# Questions tagged [digital]

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87 views

### Removing DC bias

I have a signal that I have recorded from a AirSpyHF and want to remove a unwanted narrow signal with a notch filter (see figure). The spike in the image below appears to be a center spike, however it ...
• 131
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### How does a time delay affect the difference equation of a LTI-system?

I'm right now working on my digital signal processing homework and among the exercises is a tough LTI-system in a canonical-like form, however right before the output is a time delay. Suppose the ...
55 views

### Digital Audio Resampling

I've been working from this reference document, essentially trying to recreate Figure 7 with the understanding that the two functions place_signal and ...
53 views

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### Band pass filter = Band stop filter if you switch the cutoff frequencies?

The normalized frequency response of a N points bandpass digital filter is: $\frac{sin(\omega_{c2}(n-M))}{\pi(n-M)}-\frac{sin(\omega_{c1}(n-M))}{\pi(n-M)}$ where $\omega_{c1}$ is the normalized lower ...
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### Learning transceiver algorithms

I want to learn basic transceiver algorithms. I already have a good grasp of the mathematics and statistics involved, so I am primarily interested in algorithms. Any books or site recommendations, so ...
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### I have a doubt regarding FFT size in 5G NR 60 MHz Bandwidth

maximum RBs for 60MHz with SCS = 30 kHz is defined to be 162 RBs, so NSubcarriers is 162 x 12 = 1944, 1944 < 2048. Then NFFT size for 60 MHz bandwidth with SCS = 30 kHz should be 2048 instead of ...
40 views

### Phase Unwrapping [duplicate]

I'm also quite new to world of radar signal processing. I don't understand why we have to make phase unwrapping process. Could you light in me about it? It would be nice conversation speak about it. I ...
1 vote
175 views

### Is the Final value theorem applicable for some non-causal signals?

A digital signal $x[n]$ is zero at odd sample numbers and one at even sample numbers. What will be the value of this Signal at $n = \infty$? Not exactly sure, but I thought that infinity (as a integer)...
18 views

### How to emulate lower resolution digitized data (higher step-size)

I am a statistician by training, and I am very new to signal processing, but I would appreciate some help and patience! Suppose I have a digitized signal measured at a given frequency, range, ...
1 vote
161 views

### Sampling Precision, Jitter, and PID

I am having difficulty understanding the effect of quantization noise and ADC resolution in a digital PID controller. I am also trying to understand the effects of sampling jitter on a PID controller. ...
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### USRP N210 Main clock rate and The transmission signal Sampling Rate

I am testing the transmission and receiving signal using two USRP N210. The communication setting as follows: ...
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### Do the digital filter coefficients need to be forced to sum to 1.0?

I coded a digital filer in Matlab based on equations I found for a Martin-Graham (low pass type). It looks like it is working. So I want to smooth some data and then calculate the first derivative. ...
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### Standardize fft amplitude with different encodings

I'm trying to "standardize" the results of the fast Fourier transformation. I've one wav with two peaks (3000 and 3300 Hz) saved with three different encodings(int16, float32, int32). And ...
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### Confusion implementing Quantization in MATLAB?

I am quantizing a continuous time signal in three different cases(using different number of bits) But Why i am getting same quantized signal in xq2 and xq3,despite using different values of D(...
• 1,884
480 views

### Can a digital signal has 3 three values(1,0 and -1)?

Typically digital signals are seen having only two values,but is it possible that a digital signal has three values(1,0 and -1)?as shown highlighted in attached snapshot,which has been extracted from ...
• 1,884
1 vote
153 views

### Why is Line coding called "Line coding"?

Guys do you now why line coding also called digital base band modulation named "line coding" where does it come? and how is the name related to modulation
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### What sampling frequency should I use if Nyquist is not available?

I have the following homework question that confuses me: We have an audio emitter that can emit two signals: It either emits a sine wave at 23 kHz or it emits a sine wave at 25 kHz. The receiver has ...
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1 vote
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### How to recover modulation symbols？

I am using GNURadio to send and receive a limited number of modulation symbols. I have constructed the following flow chart:random source(no repeat)->chuncks to symbols(file sink1)->polyphase ...
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### Dual functional integrated Digital Cathode Ray Oscilloscope and Digital Multimeter product

Is it feasible to design & construct a Dual functional integrated Digital Cathode Ray Oscilloscope and Digital Multimeter products in a single product? Idea is to integrate the Digital Multimeter ...
62 views

### Phase Error Growth in Digital Mixer Signal

I am working on a code where digital mixing is to be performed for down-conversion of incoming signal. The mixer signal is created using the phase accumulation approach. However it was observed that ...
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### Speaker Walkaround

Does anyone know what Speaker Walkaround means in context of a digital amplifier? Also how is this test performed? Lastly, how is it different from Load Diagnostics in Amplifiers?
360 views

### Why symbols have to be upsampling, if the symbol rate and sample rate is same what happen?

In digital modulation process, after constellation mapping and before pulse shaping, the symbols are upsampled with the number L(samples per symbol). At this moment, why symbol have to be upsampled, ...
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1 vote
236 views

### Balance Fader in Digital Amplifiers

What is the purpose of Balance / Fader in a digital Audio amplifier? In a signal flow what is the most apt position to place balance and fader(for example after before a compressor unit or at the ...
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### Centre channel derivation using correlation

I would like to know the algorithm for how centre channel is derived from rejecting left and right channel in audio upmixing process. Can someone explain intuitively rather than hard hitting ...
36 views

### Is there a separate word for the time domain when working with digital signals?

Typically the phrase "time domain" implies an analog signal x(t), but I've also seen it referring to a digital signal x[n]. Is there any phrase that refers to x[n], but not x(t)?
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### 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 ...
• 95
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### 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 ...
476 views

### how to convert SPL in dBA to dB

I wonder how I can convert dBA (A weighted) to dB and vice versa. can anybody provide any kind of table or online conversion app? thanks following formula comes from https://en.wikipedia.org/wiki/A-...
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### Band limited discrete signals division

If I take two analog, band limited signals $x(t)$ and $y(t)$ with non-zero $y(t)$ I can define the division: $$z(t) = \frac{x(t)}{y(t)}$$ In general $z(t)$ may have a very wide bandwidth, also ...
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### Find which signal was transferred in 32QAM

I've been assigned to solve a problem for 32QAM signals. The thing is, there are little to none sources in my native language to get any decent information on the topic. The problem is (in its ...
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### 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 ...
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### MAP Estimation Problem for Frequency Band Occupancy Calculation

Consider designing a wireless communication system. Your communication link is not iso- lated in the environment, there are other similar devices trying to communicate in the same general frequency ...
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### Decoder implementation

Im struggling to implement / build convolutional decoder . I've done implementation of FEC encoder which it's as shown in the photo below: So this is the encoder that I've implemented, and I want to ...
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### Hw does a digital piano work?

I know someohow it combines different harmonics to synthsis note, but I don't exactly know how this happens. Does digital piano use pwm to synthesis a note?
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### For an LTI system, the zeos and poles are defined in the z plane. How to add additional poles and zeroes so LTI system is real valued?

The question already has a zero and a pole in the complex plane. It is asking to add additional zero and pole so LTI becomes zero valued. zeros=-1/2 + 1/2 i , poles = -1/3 -1/3 i . What I understand ...
1 vote
176 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
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1 vote
992 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 ...
• 1,884
1 vote
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### How the Grayscale images are converted back to RGB?

In case of RGB to grayscale conversion we take the average of R,G,B channels and convert them to Grayscale which has songle channel. How to convert back the Grayscale to RGB ??
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