# All Questions

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12 views

### cascade and summation process in frequency domain using overlap and save method

hello i'm doing signal processing like this S : FFT of input signal from microphone Exp : just gain 1/(Q*J) : include frequency component, I convert this equation to frequency domain digital filter ...
25 views

### BPSK based audio digital communication system

As part of my diploma thesis I'm implementing digital communication system based on audio transmission in free space (STMF401RE + analog microphone). I'm using BPSK modulation and I've implemented ...
33 views

### Sample Rate Harmonics in a Multi-Rate System

I've observed an interesting phenomena in a system I am working on that almost seems intuitive, but I don't have a good explanation of. I'm hoping someone can offer an explanation of what's happening. ...
19 views

### Confusion regarding STFT phase vocoder-based pitch shifting

I'm currently working on a phase vocoder implementation based on the Short-Time Fourier Transform; it's heavily based on the models described here and here. I have successfully completed the analysis ...
73 views

### Why is Line coding called "Line coding"?

Guys do you now why line coding also called digital base band modulation named "line coding" where does it come? and how is the name related to modulation
26 views

### How to use a boxcar averager in conjunction with lock-in amplifier

Suppose there exists a temporal voltage signal composed of short pulses, modulated by a sinusoidal envelope. One desires a hardware-based signal processing scheme to maximize signal to noise ratio (...
48 views

### Energy and Time Signals

In Signal Processing, we broadly categorize signals as either being "Energy Signals" or "Power Signals". If the total Energy for a signal is finite, we categorize it as a Energy ...
19 views

### How to deal with [h] coefficients which are 0 from sos-matrix

Calling scipy.signal.sosfreqz with a sos-matrix describing an ordinary butterworth bandpass returns an array of h coefficients, ...
48 views

### How can I generate a sine wave with time varying frequency that is continuous in PYTHON!

The question was asked before in C: How can I generate a sine wave with time varying frequency that is continuous? How can I resolve the following problem? I want a continuous graph. But how do I do I ...
31 views

### cramer lower bound, MAE, and MSE

I am quite confused, is there any relation between MSE, CRLB and MAE. Can we test the efficiency of a Maximum likelihood estimator with the MAE, or must we use CRLB? Also is it true that CRLB is MSE?
33 views

### LMS beamforming Julia Programming

I have been trying to implement a simple LMS adaptive beamforming code. Since I don't have a Matlab license I decided to use Julia since they are quite similar. In order to get a basic code working I ...
15 views

### Viterbi decoder algorithm: metrics overflow

I am working on a Viterbi decoder of a convolutional-coded messages with rate = ½ and constraint length = 7. I work with a soft-decision algorithm with 4 Bit (+7/-8). I used the MATLAB function ...
21 views

### Filter characteristic frequencies of one time series signal dataset and paste/add them into another

I have two categories of a time series signal dataset in the time domain - one "good" and one "bad" category. My goal is to create "fake" bad data by filtering out the ...
26 views

### DFT algorithm output meanning

The result of calculating the amplitude of the audio through the DFT algorithm above is It came out as below. ...
17 views

### pattern recognition with some features in time series data

I am trying to capture peaks in a time series data which has some predefined feature. Here is a snapshot of time-series data (Time series data with peaks) In this time-series I want to detect peaks ...
19 views

### Is Discrete cosine transform Translational Invariant

I am using 2D Mellin-Cepstrum to extract features, If I use log-polar transform to get rotational invariance, the rotation is transformed to translation. Can I use DCT next to get translational ...
17 views

### Why is there fear of interference between 5G and airline altimeter C-band?

The C-band frequency range to be used for the 5G-advanced rollout is the US is in the 3.7-3.98 GHz range. Whereas altimeters operate in the 4.2-4.4 GHz range. Is there any genuine reasons to worry ...
12 views

### How important or interesting to increase the spatial resolution of linear array for narrow band or broadband radar for SONAR or other areas?

May I request your comments, please? Consider we have a linear array (radar) to detect some targets. The system may be narrowband or broadband. Using broadband we may get better time resolution but ...
115 views

### Why is taking the inverse Fourier transform the same as taking the Fourier transform when computing the cepstrum?

Usually, the cepstrum of a signal is introduced as the result of taking the logarithm of its power spectrum, then applying the inverse Fourier transform: $$C_p = |F^{-1}\{\log(|F\{f(t)\}|^2)\}|^2$$ It ...
44 views

### Telecommunication with same frequencies

If signal is transmitted with same frequencies they interfers, but why can't we use the technique of encryption and decryption to stop from interfering signals with same frequencies?
85 views

### range-doppler map to range-velocity map conversion

I'm trying to implement the pulsed-doppler radar algorithm. I've went through most of the steps and generated range-doppler map where the y axis is the pulse number and the x axis is the range. I'm ...
19 views

### How to calculate the average power of each frequency band?

I have EEG data from 30 participants, each recording is about 3 mins, and I'm trying to calculate the average power of each frequency band. I tried using Welch's or multitaper functions, but my values ...
57 views

### The Effect of Spatial or Temporal Averaging on Noise Properties

I generate two noise images using MATLAB's function imnoise(). If I average the two noise images, the resultant image looks like the original noise image but only ...
241 views

