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I have built 3x3 microphone array using 24bit ICS-52000 microphones. I want to convert digital values to decibels. I'm getting data via serial port into MATLAB and I used this code to convert those values to dB:
%get data from .txt
data = load('pelne obc.txt');
%get data from microphones
time = data(:, 1);
signals = d... |
Let's say $X \sim N(0, 1)$ is a standard Gaussian input signal and $Y \sim U\{y_1, y_2, \cdots, y_{16}\}$ follows a discrete uniform distribution (in fact, $\{y_1, y_2, \cdots, y_{16}\}$ is a reconstruction alphabet for $X$). Under the MSE distortion measure $d(x, y) = (x - y)^2$, for a given rate $R^* = 2$ (bits, not ... |
I am looking to apply Matlab's nufft.m function to a signal non-uniformly sampled with a spectrometer, hence measuring values at discrete frequencies.
In this case I believe my sample points t will be the discrete frequencies of my spectrometer and X will be my interference fringe data, following Matlab convention. Wha... |
For standard gaussian white noise, the covariance matrix is a identity matrix. What about other coloured noises (generated from standard gaussian): Brown(red), Pink, Blue, Violet?
Additional details / thoughts:
Preferably looking for a python code, since I don't have domain knowledge to understand the "process".
Maybe ... |
I'm studying MRI and I couldn't understand this assumption(?)
The sentence 'The signal from one channel is no more or less "real" than that from the other channel.' Does not make sense to me. (+ and the one before that, too)
all the equations are using that expression and its actually working. Why treating real number... |
What is the logical reason behind this? Why are P1,P2, P3, P4 codes unaffected by doppler shifts?
|
If you are in an environment with multiple transmitters of similar signal strengths, before band selection has taken place, how do receivers parse out overlapping OFDM signals from multiple transmitters?
Do systems just detect something off about the received packet and throw it out or is something else done?
|
$X(t)$ is a stochastic process defined on the time interval $(0, T)$. Discretizing the time interval one specify the time instants $t_0=0 < t_1 < t_2,\cdots,< t_{n-1} < t_n = T$.
A random variable $X(t_i)$ may be considered as being dependent on the previous random variables $X(t_1), X(t_2), \cdots , X(t_{i-1})$ and $X... |
Most literature about sampling explains the need for anti-alias filters in terms of periodic signals, preventing a periodic signal with frequency greater than half the sampling frequency from appearing as a mirrored low frequency signal.
However I acquire transient signals (not periodic) in my measurements, one-sided e... |
I'm interested in tracking the gravity vector for a UAV supposing we don't have external input or GPS.
I think a solution to the problem is as a follows:
We have a past gravity direction vector which was correct.
We have a gyro which we use to update that gravity vector when angular movement is detected.
We assume t... |
I understand that Sobel operator approximate "changes in x-y direction" of an image using three consecutive pixels. But why are these numbers 1 2 1? Where do they come from. I tried to search in Google but none of the results answer my question. Hope you help me clarify this
|
I'm reading the implementation of "Canny edge detector" in Wiki page: Canny edge detector. In the section "Gradient magnitude thresholding", it says:
In more accurate implementations, linear interpolation is used between
the two neighbouring pixels that straddle the gradient direction. For
example, if the gradient ang... |
We were testing our visual SLAM algorithm on robots. We were getting poor performance. Then we calculated wite noise and random walk parameters (using kalibr) for the IMU and used it in our algorithm and the performance included significantly.
Given that calculating random walk requires keeping IMU steady for longer du... |
My problem is that I have a mic that delivers 24 bits 2's complement signed. There is nothing in that data sheet that hints at it not also delivering INT_MIN. The 8 LSB bits are zero and INT_MIN is 0x80000000. I have myself written the driver, which takes in bits for stereo (needed even if I only use one mic) at an SCK... |
I am trying to identify and remove airplanes in a time series obtained at a radio meteor receiver. Here we have a spectrogram which displays the power content of my signal as a function of frequency and time:
The vertical lines are the meteors (the signals of interest for me) while the S-shaped horizontal traces are t... |
I have generated some ECG Signals in MATLAB workspace and then exported the signal data in the Simulink using the from Workspace Block. Now, I want to use the exported signal as an input signal to a filter network. How can I use this exported data as input signal. I am attaching the Simulink model diagram for better un... |
I'm coming from a math background with no prior knowledge in physics or engineering and currently teaching myself signals processing. Upon learning the definition of a Hilbert transform for a real signal $s(t)$ I find it difficult to determine exactly what the Hilbert transform is doing.
