## Noise cancelling approach

Started by in comp.dsp13 years ago 1 reply

Hello I have a data vector/time-series d = s + n (where s is signal and n is noise). n is somewhat localized in frequency, with two distinct...

Hello I have a data vector/time-series d = s + n (where s is signal and n is noise). n is somewhat localized in frequency, with two distinct peaks. (in actuality of course, there is also white noise, but that's a different subject). I have around 1 second of reference noise (compared to 12 seconds of data) that was recorded before the onset of the signal. Call this reference n'. What I am doin...

## MUSIC and ESPRIT

Started by in comp.dsp11 years ago 6 replies

can MUSIC and ESPRIT algorithm work if i add rayleigh noise channel.I have implemented them with guassian noise having zero mean.i am not gettin...

can MUSIC and ESPRIT algorithm work if i add rayleigh noise channel.I have implemented them with guassian noise having zero mean.i am not gettin can i change the noise and what noise can i add to these algorithms. _____________________________________ Do you know a company who employs DSP engineers? Is it already listed at http://dsprelated.com/employers.php ?

## White noise reduction

Started by in comp.dsp15 years ago

Hi, Do you know some noise reduction methods when a signal with a bandwidth of several MHz is in a white noise? I would like to reduce noise in...

Hi, Do you know some noise reduction methods when a signal with a bandwidth of several MHz is in a white noise? I would like to reduce noise in the band of interest. I'd be very happy if you told me at least some methods names ;) Thank you

## Double integrated white noise

Started by in comp.dsp14 years ago 24 replies

Hi, I am trying to generate noise with an f^-4 PSD, and am having some difficulty getting the spectrum desired. The problem is...

Hi, I am trying to generate noise with an f^-4 PSD, and am having some difficulty getting the spectrum desired. The problem is this: Applying a filter with the transfer function co-efficients b = [1] and a=[1 -1] to white noise creates noise (as expected) with an f^-2 PSD. The rolloff of this filter is 20dB per decade, so it's pretty clear why it works. The theory (as far as I can...

## Noise reduction through multi-tracking

Started by in comp.dsp16 years ago 4 replies

Hi. I'm vaguely aware that noise in a recording can be reduced by recording a sound (say on analogue) tape multiple times, and then mixing the...

Hi. I'm vaguely aware that noise in a recording can be reduced by recording a sound (say on analogue) tape multiple times, and then mixing the multiple recordings together on playback. The noise should, to a degree, cancel, while the signal reinforces. I'm just wondering if there is a more technical description of this. Assuming that the noise is random, then adding together multiple sourc...

## amplify without increase of noise

Started by in comp.dsp15 years ago 7 replies

Hi! I have a recorded file (wav) where the recorded signal is very weak. When I try to aplify the signal the signal is almost lost in all the...

Hi! I have a recorded file (wav) where the recorded signal is very weak. When I try to aplify the signal the signal is almost lost in all the noise (mostly high frequency) that also seems to be added from nowhere... maybe it is "white noise"? Are there any program (not expensive) that can can remove this unwanted noise from the file?

## Question about Active Noise Cancellation

Started by in comp.dsp7 years ago 11 replies

Hello, I'm hoping the experienced folks in this newsgroup would be so kind so point me to some good tutorials (and books) on the subject of...

Hello, I'm hoping the experienced folks in this newsgroup would be so kind so point me to some good tutorials (and books) on the subject of active noise cancellation. Being new to ANC, this is my understanding of how ANC works: Ambient noise (n) is entering a geographically small zone. To suppress the noise, an interfering (corrective) sound is injected acoustically into the z

## EKF process/noise modeling with non-additive noise

Started by in comp.dsp13 years ago 3 replies

Hi, I am trying to model an EKF where the noise is not simply additive and I am not sure how to begin. Perhaps someone could give...

Hi, I am trying to model an EKF where the noise is not simply additive and I am not sure how to begin. Perhaps someone could give some pointers... To explain my model I start with a simple linear (and very common) discrete model: x(k) = x(k-1) + dt * xd(k-1) + dt^2/2 * v(k) xd(k) = xd(k-1) + dt * v(k) where, x => position xd => speed v => noise dt=> time step On my non-line

## Single Channel Adaptive Noise Cancellation algorithm for Speech Enhancement

Started by in comp.dsp14 years ago 8 replies

Hi Everybody, I am working on removing 'White Gaussian Noise' from speech using adaptive method. Since I don't have access to the reference...

Hi Everybody, I am working on removing 'White Gaussian Noise' from speech using adaptive method. Since I don't have access to the reference noise and the only thing at hand is speech+noise record, that's why it is a bit tricky. Can anyone help me in this regard. Many Thanks... _____________________________________ Do you know a company who employs DSP engineers? Is it already listed a...

## algorithms for fat-tailed random noise generators?

Started by in comp.dsp14 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, ...

## NOISE AND DATA

Started by in comp.dsp13 years ago 3 replies

Suggestion needed I have a set of noiseless data , x= [1 2 3 4 5 6 ]. I want to add noise to it using g= x+ 0.5* rand(1,6) How do i...

