiple output control system, and in particular a two inputs two outputs system. I want to find the zero state direction and the zero input direction of the system, which has ...
34 views

### Frequency prewarping of a bilinear transform (Tustin transform)

sadly I'm not too well aquinted with discretazation methods. At the moment I struggle to reproduce a bilinear transform with frequency prewarping. I have the following transfer function in the s-...
136 views

### Real time numerical differentiation of signals

I am trying to implement a PID controller in Python and I am having some problems with real time numerical differentiation of my my discrete signal. I am using the following method: d{\frac{x_n}{...
66 views

### Calculating phase shift between two sines of equal, unknown, amplitude and frequency

I've got a source signal $s_1(t)$ and a system affecting that, yielding a phase-shifted version $s_2(t)$; \begin{align} \color{blue}{s_1(t)} &= A\sin(t+\phi_1)\\ \color{red}{s_2(t)} &= A\sin(...
25 views

### IQ to RF data conversion [closed]

I appreciate any help: I wanna convert IQ data to its RF data, representing an image. The center frequency and sampling rate are available. What I do is: First I do up-sampling in MATLAB by ...
31 views

### Hand written DFT vs MATLAB FFT has flipped conjugates?

I had to compute the DFT of a signal with 5 points with a hand-written method and using MATLAB's FFT just to see if they are equal. Taking the absolute value of both gives the same spectrum, however ...
31 views

### std::cosf fluctuation: Results are off in low frequencies

I attempted to generate a continuous wave signal by using the C++ cos/sin functions. It's partly successful, meaning high frequencies seems ok, but very low frequencies give unexpected results. The ...
10 views

### Path delay influence in BER performance using Rayleigh channel

I am simulating a DSSS modulation in a Rayleigh channel to get the BER performance. For these purpose I am using the comm.RayleighChannel object. My problem comes when I change the Paths delays of the ...
140 views

### Down sampling an EEG signal

I have a set of 10 minute EEG signals that were sampled at 400 Hz and have 16 channels which corresponds to a 16x240000 matrix. These EEG signals belong to two different classes. I am trying to ...
40 views

### Kalman filter using only location information

I have never used a Kalman filter. Is it possible to implement a Kalman filter using only location information? In addition, if you can implement it, what kind of procedure should be used to program ...
12 views

### How to prepare different input size in CNN

I'm doing a research about personality identification based on their signature using CNN method, however the learning feature for the personality traits have a different input size. I understand that ...
31 views

### How to derive low pass filter $\frac{N}{N+S}$

I watched the video for PID control system where it mentioned the Laplace domain function and low pass filter to be $\frac{N}{N+S}$. I used asymptotic analysis to see that it made sense. However, I'm ...
5k views

### Edge Detection on a Color Image

I understand the process of using a Sobel kernel for edge detection in greyscale images. The input is a greyscale image, and the output is a greyscale image. I'm having trouble, however, figuring out ...
483 views

### Best algorithm for time-scaling

what is the best algorithm for time_scaling of a speech signal in which I've seen two of them and I don't know which one to use : Psola:Pitch synchronous overlap and add. time scaling modification ...
36 views

### Is HSV Color Space Sufficient for Rudimentary Color ID and Edge Detection

I want to, as part of a C++ school project (no OpenCV), work with an RGB image taken from a camera filming smarties (round colored pellets) from above and extract the number of candies in each color. ...
9 views

### Use sparse optical tracking to track a Bounding Box object

I need some help on solving this issue. Any tips are appreciated. The goal of the project is to try to track a Bounding Box object, chosen arbitrarily in an image, throughout many frames of a ...
19 views

### How to extract speech features using deep learning?

I found deep learning for classification, but I want to extract features from speech signal using deep learning in python.Is it possible, if yes then how?
39 views

### Why are 8 points needed to compute a fundamental matrix?

Homograpies have 8 degrees of freedom. Fundamental matrices have 7. Essential matrices have 5. To the best I could find, all those matrices are obtained by using the 8 point algorithm. I don't see ...
84 views

### Sample-rate, filtering, digital-filtering and aliasing

I am strugling with a question that I hope someone can help me with. I am recording single molecule events which I detect is picoampere square deflections. I wish to use as gentle low-pass bessel ...
22 views

### Synthesis of 75% Window Overlap Add method for Short-Time Fourier Transform (STFT)

I'm doing the overlap-add method for STFT and I quite understand the implementation if it's a 50% overlap (where I add the 2nd half of the previous frame to the 1st half of the current frame during ...
68 views

### How to approximate a moving RMS without iterating over N samples for each required output?

I have a signal with a sampling rate of F Hertz. From it I want to produce an RMS signal, also with F samples per second with a window size of N samples. Using a standard moving RMS algorithm I must ...
153 views

### Overlapping in real time fourier transform?

I have an algorithm and I need to record audio and perform short time Fourier transform to obtain which frequency is the most common. I am using a Hanning window to try and reduce spectral leakage as ...