0
votes
0answers
15 views

What does it take to design a 4th order band-pass filter with -24dB/Octave?

I would like to implement in software the same isolators that the Pioneer EFX-500 features: The manual says the following about the isolators: High-performance 3-band Isolator Function [Fourth-order ...
0
votes
0answers
11 views

How to find the probability of Kalman filter states? [OpenCV+Python]

I am working on a video object tracking problem. I am using Kalman filter to predict and correct the object position return by an algorithm such as CamShift. I want to adjust the likelihood ...
0
votes
1answer
19 views

How range of the signal increases when modulation is done?

I am very confused because we know by increasing frequency we decrease the wavelength hence the distance covered will be very less but when we modulate a signal we are basically increasing the signal ...
-2
votes
0answers
9 views

coupling a 56K modem in V32 mode over a full duplex HF radio link

While it seems more a HAM Radio project, I think i may find some hints here over the feasibility of the project. Suppose that i have two transceivers operating over two HF frequencies, a phone line ...
2
votes
2answers
138 views

Can the instantaneous frequency be always derived from an analytic signal?

Instantaneous frequency can be defined as a derivative of an instantaneous phase of an analytic signal which can be nicely seen in practice in this example from Scipy's documentation. But it seems ...
0
votes
0answers
10 views

BCJR equalizer modification to begin and end at non zero state

I use the "decode_bcjr" function as my ISI channel equalizer in the following code: https://github.com/susalib/susa/blob/master/inc/susa/channel.h This assumes the channel output begins and ends at ...
0
votes
0answers
21 views

Hilbert transform “pass band”

I sample a human speech at 24kHz, to make the Hilbert transform using FFT and iFFT. What are the minimum and maximum frequencies (or range of frequencies), which will be 90 degrees shifted? Maximum ...
0
votes
1answer
20 views

Computation of the Inverse DCT (IDCT) Using DCT Or IFFT

Is there a way to compute the inverse discrete cosine transform (type-2) by leveraging either a DCT, FFT, or IFFT algorithm? I have seen ways to compute the DCT using FFTs, and I've seen ways to ...
1
vote
2answers
32 views

Signal bandwidth of an 802.15.4 signal at 2.4 GHz

This signal uses Offset QPSK with a half sine pulse shaping filter for the purpose of getting a constant signal envelop. Does anyone know the exact bandwidth of this signal after being pulse shaped, ...
0
votes
0answers
23 views

Synchronization , channel estimation, frequency error correction challenges in a digital receiver

A digital receiver is supposed to do carrier phase synchronization, symbol timing synchronization, channel estimation for the purpose of equalization and also correct for any residual frequency error ....
0
votes
0answers
13 views

Half wave rectified difference in python

I'm trying to calculate a half-wave rectified difference between two audio files using librosa and then convert this output back to an audio file. I'm having difficulty figuring it out. In particular, ...
2
votes
4answers
28 views

Bandlimiting and OFDM spectrum - what is considered “bandlimited”?

I have been reading about OFDM modulation, it's not clear to me how you can have band-limited OFDM but given its prevalence in wireless communication there must be some designation of approximately ...
2
votes
0answers
21 views

Help designing a fast linear operator of {-1,+1} entries with low condition number *and* low hamming distance between consecutive rows

I need to design a matrix for compressive imaging where each row represents an N-pixel filter in a focal plane through which light is masked, summed, and measured (think Rice's "single-pixel camera"). ...
0
votes
1answer
25 views

Phase of a signal with multi delayed windowed (rectangular window) signal with different amplitudes

I have a signal $x(t)$ which is composed of multi delayed linear chirps with different amplitudes and phases but they share the same $w$ and $\alpha$, the signal can be expressed as follows: $$\...
1
vote
1answer
50 views

Goertzel algorithm produces incorrect phase

I've implemented Goertzel algorithm according to the Wikipedia page (https://en.wikipedia.org/wiki/Goertzel_algorithm) and another page (http://www.mstarlabs.com/dsp/goertzel/goertzel.html), which are ...
0
votes
1answer
24 views

How to make sinewives with array input, for-loop functions and operate array with others [matlab]? [on hold]

Thanks to previous question, I got some clues to resolve this one. But, I still get some problems here. ...
1
vote
1answer
14 views

