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modulation & demodulation of GPS output digital data

I need to add GPS digital output (in form of Lat/Long) in an existing analog audio signal whose bandwidth is 100 Hz-20 KHz. This GPS data should be added in such a way that it should not interfere ...
naumankalia's user avatar
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0 answers
9 views

Derivation of Shannon Limit for soft and hard decoders

I've been reading up on some design considerations for FECs, and have been trying to derive a theoretical bound for performance of a FEC. I have found the following sources, with these images From ...
user74051's user avatar
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1 answer
28 views

Why do we care about the STFT of a signal?

As far as I know, the STFT is used to analyze the frequency content of a non-stationary signal - a signal whose frequency varies with time. For example, a signal like this: - Performing the DFT on ...
Carl's user avatar
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0 answers
27 views

Time domain expression of a stationary continous broadband signal and its autocorrelation

I want to find the auto-correlation of a stationary continous broadband signal. The auto-correaltion is $$f\star f=\int_{-\infty}^\infty f^*(t)f(t+\tau)\ \mathrm{d}t.\tag{*}\label{*}$$ The power ...
user74037's user avatar
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8 views

Why isn't the Gaussian blur kernel defined via the cdf?

A 1-D Gaussian blur kernel of size $2k + 1$ is defined as: $$K = \text{Normalize}([G(-k), \ldots, G(k-1), G(k)])$$ where $${\displaystyle G(r) = {\frac {1}{\sqrt {2\pi \sigma ^{2}}}}e^{-{\frac {r^{2}}{...
Mateen Ulhaq's user avatar
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1 answer
28 views

Scipy butterworth filter sos (second order sections) output - what it is and what is the benefit?

scipy butterworth filter has sos output option. Please help understand what it is and what the benefit in layman's term. output{‘ba’, ‘zpk’, ‘sos’}, optional Type of output: numerator/denominator (‘...
mon's user avatar
  • 129
1 vote
0 answers
12 views

Calibration/Filtering Order

Let's suppose we have a stream of data from a 3-axis sensor like a MEMS magnetometer. Each of the sensor's axes have an output bias, gain, and misalignment (all axes should be orthogonal). ...
P_B's user avatar
  • 111
1 vote
1 answer
19 views

fsk signal duration

I have a bandwidth $B$ and a FSK modulation. The duration of an FSK signal is usually $T_s=1/B$. By drawing a parallel with spread spectrum communication, I can take $T_s=SF/B$ with for example $SF=32$...
user73994's user avatar
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1 answer
25 views

How to tackle Propagation delay using Early late gate synchronization?

I am simulating a basic communication system in baseband I'm transmitting QPSK symbols at 2 samples / symbol using RRC for pulse shaping and I have added zeros before the actual symbol for propagation ...
Muhammad Umar's user avatar
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2 answers
53 views

The moving of the poles and zeroes during the low-pass tranform

Usually, we start the design of a filter using a low-pass prototype. Then we transform it to the required high-pass, band-pass or band-stop form as required. I'm looking for a good explanation on how ...
Claude Frantz's user avatar
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1 answer
33 views

The order of filtering and convolution

Assume I have a source signal s(t) to pass through a system. I record the signal at system output place, which is denoted as d(t)...
user73970's user avatar
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0 answers
28 views

How to find the bias gradient for localization problem?

I am doing the work to find the cramer-rao bound when the estimator is biased. The algorithm I am based on is from Rethinking Biased Estimation: Improving Maximum Likelihood and the Cram´er–Rao Bound, ...
Loco Citato's user avatar
1 vote
1 answer
52 views

PSD calculated without sampling rate $F_s$

Professor Steve Brunton mentioned in Denoising Data with FFT that fhat * np.conj(fhat) / n is computing the power at each frequency. However, the code says it is ...
mon's user avatar
  • 129
2 votes
1 answer
236 views

Calculating Shannon-like entropy function of a 1D signal with random noise

I have been searching for a measure of Shannon's entropy $\ H $ or other entropy-like formulae that vary smoothly with noise for real 1D signals. MATLAB has built in functions for image entropy. The ...
ACR's user avatar
  • 604
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0 answers
19 views

Comparing large 3d datasets for Grid map data

I am working on Grid maps.Grid maps are a representation of the environment in terms of 2d or 3d cells which store a value in them that can be plotted to make a map of the area. I am having a lot of ...
Shubham Kapoor's user avatar
0 votes
1 answer
33 views

Adaptive Correlation Threshold for QPSK

A single-carrier QPSK signal passed through a fading channel is correlated in the receiver using standard complex-conj correlation with a known sequence. The received signal's amplitude fluctuates ...
Clayton Loecher's user avatar
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0 answers
23 views

How to normalize STFT to make it the same with that of librosa

Question How to normalize the FFT of each window in STFT so that the spectrogram become the same with that of librosa? Background Trying to create a spectrogram using STFT from scratch. The audio data ...
mon's user avatar
  • 129
4 votes
3 answers
338 views

Is the system $y(t) = \frac{dx(t)}{dt}$ memoryless?

