## Help needed in Finding of Standard deviation of Random Noise

Started by in comp.dsp18 years ago 3 replies

I am reading a digital signal processing book "The Scientist and Engineer's Guide to Digital Signal Processing" 2nd Edition by "Steven W....

I am reading a digital signal processing book "The Scientist and Engineer's Guide to Digital Signal Processing" 2nd Edition by "Steven W. Smith" I could not understand the following concept in its second chapter QUOTE Each random number has a value between zero and one, with an equal probability of being anywhere between these two extremes. Figure 2-10a shows a signal formed by t...

## covariance question

Started by in comp.dsp17 years ago 4 replies

If a zero-mean Gaussian random noise signal is at the input to a matched filter bank (so the input to each filter is identical), what is the...

If a zero-mean Gaussian random noise signal is at the input to a matched filter bank (so the input to each filter is identical), what is the nature of the outputs of each filter in the bank? Assuming the filters are linear then each output should also be Gaussian, but are they correlated or made independent by the filters.. is there a way of calculating the covariance matrix from the tran...

## Random Noise generators

Started by in comp.dsp17 years ago 8 replies

Hello, Can somebody please tell me how to generate a noise signal on the basis of its statistical characteristics? i want to create a c++...

Hello, Can somebody please tell me how to generate a noise signal on the basis of its statistical characteristics? i want to create a c++ function with the following syntax: ============================================================= valarray GenerateNoise(int type,double* stats, size_t sample_size) ============================================================= arguments: t

## Adaptive Feedback Path Tracing Mismatch Problem

Started by in comp.dsp17 years ago 8 replies

Hi, all I'm doing the acoustic feedback path tracing for hearing aids applications. My method belongs to non-continuous method. i have a random...

Hi, all I'm doing the acoustic feedback path tracing for hearing aids applications. My method belongs to non-continuous method. i have a random noise u(n)as the input of my adapitve filter and a prescribed 160-tap feedback path F(z). I use 160FIR adaptive FIR filter W(z) to model the original 160-tap feedback path. The echo is obtained by passing u(n) through the F(z), and outside there is a spee...

## How to create random noise in a signal

Started by in comp.dsp16 years ago

Hi NG, I am making an artificial signal, composed of a number of sinusoids which reflect "real" detections/data, but I would like to get...

Hi NG, I am making an artificial signal, composed of a number of sinusoids which reflect "real" detections/data, but I would like to get closer to the real thing by adding some random noise to the signal. Is there a "standard" way of doing this, provided I have access to a random number generator? Any ideas with regard to the actual implementation are also welcome. I was thinking creati...

## Tracking one frequency

Started by in comp.dsp16 years ago 4 replies

Please excuse this beginner question. I have about a minute's worth of sound data taken by a microphone and recorded into a file. The...

Please excuse this beginner question. I have about a minute's worth of sound data taken by a microphone and recorded into a file. The sound field has one frequency of interest and some random noise (at a lower magnitude than the random noise). My sample rate is about 6x the frequency of interest. I want to show the change in the frequency of interest alone. I am thinking to perfo...

## Distrubution of noise times noise

Started by in comp.dsp16 years ago 9 replies

If I have two signals that are corrupted with Gaussian random noise and I multiply them, what is the noise distribution called? x1 = s+n1 x2...

If I have two signals that are corrupted with Gaussian random noise and I multiply them, what is the noise distribution called? x1 = s+n1 x2 = s+n2 x1*x2 = s*s+(n1+n2)*s+n1*n2 Is noise times noise (n1*n2) the focus of any study? I would be interested to read about it. Thanks.

## algorithms for fat-tailed random noise generators?

Started by in comp.dsp15 years ago

I would like to experiment with chaotic noise versus Gaussian noise sources. Previous threads in comp.dsp have recommend summing 12...

I would like to experiment with chaotic noise versus Gaussian noise sources. Previous threads in comp.dsp have recommend summing 12 uniform RNG's to approximate Gaussian random noise, which can be done with a reasonably small computational overhead per sample. Does anyone know of any reasonably low overhead algorithms to generate random noise samples from an approximation to fat-tailed, ...

## medical imaging is the vanguard of signal processing in 21st

Started by in comp.dsp14 years ago 60 replies

I reckon once upon time that geophysics (particularly seismology) was driving a lot of research into signal processing. Now it seems to me they...

I reckon once upon time that geophysics (particularly seismology) was driving a lot of research into signal processing. Now it seems to me they are falling behind. I think that medical imaging is now ahead of them in finding new random noise attenuation tricks, for example. A penny for your thoughts? Il mittente di questo messaggio|The sender address of this non corrisponde ad un ut...

## characterizing frequency domain performance of a digital controller

Started by in comp.dsp14 years ago 6 replies

I have a digital controller that has been hand-tuned to sort-of-work. [ G[z] = ( 25z - 23 ) / (z-1) and sampling frequency is 90kHz ]. I...

I have a digital controller that has been hand-tuned to sort-of-work. [ G[z] = ( 25z - 23 ) / (z-1) and sampling frequency is 90kHz ]. I would like to know how to determine its gain at various frequencies. If it were an ordinary filter, I could take the fft of its impulse response. As it is, I've tried stimulating it with random noise (vector x), to get a response, (vector y), then done an ff...

## what's the different between a frequency shifted signal band and a normal signal?

Started by in comp.dsp13 years ago 3 replies

Hi, I am facing some confusion about frequency shifting. I have sampled a random noise signal at 48K . Now I have taken 5K to 11K signal band...

Hi, I am facing some confusion about frequency shifting. I have sampled a random noise signal at 48K . Now I have taken 5K to 11K signal band from the main signal and shift this band at zero to 6K. I have done it multiplying the 5K to 11K band signal by 2*cos(2.pi.5000.t). After multiplying there is two band : one from 0 to 6K and another from 10K to 16K. Then using a a low pass filter I ha...

## Locate the robust max in an 2D array?

Started by in comp.dsp12 years ago 9 replies

Hi all, We have a task in Matlab that I don't know how to it: We would like to find the "robust" peak/max in an numeric array. The...

Hi all, We have a task in Matlab that I don't know how to it: We would like to find the "robust" peak/max in an numeric array. The "robust" here means that if the peak or max is a singleton and all the surrounding regions around that peak/spike/max are deep valleys, then this peak/max is not a "robust" max, it's a spike, or random noise. We don't want to get such a max. Instead, ...

## normalized RMS?

Started by in comp.dsp5 years ago 3 replies

I came across "normalized RMS", defined as RMS(a-b)/(RMS(a)+RMS(b)) as a measure of similarity. It is obviously zero for identical signals,...

I came across "normalized RMS", defined as RMS(a-b)/(RMS(a)+RMS(b)) as a measure of similarity. It is obviously zero for identical signals, and increases with difference. If a or b is zero, then it is 1. If a and b are both random noise, it will be 0.7 (half sqare root of 2). It is also sensitive to amplitudes: if b=a/2, then normalized RMS is 2/3. That contrasts with normalised cross-co...