### How are sounds recorded and reproduced (played back)?

Someday I have suddenly got wondered how sounds are recorded and reproduced. I searched a little bit but the information I got was composed of difficult words and contents, so I couldn't understand ...
31 views

### How whip antenna even work if they don't have two terminals?

I understand antenna should have two terminals to emit radio waves like this: But in whip antenna it has only one pointy terminal, how does it work?
14 views

### Symbol time synchronization - Rounding up average symbol time and instantaneous time

I have a symbol timing synchronizer based on the techniques discussed here. My symbol time synchronizer seems to wander too far off (and fails to lock in some cases). I have tried to limit the average ...
21 views

### Complexity of ZF precoding at the transmitter

If we have a modulated signal $s$ and ($m\times n$) MIMO channel $H$ where $m$ and $n$ are number of receive and transmit antenna, respectively. The ZF pre-coded signal is x=Fs \end{...
42 views

### How fast is an histogram suppose to decay?

I am working on a software which receives streaming audio data, is expected to process that data on the fly, and then outputs the results. The module I'm working on is expected to adjust the audio ...
76 views

### Calculating complex AWGN in BPAM and QPSK

I was trying to add complex AWGN in a BPAM and a QPSK signal, manually. However I started using formulas as it is shown below (e.g. in BPAM) but the result was not the expected (also using as a ...
27 views

### Reconstructing function from samples

Assuming I have sampled my function with frequency above nyquist frequency, using the sampling theorem I can reconstruct my original function from the sampled values. Let's assume though that I change ...
35 views

### Understanding the high-pass filters in image processing

I am new to signal processing and I see that high-pass filters in image processing always have negative and positive value. In the image processing concept, why do masks have negative and positive ...
13 views

### How to systematically ignore image features (from a spatial light modulator)

(I am unsure if this is the best Stack Exchange site for this question. If not, please point me to the right one.) I am generating light patterns with a device called a spatial light modulator (SLM). ...
26 views

### Difference between Cramer Rao bound and mean absolute error MAE

Difference between Cramer Rao bound and mean absolute error MAE? I cannot see the difference, or where to use one and not the other. I know that Cramer and MAE are used to measure the quality of an ...
33 views

### Recognizing bees in a beehive

I would like to know if image recognition software would be sophisticated enough to recognize reach single bee in a bee hive separately (for the purpose of tracking it, and tracking, and accounting, ...
25 views

### Linearity of the system with Pearson correlation sliding window

I have a sampling system that consists of linear and non-linear components(analog filters, ADC, CPU, and so on). I made some HW changes and I want to verify that the linearity was preserved. My method:...
477 views

### Why is the arithmetic mean the same as the DC component of its fourier transform?

When we define $$\overline{\left|x\right|} = \frac1T\int_0^T x(t) dt$$ as the arithmetic mean of a signal we can see that it is the same as its dc component in the fourier transform. Why is this the ...
61 views

### What is the result of taking the real part and imaginary part of a complex signal in the frequency domain?

Suppose that $g(t)$ is a lowpass complex signal with magnitude (solid line) and phase (dashed line) To modulate $g(t)$ into a bandpass equivalent signal $f(t)$ with center frequency $f_c$, we compute ...
16 views

### Combining position estimates to enhance user localization

I have several estimated positions for an object. These positions come from several sensors. I would like to know if it is possible to combine these different positions into a single position. If yes ...
12 views

### Detecting bounded regions in JavaScript

I have an image of a crossword (i.e https://i.stack.imgur.com/qqy4X.png), and I would like to find the x,y coordinates of every valid square and the number associated with it, then I would feed it ...
16 views

### Filtering out motion noise from ECG

I have some ECG data that have some noise from motion in it. I also have have accelerometer data sampled at the same time. The idea is to use the accelerometer data to filter out motion noise from the ...
29 views

### What is reference sample in angle of arrival (AoA)?

I'm studying Bluetooth direction finding. The antenna sent I/Q data sampled start with first eight samples as reference sample and ninth sample began with sample data. Now I can calculate angle using ...
34 views

31 views

### Why doesn't the magnitude of Fourier Transform change when signal is shifted (i.e when a time shift is introduced)?

I understand that a time shift in the time domain produces a corresponding phase change / phase shift in the frequency domain. But I don't understand why the magnitude is unchanged (I am referring to ...
17 views

### Estimate a Wiener Filter with a defined inputs and system

I need to estimate a Wiener filter with two coefficients using the system h[n] = [1, 2, 3] and input x[n] = [1, 0, 2, 4]. May ...
52 views

### Identifying Instruments within a music file

Say I have a file that contains a few musical instruments, how can Identify the name of each one (ultimate goal) or at least the category they belong to, like wind instruments? For example, if I load ...
46 views

### Changing time base after applying raised cosine filter

I am generating a random sequence binary 0 and 1 to have OOK signal. ...
29 views

### Identifying an Instrument

Say I have a file that contains a single musical instrument, how can I use python code to detect which instrument is it (ultimate goal), or at least what is the category of instruments it belongs to (...
There is a random process, $X:\mathbb{Z}\rightarrow\mathbb{R}$ in discrete-time domain, which is wide-sense stationary with zero mean and autocorrelation function $R_X(\tau)$. a) What range of values ...