The source I am reading describ... |
I'm trying to cross corelate two audio files to see where they line up.
In scipy im doing: correlation = correlate(audio1, audio2, mode='full')
Given the graph below it looks like the songs line up at the peak around 2.5. However, the true point where the songs line up is a bit before 1. I think the issue is that a son... |
I am trying to implement masking in 1D signal data,
I saw in one paper that they are masking 70% of the signal as in the figure below:
In another study, they have mentioned that the mask part is replaced by a weak Gaussian noise.
How to do this kind of masking? Is there any sample python code?
|
I'm currently interested in measuring the quality factor of a noisy signal. For the purposes of example, consider a single degree of freedom mechanical system excited by white noise:
\begin{equation}
\begin{bmatrix}
\dot{x}_1 \\
\dot{x}_2
\end{bmatrix}
=
\begin{bmatrix}
0 & 1 \\
-\kappa & -\mu
\end{bmatrix}
\begin{bma... |
I'm trying to reproduce the scale-dependent Gaussian averaging of a time series as described in this paper: https://arxiv.org/pdf/1706.01126.pdf
The process involves performing a continuous wavelet transform and then using a Gaussian window to
estimate a scale-dependent average of the timeseries using the envelope of ... |
I have two signal sequences $u$ and $y$, where the former is the input to a system and the latter is the output of the same system. I would like to find second-order correlation between the two signals, to see if there is a nonlinear relationship existing between the signals. The second-order cross correlation function... |
I have 2 images, one original and other is reconstructed from the original via some processing. I want to find the PSNR for the reconstructed image The original has a size of (180, 180) but the reconstructed image has size of (71,81). I am using cv2.reshape() to reshape the reconstructed image.
shape = 180
reconstructe... |
I'm facing with a code I'm implementing for an exam using the GPU. Specifically, the code I'm writing is in C++, and I'm using the CUFFT library to perform the Fast Fourier Transform (FFT). The purpose of the project is to resize images that have both even and odd dimensions. The current steps I am taking are as follow... |
Consider a binary signal $x(t) = \sum_{n=-\infty}^{\infty}a_ns(t-nT_b)$ where,
$$
s(t) = \left\{\begin{matrix}
1& t\in[0, T_b) \\
0& o.w.
\end{matrix}\right.
$$
and
$$
a_n = \left\{\begin{matrix}
+A& \text{with a prior probability of } P_{A^+}\\
-A & \text{with a prior probability of } 1 - P_{A^+}
\end{matrix}\ri... |
Recently I am reading Books "Signals and Systems" from Oppenheim and "Ultrasonic testing of materials" from Krautkrämer. In those books there are some definitions about wave energy:
In the book of Oppenheim, it is written that the signal energy is defined as summed squares of amplitudes.
In the book of Krautkrämer, t... |
I am interested in the effect frequency modulation has on the signal.
I am using an acousto-optic deflector to steer a laser beam. The deflector receives a Radio-frequency (RF) signal (~100 MHz, sine-like) in order to deflect the beam.
By changing the RF frequency, one can control the deflection angle.
E.g. by changing... |
Let $X \left( e^{j \omega} \right)$ be the DTFT of a discrete-time signal $x \left[ n \right]$ given as
$$ x \left[ n \right] = \left( \frac{1}{3} \right)^{n} u \left[ n \right] \tag{1} $$
Determine a $6$-point causal sequence $a \left[ n \right]$ whose $6$-point DFT $A \left[ k \right]$ is the $6$ samples of the DTFT ... |
In textbook "Wireless Communications Principles and Practice" by Theodore S. Rappaport, the expression of Fresnel reflection coefficient ($\Gamma$) for parallel polarization is given as
$\Gamma_{||} = \frac{E_r}{E_i} = \frac{\eta_2 \text{sin} \theta_t- \eta_1 \text{sin} \theta_i}{\eta_2 \text{sin} \theta_t+ \eta_1 \tex... |
I want to track a user using only the magnetometer data from their smartphone. For that I calculated the magnetic reading of every part of a room using an app. Then I put those readings in a python script and used matplotlib.tri.Triangulation to plot them on the floor map of the room. That part is accurate.
