# All Questions

24,724 questions
Filter by
Sorted by
Tagged with
2 views

### FIR filter phase response at fs/2

0 I am currently building a FIR filter based on frequency sweeping data (0 Hz to Fs/2), i.e., transfer curve in frequency with the sampling rate of Fs. The phase response is shown in the following ...
22 views

### Use of "Audacity"for teaching undergraduate labs of digital signal processing?

Can we use"audacity"for teaching undergraduate labs/practicals of digital signal processing? or only MATLAB/Octave should be used? Weblink of "audacity" https://www.audacityteam....
• 841
10 views

### Interpretation of wavelet trasformation (synchrosqueezing)

I'm working on a dataset of spectroscopies and i'm classifing them by transforming the 1D signal into a 2D one by the library https://github.com/OverLordGoldDragon/ssqueezepy. For istance, consider to ...
18 views

### Pathloss calculation in RIS-assisted communication

If we have a path from the Base station to the User via RIS, There are two channels, one is from BS to RIS, and another one is RIS to User. Let's denote the distance between BS to RIS and RIS to User ...
7 views

### Why does EOG (eye EEG) spike and fall back down when you look to one direction?

Why does EOG (eye EEG) first spike and then immediately fall back down when you look to one direction instead if staying spiked and only falling back down when your eyes go back to neutral? From what ...
11 views

### Inverse Continuous Wavelet Transform off by constant factors

I am implementing a continuous wavelet transform and its inverse using morlet wavelets. When I compute the inverse, the resulting signal is off by some constant factor (but otherwise correct). ...
21 views

Single ADC is sampling at 16000 Hz the I and Q outputs of quadrature detector. So each I and Q signal is sampled at 8000 Hz, with phase offset 90 degrees between them. Bandwidth of interest is 3400 Hz....
• 25
1 vote
16 views

### How can a common trends be detected and filtered from multiple spectra data?

I'm looking at spectral data collected through Cavity ring-down spectroscopy. I'm comparing a few samples of similar analytes and expect slightly different peak heights and trends. However, there are ...
1 vote
29 views

### FFT Artifacts and their cause beyond frequency resolution

I am trying to work through an issue with an FFT for audio : I have no spectral leakage while playing back audio, but the moment I change or zero out a value in any of the FFT bins, artifacts are ...
• 11
28 views

### FMCW Transmit Signal and Fly-back Effect

I am studying a thesis about nonlinearities in the transmit signal and it mentions the following: The first 2,500 samples, which correspond to the Tmax of each of each sweep period and are affected ...
• 23
1 vote
234 views

### Why do some signals have "DC component" whilst others don't?

I am analyzing a series of oscillating data of items that gradually become less "floppy"/oscillatory and I have observed that those items that are less floppy/oscillatory tend to have, what ...
1 vote
17 views

### How to determine the permutation parameters for a Turbo Code Interleaver?

In the 2004 paper Designing good permutations for turbo codes: towards a single model it is mentioned you mention that : "turbo code permutation of DVB-RCS [5] and DVB-RCT [6] standards, which ...
• 962
1 vote
28 views

### Spreading sequence in DSSS [closed]

In DSSS, the spreading sequence is known only to the receiver and the transmitter. But for example, if we consider a spreading sequence built around a certain signal known only to the receiver and not ...
26 views

### Expressing mathematically the number of real addition operation for a vector after dividing it

I assume I have the length of such vector $y$ is $N$. In the first time I divide that vector into two columns and then sum them point-wise summation. The second time, I divide the same vector $y$ ...
• 593
1 vote
82 views

### Basics of interpolation: is filter or upsample first?

I am studying interpolation filter. I have thought if we speak about interpolation, we filter and then upsample a signal. BUT In an article, Interpolation (Digital Filter Design Toolkit, is given a ...
• 69
1 vote
20 views

### Stability analysis of hybrid discrete-continuous systems

I'm trying to derive the overall state-space system model for a hybrid system, in order to plot its eigenvalues. The system is shown as follows: Which is originally from this paper: Modeling and ...
1 vote
26 views

### How do I convert the Amplitude from Power/Amplitude spectral density?

I recently started working on PSD of seismic signals. PSD signal can be expressed in 2 ways. One in ($PSD=g^2/Hz$) and other in $PSD=((meter/sec.^2)^2/Hz)$ and $ASD = \sqrt(PSD)$. More details have ...
• 21
36 views

### Interpolate & sample period GNU Radio

I've a little question regarding interpolation in GNU Radio: I'd like to do an interpolation (by a factor of 2) and be able to change the sampling period of the samples interpolated but im having a ...
• 1
67 views

### Help Understanding FFT Plot?

I want to analyze FFT and Harmonics of my signal. As a proof of concept I tested FFT against standard signal. I am unable to understand why the frequency output is going to -1. Shouldn't it be +1 at <...
• 101
598 views

### Downsample a signal by a non-integer factor

I have a signal with a sample rate of 8.9286 MHz and I want to downsample it to 500 kHz. Since 8.9286 is not an integer multiple of 0.5 I can't simply decimate. Which downsample techniques are ...
33 views

