## Forums Search for: White Noise

## Eb/N0 computation when adding noise in frequency domain

inHello I just want to know if the computations I do to know the relation Energy_per_Bit/No are correct in the next situation: I add white...

Hello I just want to know if the computations I do to know the relation Energy_per_Bit/No are correct in the next situation: I add white noise after performing the FFT in a OFDM receiver as shown next: Signal_Power=var(Noiseless_Signal_in_Frequency); VarianceNoise=SNR/Signal_Power; Noisy_Signal=Noiseless_Signal_in_Frequency+sqrt()*(randn()+1i*randn())...; Is the Energy_per_Bit/No relati...

## Filtering...looking for constant amplitudes

inHello, I have a continuous spectral plot that I need to filter. The spectrum is unique in that at a glance it looks like white noise, however...

Hello, I have a continuous spectral plot that I need to filter. The spectrum is unique in that at a glance it looks like white noise, however if you look closer there are bins (frequencies) that have constant amplitudes. The problem is if I simply average the continuous spectrum, the noise averages to the same amplitudes as the constants. What would be the best algorithm to extract th...

## white noise power

inMatlab command y1 = wgn(100,1,10) generates a column vector of length 100 containing real white Gaussian noise of power 10 dBW. How can I...

Matlab command y1 = wgn(100,1,10) generates a column vector of length 100 containing real white Gaussian noise of power 10 dBW. How can I verify that the power of the 100 samples is 10 dBW ?

## Correlation

inSuppose we pass white noise u(k) through a filter H(z-1) giving an output y(k)=H(z^-1)u(k) now u(k) and u(k-1) are uncorrelated. Can we say...

Suppose we pass white noise u(k) through a filter H(z-1) giving an output y(k)=H(z^-1)u(k) now u(k) and u(k-1) are uncorrelated. Can we say the same for y(k) and y(k-1)? Hardy

## Decorrelation vs Whitening

inTo me, whitening is takinga coloured noise signal and reproducing it's white noise input.(as Weiner has it) However, I have seen otehr...

To me, whitening is takinga coloured noise signal and reproducing it's white noise input.(as Weiner has it) However, I have seen otehr definitions eg suppose we have a mixture of signals via a matrix A X=A.S where S is a vector of signals. Does decorrelating then result in a diagonal matrix? Is this what some people call whitening? Also, can I decorrelate by taking the correlation mat...

## Measurement Noise of PSD estimation (AR)

inHallo, 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...

## confused about white noise definition

inHello, Per definition a white noise signal has a zero mean value. yet by definition also , it has a flat power density, i,e. every...

Hello, Per definition a white noise signal has a zero mean value. yet by definition also , it has a flat power density, i,e. every frequency including zero has the same power which means it has a DC value, hence its mean is not equal to zero. I am confused. any help please?

## phase of noisy sine wave

inHello, I have following problem: I should get phases of noisy (white noise, SNR is about 1), long sine waves (thousands of periods), and...

Hello, I have following problem: I should get phases of noisy (white noise, SNR is about 1), long sine waves (thousands of periods), and hopefully probability phases are between certain values. Is there any methods implemented in matlab, or could you offer me some solution for problem, Thanks already for answers!

## Allan variance

inHi. I'm trying to understand the concept of Allan variance with applications to gyroscope data. I have read a lot of articles in which they...

Hi. I'm trying to understand the concept of Allan variance with applications to gyroscope data. I have read a lot of articles in which they use the Allan variance to decompose the variance into different random processes (random walk, bias white noise and so on). I have, however, not found any articles where they actually explain how this is possible and how it works (with regards to ...

## filtering random processes

inLet's assume on an input of the passband filter there is a complex white noise. As on known spectral density on an input it is possible to...

Let's assume on an input of the passband filter there is a complex white noise. As on known spectral density on an input it is possible to calculate noise level on an output of the passband filter? %================================================================= clear all fd=1000; sko=95; N=2^16; t=0:1/fd:(N-1)*1/fd; smes_s=sko*(randn(1,N)+j*randn(1,N)); sp0=((fft(smes_s)))/N;...

## how convert sampled scope data into dBV/sqrt(Hz)?

inHi Everyone, I've not been able to find this online, but I think it's a fundamental question perhaps some of you have had to deal with in the...