The datafra... |
I have a dataset where a certain pattern is repeatating in different time interval. The repetation of data pattern can come with slight change. I want first find the pattern (or cycle) and later by checking autocorrelation, fft or similar strategy I filter future data. I have attached a sample data google drive link in... |
While studying and applying different window functions in a project I am working on, I found that known windows (here is an example paper which cataloged numerous windows) suffer from 2 kinds of trade-offs:
Simple (from processing speed/complexity point of view) windows (predominantly variations of $cos$ and $exp$) wh... |
I am understanding the HMM concept for Speech Recognition. One of the three problems (HMM) to be solved is Probability evaluation $P(O|\lambda)$. Instead of a straightforward approach which is computationally expensive, we go for the Forward Procedure. The three steps involved in this procedure are
($a_{ij}$ is transit... |
Here is the minimum working examples of fast spherical filter in
c++
The reference paper is Fast Spherical Filter
There is a bug in the implementation where the computed_grid values does not match with filtered_grid values.
Any help will be much appreciated.
|
Cross-posted from physics stackexchange
Summary: Eigenvalues of a "non-normalized" covariance matrix of time-series measurements from a linear system have units of Action (energy * time). Can we interpret this to obtain meaningful statistical thresholds?
Recently I've been doing some volunteer work on an open-source s... |
I am trying to make sure I understand the output scaling of pwelch. I am using the PWelch function to compute the PSD of a signal and I have manually computed the PSD from an STFT output. The results are equivalent when I use a rectangular (boxcar) window, but if I use another window (Hann) the PSD outputs are no longe... |
I'm looking for an algorithm to compute the numeric derivative $\dot x_i$ of a discrete time serie $(x_i, t_i)$.
It should runs as the data is generated, hence $\dot x_i$ can only depend on $x_{j<=i}$.
The memory resource is scarce, ideally it would only access the passed sample and andother value (either state or a ... |
In https://stanford.edu/~dntse/Chapters_PDF/Fundamentals_Wireless_Communication_chapter8.pdf page 360, it is stated that for a flat fading MIMO channel with receiver CSI only: at high SNR, the $\mathbf{K}_{z_k}^{-\frac{1}{2}}$ operation reduces to the projection of $\mathbf{y}$ onto the subspace orthogonal to that span... |
I am trying to measure the delay introduced by smoothening filters to my data, including a double-exponential smoothening filter. I run my series data through this function:
def double_exponential_smoothing(series, alpha, beta, n_preds=1):
"""
Given a series, alpha, beta and n_preds (number of
forecast/pred... |
Here you can see building blocks of DFE from "Adaptive Filters: Theory and Applications” a book by Behrouz Farhang-Boroujeny in chapter 17.
Figure 17.9 shows the overall building blocks of DFE which in the input we have noisy signal x that passed through channel and feeds to equalizer to have an estimated version of tr... |
I am studying HMM from "Fundamentals of Speech Recognition" by Rabiner. Regarding the problem of how to adjust the parameters of a HMM, the proposed method was Baum Welch method (Expectation-Maximization).
The text tells to maximize Baum's auxiliary function $Q(\lambda',\lambda)$ over $\lambda$, where $\lambda'$ is the... |
I have a question that i can not find a concrete answer.
Haw many matched filters should be used for 8-PAM/16-QAM/64-QAM/BPSK?
Can somebody shortly explain the logic we should follow?