Suggestion needed I have a set of noiseless data , x= [1 2 3 4 5 6 ]. I want to add noise to it using g= x+ 0.5* rand(1,6) How do i calculate the signal to noise ratio of this signal if the variance of the noise is 0.5.I know the relationship between SNR and variance, mathematicallly and can implement that in MATLAB. Is there any inbuilt function that can calculate that easily ? Th...

## NOISE AND DATA

Started by in comp.dsp13 years ago

Suggestion needed I have a set of noiseless data , x= [1 2 3 4 5 6 ]. I want to add noise to it using g= x+ 0.5* rand(1,6) How do i...

Suggestion needed I have a set of noiseless data , x= [1 2 3 4 5 6 ]. I want to add noise to it using g= x+ 0.5* rand(1,6) How do i calculate the signal to noise ratio of this signal if the variance of the noise is 0.5.I know the relationship between SNR and variance, mathematicallly and can implement that in MATLAB. Is there any inbuilt function that can calculate that easily ? Th...

## deconvolution in time?

Started by in comp.dsp16 years ago 21 replies

Hello! I have a output signal y(k) and a plant P(z). The signal y(k) contains some noise and I know the PSD of the noise. But lets assume that...

Hello! I have a output signal y(k) and a plant P(z). The signal y(k) contains some noise and I know the PSD of the noise. But lets assume that for now that the noise is qhite and the system looks like this: Y(z)=U(z)P(z)+E(z) u(k) y(k) ----------> [P(z)]--> [+]---> | e(k) | -------| I want to restore the sig

## Audio - Noise removal

Started by in comp.dsp15 years ago 4 replies

Hi I am using Kalman filter in building a noise removal tool for speech signal. The questions I am faced with are: a) To find right...

Hi I am using Kalman filter in building a noise removal tool for speech signal. The questions I am faced with are: a) To find right estimate of Signal variance b) To find right estimate of Noise variance I do a rough estimate of signal variance from LPC analysis of the noisy i/p and amd updating noise variance during silence period. But, with this technique a short lived noise durin...

## decreasing signal power..does it mean.increasing noise power

Started by in comp.dsp13 years ago 1 reply

hi all, i am carrying out a small test in where i need to introduce 1 db of noise. Since i don't have any noise generator can i decrease...

hi all, i am carrying out a small test in where i need to introduce 1 db of noise. Since i don't have any noise generator can i decrease the input signal by 1 db.Is it equivalent to injecting noise of 1 db? I am doing the test in awgn channel. Does it also hold good for multipath channel models? Thanks particlereddy

## Automatic RF noise cancellation and audio noise measurement

Started by in comp.dsp18 years ago 33 replies

THE BIG QUESTION: How do you measure the audio noise level in a receiver? Does anyone here know of any circuits that show the overall audio...

THE BIG QUESTION: How do you measure the audio noise level in a receiver? Does anyone here know of any circuits that show the overall audio noise level? Let me tell you what this is all about. SIDE NOTE: Thanks again to those of you who helped me with the SWR/wattmeter project I worked on last semester. This project taught me more about ferrite cores, op amps, and diodes than ANY class...

## VCO Phase noise: consequence for mixing...

Started by in comp.dsp16 years ago 2 replies

Hi, there! I'm new on this board, and maybe I'm veryy close to rules, so sorry in advance! My question, despite its simplicity, is rather head...

Hi, there! I'm new on this board, and maybe I'm veryy close to rules, so sorry in advance! My question, despite its simplicity, is rather head breaking: I'm trying to understand and quantify the consequence of phase noise, due to a VCO, when injected in a mixer. As I think this phase noise could be assimilated as a coloured noise, so a gaussian SPD, I don't really imagine what could happen ...

## decreasing signal power..does it mean.increasing noise power

Started by in comp.dsp13 years ago 4 replies

hi all, i am carrying out a small test in where i need to introduce 1 db of noise. Since i don't have any noise generator can i decrease...

hi all, i am carrying out a small test in where i need to introduce 1 db of noise. Since i don't have any noise generator can i decrease the input signal by 1 db.Is it equivalent to injecting noise of 1 db? I am doing the test in awgn channel. Does it also hold good for multipath channel models? Thanks particlereddy (straydog)

## Help! A puzzlement about noise sampling & reconstruction.

Started by in comp.dsp13 years ago 4 replies

a bandlimit white noise x(t) with PSD of S0 is sampled (no aliasing) to produce x[n]. The PSD of x[n] is calculated to be S0/Ts (Ts is...

a bandlimit white noise x(t) with PSD of S0 is sampled (no aliasing) to produce x[n]. The PSD of x[n] is calculated to be S0/Ts (Ts is the sample period). Now I just reconstruct the continuous noise xr(t) by passing x[n] impulses to the ideal reconstruction filter (gain=Ts, -fs

## Measurement Noise of PSD estimation (AR)

Started by in comp.dsp12 years ago 7 replies

Hallo, I am quite new to this topic and I hope I can get some help here. suppose we have a system driven by white noise resulting in a...

Hallo, I am quite new to this topic and I hope I can get some help here. suppose we have a system driven by white noise resulting in a Random Process. The measurement I get is the addition of the Random process with the measurement noise. my question is : Is it possible to identify the measurement noise from the recieved noisy signal? Do anyone has a paper or a book approaching such topi...