10 votes
Accepted

Delay a signal in time vs in frequency

Is there any trade-off in numerical precision or speed? Yes. For delays that are integer multiples of the sampling period method 1 is far superior: it's computationally efficient, it's bit-exact, it'...
Hilmar's user avatar
  • 44.5k
9 votes

Fast Integer 8 Hz 2nd Order LP for Microcontroller

This answer provides a quick introduction to decimation concepts and CIC filters which I would consider as one solution given the description. Bottom Line First Given your use of a microcontroller, (...
Dan Boschen's user avatar
  • 50.8k
9 votes

Estimate Sine Frequency under White Noise — simple and effective method

I assume the model to be: $$ x \left[ n \right] = \sin \left[ 2 \pi \frac{f}{ {f}_{s} } n + \phi \right] + w \left[ n \right] $$ Where $ w \left[ n \right] $ is white noise uncorrelated with the ...
Royi's user avatar
  • 19.5k
7 votes

How Best to Characterise a Window Function

An oldie but a goodie it fred harris's "On the Use of Windows for Harmonic Analysis with the Discrete Fourier Transform". It has a nice table showing different figures of merit for different ...
Peter K.'s user avatar
  • 25.7k
7 votes

Estimate Sine Frequency under White Noise — simple and effective method

If you have a low-noise and well-sampled signal, a quick way to estimate it is to find $\sqrt{-f''(t)/f(t)}$. For a signal $$f(t)=A \sin(\omega t+\phi)$$ the second derivative is $$-A \omega^2 \sin(\...
Nullius in Verba's user avatar
7 votes

Estimate Sine Frequency under White Noise — simple and effective method

A common way to do this is to take the FFT of the input signal. Since the frequency might not be right at a FFT bin, usually a second step of interpolation is done after choosing the initial peak. A ...
Engineer's user avatar
  • 3,032
6 votes

Estimate Sine Frequency under White Noise — simple and effective method

This depends on the precision needed. If it's a pure sine wave that's noise free, you can get a very quick estimate by measuring the difference between two zero crossings. The tricky part is that most ...
Hilmar's user avatar
  • 44.5k
5 votes

Estimate Sine Frequency under White Noise — simple and effective method

I wasn't going to answer this, since the question is stale. But I'm a little bit dissatisfied with Royi's answer and with the Kay algorithm as presented. The Kay method is, at first glance, simply ...
robert bristow-johnson's user avatar
4 votes
Accepted

Strategy / Method for Implementation of the Fastest 1D Linear Convolution / Correlation

I compared 3 implementations for Linear Convolution of 1D signals: Direct - Using MATLAB's conv() function. Overlap and Save - Implemented in MATLAB with tuned ...
Royi's user avatar
  • 19.5k
4 votes

Delay a signal in time vs in frequency

At the risk of blowing my own trumpet and that of my co-author, Bob Williamson, there is also this paper which shows the equivalence of three techniques referred to in the FIR link in Ben's answer and ...
Peter K.'s user avatar
  • 25.7k
3 votes

Solving linear equation of discrete convolution kernels using black box model for the convolution

This is not an easy question, not because ideas are complex but since the details matter a lot. As I wrote in my answer in the question Solving Inverse Problem Using Black Box Implementation of the ...
Royi's user avatar
  • 19.5k
3 votes

Estimate Sine Frequency under White Noise — simple and effective method

As others have already mentioned in the comments, the question shows on research effort, is far too broad and needs clarification. Depending on the requirements, the MUSIC (or ESPRIT) algorithm may be ...
juliusd's user avatar
  • 31
3 votes

Do BPSK vs QPSK have the same performance?

BPSK and QPSK have the same BER performance under additive white Gaussian noise only if the symbols are appropriately mapped to bits (such as Gray coding) since they can be viewed / treated as two ...
Dan Boschen's user avatar
  • 50.8k
3 votes

Delay a signal in time vs in frequency

As Hilmar pointed out, for delays that are integer multiples of the sampling period, method 1 is far superior. Also, Method 1 is more suitable for real-time operations as you don't need to buffer the ...
Ben's user avatar
  • 3,765
3 votes

Fastest Available Algorithm to Blur an Image (Low Pass Filter)

I have implemented a fast 5x5 Gaussian-blur in C++ and compared the performance to OpenCV on Raspberry Pi 3B+ running 32bit Raspbian OS. The function uses all the 4 cores of the Raspberry Pi and works ...
zana zakaryaie nejad's user avatar
3 votes
Accepted

Fastest Available Algorithm to Blur an Image (Low Pass Filter)

The fastest blur would be Box Blur. You can implement it using Running Sum. I think Intel FilterBoxBorder works in that manner. If you'd like you can do a few ...
Royi's user avatar
  • 19.5k
3 votes
Accepted

Predicting Execution Time of DSP programs

Top is terrible tool for measuring CPU time. Set up a bunch of counters or timer around the execution of individual and collect statistics on that. Each of your block should have a "should cost" that'...
Hilmar's user avatar
  • 44.5k
2 votes

Predicting Execution Time of DSP programs

we can get within 5 to 20%, but always underestimating top. Now, if it is always that much underestimated (as you stated so) then multiply your estimate with an approximate scale to get the more ...
Fat32's user avatar
  • 28.1k
2 votes
Accepted

Highest rate achievable by current DSP and A/D chips?

This is a pretty benign requirement. The Open Source software defined radio community does significantly more than 100 MS/s complex samples in software running on stock PC hardware. The samples come ...
Marcus Müller's user avatar
2 votes

Estimate Sine Frequency under White Noise — simple and effective method

Since @OverLordGoldDragon raised methods based on applying the DFT, I'd like to share another simple idea. Given the DFT, if the number of bins is high enough (Zero padding if needed, choosing power ...
Royi's user avatar
  • 19.5k
1 vote
Accepted

Definition of ERLE - echo return loss enhancement, measure when there is only echo?

The answer is yes. It might be misleading sometimes, when there is a concern of distorting the desired signal. But, usually, as the desired signal is uncorrelated with the reference signal, this issue ...
TomTim's user avatar
  • 26
1 vote

programing paradigms in SSB

In most DSP the problems the decision of frame based vs. sample-by-sample (stream based) processing comes down to practicalities and priorities. Stream based has lower latency and requires less memory ...
Hilmar's user avatar
  • 44.5k
1 vote
Accepted

Do BPSK vs QPSK have the same performance?

Yes, they do have the same bit error rate (there are other ways to measure performance, though!) All else being equal, there are few reasons to use BPSK instead of QPSK. Probably its main advantage in ...
MBaz's user avatar
  • 15.3k
1 vote

Estimate Sine Frequency under White Noise — simple and effective method

Summary Possible State of the Art by Cedron in compute-limited settings, as it beats Kay and many other methods In accuracy, Cedron is superior to Kay in nearly all settings, for both real and ...
OverLordGoldDragon's user avatar
1 vote
Accepted

pairwise error probability and union bound of space time code

The union bound can indeed result in a BER higher than 1. As you say, it is just an upper bound, and it becomes tighter as the SNR increases. For low SNR, the union bound can be quite loose.
MBaz's user avatar
  • 15.3k

Only top scored, non community-wiki answers of a minimum length are eligible