# What is Signal processing: Definition and 131 Discussions

Signal processing is an electrical engineering subfield that focuses on analysing, modifying, and synthesizing signals such as sound, images, and scientific measurements. Signal processing techniques can be used to improve transmission, storage efficiency and subjective quality and to also emphasize or detect components of interest in a measured signal.

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1. ### Studying Critique My Self-Study Schedule (Signal Processing & RF Electronics)

Hello everybody. I have already graduated I am currently in training at work which I am required to finish intensive courses. So I will start when it's completed. My interests are in Signal Processing & RF Electronics which you could tell by the study plan I created. I will be taking a slow...
2. ### I Making Sense of Notation Confusion in Statistical Digital Signal Processing

I started my research in statistical digital signal processing two years ago, so I need to familiarize myself with all the notations people use in probability and statistics. I come from a deterministic science background. I name my variables based on what they mean. A velocity is a v , a...
3. ### I What is a distinct feature of an ambiguous result?

This question comes from my experience in radar signal processing. As I am going more deep into the theory of sampling, statistical signal processing and estimation theory in general, I have a very silly but important mathematical question that I want to ask here. For example, we are estimating...
4. ### Wavelength / signal which would pass through concrete and rubble

Greetings, Please imagine a huge pile of rubble, meters deep. Somewhere inside, there's a device emitting a certain signal. This signal can be picked up by a radar-like device which locates the origin of that signal, with the least interference from the pile of rubble, concrete blocks, metals...
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### Link between Z-transform and Taylor series expansion

Hello, I am reading a course on signal processing involving the Z-transform, and I just read something that leaves me confused. Let ##F(z)## be the given Z-transform of a numerical function ##f[n]## (discrete amplitudes, discrete variable), which has a positive semi-finite support and finite...
6. ### Signal Processing: Finding the auto-correlation

Hi, I am working on the following problem from a textbook, but am getting stuck and am not sure how to proceed. Question: For the system below: v(t) = -cv(t - 1) + e(t) where ## e(t) ## is a zero mean white noise sequence with variance ##\sigma_e ^2## , determine the first two terms in the...
7. ### How to make an audio processing device for noise reduction ?

Hello everyone !I am working on noise reduction and I wanted to do some experiments with an arduino. I took an arduino which get music (as an example) in input by jack. It also has a microphone and in a first try the goal is to get as an output the music - the noise around... To act like a kind...
8. ### Engineering Power and RMS Value of a Signal

I need to calculate the power and RMS value of some equations. The problem is, I found two methods to do that and don't know which is the right method. I have few equations to find the power and RMS value, but here is one equation. $$x( t) \ =\ 7\cos\left( 20t+\frac{\pi }{2}\right),$$ Method...
9. ### Can someone give me a better intuition of bandwidth?

Can someone give me a better intuition of bandwidth. The way I see it, is that the bandwidth is the range of frequencies which a signal/wave is allowed to have. This doesn't feel complete though. For example, how can I explain that TDMA, FDMA and CDMA are similar in this sense. As far as I know...
10. ### Signal Processing: DFT spectrum of sinusoid signals

Hi, I was recently reading about the discrete Fourier transform and its application to a basic sinusoidal signal. If we know that it has an integer number of cycles in ## N ## samples (and thus no leakage), why would there be two peaks in the spectrum: one at ## m ## and another at ## N - m##...
11. ### Advice for my first course in Discrete Signal Processing?

Summary:: I'm about to take my first course in DSP. It is a one term graduate course using the 4th edition of Proakis. I'm about to take my first course in DSP. It is a one term graduate EE course using the 4th edition of Proakis. Does anyone with experience in this have useful advice for such...
12. ### A Applications of analysis in signal processing/machine learning?

Hello everyone, My question for this thread concerns the application of (mainly) mathematical analysis to fields such as signal processing and machine learning. More specifically, I was wondering if you happen to know of some interesting application of things like measure theory or functional...
13. ### Engineering How to find RMS, and Peak Voltages of this signal?