Audio Processing Used in Voip Mobile Apps

I am new to VoIP apps and am learning about the various audio processing that are applied in such apps. I have looked at Linphone and ...
0
votes
2answers
31 views

Spectrogram from scipy.signal with Python

To test the python spectrogram (from scipy.signal) , I've created a signal with 2 harmonics: 2 Hz and 8 Hz. Then I've added 50Hz noise and a trend (https://i.imgur.com/t1SnQck.png). I wanted to ...
0
votes
1answer
25 views

Emulating a Variable Delay

I am trying to emulate a satellite link where the delay time between the satellite and ground station changes over time due to the satellite's motion. I plan do this by converting to the frequency ...
0
votes
0answers
16 views

Doppler compensation in a multi-user communication [on hold]

How to estimate and compensate for doppler shift in a multi-user communication for example the cdma?
-3
votes
1answer
20 views

How do I generate sine waves with MATLAB’s max operator and the plot the resulting values in dB versus log frequency?

I just start learning about matlab. Im very confuse with this. Can anyone gives me such an example solution or any kind of help? HINT: Put the desired input frequencies in an array and use a for-loop ...
0
votes
1answer
22 views

How to make semilogx to get a plot gain against log frequency with several values? [beginner]

Gain: 20 log (Vout/Vin) with Vin = 1.0. I've been searching for gain values: a. -156.48 dB b. -80 dB c. -53.98 dB d. -13.98 dB e. 3.52 dB f. 10.32 dB g. 13 dB h. 13.93 dB i. 13.96 dB j. 13.98 dB I am ...
0
votes
1answer
48 views

FIR filter design: evaluating the error function

Question 1 $$ H(e^{j\omega})=\sum_{n=0}^{N-1}h[n]e^{-jn\omega} =\mathbf{c}^H(\omega)\cdot \mathbf{h} \tag{1} $$ $$ =\mathbf{h}^H\cdot\mathbf{c}(\omega) \tag{2} $$ $$H(\mathbf{h})=\sum_{k=1}^Kh[k]e^{...
1
vote
1answer
26 views

Where to learn about “analog prototype filters”?

Where to learn about "analog prototype filters"? I've heard about them, but I'm unsure about what they really are and how they're constructed.
0
votes
1answer
31 views

Extracting positive frequencies of discrete-time signal

Convolution in the time domain is the same as multiplication in the frequency domain. My data is sampled at 200 Hz, which means that the Nyquist frequency is 100 Hz, and all frequency content is <=...
0
votes
1answer
39 views

Equalizers with low data rate systems

In case of using equalizers with ZigBee systems, what type of fading does the channel show, flat or frequency selective, fast or slow? Is the inter-symbol interference (ISI) problem encountered in ...
0
votes
0answers
9 views

How to align two images with OpenCV and python?

I have below reference image and defective image to align to find the errors of the defective image using subtraction. How can I align defective image with reference image?
1
vote
0answers
12 views

motion compensation for range migration algorithm

Is there a simple to follow explanation of how to do second order motion compensation for range migration algorithm? The one described in Carrara et al is for the ideal case. For the Extended Omega K ...
0
votes
2answers
16 views

Detect gradual increase then decrease in slightly noisy data

I have data thats not too noisy and I am trying to detect a pattern where it gradually increases then decreases in a short period of time (20 ticks? it should be roughly similar per session but can ...
0
votes
0answers
15 views

Compare images of road marker

I just want to check my approaches to the problem and see if they are really correct or whether there can be a better way Problem: I have a scene of road marker (they are predominately lane lines, ...
0
votes
1answer
32 views

How to measure acoustic pressure level under water with a hydrophone?

this is my first post here and I am also new in signal processing. Let's say I have a hydrophone with amplifier which is connected to a sound card plugged in to a computer. I gather the sounds to a ...
2
votes
2answers
43 views

Level Correction For Digital Down-Convertion?

I am trying to understand a subtle (sorry if this is obvious) difference in the computed output power after a DDC process. Here is the story: Suppose I generated a 10 MHz signal from a microwave ...
-1
votes
1answer
38 views

Is this a FIR algorithm?

