## Proof regarding autocorrelation of a pulse in white noise

Started by in comp.dsp17 years ago 9 replies

Let x[n] = s[n] + p[n] where s[n] is complex Gaussian white noise (GWN) and p[n] is a complex signal in the for Ae^{j2pi w + phi} where w is...

Let x[n] = s[n] + p[n] where s[n] is complex Gaussian white noise (GWN) and p[n] is a complex signal in the for Ae^{j2pi w + phi} where w is radian frequency and phi is a phase factor. I want to show that if I do the autocorrelation of x[n] (ie x[n]x[n-1]* , where * denotes the complex conjugate) that the argument will more closely approach the actual frequency of p[n], so, if I did th...

## 1/f noise generation

Started by in comp.dsp15 years ago 13 replies

Hi All, Is there anyone know how to generate 1/f noise for simulating the phase noise. Someone told me though passing a white noise to a FIR...

Hi All, Is there anyone know how to generate 1/f noise for simulating the phase noise. Someone told me though passing a white noise to a FIR the noise can be generated. Any clue about the FIR? Thanks alot R. Y.

## Discrete time PLL - mean time between slips

Started by in comp.dsp17 years ago 1 reply

Hi guys, Can anyone point me to a paper/book describing the analysis of the discrete time PLL? All I could find are books describing the...

Hi guys, Can anyone point me to a paper/book describing the analysis of the discrete time PLL? All I could find are books describing the nonlinear analysis of the continuous time PLL -- an analysis that is based on nonlinear differential equations. A discrete time analysis avoids the difficulty of continuous time white noise, etc. This is all for analysing the mean time between pha...

## FM modulation with a PRN code.is it a way for generating white noise

Started by in comp.dsp17 years ago 1 reply

My carrier freq is 1.575GHz.PRN code is generated by a 168bit length LFSR.So the code tends to be a random sequence.Clock to LFSR is 1 MHz.So I...

My carrier freq is 1.575GHz.PRN code is generated by a 168bit length LFSR.So the code tends to be a random sequence.Clock to LFSR is 1 MHz.So I wanted to know that how the FM spectrum look like.here the modulating signal will be like sqaure wave with randomly varying duty cycle.Frequency spectrum will be a discrete one.I wanted to know the spacing between each spectum line.The spacing must be...

## Time delay estimation question

Started by in comp.dsp17 years ago 7 replies

I have read quite a few papers on teh subject and have a question. Suppose we have two sensors x1 and...

I have read quite a few papers on teh subject and have a question. Suppose we have two sensors x1 and x2 x1(t)=s1(t)+n1(t) and x2(t)=a.s2(t-D)+n2(t) where n1(t) and n2(t) are uncorrelated white noise sources also uncorrelated with the two signals s1 and s2. I need to find the delay D.The constant a is an attenuation factor. The Knapp-Carter give an expression for cross-correlat...

## Fitting AR model to stohastic signal

Started by in comp.dsp17 years ago 3 replies

Hi I have a sample of a Stohastic signal with very slowly variable mean, and would like to find AR model for it perhaps using Burg...

Hi I have a sample of a Stohastic signal with very slowly variable mean, and would like to find AR model for it perhaps using Burg parameter estimation model (explained in book by Kay). I would like to try diffent model order until I get the Power spectral density of white noise driven AR model's output, to look like the PSD of my sample. Is the aforementioned possible?(any other ideas?) ...

## DC shift of the h(impulse response of the room) when using NLMS adaptive filtering

Started by in comp.dsp17 years ago 6 replies

Anyone encountered this problem when using NLMS? The h shifts up after running for sometime, I noticed this for both white noise and color voice...

Anyone encountered this problem when using NLMS? The h shifts up after running for sometime, I noticed this for both white noise and color voice signals. What caused the shift and how to avoid it? thanks Andrew

## gaussian white noise using only integer arithmetic

Started by in comp.dsp17 years ago 9 replies

Hi Guys, I need to generate gaussian white noise on an integer DSP. I have the fast Numerical Recipes generator but it has a log, a...

Hi Guys, I need to generate gaussian white noise on an integer DSP. I have the fast Numerical Recipes generator but it has a log, a sqrt and divides in it. Does anyone know where I can find one or where I can read about how to write one? Thanks Dimiter

## Dthering....

Started by in comp.dsp17 years ago 35 replies

Hi, I've a question about dithering in the digital domain. Let's say I've to quantize a signal from 12 bits to 8 bits. 1) Does it make...

Hi, I've a question about dithering in the digital domain. Let's say I've to quantize a signal from 12 bits to 8 bits. 1) Does it make sense to apply dithering at all? 2) The noise (dithering) signal, must be real noise, or it is enough to be just an uncorrelated signal? For 2) I mean some signal with spectral properties similar to white noise, but not a real random signal. For ...

## easy estimate of bandwidth?

Started by in comp.dsp17 years ago 5 replies

Hi all! I would like to have an fast, easy method to esimate the bandwidth (or kind of degrees of freedom) of a given piece of signal. Lets...

Hi all! I would like to have an fast, easy method to esimate the bandwidth (or kind of degrees of freedom) of a given piece of signal. Lets say, if there is a sine wave, that number should be very low (or zero), if there is white noise, it should be 1 (or something defined). Signal pieces are about 200 samples long. I have a 16 bit dsp. Any idea? Thanks, Andre -- ----...

