Questions tagged [digital]
The digital tag has no usage guidance.
107
questions
-1
votes
2answers
65 views
Why is the fft magnitude spectra of sine not symmetric?
I thought that the magnitude spectra of real signals was symmetric.
When I take the absolute value of the fft of a sine wave the result is not symmetric. There seems to be a peak at the first ...
0
votes
1answer
19 views
Understanding Baud Rate
I am new to signal processing and just trying to understand what Baud rate really means.
As I understand it, the baud rate speed is really the time that the processor takes when it is ON and when it ...
0
votes
1answer
29 views
digital phase lead algorithm
I have two sine signals A and B which are simultaneously sampled at 2500 Hz using ADC. Through oscilloscope, I find that signal B lags A by about 5 degrees. I would like to digitally lead signal B to ...
0
votes
0answers
18 views
Hisotgram equalisation error, help with my code
Iam working on implenting a histogram equalisation of an image without using inbuilt functions specifcally imhist and histeq, I have, for the most part understood what do during a histogram ...
0
votes
0answers
29 views
Training Fractionally Spaced Channel Estimator and Equalizer
If you are attempting least squares channel estimation with a fractionally spaced channel estimator, do you want the training sequence to also be fractionally spaced or symbol spaced? It looks like ...
1
vote
1answer
171 views
polyBLAMP anti-aliasing in C++
How should 4 point polyBLAMP work. It does not really seem to dampen aliasing.
I have an floating point digital audio oscillator that makes a +1.0f jump at the end of every period.
My question is, ...
0
votes
1answer
22 views
Can we band-limit a PCM signal? Is it even relevant to relate a totally Analog term(Band limit) with digital one(PCM)
Can we band-limit a PCM signal?
0
votes
1answer
74 views
Follow up question regarding: “Complex sampling can break Nyquist?”
I'm having some trouble understanding the sample rate limitations when considering a complex baseband signal.
I understand (based on the linked SE questions below), the either (1) physically ...
0
votes
1answer
46 views
Using Matlab/Simulink to build Reader based on Software Define Radio
I am a student. I want to learn about Software Defined Radio to build a Reader for Saw tag and simulate them on Matlab/Simulink.
These bocks below is what I want to build in Matlab/Simulink
I found ...
1
vote
1answer
48 views
Modulating ofdm in audio spectrum
Trying to modulate audio with OFDM data.
My fs = 44.1khz, i'm using 64 sub-carriers, but i'm only using 5 sub-carriers for data, so my bandwidth is about 3.445khz. I'm not sure how to properly write ...
1
vote
1answer
34 views
How do I add more resolution / taps to an analog -> digital filter?
(I am trying to create an IIR audio filter that adds reverb to an initial sample)
Say I designed an analog filter to model acoustic attenuation based on the following mathematical model:
$$
I = I_0 ...
1
vote
1answer
87 views
How does cascading low pass modules affect pass band ripples?
This question 10.21 is taken from GATE IN paper 2015.
I don't understand the answer given,
I mean why is the frequency response at the pass band frequency considered to be $(1-\delta)$, isn't the ...
1
vote
0answers
43 views
Noise Shape Digital Filter
My objective is to build a noise shape filter from a given transfer function (in one case) and from a given PSD (for another case). Checking my precedent questions you can see that this argument is ...
0
votes
1answer
357 views
BIBO Stability in Z-domain
I'd really appreciate it if someone could please explain to me the condition for a LTI system to be BIBO stable, in z-domain.
I have a background in control, and in linear control for example, if we ...
-1
votes
1answer
95 views
Digital Derivative
I need to calculate the derivative of a digital signal (sinusoidal). In one of the papers they have mentioned Gilbert transformation is used to calculate the derivative. But I have searched in the net ...
2
votes
1answer
282 views
Block Diagram for a difference equation
I have this little doubt regarding how to draw a block diagram representation of a difference equation. Let us implement $ y(n) = ay(n-3) + by(n-2)+cy(n-1) + x(n)$ in block diagram where $a, b, c$ are ...
1
vote
1answer
59 views
Why are binary signals drawn continuous in time despite being a digital signal
The conventional definiton of a Digital signal is as follows:
A digital signal is a signal that is discrete in time and quantized in amplitude. Almost all resources (textbooks, online sources,etc) ...