Thank you.
|
For a 5G NSA UE supports 4x4 DL MIMO, in theory, is there any restriction for the device to get maximum throughput with 4x4 DL MIMO in both LTE and NR in ENDC mode?
|
I hope that my question suits well within the topics discussed in this SE website. It was reported some time ago how a man
was identified after he shared the photo on the encrypted messaging service EncroChat, from which police were able to analyse his fingerprints.
and again:
His palm and fingerprints were analysed... |
I used PyFDA to design a low-pass FIR filter for the final stage of decimation of a complex (I/Q) stream, from 2048 MHz to 16kHz. The last stage, 32kHz to 16kHz is the only non half-band filter, as the transition needs to be wholly within the lower half of the frequency range to prevent aliasing. I'm using 14-bit data ... |
I’m a beginner to this field, so sorry if my questions aren’t the best, or if I’m missing information.
Anyways, I’m working with raw data samples from a FMCW radar. Basically, a frame constitutes of [Rx_Ant, Chirps, Samples] in Python.
My first question is what exactly this shape means. For instance, what does it mean ... |
I am new to wireless communication and want to model a wireless communication system
y = h * s + n
where h = x + iy and |h| follow rayleigh distribution
However, I am confused about the following code
what should I use
h = np.abs((np.random.randn(n)+1j*np.random.randn(n))*(1/np.sqrt(2)))
or
h = (np.random.randn(n)+1j... |
I am working on this project "EMLight".
Data: HDR Panoramic Photos
y: Illumination Map of the Panorama
X: HDR Croppings from the Panorama
I want to make this project work with LDR photos, and a question arose:
Should I train with LDR representations from the HDR crops, OR train with the HDR crops to infer with HDR re... |
Consider the problem of lossily compressing a memoryless binary source $X
\sim \operatorname{Bernoulli}\left(\frac{1}{2}\right)$ at target Hamming distortion $D < \frac{1}{2}$. According to the analysis in 9.3.1 Example: Binary Source from this note, the marginal distribution of the optimal reconstruction $\hat{X}$ is... |
I am using a 14 channel EEG device. To do away with the need for any handcrafted features, I wish to implement an ML classification task with the EEG data collected using deep neural networks (such as 2D-CNN) directly on the spectrograms.
I get decent results by concatenating all 14 spectrograms (per training example) ... |
I have a baseband IQ sampled signal from a Pluto SDR with a bandwidth B and also fs = B, how can I calculate its PSNR using the STFT of the signal in Matlab.
Do I need to take into account the RBW of the STFT while calculating the PSNR ?
|
Suppose $x(t)$ is temperature and $y(t)$ is sweat. If the following equation describes the system, answer if is it linear or not.
$y(t) = [H(x)](t)$ . I would say that it isn't linear because we dont know explicitly the function $H$, for example $H(t)=e^t$
|
I have a lack of mathematical knowledge, and notably in mathematical vocabulary, so maybe a similar question exists but with a different wording.
What I want to know, is actually how to know if a function, given its properties (for example, a polynomial with natural-number coefficients) can be converted to a finite sum... |
I want to isolate a reflection part of a signal which I've transformed from Frequency to Time-Domain (see Picture). So far, I've tried to create a Hamming-Window with the specific window-width for the red marked part of the signal. Then I created a signal with zeros (gate), which has the exact same length as the time-d... |
Consider we have $N$ samples. In that $N$ samples we may have $M$ samples from sum of sinusoidal signal plus noise. Obviously $M<N$. In case $N=M$ we have only $N$ noise samples. Let us assume $M$ is known i.e length or number of sinusoids samples if present, is known.
Is there a way to know which $M$ samples belong ... |
I am familiar with the spectral leakage problem in FFT due to a rectangle window for a sin signal giving two peaks that leak to each other. My question is will the leakage to the frequency bins near the peaks increase if the peaks are closer to each other?
|
I'm struggling with this because I don't fully understand it.
My goal is to estimate a received signal that is transmitted through a channel that follow a stochastic process. My doubt is, if the PDF and its parameters that describes the behaviour of this channel is known, how can I generate the H matrix to estimate the... |
I'm trying to understand the math behind FIR filter design. I'm focusing on the simple case of an ideal LPF with the following frequency domain behavior:
When the IDFT is applied, I end up with:
I select N (filter order) = 8, so my filter length = 9. Then, let n = n - N/2, yielding:
If I then evaluate h[n] for n = 0... |
My professor explained this to me in a super convoluted way, so hopefully someone can explain this to me better.