Hi all! I have a complex waveform, something like what I have attached, and I need to extract the RMS and Peak Voltage from this. However, this signal can and will change after a number of cycles on a certain setting. So, this means the period and duration of pulse can change and so can the...
14. ### Engineering Signal Conditioning and Processing

I'm thinking that I am going to need something like a low pass filter around 100 Hz so that low noise disturbances from a nearby PSU and such won't disturb my sampling. However, the unit will have to operate around 50 Hz sometimes. Is it possible to use a Fast Fourier Transform to filter out...
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### A Signal Processing and the Duffing ODE

Hi PF! Attached are two plots: signal.pdf is a solution from the Duffing ODE, and plots vertical displacement over time, both the raw signal (blue) and the reconstructed signal from an FFT (red). I've also shown a zoomed in view so you can see how oscillatory the signal is. pow.pdf plots the...
16. ### Gibbs phenomenon caused by digital signal processing?

Hi, I'm an electrical engineer for a few years now, but it's been a while since I had to deal with this kind of stuff, I turned out to become mostly a programmer in the end, but i was thinking: is Gibbs phenomenon, which was demonstrated to me during my studies while working on Fourier series...
17. ### Is a Brain-to-Computer Interface Possible? Join Me in My Journey to Find Out!

My name is Chad and I am a senior level undergraduate Electrical Engineering major. I have an interest in physics as well and am doing undergraduate research currently on semiconductor materials that can convert beta particles into electrical energy. I am knowledgeable in the area of EM waves...
18. ### Problem understanding a parameter in a digital filter

Homework Statement Digital causal recursive filter is a part of a digital signal processing system which has sampling frequency ##fs = 1200Hz## and is given by a differece equation: where ##r = 0.9## and ##θ## is such that it filters out the spectral components at ##f = 200Hz## Find ##H(z)##...
19. ### How to use the window functions on a signal in MATLAB?

Homework Statement I am suppose to write a program that compares the FFT (Fast Fourier Transform Diagrams) of a sampled signal without the use of a window function and with it. The window function should be as long as the signal and the signal should have N points, N chosen as to not cause...
20. ### Delay and Sum Beamforming Equation Derivation

Homework Statement I have to simplify this beam form (equation 1) which simplifies to equation 2 and then finally to equation 3. Homework Equations equation 1: e^-ix((1-e^y)/(1-e^z)) where x = Beta*M_(1/2), y = beta*M, z= Beta equation 2: sin(M*Beta/2)/(sin(Beta/2)) equation 3...
21. ### I Informational content in 2D discrete Fourier transform

When you do a discrete Fourier transform (DFT) of a one-dimensional signal, I understand that the second half of the result is the complex conjugate of the first half. If you threw out the second half of the result, you're not actually losing any data and you would be able to recreate the entire...
22. ### Angular frequency of a non-sinusoidal pulse

Hey all, so I’ve been learning nonlinear acoustics and have encountered a conceptual hurdle in my studies. When using a model, such as a form of the classical Burgers equation, to propagate sound waves, you generally have a “characteristic angular frequency” in the equation (often represented by...
23. ### Engineering Course Choice: Robotics, ML, Adaptive Signal Processing

I wasn't sure if I should post this here or academic guidance but given the career factor in this question I will post it here: I am doing a masters in electrical engineering with a focus on signal processing but I am also interested in others areas such as machine learning and robotics. I need...
24. ### Magnetic encoder signal processing

I've been using DC motors with magnetic hall effect encoders on them to measure position control. It's basically a feedback servomotor system. i've so far been feeding the signal into my microcontroller's interrupts. This has been causing some problems with my timers and program. Let's say the...
25. ### I Can Complex Equations Break the Bounds of the Unit Circle?

Is doing the same thing repeatedly... Can I spin out of the unit circle with the solution to this equation: (a^2 + b^2) / (a * b - a / b) = (a / b + b / a) Extra Credit for a refutation. Hint: signal processing.
26. ### Steady state responses clarification of problem

Homework Statement I am trying to understand what the difference in the two questions (linked) are. I understand how to find the steady state response for x. Is the second question just asking for the first and fourth element in the Xss matrix? Homework Equations Xss=[q1 q2 q1dot q2dot] The...
27. ### Problems designing an FIR band pass filter on MATLAB?

