Questions tagged [discrete-signals]

A discrete signal or discrete-time signal is a time series consisting of a sequence of quantities.

318 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
0
votes
1answer
79 views

Harmonics in Quantal Histogram

I'm studying what I believe to be a system that produces a (noisy) quantal response (i.e. there should be a minimum increment of response). To do this, I've plotted a histogram of some ~6000 amplitude ...
0
votes
1answer
165 views

How to choose the right segment length for a given signal?

Im working on plotting the power spectral density of a random time series measured. I know the target spectrum.The idea is check the measurement vis-a-vis the target spectrum. However, I get slightly ...
0
votes
1answer
52 views

Measure 3-D length using smart-phone's accelerometer

I'm wondering if we can measure 3-D length only by our smart-phone's accelerometer. And we all know these low cost IMUs are not accurate. You can model accelerometer's error this way: $$ a = f*a' + g ...
0
votes
0answers
68 views

How can I find a relation between the input and output of the overall system?

I have system for filtering a continuous-time signal using a discrete-time filter where sampling is performed by multiplication with the impulse train. The frequency response of the discrete-time ...
0
votes
0answers
35 views

Sampling Process Question

This is what I know about the basic sampling process I am told that fbar(t) (i.e the sampled signal) is defined for all t. I don't understand that. If n is a finite integer (..,-3, -2, -1, 0, 1...), ...
0
votes
0answers
21 views

Find which groups of ants are coexisted in the location from their signal profiles using NMF

I try to solve biological problem to tell which groups of ants are co-existed at this location by their sounds in specific time frame. My chosen framework is Non-negative Matrix Factorisation (NMF) ...
0
votes
1answer
119 views

Amplitude problem by puting 5 FIR in a row

I'm trying to use 5 FIR in a row to improve the S/N ratio on my signal, but I have some difficulties doing it. In fact I have 2 signals, let's call them sig_I and sig_Q. I want to apply my 5 filter ...
0
votes
0answers
19 views

Join 2 NMF models where dictionaries has hierarchical structure

I have two NMF models $A = W_1A_{dict}$ and $B = W_2B_{dict}$ (where the $W$ represents weight coefficient matrix). What is a good way to join two NMFs if I know each column of $B_{dict}$ is summed up ...
0
votes
0answers
53 views

How do I improve the SNR of my signal given a noise profile (additive noise)?

From an iPhone microphone, I have a background recording of 5s(fs = 44.1 Khz), and immediately after that, I have a voice recording of a person saying 'aaa...' for 10s(fs = 44.1 Khz). How can I use ...
0
votes
0answers
53 views

Analog to digital controller- What sampling rate?

I'm studying about the design of controller in digital control systems. Right now I see the method in which I design my controller in the s domain and then convert it to the z domain. However, in ...
0
votes
0answers
618 views

Normalizing OFDM after IFFT

I had a question about normalizing OFDM transmit power after IFFT across each subcarrier. I have simulated OFDM with BPSK and according to different website I have used ...
0
votes
2answers
488 views

Design discrete controller for zero steady state error

I have the following system where $$G(s)=\frac{0.5}{s+1}+\frac{5}{s+10}$$ How can I design the C(z) controller so that the steady state error for a step input r(t)=1(t) is zero? I know that this ...
0
votes
0answers
155 views

how to simulate the Johnson noise in ccoomputer?

I am wondering how someone can simulate the Johnson noise in computer? I know it is random however I do not know what distribution it has. According to following link : its power can be calculated but ...
0
votes
0answers
96 views

DTFT of $ f[k] = 3^k u(-k-1)$

Find the Discrete-time Fourier transform of $ f[k] = 3^k u(-k-1)$ (then sketch it and find its magnitude & angle). It doesn't fit any templates on the Fourier table, and I don't see how one ...
0
votes
0answers
165 views

Convolving a signal with the impulse response of the channel

For a complex signal x to be transmitted over a channel with complex impulse response h, x will be convolved with h. What will the mathematical operation done in the reveiver to cancel the effect of h?...
0
votes
0answers
71 views

Are the bit-changing frequencies in a binary sequence related to the dft of that sequence?

I work with binary a lot, and I've always noticed that an incrementing binary sequence has sub-frequencies in the columns: 000 001 010 011 100 101 110 111 So ...
0
votes
0answers
24 views

Which filter to use for data with high amount of errors?