I'm trying to find the PSF of the following signals. I also need to check if it's FIR or IIR and comment on BIBO-ness.
a) $y(m,n) = 3x(m,n) + 9$
and
b) $y(m,n) = \sum_{k = -inf}^{m} \sum_{l = -inf}^{n}x(k,l)... |
I was instructed here:
In the sampled-time domain a Kronecker delta, $\delta(n)$, has a perfectly flat spectrum. If you look at a table of discrete-time Fourier transform pairs, this is at the top of the list: $\mathcal F^{-1}\left \{ \delta(n) \right \} = A$, where $A$ is a positive real number whose value depends o... |
How can I plot a similar comparison plot in Matlab?
My attempt
I have tried to create a random function like/ Matlab:
rand(M, N)
and then take SFFT of it
fft(ifft(rand(M, N)))
and plot them using bar3 function in Matlab
|
In SISO systems of OFDM, I am interested in applying deep learning for channel estimation, but I am unsure of how to obtain perfect channel estimation as the label in simulations. If you have any insights on obtaining perfect channel estimation in a simulation, I would greatly appreciate your guidance. Thank you.
|
I have an accelerometer and I've written a program for it in the ESP32. The program uses a 750sps ADC sampling rate and an accurate 100Hz interrupt for calculations. P.S. The high-pass filter is at 0.5Hz and the low-pass filter is at 10Hz Butterworth filter.
In the video below, I move the accelerometer through a linear... |
Does anyone have a reference that specifically discusses choosing the frequency scale for a simple 1D data for non-uniformly sampled time-domain data when performing the discrete Fourier transform.
In the ordinary uniform sample case, $N$ be the total number of samples in the signal, and $T_s$ be the sampling period (t... |
A quick question I was asked by a friend for homework.
We have an LTI system and we needed an example for reconstruction and such...
Anyway, he asked me if the constant signal is bandwidth limited.
Since the Fourier Transform of a constant is $\delta(\omega)$ with a constant.
And for $\omega=0$ we will receive $\infty$... |
I am running white noise bursts (with very short ramps on/off to prevent discontinuities) through underdamped resonant bandpasses which are tuned to any given $f_0$ and an underdamped $Q$.
Continuous white noise at an amplitude of $1$ if run through a completely underdamped resonant bandpass should bring that resonant ... |
Shot noise is generally a white noise. For an imaging system based on detectors the shot noise variance that scalers linearly with flux and time (details here and here):
$$\sigma^2=I\cdot QE\cdot\Delta t$$
My question is, if optics color that noise. Consider the fact that the point spread function may have a relatively... |
It's been a few days that I have been searching the term eigen beamforming, but still haven't get any satisfactory literature reference. It would be great if you could give any details or point to any literature regarding the topic eigen beamforming.
Furthermore, one more specific question, is precoding essential for e... |
Suppose we have 2 orthogonal signals $x_{1}(t)$ and $x_{2}(t)$ and we add them up.
Can we always say that the resulting signal will be of this form:
$$x_{3}(t)=x_{1}(t)+jx_{2}(t)$$ ?
If that is true then we can write down the complex signal in the Fourier domain as $|X_{3}(j\omega)|e^{\phi(j\omega)}$.
What kind of info... |
Im currently working on a project to get navigation information of a robot from Data-Fusion through different IMUs.
First step is to make a calibration and I picked a method where I need to detect several "quasi-static-states" for the calibration process of a 9 DOF IMU (see Paper "Automatic Calibration for Inertial Mea... |
I try to write down the equations that show how constellation symbols (PSK, QAM etc.) are modulated into a time-continuous signal. I read the articles referenced at the end. However, I am still stuck at how the inverse discrete Fourier transform (IDFT) is supposed to produce the subcarriers at frequencies $f_\mathrm C ... |
How can I implement a 256-point polyphase FFT whose sidelobe level is 40db down and main lobe width of rectangular window?
If we perform FFT of 256 point with some window, The window will have effect on spectrum and we are going to get spectral leakage which we call as sidelobe as well as the main lobe width increase b... |
I would like to know whether there is a condition in selecting the number of channels $M$ and filter length $N$. As of now I am trying to design a channelizer where the data length $M$ is much less than the FIR filter length $N$.