The system $y(t) = \frac{dx(t)}{dt}$ has been shown to be not memoryless, in many texts, based on the argument that it depends on the future value of the input i.e.,$x(t+\delta)$ or the past value $x(...
Guna's user avatar
  • 43
3 votes
2 answers
400 views

How does a quantized signal represent all magnitudes?

I am having trouble with some intuition with quantization, bit-depth, noise floor, dynamic range and signal/noise ratio. Let's say I have two signals, $s_1$ and $s_2$ that are 1hz sine waves, with ...
little_brindle_dog's user avatar
0 votes
1 answer
54 views

Finding Modulation Type and Transmission Power Given Link Requirements

I know that the key to choose the modulation is to find the signal to noise ratio and "cross it" with the given error probability, but I am facing some problems during the calculation of ...
Naryal's user avatar
  • 1
0 votes
1 answer
48 views

PSD calculation from FFT does not match with the value from scipy.signal.welch

Please help understand why the PSD calculation from FFT does not match with the value from Scipy signal.welch function. According to Understanding Power Spectral ...
mon's user avatar
  • 129
0 votes
1 answer
10 views

An OCR steps to detect and extract the line pairs english text from image

I am trying to extract the text from an image using OCR. The challenge I am facing is how to map the key and value. For example, the key - Last Name should have the value XYZ. After getting the key ...
Harshith's user avatar
  • 101
0 votes
0 answers
31 views

Eigenvalue of integral operator with weak polar kernel

There is linear integral operator $A\phi=\mu \int_\Omega |x-y|^{-1}\phi(y)dy$, $x,y \in R^3$, $diam(\Omega)<R_\Omega=const$. What are system of eigenvalues ($\lambda_k=1/\mu_k$) and eigenfunctions $...
Nikolay Fimin's user avatar
1 vote
1 answer
34 views

Synchronize to coded signal for detection

Forgive my ignorance of terminology. I've achieved synchronous demodulation (lock-in amplification) of an optically transmitted code a few years back, i.e. transmit and integrate whatever gets picked ...
handle's user avatar
  • 113
0 votes
0 answers
34 views

What is the best way to sync I/O audio streams to mix them in real-time?

I want to mix loopback stream with audio from microphone in real-time and use the result of mixing for speech recognition. The project is for Windows, so I use WASAPI and am willing to know what is ...
recei's user avatar
  • 1
1 vote
2 answers
207 views

Connection between Parseval's Theorem to Fourier Transform is Unitary

In YouTube Parseval's Theorem, Professor Steve Brunton indicated there is a connection between Parseval's Theorem and Fourier Transform is Unitary. But how a Unitary (preserving inner products, ...
mon's user avatar
  • 129
1 vote
0 answers
55 views

Phase equalization for a notch-like filter

Consider the following filter with DC-notch-like characteristics: $H(z) = \frac{1-2z^{-1} + z^{-2}}{1+a_1z^{-1}+a_2z^{-2}}$ where $a_1= -1.99396970948671$ and $a_2=0.994002716421032$. The magnitude ...
rhz's user avatar
  • 489
0 votes
0 answers
36 views

Sliding window with fading tail

I am new to signal processing. So far, I know how to analyze time series of a signal using a sliding window and I have used that approach before while analyzing a signal in frequency domain to improve ...
Engineer's user avatar
  • 183
0 votes
0 answers
32 views

CPFSK Modulation

I am doing research on how the output of the CPFSK complex signal should be. The main difference between FSK modulation and CPFSK modulation is continuous phase. However, a different image was ...
bb0667's user avatar
  • 162
0 votes
2 answers
76 views

Why Power of a signal of amplitude $A$ is $A^2$

MATLAB YouTube Understanding Power Spectral Density and the Power Spectrum says Power P of frequency k is $A^2 / 2$ . $$ P = \frac {A^2}{2}$$ Is this correct? ...
mon's user avatar
  • 129
0 votes
0 answers
35 views

Meaning of "non constraint envelope signal"

I am studying signal processing. In the power amplifier theory and its affect on satellite system I have found the following: Compared to the conventional terrestrial system, non-terrestrial radio ...
Aid22's user avatar
  • 23
3 votes
1 answer
74 views

What does stability of an LTI system guarantee

I am working through some example problems about stability in systems and came across this one that I can't find the answer to. I'm wondering whether I am misunderstanding something about the ...
Keara's user avatar
  • 133
0 votes
0 answers
19 views

Stumped on demodulation, using python simulation end to end example of modulating a BPSK signal and demodulation but getting ~50% bit error

Can someone spot my mistake here: ...
max twente's user avatar
0 votes
0 answers
12 views

Determining Object Visibility with Metrics

I am wondering if anyone has suggestions for metrics to use to quantify the edge strength and contrast of a target from its background in single channel images. I am trying to find the effectiveness ...
JmsChf's user avatar
  • 1
-1 votes
0 answers
31 views