0
votes
1answer
68 views
confusion between frequency and amplitude in digital to analog and vice versa conversion
bandwidth is defined as the difference between the highest frequency and lowest frequency.
amplitude is the distance between the, let's call it a crest and a trough, in a wave.
cycle is the time per ...
2
votes
3answers
81 views
Why must the angle contain $\pi$ for $\cos$ be periodic?
The $\cos(\frac{n}{6})$ is aperiodic, and $\cos(\frac{n\pi}{6})$ is periodic, why? What role does the $\pi$ play? By the way, $n$ must be integer
I have seen this question,Why is cos(n/6) aperiodic? ...
0
votes
1answer
44 views
Glitches in certain frequencies
I am trying to produce some simple audio waves using WASAPI (Windows Audio Session API). If I skip all the abstractions, my program basically receives a buffer from the API, then writes results of a ...
-1
votes
2answers
378 views
Amplitude ranges for different bit-depths
In Python, I am using the library Soundfile (which uses the library libsndfile) for digital sound processing. I am working with different sound files coming from different internet databases, and ...
1
vote
1answer
86 views
Do integration/differentiation processes work as simple filters?
How these processes are different from simple IIR 1 order filtering, FIR filters in terms of amplitude and phase characteristics?
0
votes
1answer
206 views
Second order section digital Bandpass
Does anyone have a ressouce on how I can calculate second order section bandpass coefficients?
What I tried allready:
I used following formulas from the Book Electronic Circuits (U.Tietze, Ch. ...
1
vote
0answers
71 views
Processing digital sound in Audiokit to sound like the 1960's
I am looking to imitate 70's analog equipments sound. I was wondering is there a way to create tape saturation / distortion inside Audiokit? I want to add that and randomized tape crackles and ...
2
votes
1answer
451 views
Bandwidth and Bit rate
I'm kind of confused about digital transmission.
Is the bandwidth occupied by some digital signal the Fourier spectrum of the bit (pulse) format,or the one determined by the bit rate?
0
votes
1answer
53 views
Subtract a digital filter from another filter
How to subtract a digital filter from another one, if their lengths are different. How to make the length equal.
1
vote
0answers
49 views
How does bandwidth affect a modulated digital signal? [duplicate]
I'm currently reading up on how the lower layers of the ISO/OSI model work and I don't quite understand how broadband communication works yet.
Suppose I want to send some data from point A to point B ...
0
votes
1answer
917 views
Compare two wave files
I have two .wav audio(stereo) files to be compared. The files may vary in frequency or amplitude or phase shift. How to compute the difference between the wave files in Scilab? The expected output is ...
-2
votes
1answer
310 views
Comparison using cross correlation [closed]
I have 2 stereo audio files to compare.
Comparison of files include change in frequency, amplitude, phase shift
Code:
...
1
vote
3answers
548 views
Applying Nyquist theorem to digital vs. analog audio quality
I had a recent conversation with a friend about analog vs. digital recordings. He shared his opinion that music recorded by analog techniques is of superior sound quality to music recorded by digital ...
0
votes
1answer
652 views
How do I calculate the bandwidth from a waveform?
Suppose I have a waveform $x(t)$
where $x(t) = 5 + 30\mathrm{cos}(2000\pi t) + 10\mathrm{cos}(6000\pi t)$ that is to be uniformly sampled for digital transmission, how do I calculate the bandwidth of ...
0
votes
1answer
1k views
difference between GMSK (Gaussian Minimum shift keying) and GFSK (Gaussain frequency shift keying) [closed]
I am unable to differentiate GMSK and GFSK.
How do the modulation techniques differ in Tx?
How do their receiving techniques differ..?
1
vote
1answer
102 views
Galois Field implementation
Just a quick question. What Galois Field is best if you need a minimum Hamming distance of $n$? I want to design a BCH generator polynomial that is acccording to this Hamming distance.
3
votes
2answers
338 views
Why is CDMA not enough for wireless communication?
I have a question about CDMA, FDMA and TDMA.
I don't understand why we suffer from limited capacity when we have CDMA.
I can understand the limitation in FDMA and TDMA, as time and frequency are ...