Right now I am referring to the paper "High Resolution Spectral Analysis and Signal Segreg... |
I have built a Bluetooth speaker using an ESP32. It can stream BLE audio and play MP3/WAV from an embedded SD card. I want to record 44.1Khz res audio from it but unfortunately the ESP32 is not powerful enough to convert WAV to MP3 in real time. I am looking for an additional component (MCu/DSP IC) which can convert wa... |
The power density of a general FM modulated signal(with modulation index close to 1) looks like this:
By picking out the carrier frequency we can make the FM signal narrowband or wideband.Now obviously when we changed the carrier frequency , the power of the FM signal wouldnt change so the smaller the bandwidth the m... |
I am developing a continuous wave Doppler radar to detect human movement at a speed of 0.2-6m/s. For a radiation frequency of 24.15 GHz, the Doppler shift during longitudinal motion will be equal to ~32.2-966 Hz. In transverse motion, the Doppler shift will depend on the angle at which I cross the detection zone. I cre... |
I have two signals, for example, $x_1[n]$ and $x_2[n]$, which are the same for every $n$ except for $n_0$ and $n_1$. They are both bounded within a frequency range of $\pi/3$.
I want to reconstruct $x_2[n]$ from $x_1[n]$. If $n_0$ and $n_1$ are divisible by 3, I can simply apply downsampling by 3, upsampling by 3, and ... |
I need to write my own resampling algorithm to resample sample and impulse response wav files between 44.1, 48 and 96 kHz. I'm on an embedded platform, so I don't have access to the usual libraries. The current plan is to write a resampler from scratch.
Is there anything between linear interpolation and polyphase filte... |
Consider an unknown, quasi-periodic signal $x(t)$ with approximate slowly varying unknown period $T_x(t)$. A noisy, amplitude modulated version of this signal is observed:
$$r(t) = a(t) x(t) + n(t)$$
While $a(t)$ is unknown, its spectral content is concentrated in a band a bit lower than that of $x(t)$. Also, the ban... |
Let's assume we have a SIMO system with multiple transmitter antennas (e.g. qty 4), and a single receiver or 4x1. Let's suppose we're talking about the SSR steady-state response, Gaussian noise, and standard LTI system as in mobile communications.
Let's suppose the receiver knows precisely the channel responses for eac... |
I have a question about the output spectrum of DDS, which consists of a phase accumulator and look-up table.
Since the look-up table stores accurate information about sinusoidal waveform, I think quantization error and corresponding spectrum information (such as total harmonic distortion) might differ from simply equal... |
I am experimenting with digital signal processing and I took the FFT of a sinusoid in Matlab. I got the frequency components that I expected to be present but there are two excess spikes that mirror them. Are these reflections of the negative frequencies present in a sinusoidal spectrum that I didn't account for in my ... |
I'd like to make digital samples that construct sine waves.
It's nothing but direct digital synthesis (DDS) before the digital-to-analog converter and filter.
I want to make a sinewave sample that swings between 1 and 10 (it could be any physical parameters such as voltage and current).
Look-up table determines almost ... |
I have a signal recorded from two different detectors, with different levels of gain.
$$
S_{1}(\omega) = \alpha_{1}S(\omega) + \beta_{1} \\
S_{2}(\omega) = \alpha_{2}S(\omega) + \beta_{2}
$$
How would you correct for the gain, considering the offset in the signal is minimial.
|
I have been given the following equation to show the difference between coherence and non-coherence in optics and how the third term represents the interference between two optical pulses. Can someone explain what the terms represents and how this equation changes when the two signals are the same continuous data signa... |
I've created a log2 AGC for an FPGA project, similar to Dan Boschen's solution in this question. I implemented a hardware version of log2 based on Dan's linked page in the previous question - efficient floating point log2 computation.
