# Questions tagged [digital]

The tag has no usage guidance.

146 questions
Filter by
Sorted by
Tagged with
1k views

### What does one need to know in order to build a software synthesizer?

For someone who has some experience in software development, loves his synths and knows the [very] basics of digital audio representation, what are the first steps he should follow in order to program ...
14k views

### Digital Distortion effect algorithm

I read the DAFX book by Udo Zölzer about the distortion effect at pages 124-125 and it says that suitable simulation of the distortion is given by the function: f(x)=\frac{x}{|x|}\left(1-e^{x^2/|x|}...
56k views

### Difference between Digital signal and Discrete signal

I have just started studying Digital Signal Processing. Can someone explain what is the difference between a Discrete Signal and a Digital Signal in simple words? Thanks in advance !
10k views

### Nyquist Frequency Phase Shift

The figure below shows in dashed lines sinusoidal signals of the same frequency at three different phase shifts. The signals are then sampled such that the sinusoidal frequency is exactly a half of ...
25k views

### What is IQ Data?

I have no background in telecommunication. Could anyone please explain to me what is the IQ data in telecommunication? It will be best to explain it with some basic analogies. Many thanks!!
228 views

### What Is the Correct Way to Apply Richarson Lucy Deconvolution to Luminance Data?

My question concerns the Richardson–Lucy deconvolution algorithm, which is described in Richardson's original paper. I am interested in applying it in the context of a raw image converter for digital ...
107 views

### Why is phase range between $-\pi$ and $+\pi$ (instead of $0$ and $2\pi$)?

I wonder why the phase range in DSP applications is between $-\pi$ and $+\pi$. For example, why is that not between $0$ and $2\pi$? This question popped when I was reading about synchronization in ...
3k views

### Digital filters with more zeros than poles

I am having trouble wrapping my head around digital filters with different orders of numerator and denominator. Let me know if any of these points is wrong: All (digital or analog) transfer ...
36k 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.
330 views

### Is it possible to do further beamforming on already beamformed data?

I've a circular array of eight FM antennas. I'm doing digital beamforming to form eight beams with the following beam patterns: The objective is to reduce my side lobes even further, and to get ...
227 views

### Low analog lowpass + ADC vs High analog lowpass + ADC + low digital lowpass

I'm doing EEG data collection and my amp forces use of an analog lowpass filter before the ADC. I'm fairly sure that I won't be interested in phenomena associated with frequencies of 30Hz or higher, ...
886 views

### Spectral images - How do they appear during ADC?

Why is it that spectral images appear? I know they appear for $F_s$, but why those replicas appear, I don't know. E.g., sampling $x(t) = sin(1000 * 2\pi t)$ with a sample frequency of 230 Hz. I know ...
319 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 ...
509 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 ...
21k 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 ...
91 views

### Papers for Teaching an Introductory Course in Image & Signal Processing

I'm preparing a digital signal/image processing introductory course and, besides the theory and practices I want the students to read and discuss a couple of research papers during the last one or two ...
330 views

### Ignoring Nyquist

What happens if I ignore Nyquist? I have a 16.368MHz digital signal coming out of a GPS front-end chip. My microcontroller (which is reading that digital stream of data) operates at a maximum of ...
163 views

### What is databending and how does it actually work?

http://www.google.com/search?q=databending It is, from what I understand, opening images as audio, applying effects, exporting back as image and voila! glitch-art Example: credit But how does ...
4k views

### What is spatial correlation and spatial convolution?

What does the term spatial correlation and spatial convolution mean with respect to digital image processing ?
290 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 ...
3k views

### Digital Gaussian White noise signal generation in C++

I am trying to generate a band limited noise signal on a Raspberry Pi. I calculate samples at every 1/48000 sec on the Pi. If I generate normally distributed random numbers as data points at every ...
139 views

### How to filter a regular ticking out of a digital (on/off) signal?

I have a digital on/off signal sampled at a regular interval. There was a problem with the sensor that produced the signal which has sometimes caused a regular on/off ticking when the sensor should ...
50 views

### Wave Digital Filter Bridge-T Resonator implementation, gives expected cutoff frequency but incorrect gain and roll-off

Trying to implement the WDF in Fig 5(a) of this publication. The response of the ideal op-amp implementation is given by the black curve in Fig 7: Here is the plot I get when trying to implement the ...
3k views

### Understanding “voltage” and “power” in SNR of a sampled signal

I'm facing a gap in my understanding of when a signal is a "voltage" signal and when it is a "power" signal that I've always managed to avoid resolving until now... First what I think I understand, ...
2k 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 ...
414 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?
178 views

### Shouldn't the Sampling Theorem imply that there should be no information loss at all after a signal is processed?

I am very, very new to signal processing (only started a few days ago) so please bear with me because I may be missing the big picture. Consider an arbitrary signal $x(t)$ with varying frequency to ...
5k views

### Carrier frequency offset (CFO) estimation using cyclic prefix

I understand the cyclic prefix, but in (1) it's said that: "If we consider that the channel effect is minimal and can be neglected. then the phase difference of the CP and the OFDM symbol which the ...
375 views

### DAC to Analog Filter to ADC

As the order of filter needed for digital information gets higher, it takes longer to process and requires more memory. Maybe analog filtering could be of use here. I know that the words analog and ...
791 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?
69 views

### phase response of an analog filter

I am trying to understand the relation between phase response of an analog filter and its influence on the quality of a signal with PSK modulation. For example I want to design a BPF for HF ...
111 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? ...
1k 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 ...
245 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 ...
930 views

### Creating a digital filter, from Laplace to $\mathcal Z$-transform (zero order hold) to code?

I'm trying to create a digital filter in code(C) but any language is fine. Now I've got an analogue filter that I have represented by an equation in the Laplace domain and I want to try and implement ...
35 views

### How can I automate the calculation for P and I coefficients of an FPGA-based digital PLL?

I am working on designing an FPGA-based PLL through an NI myRI0-1900 FPGA and LabVIEW software. I have been able to create a functioning PLL with a PI loop filter, and but I found functioning P and I ...
2k 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 ...
441 views

### Digital Vs. Analog Phase measurement [closed]

I'm working on a Ultrasonic Transducers resonance tracking system. Where phase shift between Voltage and Current is the feedback signal for my system when phase difference is Zero that means system is ...
247 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 ...
142 views

### Are there analog re-configurable filters?

I know that we can build a chip (or circuit) or use FPGA to have re-configurable digital filters. But how about analog filters, can we have re-configurable analog filters? thanks
784 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 ...
357 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?
3k 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 ...
79 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 ...
532 views

How are Radix-8 and Radix-2^3 FFT are related? Are they same? I got some more details in IEEE paper by S.He and M. Torkelson, "Designing pipeline FFT processor for OFDM (de)modulation," in Proc. Int....
3k views

### Explanation of binning in frequency analysis post-FFT

I am creating an Android app which records sound for t seconds at a sampling rate of 44.1kHz with a buffer size of 8192 (16 bit mono samples). I need to plot a ...
133 views

### Discrete signal vs digital signal?

Is there any difference between the two? When we say discrete signal, does it only imply that the x-axis or time is discrete? Or it can also mean discrete amplitudes on the y-axis? Or is the signal ...
229 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 ...