Histogram Technique for Sine Wave

I am collecting a data set of 50k samples using a 14 bit 100 MS ADC. The frequency of the sine I collected is 6 kHz. (I collected and experimented for lower and higher frequencies. Especially 9.7 Mhz, ...
bb0667's user avatar
  • 162
1 vote
1 answer
80 views

Artifacts introduced by Fourier Transform

I am new to signal processing. My background is Petroleum engineering, however I am concerned with analyzing acoustic data for some applications. I am using Fourier transform to transform signal from ...
Engineer's user avatar
  • 183
0 votes
1 answer
20 views

Detect active channel used in a lora network

I am trying for quite some days now to detect which channel was used for a transmitted LoRaWAN frame. For those who are not familiar with lora: LoRa makes use of the CSS modulation technique, which is ...
leoposc's user avatar
0 votes
0 answers
30 views

Fixing distorted part of the signal for signal preprocessing?

i'm trying to replace the distorted part of my signal wich is a multiplicative season + linear trend kind of signal , i tryed replacing it with the mean or median value but it's not what i want really ...
Syrine Braham's user avatar
0 votes
0 answers
23 views

Removing Phase Offset from QPSK Received symbols with Phase offset and Noise using Phase locked loop [duplicate]

I'm designing a basic baseband transmitter and receiver that does QPSK modulation along with pulse shaping with Root raised cosine, some impairments are added to the transmitted signal to analyze the ...
Muhammad Umar's user avatar
0 votes
2 answers
61 views

Is there a function whose Fourier transform gives peaks/impulse at multiple desired locations?

Fourier transform of sinusoidal waveforms have 2 peaks depending on the frequency of waveform. We can change their frequency to get a peak at desired location. Similarly, is/are there functions whose ...
RajaKrishnappa's user avatar
0 votes
1 answer
35 views

How can we tell a sinusoid existing in a time series data is cosine by just looking at DFT?

Coursera Signal processing by EPFL says the function that represents the peaks are cosine by looking at the DFT of 1024 samples. But why on what basis it can be said so? Now if you look in detail and ...
mon's user avatar
  • 129
0 votes
0 answers
19 views

Using GNU Radio how would I create a demodulator/modulator for BPSK?

Using GNU Radio how would I create a demodulate/modulator for BPSK? I want to then phase shift out the re-modulated signal to remove it as much as possible
max twente's user avatar
0 votes
0 answers
21 views

DIgital QPSK demodulation of I/Q Data (Costas Loop, Symbol Sync, etc.)

I am trying to implement in hardware demodulation of QPSK-modulated I/Q samples from an SDR. The data would come from the reception of satellite transmissions. My approach is based on mapping onto ...
Jake T.'s user avatar
0 votes
1 answer
31 views

Partial derivative of transfer function in Laplace domain

For some LTI transfer function $g(t,\rho)$ with a constant parameter $\rho$, with the transformed equivalent: $$\begin{align} g(t,\rho)&\leftrightarrows G(s,\rho)\\ \end{align}$$ Is it equivalent ...
Martin CR's user avatar
  • 113
0 votes
0 answers
27 views

Recreating waves/sound given a frequency spectrum?

I'm currently working on a project with a decibel meter capable of measuring the frequency spectrum of a given sound. It gives it in the form of 64 bands from 0 Hz - 8 kHz (250 Hz increments) and I'm ...
etercnoc's user avatar
0 votes
0 answers
14 views

How does one demodulate a signal correctly in python using komm.dev library?

Im not sure if I need to downsample or filter but as of now this code has a 45% bit error rate and I need to understand how to correctly demodulate something like this coming off an SDR. Thanks! ...
max twente's user avatar
0 votes
1 answer
35 views

For a symmetric FIR filter, can the number of coefficients be even and half of the filter order?

I'm trying to use an assembly DSP library (TriLib by Infineon) and for one of the FIR functions, FirSym_4_16, the implementation has the following constrains: Number of coefficients given by user ...
Diego's user avatar
  • 3
2 votes
2 answers
53 views

High pass filter with narrow stop band and low group delay over part of passband

Consider the following filtering requirements for a nominally high pass IIR or FIR filter (assume a sample rate of $F_s =1$): Stopband: $f\in[0, 0.00144]$ -- looking for around 20dB attenuation ...
rhz's user avatar
  • 489
0 votes
1 answer
47 views

How come when I plot the psd of a signal using welch the signal looks like it spans all frequencies instead of being a bump?

something like: ...
max twente's user avatar
2 votes
1 answer
23 views

The zero-state response of a linear-constant-coefficient-differential-equations (LCCDE) with non-zero initial conditions

I have started to learn about signals and systems, and my textbook is the second edition of Signals & System by Alan Oppenheim. I got really confused about the solution of linear constant ...
X.X.W's user avatar
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