For the antilog2 operation, I used simple bit shifting for the integer component, but... |
I have a data series containing underlying noise, the plot of which is :
The issue is to remove the noise leaving the pattern which is raised above the lower level. The lower level is road surface and the protruding patterns are metalwork, think of them as drain covers or 'manholes'. The noise also appears to some ext... |
I'm trying to estimate the number of words in a record
I tried to extract the Short term energy(STE) feature, denoise it, then count the number of peaks in the STE, it gives a very close result to the real number of words, but I'm struggling with the implementation since there are variables which vary from one record t... |
I am currently working on characterizing the noise sources of a Global Navigation Satellite System (GNSS) sensor using an Allan Variance plot, which is commonly employed to analyze frequency stability in atomic clocks, but has since been extended to other applications such as Inertial Measurement Units (IMUs) and senso... |
Let $F=\frac{1}{\sqrt{n}}(w^{kl})_{k,l=0}^{n-1}$ be the discrete Fourier matrix of size $n$ where $w=\exp^{-\frac{2\pi i}{n}}$.
It is a well-known that $F_n^4 = I_n$ where $I_n$ represents the identity matrix of dimension $n$. This leads to the conclusion that $F$ possess precisely four eigenvalues, namely $\{\pm1,\... |
I would like to do formants extraction using LPC. I made the necessary pre-emphasis before feeding the speech samples to the LPC function.
N = len(X)
w = np.hamming(N)
x1 = X * w
x1 = lfilter([1], [1., 0.63], x1)
ncoeff= int(2 + Fs/1000)
lpc=librosa.lpc(x1,order=ncoeff)
Solving the poles from the all-poles system-Tr... |
Having pulled data from a MAX2769B in device state 2 (2-bit I only), I have found satellite signals by multiplying the I-only data by the respective PRN and taking the FFT of the data. Using this approach, I set the imaginary part to zero, and fill in the I*PRN data for the real part, thus real only data. If I configur... |
I'm trying to figure out how a continuous wave Doppler radar works. When moving towards the radar, the Doppler frequency should increase, and when moving away from the radar, the frequency should decrease. I am using a microwave module at a frequency of 24 GHz. At "output I" I see a change in frequency depending on the... |
Suppose you have $K$ users, each seeing a point to point fading channel with $n$ receive diversity. So the rate of the kth user is at most $\log(1+ SNR|h_k|^2)$. Now suppose, each user transmits at rate $R$, then the probability of outage is $P(\cup log(1+ SNR|h_k|^2) < R)$ (ie, the system is in outage when at least on... |
Given the continuous time signal
$$ x \left( t \right)= 2 \cos \left( 100 \pi t \right) + 3 \sin \left( 250 \pi t \right) \tag{1} $$
The signal is sampled in point sampling with sampling interval $T_{1} = 0.006 \textrm{s}$ and reconstructed (assuming that sampled above Nyquist sampling rate) by an ideal low-pass filter... |
what i understood is the equation of AF looks similar to DFT equation as we are multiplying with exponential term
|
I am try to plot the maximum ratio combining of BPSK on a Rayleigh fading channel by integration i.e,
$$
\bar{P_e} = \int_0^\infty Q(\sqrt{2\gamma})p_\Sigma(\gamma) \ d\gamma
$$
but I can't seem to get the same as the closed form answer.
$$
\bar{P_e} = \left( \frac{1 - T}{2}\right)^M \sum_{m=0}^{M-1} \begin{pmatrix}
M ... |
I'm learning about Low Pass Filters. My professor said the following is the transfer function of an ideal LPF:
$$H_{LPF}(f) = G\Pi\left(\frac{f}{2B_{pass}}\right) e^{-j2\pi ft_0}$$
However, i don't understand why a phasor is needed. Wouldn't the fact that the LPF is centered around the DC component remove the need for ... |
As far as I know that one of the sufficient conditions of fourier transform to exist is that the function must be absolutely integrable(I learnt this from "Continuous and Discrete Signals and Systems" by Samir S. Soliman, 2nd edition). But so I'm concerned that the unit step function is not absolutely integrable yet it... |
I'm working on a Bluetooth speaker system where the same music file results in different SPL up to 10 dBA when played through different devices, such as iPhones and Android smartphones. The system involves passing different decoded audio sources through a same electro-acoustic system, and the outputs are measured using... |
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