0
votes
0answers
19 views

Formula for S/N ratio

I'm trying to calculate the energy balance of satellite link, I know that: $$P_t=100 {\rm\ W,}$$ $$G_t =206340 {\rm\ W/W,}$$ $$G_r=6650 {\rm\ W/W,}$$ $$L_{fs} = 5,502 \times 10^{20} {\rm\ W/W.}$$ I ...
0
votes
0answers
11 views

Indexing problem with using FFT convolution to remove echo

I've been using a very basic kernel to remove a known echo from a signal via convolution in the time domain e.g assuming a signal contains a delay of 5 samples ...
0
votes
1answer
10 views

What do the Contour Levels Produced by Matlab Function Contourc Represent

I have been trying to understand what the contour levels are. As far as I understand a contour of the function $Z(x,y)$ is a set of points in the $(x,y)$ plane, such that $Z(x,y)$ is fixed at some ...
0
votes
0answers
14 views

what are the hot area of searching in FMBC and Massive MIMO

I'd like to ask about Massive MIMO, and FBMC .. what are the hot areas of searching in these two topics ? I mean for example in OFDM, it's needed to check the ISI, ICI and channel estimation and so ...
0
votes
1answer
13 views

upconverting a kHz/MHz signal to GHz

I want to know how in practice we can take a kHz/MHz signal to a GHz band? Suppose we have an FSK modulated signal at around 300 kHz (or 20 MHz). I want to take it to 3.5 GHz, so about 3499700 kHz ...
-1
votes
0answers
4 views

DTW MFCC pronunciation similarity

There are two wav files with the same word recorded. To compare this, we extracted the wav file pcm, MFCC (Mel frequency factor) and obtained the Euclidean distance value through DTW. (1) and (2) are ...
1
vote
1answer
15 views

Finding the fundamental period by using four elementary operations (+,-,x,/)

The idea is to find the fundamental period of any periodic and bounded signal. This is all that we know about the signal. Nothing else. Only allowed operations are: $+,-,\times , \div$. We can also ...
0
votes
0answers
14 views

Frequency hopping signal bandwidth

I am confused about how to calculate the signal BW in a frequency hopping system, is the signal BW a function of the frequency separation and the number of frequencies used or is the hopping rate ...
0
votes
0answers
15 views

Single frequency missing in time domain effect

How to explain effect of a missing frequency in time domain ? As we know it is simple task when we talk about frequency domain and missing a frequency component in there (in spectrum).What about time ...
0
votes
1answer
36 views

Convolution Strategy

I would like your help on a theoretical question regarding convolution. The point is to design a faster discrete-time convolution operator functioning on one-dimensional space so that y[n] = x[n] * h[...
0
votes
0answers
15 views

Decimation for upsampling and downsampling

Prologue of the problem I have a dataset of ADLs (Activities of Daily Living) - MobiFall. It's been stated that accelerometer sampling frequency was 87Hz, orientation and gyroscope were 200Hz. But in ...
0
votes
1answer
22 views

What reference power should I use?

My professor asked me to convert following powers into decibels: 15W, 25W, 33W, 450mW, 24MW, 44 GW,120pW. I know that decibels are about ratio power/reference_power. I don't have reference power ...
1
vote
3answers
28 views

Ideal sampling of audio signals-Periodic spectrum

When applying ideal sampling on audio singals, why is the spectrum periodic ?
1
vote
1answer
15 views

DFT as an Orthogonal Basis Change

In one of the homeworks that I am dealing with for Linear Systems course, I have encountered with such a statement: Consider $\mathbb{C}^N$ the vector space of N dimensional complex vectors. We can ...
0
votes
0answers
19 views

Unexpected results from DTW comparing two MFCC feature vectors

I'm trying to compare two people's pronunciations of the same sentence: "no signal." I ran the following code on said pronunciations and the DTW distance output was 8.4. However, when I used one of ...
1
vote
3answers
23 views

Why do we substract a background image and not divide it?