Homework Statement So I've been tasked with designing and band pass filter for my signals class. We're given the specifications that it needs to go from 200-5000Hz, and we need to use a kaiser window as the window function. Homework Equations There are 2 parameters, beta and N, given by these...
28. ### Engineering Signal Processing jobs with a Biomedical Engineering degree

I'm starting a new job search where I'm interested in getting an entry level engineering position so I'm trying to figure out the industries where I would realistically be able to obtain a job as an engineer. I obtained my A.S in Engineering Science, my B.S in Physics, and my M.S in Biomedical...
29. ### How to center the bandwidth for carrier frequency?

I have a baseband signal in IQ form. I have a method to calculate the carrier offset and estimate the carrier bin. I want to center the carrier to the middle of the bandwidth. How do I do so? Do I simply multiply the IQ data by the exponential with the carrier offset, but doesn't that shift the...
30. ### DSP Tuner - Is this correct for freq offset?

Say I already calculated the frequency offset after the ADC, which was calculated using a 1,048,576 FFT, but I only have 1,040,000 IQ samples. Do I need to use a non power of two FFT method or will the follow work? freq corrected IQdata = sum of iqData(i)*[exp(i*2*pi* n*freq_offset*(diff...
31. ### Complex Exponentials Signal processing

Hello everyone. Iam about to read a course in DSP and I can't get my head why complex exponentials are used as input signals that often? Is it just to simplify the math? If not, what exactly is the imaginary part of a complex exponential? Does it "do" anything special compared to a real valued...
32. S

### Baseband Signal Processing and Digital to Analog Converters

Hi Guys, I have a question on the need for Digital to analog converters in Transmitters. To elaborate bit further: 1) Because of the advantages of the Digital signals, most go the signal processing in wireless communications is performed in baseband. But my question is: Since digital...
33. ### A Difference of WMA & EMA on a sinusoid becomes superposed?

This is about signal processing, moving averages & superposed / standing waves. This is an online system: causal (univariate) time series analysis. Suppose you have a sinusoid of period n (i.e. n=40, so its frequency is 0.025). If you calculate a "weighted moving average" (WMA) on this sinusoid...
34. ### A Calculate Third Octave Band Response from Narrowband Data

I have a signal that I am able to calculate through an acoustic model for airfoil noise. I am told that the model solves for a narrowband frequency response, however, my measurement data is provided in third-octave band representation. How do I convert my current dataset to the third octave...
35. ### What is preventing me from achieving better accuracy for this delay?

I have 2 PERFECT data of the transmitter and receiver. From 2 data, I can calculate the delay estimation: Fs = 8e6; % sample rate ... for i = 1:2 [cc_correlation,lag] = xcorr(signal2(i), signal1); [cc_maximum, cc_time] = max(abs(cc_correlation)); cc_estimation...
36. ### How to calculate standard deviation?

I have 2 signals: signal1: https://www.dropbox.com/s/zr04pff9skeh8cn/TX.dat?dl=0 signal2: https://www.dropbox.com/s/h436a915dd99hln/RX1.dat?dl=0 signal2 represents for 20 measurements, each measurement combines with signal1 to get time delay estimation using xcorr. So, I will have 20 delays...
37. ### How to calculate Time Delay Estimation?

I have 2 data files, which links are attached below: Transmitted data https://www.dropbox.com/s/0nmhw6mpgh7upmv/TX.dat?dl=0 Received data https://www.dropbox.com/s/xgyo6le3bcmd25r/RX.dat?dl=0 Those binary data are read by this MATLAB code: %% initial values: nsamps = inf; nstart = 0; %% input...
38. ### Understanding time delay estimation for GPS?

