Questions tagged [digital]
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178 questions
0 votes
0 answers
76 views
How to prove $y[n] = x[n] + x[n + 1]$ is not causal given a step input signal?
I have this problem where it asks me to prove, by counter-example, that $y[n] = x[n] + x[n+1]$ is not causal. I am given the input signal $x[n] = u[n]$ that I have to use to prove this. I went ahead ...
- 1
0 votes
0 answers
38 views
Estimating SNR from analytic fourier transform and variance
Consider a received digital signal composed by a transmitted signal plus AWGN at a double sided power spectral density of $N_0/2$. This signal is sampled at a given frequency $f_s$ and the transmitted ...
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1 vote
1 answer
77 views
Resolution of NCO as a digital clock
I have a question regarding the resolution of Numerically Controlled Oscillator where the most significant bit is being used as the digital clock. I am not including the phase look-up table where the ...
- 11
1 vote
1 answer
76 views
Automatic detection of PCM sample errors?
I was upsampling a track from 44.1/16 to 88.2/24 and it clipped at one spot. Looking at this sample in the original file reveals an evident PCM error - the sample sign is reversed. As a result, the ...
- 111
0 votes
1 answer
64 views
Why can Euler's identity be used to express a sinusoid with a single exponential?
I'm unsure how 4.1.5 is used to express the value in 4.1.4... any advice or tips?
0 votes
1 answer
432 views
How calculate dB SPL from microphone signal
I have UMIK-1(24bit depth) and calibration file for it, where there is sens factor in dbFS and mic correction. I wrote a script in Python, where I receive a signal from the microphone and I can no ...
0 votes
1 answer
227 views
Meaning of the phase of a sample
In a sampled signal RF signal with I,Q parts, if we represent each sample as an amplitude and phase, what does the phase of a sample mean? Does it say something about the RF signal at that point of ...
- 109
1 vote
1 answer
138 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 ...
- 143
2 votes
1 answer
177 views
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 ...
- 23
2 votes
1 answer
76 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 ...
4 votes
1 answer
70 views
Show that the similarity between a signal at an analysis frequency with a phase offset with a reference signal is $\frac{N}{2}\text{cos}(\phi)$
I'm reading Brian McFee's excellent book Digital Signals Theory. He presents the DFT as a measure of similarity $S$ between a digital signal $x[n]$ with $N$ samples and a set of reference signals $y_m[...
- 143
1 vote
3 answers
230 views
Energy of Transmit Pulses in Digital Communication
Consider the problem of transmitting just two SRRC pulses through an noiseless Channel. The two transmit bits are {+/-1}. In plots below, the individual transmit pulses are shown in black, while the ...
2 votes
3 answers
2k views
Trying to understand the general scheme of how real-time audio signal processing works on embedded system
I played around with many microcontrollers before but never had a chance to do any kind of signal processing. I'm trying to learn how to implement digital signal processing algorithms on the ...
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0 votes
2 answers
82 views
What does the frequency domain of bipolar Alternate Mark Inversion (AMI) look like?
Someone said to me that Bipolar AMI is not low-pass; it does not include the 0Hz in its frequency domain. I doubt that that is the case. However, at present I am unable to do Fourier transformations. ...
- 149
1 vote
1 answer
68 views
What method is used in DSP to determine which discrete time frequency another frequency aliases to?
I am reading a DSP textbook and I am on the sampling portion. I understand that a discrete time frequency greater than 1/2 will alias to frequencies in the interval -0.5 to 0.5 and other frequencies ...
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