Subtracting a background image for background correction is the standard way of doing background correction to obtain the foreground. I am wondering if there are situations, where it would make sense ...
1
vote
1answer
251 views

Practical book in C [duplicate]

Is there any practical “go to” book that demonstrates the main dsp methods for time series written in C for practical applications? (Doesn’t have to be for hardware, but for any raw data such as ...
0
votes
0answers
7 views

Log likelihood ratio values

How to compute/calculate the log likelihood ratio values from iq's of a GMSK signal
0
votes
1answer
31 views

How to compare multiple polynomials in MATLAB?

I am trying to fit a second order polynomial to various curves on a binary image using MATLAB polyfit function.There are many such curves on the image, and the ...
0
votes
1answer
33 views

OFDM RF signal waveform

From the Wikipedia article: "An inverse FFT is computed on each set of symbols, giving a set of complex time-domain samples. These samples are then quadrature-mixed to passband in the standard way. ...
0
votes
1answer
18 views

Question based on scaling the FFT for obtaining PSD

Following is the code given in MATLAB's site to estimate PSD using FFT. ...
0
votes
0answers
9 views

FFT and correlation between two signals for word detection

I have a task where I am supposed to make a python script for word recognition and I am not allowed to use any high order python commands without the fft and ifft command. The audio signal is ...
4
votes
1answer
56 views

What is Faster Than Nyquist signaling?

Faster than Nyquist signaling is used to improve the spectral efficiency by reducing the time spacing (relaxing the orthogonality constraint) to pack more data in the same channel while tolerating a ...
0
votes
1answer
29 views

Signal reconstruction from sampled signal?

Can we construct exact analog signal at receiver as same as source from the sampled signal????
0
votes
1answer
33 views

Correlation of a signal

I have one sample for a signal. This sample is a vector of length 384. I need to calculate the correlation matrix for this signal,So I need many samples for the same signal. How can i generate these ...
0
votes
0answers
9 views

Difference between morphological gradient and derivative of 1-D signal

What is the difference(s) between morphological gradient and derivative of 1-D signal (x(t))? Thanks in advance.
1
vote
0answers
15 views

“Image Processing” [on hold]

I'm an Italian student. I'm studying Gnu Radio and I would like to upload a photo, can I upload it with "file image source" or other blocks? I need to make FFT of an a image. -> image 2D Thank you ...
5
votes
2answers
753 views

Why should an image be blurred using a Gaussian Kernel before downsampling?

I recently read that before downsampling an image, it should be blurred using a Gaussian Kernel. This way, the downsampled image is better than just picking a single pixel out of a NxN block or ...
0
votes
1answer
22 views

Implementing real-time signal processing filters

I’m currently working on my capstone for school, and I’m looking for some guidance/tips when it comes to real-time filtering. The nature of the project is to monitor breathing patterns, send the ...
0
votes
1answer
23 views

how to create a harmonic mask from fundamental frequency?

Using an algorithm that gives the fundamental frequency across time, example https://www.mathworks.com/help/audio/ref/pitch.html (or some other one?) how would I then use that, to create a harmonic ...
0
votes
0answers
14 views

Multirate System - reduce to QMF

I have the following digital system shown below, the problem is to first redraw the schematic using multirate and single rate blocks. I understand that to split into even samples, decimate x[n] by two ...
0
votes
1answer
13 views

What is an intuitive understanding of the difference between the minimum required bandwidth and actual bandwidth?

When using for example, polar signaling of full width rectangular pulses, the bandwidth is equal to the pulse rate $Rb$, which is also the bit rate. $B=R_b$ for full width rectangular pulses. But ...
0
votes
0answers
21 views

Expressing a square as product of rect functions

A square is centered at origin and length of one of its side is 'a' units. In terms of rect functions, such a square can be expressed as product of two rect functions, i.e., $f_a(x,y) = A [rect(mx)] ...
0
votes
1answer
25 views

Using IFFT for the purpose of “Multiple Orthogonal Frequency Shift Keying”

Is it possible to create a set of complex orthogonal sinusoids using FFT or IFFT In other words a kind of "Multiple Frequency Shift Keying" using multiple sinusoids that are created with a fourier ...
0
votes
0answers
20 views

How to use signal.lfilter?