### Demodulate qpsk with gnu radio

I'm trying to demodulate a qpsk signal with gnu radio. The signal is from the meteor satellite on 137MHz https://www.sigidwiki.com/wiki/Low_Rate_Picture_Transmission_(LRPT). I recorded the signal with ...
35 views

• 55
29 views

I am looking for an efficient image warping function $$f: (\text{image}\in \mathbb R ^{M\times N\times3}, \text{heatMap} \in \mathbb R ^{M\times N}) \to \text{warpedImage} \in \mathbb R ^{M\times N\... • 123 3 votes 1 answer 83 views ### MUSIC implementation in Pyroomacoustics library I am currently using the multiple signal classification (MUSIC) algorithm provided by the Pyroomacoustics library in order to estimate direction of arrival angles and it works pretty well for both ... • 152 0 votes 2 answers 30 views ### \min(\{Z_i\}) for non-i.i.d. random variables Z_i the same as for i.i.d.? My question is with reference to wireless communication. There are N independent and identically distributed random channels i.e., Z_i \in \{ Z_1, Z_2,\ldots, Z_N\} with PDFs f_{Z_i}(z) ordered ... • 17 1 vote 2 answers 37 views ### Random gaussian noise estimation from a given trajectory I wish to estimate the noise of given trajectory from a measurement (data which is provided). I consider that the noise is random gaussian noise. I add here examples of two trajectories, one of the ... • 111 1 vote 1 answer 33 views ### RRC filter has massive impulse response I am trying to pass a BPSK signal through a root-raised cosine filter in Octave. To do this, I convolve the signal with the impulse response of an RRC filter, defined as follows (source): The BPSK ... 1 vote 1 answer 44 views ### How to Calculate Frequency "X values" from a FFT/DFT Transformation First of all I am totally new to the DSP field and I have no background in it whatsoever, but my work in biology has led me to data that would greatly benefit from DSP. Any answers devoid of specific ... 0 votes 1 answer 57 views ### (Python - Scipy - Wave files) Can a float signal be written with values higher than 1? While developing an application, I noticed strange behaviour while using scipy.io.wavfile to write audio files. The documentation says that floating-point data is written within a range between -1 and ... 0 votes 0 answers 30 views ### What does the following structure mean and how to implement this structure in matlab？ Looking forward to explaining what this structure means, and the relationship between the two structures. Paper: An Efficient Spur-Aliasing-Free Spectral Calibration Technique in Time-Interleaved ADCs 0 votes 0 answers 22 views ### Research on SDR security Gnu Radio and legal transmission with filters In fact, I am doing research around SDR and possible dangers. Then I stumbled upon the most well known "replay attack". Via Black hills, I came across the following diagram in gnuradio: The ... 0 votes 0 answers 11 views ### Upsampling after S/P convertor in MSK modulation I have found this post "implementation a S/P conversion: different length / in Matlab" In the given implementation, Tsym = 2*ovs. ... • 69 0 votes 1 answer 48 views ### How to create an ideal sine wave that will be the best fit for given sine wave with noise and distortion I have a sine waveform that is a result of simulation. This is always single tone with a constant offset, but with distortion and noise and may have some jitter:$$s[k] = A\sin\left(2\pi \frac{f}{f_\...
• 261
10 views

I am trying to implement a GMSK transmission chain, over AWGN. I tried both the precoded GMSK and the GMSK without precoding, and in principle with the precoding we should see the BER halved. However ...
• 13
38 views

### Equivalence between two PSDs

I'm very very new to these topics, as I started last week my master thesis (mechanical engineering) on something related to vibration analysis. From an engine RPM distribution and the acceleration ...
1 vote
20 views

### Stationarity Test on Dataset

I have a nice and clean noise signal sampled at a fixed rate for several hours. When I calculate the PSD I see it's pure flicker noise. But I don't know much about the process. I've seen some ...
• 61
25 views

### Order statistics: always applicable tool in wireless communication?

I have seen few papers where generalized order statistics is used to obtain statistics of the instantaneous SNR. "Performance analysis of monostatic multi-tag backscatter systems with general ...
• 17
1 vote
27 views

### Inverse continuous wavelet transform output has significant error in magnitude and phase

For the inverse continuous wavelet transform, I am using a for-loop which runs through each frequency. At each frequency, I convolve the corresponding morlet wavelet with the signal at that frequency, ...
25 views

### A python-based implementation of time-frequency block thresholding for audio signals?

I'm looking for a python implementation of the block-thresholding algorithm introduced in this classic paper. I've been searching a while but I couldn't find it :(. There is of course a Matlab ...
1 vote
36 views

### Understanding Pathloss and latency

In my class on wireless communication, I came across the following sentence: The round trip path-loss can be defined to include aspects such as attenuation and/or latency etc Hence I am looking for ...
• 17
1 vote
52 views

### Meaning of "standard deviation noises of wavelet coefficients"

I am currently working on a research project based on the paper titled A deep learning approach for anomaly detection based on SAE and LSTM in mechanical equipment. The paper uses data in the acoustic ...