2
votes
2answers
1k views
Average bit error and symbol energy
How do you draw decision boundaries given this type of 16-qam constellation diagram, I know that there should be no vacant decision boundary but I can't seem to get it.Also, assuming that the correct ...
1
vote
2answers
2k views
Analyzing a 16-QAM modulated waveform?
Okay I'm really confused about analyzing the waveform I generated using 16-QAM on MATLAB... I transmitted a $y = [0 \ 1 \ 2 \ 3 \ 4 \ldots \ 15]$ discrete signal (in order) to ...
4
votes
1answer
22k views
what's the pass band ripple and stop band attenuation of a digital filter?
Hi i'm a beginner in signal processing i want to know what'sthe pass band ripple and stop band attenuation of a digital filter ?
Thanks.
4
votes
1answer
229 views
Why in Overlap Save Method in DSP output length comes out to be same as input length?
I know that when we do convolution of $x(n)$ (Length $L$) and $h(m)$ (Length=$M$), length of output data comes out to be $L+M-1$, but when we break a large sequence of data and find output using ...
0
votes
2answers
67 views
Why the correct probability for a square M-QAM is equal to the square of correct probability of ($\sqrt M$)-PAM?
The question is why:
$P_c (\text{square} $ $M-QAM) = (1 - P_{\sqrt M})^2$
where: $P_{\sqrt M}$ is the error probability for $\sqrt M$-PAM signal.
Thanks.
3
votes
3answers
214 views
Sampling and Reconstructing Digital Signal
Say that I have a digital signal (a bitstream actually) whose output changes every 100 mS. I don't know exactly when it changes relative to my sampling, only that that the next bit to capture appears ...
2
votes
5answers
313 views
Differentiating between zero and not sending for OOK
How would a trigger works for on-off keying (OOK)? How would it differentiate between not receiving anything and zero?
0
votes
1answer
17k views
What is the difference between continuous, discrete, analog and digital signal?
It's my first time studying DSP and I've faced a problem finding a convenient definition.
Are the following definitions correct? And if so why there are some resources defining it in other terms such ...
0
votes
1answer
57 views
Canonical Rectangular Modulation
http://zone.ni.com/images/reference/en-XX/help/371025N-01/loc_eps_rectangular_modulation.gif
I just wanted to make sure that my assumption that in this figure $\phi(t)$ is representing $m(t)$, and $R(...
1
vote
2answers
534 views
Detecting which digital number an image represents
I photograph the dashboard of my car every day to register the mileage for work.
I use OpenCv to detect the region of the digital displayed mileage, crop to the numbers and match them. The method I ...
1
vote
2answers
477 views
Calculation of actual analog input from bipolar ADC's output
I have a $14$-$\textrm{bit}$ ADC which can take $-10\textrm{ V}$ to $10\textrm{ V}$ as input. So, $0$ to $16383$ (digital) represents the voltage from $-10$ to $10$. If I want to get the actual ...
0
votes
1answer
224 views
why does the decision boundary change in BPSK? is it true?
I am working on modulation and demodulation of BPSK using python. i made a code for modulation and demodulation,while demodulate i tried to compare my actual data bit stream with demodulated bit ...
1
vote
3answers
146 views
Linearizing digital-analog converters
I'm looking at ways to improve the effective resolution of DACs. It seems that element mismatch (i.e. integral non-linearity) is the main contributor to distortion in modern DACs. Apart from ...
1
vote
1answer
75 views
Digital Filters deal only with samples, right?
I'm new to digital filters. So I'm trying to get things right and I can't find an explicit answer to my question on the internet.
Question: Digital filters only accept samples as input? I mean the ...
2
votes
1answer
146 views
2D Digital Signal Processing - Applying High Pass on and Image
I have been doing my research on 2D digital signal processing. What I am doing is about noise removal of digital image:
Type of noise that I want to remove from an images is like the Gaussian noise ...
2
votes
0answers
1k views
Simple (Arduino) digital butterworth filter : why do I see oscillations?
I want to filter deviations from an ADC over time (low pass), not very critical. So I first tried exponential averaging, something like y= (7*y+x)/8. That gave useful results, but there is an obvious ...