I have the following data collected from a heart rate sensor. The data is in bpm vs. milliseconds. All the data points below 80 is incorrect (errors/noise). When it plummets below 80, it's because ...
0
votes
1answer
797 views

How to implement an improper discrete-time transfer function into Simulink

I am trying to model a discrete-time control system in Simulink. The control system contains an inner loop that utilizes the inverse of the plant model. The plant in question takes the form of: $P(s)...
0
votes
1answer
1k views

Adaptive Piecewise Constant Approximation (APCA) with wavelets/DWT

I am trying to approximate a vector or a time series, in order to have as little changes as possible. To do so, I pretend to apply the Adaptive piecewise constant approximation (APCA) algorithm. ...
0
votes
0answers
54 views

How to get cofficients in DFT?

In my recent study of signal processing I came to know that we can compress images/signal using DFT/DCT. If we consider the lossy compression of audio or any image then it follows the same steps: ...
0
votes
0answers
112 views

Confusion in understanding the Proof of DTFT

While understanding the proof of DTFT from Signals and Systems by Oppenheim, I have confusion in understanding few steps. $$ x'[n]=\sum_ {k=<N>} a_ke^{jk(2\pi/N)n}$$ $$ a_k= \frac{1}{N} \sum_ {...
0
votes
0answers
88 views

Approaching the response of an RC circuit via y=ifft(fft(x)fft(h)). Why is this valid?

Some textbooks like (Numerical recipes the art of scientific computing) derive the DFT as a Riemann sum of the CTFT. With this in mind it would be natural then to approximate the identity $$y(t)=x*h=\...
0
votes
0answers
60 views

Estimating the power consumption of an arbitrary, real-time DSP algorithm

Consider a digital signal processing algorithm that operates over a block of $L$ [samples], with a real-time constraint $\tau$ [s] (i.e. its throughput must be $L/\tau$ [samples/s]). The theoretical ...
0
votes
0answers
85 views

How to take IFFT of Connes Window?

The Connes Window function is defined as : w(f)=$(1-(\frac{f}{ \Delta f})^2)^2$ for $f<|\Delta f| $ w(f)=0 otherwise The inverse fourier transform of this function can be ...
0
votes
0answers
53 views

How accurate is Wavelet packet decomposition for emg signals with frequencies from 10 to 40 Hz?

I have an electromyographic signal sampled at a frequency between 10 and 40 Hz in a time window of 300ms. Is wavelet packet decomposition adequate in order to perform features extraction for ...
0
votes
0answers
119 views

how to find the distance of the root from the origin?

Good Day, I have 9 polynomial roots. i have plotted the roots. my problems are: 1)how to find the distance of the roots from origin? I want to find the distance of all the roots from the origin. 2) ...
0
votes
0answers
131 views

PID Control - process variable / setpoint

I'm trying to design a PID controller but I have a problem in the following case: The process variable can only be between 0 and 1. The setpoint can be close to one, for instance 0.97. Hence the ...
0
votes
0answers
173 views

MATLAB, recover a signal that has a cosinusoidal interference and that has been AM modulated

I have a signal which has been AM modulated but the channel also added a cosinusoidal interference A cos(2 * Pi * f0 * n * Tc + Phase), at the same ...
0
votes
0answers
903 views

Finding if a signal is periodic

Hello I just started learning Signals and Systems and I have a question regarding periodic signals. For instance: $x(t) = \cos(3.2t) + \sin(1.6t) + e ^{j2.8t}$ is periodic because of the HCF of the ...
0
votes
0answers
38 views

Approximating the fourier coefficients from a discrete time signal

Suppose I have a discrete time signal $x_t$ sampled with a frequency $f_s$. I know that if I take the discrete fourier transform of the signal and compute the power, I can easily (by visual ...
0
votes
0answers
149 views

Sub-clock FPGA delays on output line

I am trying to include the ability to have sub-clock delays on an FPGA system's data bus without the need of fractional delay filters. I am using a Xilinx V6 part, and could utilize its IODELAYE1 ...
0
votes
0answers
153 views

What is the preferred method of aggregating audio FFT data given variable-size frequency bins?