I really need help to understand these questions which is highlight, for the GPS situation, I hope anyone who has been working in this situation before, please help me to have a clear understanding about "time delay estimation": Here is the scenario: 1. Suppose I know precisely I have transmit...
39. ### Why OMP is iterative? Can we find the support in one step?

In OMP why the 'support' of the received signal is not found in one step, by selecting the $K$ maximum correlated columns of the sensing matrix $A$? where $K$ is the sparsity of the signal. Like in MATLAB [val ind] = sort(A'*Y); %Y is received signal signal_Support = ind(1:K)...
40. ### Upsampled input to an Adaptive filter?

I will try to explain the issue I am having as clearly as possible without going into my coding or maths. I have my own and a MATLAB Central implementation pf standard LMS in MATLAB. Fixed step size. No normalization or other stuff. I am trying to use it in a system identification setup. I...
41. ### How to compute the location of the antenna when I rotate it?

Hi group, I have a question regarding to detect the location of the antenna. I read this link: https://en.wikipedia.org/wiki/Plane_wave In the "Complex exponential form" part, the equation: U(r,t) = U0 * exp(j*(k.r - w*t) as the function of location and time U0 = A0 * exp(j*phi) : A0 and...
42. ### How to calculate standard deviation from the delay?

I am trying to calculate the unit vector and standard deviation of the signal. I hope everyone can give me ideas. Here is my scenario: I have 2 rx channels: - f is channel 1 with the length 1x256 complex, then FFT. - g is channel 2 with the length 1x256 complex, then FFT. - from f and g, I can...
43. ### Just curious, searching for explanations or research

Outdated Control Systems Engineer with a PhD in Industrial Preventive Maintenance, in training for a double major in Chemistry and Biology. Prefer to work the math, reason and deduct, infer, interpolate and extrapolate, yet a lot is presented to me as to be "simple memorization", so I have to...
44. ### How to calculate the time delay based on a function of antenna angle?

Hi everyone, I am a new student who is studying on collecting data from TV signal. I hope everyone can help me for ideas. I am having spectrum analyzer which can define a TV station around me, so I chose 4 stations WHUT-TV [584MHz 590MHz], WPXN-TV [590MHz 596MHz], WTTG [60 MHz 608MHz], and WNVC...
45. ### Digital signal processing and the z-transform

Hi I am currently learning Digital Signal Processing from Applied Digital Signal Processing by Manolakis and Ingle. However, my background is in mathematics, so I like being shown why an assertion is true. So, in the chapter about the z-transform is where I start seeing this becoming an issue...
46. ### I Discrete Convolution of Continuous Fourier Coefficients

Suppose that we have a 2\pi-periodic, integrable function f: \mathbb{R} \rightarrow \mathbb{R}, whose continuous Fourier coefficients \hat{f} are known. The convolution theorem tells us that: $$\displaystyle \widehat{{f^2}} = \widehat{f \cdot f} = \hat{f} \ast \hat{f},$$ where \ast denotes the...
47. ### Studying Supplementary book for intro signal processing class

The required textbook for my intro signal processing class is "Signal Processing First" by James McClellan. So far I like the book quite a lot because the author does a good job to explain the concepts clearly. However I feel like the book doesn't provide enough practice problems. I just want to...
48. ### Identifying Fundamental Frequencies

Homework Statement I have made a plot of a given .wav file in Matlab. The problem asks: find the fundamental frequencies of the 3 vibrating strings, and identify some of their harmonics. Homework Equations 3. The Attempt at a Solution [/B] So I made a Matlab plot of the power spectrum over...
49. ### Non-uniformly sampled transfer function data

I have non-uniformly sampled transfer function data (magnitude only) in the range of 100kHz and 200MHz. Using this transfer function, I would like to calculate output from specific input. Question : To obtain phase of the transfer function from the magnitude data, I am trying to use Hilbert...
50. ### Just how broad is a focus in signal processing?

I see a lot of electrical engineering graduate programs that offer concentrations in signal processing (analog or digital or both). I understand signal processing is used virtually everywhere, but how does one break into a particular industry with a concentration in signal processing? Can you...