I'm kind of out of my element here trying to understand this algorithm and I wanted to see if this is a FIR algorithm or not? If this isn't the right place to ask this, can someone point me to a place?...
0
votes
1answer
31 views

Covariance matrix associated with random DC level in Gaussian noise

Given a signal $x[n] = A + w[n]$ where $A$ is a Gaussian random variable and $w[n]$ is Gaussian white noise, then the covariance matrix of the signal is given by $[C(\sigma^2_A)]_{ij}=E[x[i-1]x[j-...
0
votes
1answer
38 views

Simple question about Sinc()

Suppose I use the ideal lowpass filter eq to attempt creating a IIR filter using it : $$ h[n] = \frac{\sin(\omega_c \, n)}{\pi \, n}, \qquad -\infty < n < \infty $$ Obviously, I can't really (...
1
vote
1answer
39 views

About speech preprocessing in mobile phones

I understand that cell phones transmit speech signals in digital form through 2G/3G or other standards. But I could not find anything about the signal processing method lying in between the analog ...
0
votes
1answer
13 views

2D CFAR detectors

Constant False Alarm Rate is an adaptive detector used to distinguish between true and false detections. There are many types of CFAR and the number of these detectors reaches 25 like (CA-CFAR, OS-...
1
vote
1answer
42 views

Derivative with respect to complex conjugate

I have a real function $C$ of a complex vector $x$. While taking the gradient of the function $C$ for minimising the same, why do we take the derivatives with respect to the complex conjugate of $x$, ...
0
votes
0answers
23 views

How can I account for the 180 degree ambiguity in radio Direction of Arrival?

I'm working on a phase interferometry direction of arrival system for radio signals. It somewhat works for a range of 180 degrees (still very jumpy / imprecise), but due to only sampling at 2.4 ...
-1
votes
0answers
11 views

emgucv how to detect a full object and it's components?

I want to detect sperms in a photo and I could only detect the head by using threshold then gave them a color and detect that color the problem is how to detect the full sperm and get the size of ...
-1
votes
1answer
53 views

How can I determine the order of filter?

This is my first study about signal analysing. I'm very confused about filter order. My problem is how can I know whether its 12-th order, or 2nd order like the book says so? I already knew that slope ...
0
votes
0answers
10 views

What is the size of Kernel I should Keep when using Sobel filters for finding Vertical Gradient of Image?

I've trying to find the vertical gradient of OCT images of retina and extracting top 3% of images to create an image containing my point of interest ...
-1
votes
0answers
14 views

how to plot data from Vector Network Analyzer using Matlab? [on hold]

Please help: I have a VNA HP8735D 30KHz-6GHz. I am working on my project to measure the spectrum of the signal. I succeeded. I am trying to do a report with a plot which I have seen on the VNA using ...
2
votes
2answers
48 views

Detect valleys of a signal

I have raw values that are coming directly from a sensor (on the fly). I do a quick calculation on these values and I end up with a graph like the bellow image. I would like to be able to detect ...
0
votes
0answers
21 views

Trying to prove BIBO stability implies the boundedness of the impulse response of an LTI system without a counterexample

I have tried to prove that BIBO stability implies that the impulse response of the LTI system, can someone please check if the proof is correct?
-1
votes
1answer
37 views

How can I evaluate the complexity of two solutions when both additions and multiplications are present?

I am evaluating FFTs algorithms radix-2/4 and split radix. (although this talk can be applied to any algorithm). Each of them has a certain amount of complex additions and multiplications. That can ...
-1
votes
0answers
11 views

open source to detect/compare a 2 tone pager audio signal

I'd like to develop a project that would detect the audio, compare that to a known pager tone and then an event action during a true detection. Is there any C++ open source code for signal ...
0
votes
1answer
66 views

Discrete Fourier transform of an exponential decay

I have a vector with an exponential decay, using Numpy: t=np.arange(128) k=0.1 decay=np.exp(-k*t) I would like to compute the discrete Fourier transform (DFT) of ...
0
votes
1answer
41 views

What's the difference between Channel shortening and time-domain equalizer

I'm asking about the difference about channel shortening and time-domain equalization. I have checked on-line and tried to get something clear but I couldn't. What I found is that channel shortening ...

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