Hi Everyone, I've not been able to find this online, but I think it's a fundamental question perhaps some of you have had to deal with in the past. If I have an analog signal input (mostly white noise, but I suppose that's irrelevant to this question) that I capture using a real-time sampling oscilloscope, how do I process the data (received in Volts by the oscilloscope) to get data in units o...

## Constant for white Noise Question

inI see in alot of communcations books the constant No used for white noise and and in other texts some authors use No/2 when doing calculations...

I see in alot of communcations books the constant No used for white noise and and in other texts some authors use No/2 when doing calculations for white noise. Many times there are no derivations given, so i cannot see where the distincion between No vs No/2 is comming from. Can somewone please explain?

## How to generate a Gaussian time correlated process?

inHi, What is the most efficient way to generate a noise process that is Gaussian correlated in time from a white noise process? I'm having...

Hi, What is the most efficient way to generate a noise process that is Gaussian correlated in time from a white noise process? I'm having trouble coming up with a simple FIR filter that will do this. Any suggestions? Thanks, ~mohan

## Whitened Matched Filter

inI am trying to figure out why all treatments of MLSE receiver for ISI channels use the idea of a matched-filter followed by a noise...

I am trying to figure out why all treatments of MLSE receiver for ISI channels use the idea of a matched-filter followed by a noise whitening filter? Isn't the latter a simple inverse of the former? In fact if we simply don't go into the matched-filter/whitening-filter duo, we can still derive what Proakis refers to as the "Equivalent Discrete-time White Noise Filter Model" for an ISI channel (a...

## Identification

inSuppose I drive a LTI system G(z) with white noise unit variance. I can then using various means make an attempt at identifying G(z) (assume the...

Suppose I drive a LTI system G(z) with white noise unit variance. I can then using various means make an attempt at identifying G(z) (assume the white noise cannot be measured but only the output of G(z)). I then drive a similar system G(z) with coloured noise (say in real life speech). I could model this for some short period of time as the cascade (convolution) of G(z) with the colouring...

## Kalman filter with non-white noise

inHi, Is it possible to make the Kalman filter work with non-white measurement noise? I have measurements which have non-zero mean, uncorrelated...

Hi, Is it possible to make the Kalman filter work with non-white measurement noise? I have measurements which have non-zero mean, uncorrelated error. I read about pre-whitening filters. But could not understand how to use them in combination with Kalman Filter and the given measurements. Thanks.

## generating a coherent signal

inIf I have a signal (say x[t]), and from previous studies I know the coherence function (Cxy[f]). Is there a way to simulate a coherent signal...

If I have a signal (say x[t]), and from previous studies I know the coherence function (Cxy[f]). Is there a way to simulate a coherent signal (say Y[t]) from these two? We have a process that we already have a shaping filter for. We first simulate signals x[t] and y[t] by passing Gaussian white noise through the shaping filter. However, we would like to make y[t] coherent with x[t], based on ...

## LMS to remove the unknown sinusoidal signal

inHi All, my problem statement is as follows Prob: ===== a feedback signal which is a form of sinusoid or mix of sinusoids is getting...

Hi All, my problem statement is as follows Prob: ===== a feedback signal which is a form of sinusoid or mix of sinusoids is getting mixed to the speech signal. So i would like to remove the unwanted sinusoidal signals. (here noise is sinusoid and not white noise) Experiment: =========== Trying to use LMS to remove the sunusoid. My understanding is that LMS will initally try to au...

## help with LP filter implementation in c

I'm new to and struggling with a c code implementation for an available LP filter, http://www.musicdsp.org/files/filters004.txt. The filter...

I'm new to and struggling with a c code implementation for an available LP filter, http://www.musicdsp.org/files/filters004.txt. The filter function, float iir_filter(float input,FILTER *iir) takes a float input and a reference to the FILTER structure. I believe I have the filter code working, and in my rudimentary implementation I can also generate white noise, window it, and analyze it using an...

## Weighted vs. non-weighted

inHello, I am attempting to reproduce the results of a psychological experiment. In the original experiments, messages were delivered -15 to...

Hello, I am attempting to reproduce the results of a psychological experiment. In the original experiments, messages were delivered -15 to 25 db(A) relative to ambient environment or white noise source using loudspeakers. In my experiments I wish to deliver messages via headphones -15 to 25 db unweighted (RMS average), in an unweighted medium such as white noise. If I keep the same level of -15...