## Rigorous definition of the Spectral Density of a random signal?

Started by in comp.dsp17 years ago 51 replies

Hi, I know this question is not 100% relevant to this newsgroup, as I'm talking about continuous-time signals, and not DSP... But I...

Hi, I know this question is not 100% relevant to this newsgroup, as I'm talking about continuous-time signals, and not DSP... But I couldn't find a more appropriate place to discuss this. Anyway, there was a big discussion in one of my classes about some characteristics of white noise, and the disagreement seemed to be driven by a discrepancy between our concepts of what the Power-spe...

## any good model for quantization error? how to design my quantization matrix?

Started by in comp.dsp17 years ago 5 replies

Dear all, I am studying some problem of the quantization error in customed designed quantization matrix for JPEG(the quantization matrix was...

Dear all, I am studying some problem of the quantization error in customed designed quantization matrix for JPEG(the quantization matrix was designed by me, so it is worse than standard JPEG in terms of quality). I am trying to design a filter to remove these error due to quantization. Current the only model I can use in my prediction is "white noise", with variance to be (quantization_ste...

## RBJ peaking filter -- off by 2 X

Started by in comp.dsp17 years ago 11 replies

hi, i've been messing about w/ the peaking filters in RBJs eq cookbook and everything has been great. .... my test is to generate a bunch of...

hi, i've been messing about w/ the peaking filters in RBJs eq cookbook and everything has been great. .... my test is to generate a bunch of white noise with a uniform distribution. and take before and after "frequency analyses" of the peaking filter (using a big blackmanharris window and 64k point fft) it is here that i'm seeing my resonant peak off by 2X, eg a peak 500 Hz, given a ...

## Image Processing and Human Perception of Distortion

Started by in comp.dsp17 years ago 1 reply

I have a very fundamental question about image processing and distortion. Suppose that we have two images: I[i,j] and J[i,j], where "i"...

I have a very fundamental question about image processing and distortion. Suppose that we have two images: I[i,j] and J[i,j], where "i" ranges from 0 to 1919 and "j" ranges from 0 to 1199. Suppose that we create J[] from I[] by adding uniform white noise at each pixel of the image. Assume that each pixel is 24-bit RGB and that we add uniform white noise, independently, to the red plane,...

## Gaussian white noise code in C

Started by in comp.dsp17 years ago 6 replies

Hello all, I'm in need of a C program which implements the Gaussian white noise algorithm in C. The program is to accept a binary file as...

Hello all, I'm in need of a C program which implements the Gaussian white noise algorithm in C. The program is to accept a binary file as input and alter it according to the algorithm. I'm affraid this project must run on Windoze :( Thank you in advance Jess

## Problem measuring frequency response of filters

Started by in comp.dsp17 years ago 15 replies

Hi everyone, I'm fairly new to DSP and am having trouble measuring the frequency response of various (mainly Butterworth) filters that I wish...

Hi everyone, I'm fairly new to DSP and am having trouble measuring the frequency response of various (mainly Butterworth) filters that I wish to use in a program. To test the response I'm running the filters on white noise using a 1024 point buffer (which is what the program will use) then taking the DFT of the output. I'm doing this 1000 times and averaging the result. The result...

## Power and variance of Gaussian White Noise

Started by in comp.dsp17 years ago 2 replies

hi there this is a newbie working on a signal denoising problem. i want to jam a given signal with a white noise pulsed jammer such that...

hi there this is a newbie working on a signal denoising problem. i want to jam a given signal with a white noise pulsed jammer such that the effective jammer to signal ratio is some known value, say 30 db for example. to generate the wgn, i specify the variance in simulink for the gaussian noise source. what is the realtion between the variance (sigma) and power of white gaussian noi...

## [Back to basics] Detection - matched filter

Started by in comp.dsp17 years ago 1 reply

Hi All. I need to detect a 1kHz square wave sampled at 48kHz. I have no idea of what the SNR will be. I remember that the optimal solution...

Hi All. I need to detect a 1kHz square wave sampled at 48kHz. I have no idea of what the SNR will be. I remember that the optimal solution to detect a known waveform in the presence of white noise is the matched filter. To reduce computation cost , I downsample by 12 And the 32-bits input buffer is converted into a full scale 16-bits buffer. I compute mean(x) , and center the buffer ...

## Where can I find speech samples (audio)?

Started by in comp.dsp17 years ago 6 replies

Hi, I'm working on a term-project in a Speech Communications course. The project's goal is to increase the quality of speech by encoding...

Hi, I'm working on a term-project in a Speech Communications course. The project's goal is to increase the quality of speech by encoding the high band (above 4kHz) with parametric information, and then (for the synthesis stage) just filter white noise and add the output to the low-passed speech signal (i.e., the speech signal samples at 8kHz, with spectral contents limited to below 4kH...

## Need proofs about digital comminucation

Started by in comp.dsp17 years ago 29 replies

Hi everybody, I need some help to prove thses statements : 1)Show that white noise has a power-spectral density SNw(f) = N0=2 knowing that...

Hi everybody, I need some help to prove thses statements : 1)Show that white noise has a power-spectral density SNw(f) = N0=2 knowing that SN(f) is the Fourier transform of the autocorrela- tion function R(?) = E[N(t+?)N(t)] of the stationary noise process N(t). 2)Show that the sinc-pulse: p(t) =sin((pi*t)/T) /((pi*t)/T) T^0.5 is the inverse Fourier transform of the spectrum P(f) = T...