I am coding a program which uses a FFT to process audio data. I need to aggregate the FFT output into three bins ("bass", "mid", and "treb") determined by two arbitrary frequency values. The end-goal ...
0
votes
0answers
3k views

Generate time-domain random signal from PSD

Given an analytical description of the PSD, for example (MATLAB "pseudocode"): ...
0
votes
0answers
174 views

Adaptive Line noise removal using IIR notch filters

I'm trying to filter out line noise(60Hz and 120Hz) from a EEG signals received over a bluetooth link. I'm proposing to use a IIR notch filter to filter out the line-noise which varies w.r.t to ...
0
votes
0answers
97 views

How to simulate two OFDM Users with low complexity FFT/IFFT?

have two User one of them sending over freq (0-B] and the other transmit over (B-2B]. Both of them are using OFDM and each one has Nc subcarriers. I wanted to simulate the received signal using Matlab....
0
votes
0answers
546 views

For discrete signals, why does phase change not correspond to time shift?

I'm going through a Signal Processing lecture where the professor mentions this fact and the argument given is: Suppose you have a sinusoidal signal: $Acos(\omega t)$ Now if you change the phase of ...
0
votes
0answers
168 views

generating a waveform in matlab for rohde and schwarz signal generator

We are doing a test which consists in sending a waveform from Matlab to the signal generator SMB100A and sending it through a cable to the r&s spectrum analyzer just to have a channel. We set the ...
0
votes
0answers
308 views

Fast Walsh-Hadamard Transform frequency spectrum?

Can the Fast Walsh-Hadamard Transform be used to find a Walsh-Hadamard frequency spectrum which some how relates to a Fourier frequency spectrum? Is the Fast Walsh-Hadamard Transform more accurate ...
0
votes
0answers
973 views

CWT for filtering / feature extraction

I had asked a question last night in regards to how to process my data (Noise rejection / feature extraction) but I have a more specific question now that I hope someone can answer. As mentioned in ...
0
votes
0answers
120 views

Describing a time delay at a maximum for maxima and minima but tends to 0 elsewhere

I have two force-time signals obtained from a couple of force plates, corresponding to input/output signals for some system. Plotting the two together one of the first things I noticed was a time ...
0
votes
0answers
557 views

Online FFT of simulated signal

it is a couple of weeks that I am thinking about the following: I have a tool which is able to simulate the dynamic behavior a steel tower exhibites due to the coupled action of wind and waves. ...
0
votes
0answers
232 views

Determining Valid DTFT's

Are the following frequency domain signals valid DTFT's (Discrete Time Fourier Transforms)? Answer yes or no, and justify your answer. a) $X(\omega) = \omega + \pi$ b) $X(\omega) = i + \pi$ c) $X(\...
0
votes
0answers
37 views

Operaion on Simple Discrete Time Signal , Very Simple Question

I got this simple Discrete time signal question on which i have to perform shifting and multiplication.But I have some Doubt regarding the answer this book shows. Please see the uploaded image.
0
votes
0answers
261 views

Why the number of poles and zeros for a RHS signal in the Z domain is equal?

I can not understand the reason why the following sentence is true: If we have a Right-Hand signal(RHS) x(n), X(z), the Z-transform of x(n), has the same number of poles and zeros except at z = ...
0
votes
0answers
107 views

How to add 2 MFCC extracted features to a variable?

I am working on signal processing for speaker verification. I have extracted MFCC features for few wav files using GMM algorithm. Now, i want to add any 2 MFCC features to another variable. How can ...
0
votes
0answers
66 views

Common mode noise from two ADC results

I am sampling two sinusoidal analogue signals that are phase separated by $\frac{2\pi}{3}$, and there appears to be a significant amount of common mode noise in my samples. What, if any approach can I ...
0
votes
0answers
851 views

Similarity of signals

I have a question concerning methods to find different aspects of "similarity" of signals. So, first, I'd like to characterize the signals to be dealt with: We have a number of close to rectangular ...
0
votes
0answers
34 views

decorrelating two image maps — reflected images from laser scattering

I am stuck on a research problem and do not know what kind of methods to use. I hope people in this forum can give me some good ideas, I've always had good brainstorming sessions here. My problem is ...
0
votes
0answers
141 views

How to measure the short-time change in an audio signal?

The choice of frame length for calculating the Mel Frequency Cepstral Coefficients of a signal, depend on the how much the signal change over a small time scale. I guess that human speech change ...
0
votes
1answer
39 views

MMSE- Channel estimated based - DFE Equalization

For HF ionospheric channels ( frequency range 3 up to 30 MHz), I Want to make channel equalization in time domain, using MMSE criterion. I have to do it using the channel estimation. I have some ...

1
3 4 5
6
7