I am processing EEG data(.tdsm) and i tried to implement the Ellipitic filter. But I can't manage to pass the signal through signal.lfilter, the end result doesnt seem correct because only the ...
0
votes
1answer
11 views

Removing lines of certain length from an image in MATLAB

I want to remove the portion of the line (highlighted by the yellow circles) where pixels form a straight vertical line segment. If I use the strel ...
0
votes
0answers
8 views

Average around pixel clusters

Im looking to replace the values of pixels / pixel clusters in a greyscale image with the average of the values of their boundaries. Suppose the greyscale image is given by $I$ and the pixels to ...
0
votes
0answers
26 views

Steps for proofing Tweedie's Formula

Assuming that $f_{X|D}(x|d)=e^{\alpha d x - \psi(d)}f_0(x)$ for some constant $\alpha$ such that it is a valid pdf for every value of $d$, i want to establish that: $$\mathbb{E}[D|X=x]=\frac{1}{\...
0
votes
2answers
32 views

Find original Hz of converted audio-file?

I have received an audio file which is 44.1kHz wav. My ears suspect this audio clip was originally lower than 44.1, and encoded to 44.1 later, much like re-encoding a 720p video to a 1080p video. Is ...
1
vote
0answers
20 views

Kalman Filter: Computation of state covariance matrix

A simple system is described with the following state vector with a and b being the states. $$ x_{k-1|k-1} = \begin{pmatrix} a \\ b\end{pmatrix} $$ For the sake of discussion, let x be assumed to be a ...
0
votes
2answers
53 views

Shifting signal smaller than discrete step

I have a image that I need to shift with less than a pixel. My plan was to do a Fourier transform and multiply the signal with $e^{-aiu-biv}$ where $a, b$ are the shifts in x and y direction. This ...
0
votes
0answers
9 views

is discrete wavelet transform (DWT) appropriate to detect and calculate noisy shear wave arrival time? [on hold]

what is suitable command in (DWT) that can be use to detect specific point like attached figure
0
votes
1answer
32 views

Signals and Systems - LTI - Transforms - Impulse Response

I have $x(t)-> LTI -> y(t)$ where $LTI=h(t),H(jw)$. and $H(jw)=ab/((a+jw)(b+jw))$ where a and B are real numbers. I am wanting to find the impulse response $h(t)$ as well as the input/...
1
vote
1answer
34 views

Real time background noise reduction or removal

I am trying to build a real time simple audio recognition that can recognize few keywords. Following this tensor flow tutorial i was able to train a simple neural network. Currently the signal flow ...
0
votes
1answer
25 views

Find identical audio signal

I have a long audio file (in wav) and a short audio file (in wav) that has been copied from the long file. Now I need to find the correct location where the short signal has been copied from. I tried ...
0
votes
1answer
19 views

Equalizing a temporal sound signal with a convolution

This question is more or less the following of a previous question. The aim is to equalize some sounds signals. By equalizing, I mean increasing or decreasing some frequency ranges, a bit like an ...
0
votes
2answers
31 views

Identify random repetitive patterns

Forgive me if it’s too basic, I finish engineering a while ago. Given any time series, not periodic, I would like to find any repetitive pattern that is distinct (by some given measurement) and is ...
1
vote
1answer
44 views

Why does SNR have an impact on the bit rate?

I have some confusion regarding the impact of SNR on the bit rate. For example, if I have a QPSK-OFDM system, then my bit rate will be 2bits mutiplied by the number of sub-carriers of the OFDM ...
0
votes
1answer
57 views

Basic confusion about the DFT and convolution

I am learning DSP (with Digital Images) and I have some elementary confusion about the convolution between two discrete periodic signals. Specifically, I have learnt that when filtering an image, we ...
-2
votes
1answer
25 views

Frequency component not filtered properly

Does frequency component other than wanted signal present in output if yes than why it not disturb original signal??? I think all practical filter response are not ideal so all frequency component ...

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