## PDF of apiltudes of DFT of sinusoidal signal

Started by in comp.dsp15 years ago 2 replies

Hi, Where can I find how to calculate the probability density function of amplitudes of the DFT coefficients of sinusoidal signal corrupted...

Hi, Where can I find how to calculate the probability density function of amplitudes of the DFT coefficients of sinusoidal signal corrupted by Gaussian noise? Are there any on-line sources? Thanks, Marek

## How is SNR computed?

Started by in comp.dsp15 years ago 2 replies

Maybe this is a very simple problem, but it troubles my mind. I consider a complex signal like x(n) = s(n) + w(n) Where s(n) =...

Maybe this is a very simple problem, but it troubles my mind. I consider a complex signal like x(n) = s(n) + w(n) Where s(n) = a*exp(-j*2*pi*f*t) and w(n) = Rew(n) + j*Imw(n) (uncorrelated) is a zero-mean complex Gaussian noise process with variance 1. I want to compute the detection probability for different SNR, so I compute the estimated power using FFT without any win...

## AWGN channel in OFDM-System

Started by in comp.dsp15 years ago 5 replies

Hallo everybody, I've just finished my OFDM-Simulation, but I'm still facing a little problem with the AWGN-function provided by Matlab. The...

Hallo everybody, I've just finished my OFDM-Simulation, but I'm still facing a little problem with the AWGN-function provided by Matlab. The transmitted OFDM-Signal s(k) consists of samples of the komplexe baseband signal. (As I've implemented a diskrete time OFDM-baseband-system). The channel should add white Gaussian noise n(k). An the resulting signal r(k) = s(k) + n(k) will than be process...

## Kalman Filter assumptions and optimality

Started by in comp.dsp15 years ago 5 replies

Hi, I understand that The Kalman filter is a linear, recursive estimator that produces the minimum variance estimate in a least...

Hi, I understand that The Kalman filter is a linear, recursive estimator that produces the minimum variance estimate in a least squares sense under the assumption of white, Gaussian noise processes. Now, some books eg. Kalman Filtering with Real-Time Applications by Chui and Chen, has added this requirement that the updated estimate x_{k/k} is an unbiased estimate of x_{k} by choos...

## Channel modelling

Started by in comp.dsp14 years ago 2 replies

Hi, I'm trying to model a multipath radio channel, I've been doing a bit of reading and I've got some idea of what I want to do but I'm not...

Hi, I'm trying to model a multipath radio channel, I've been doing a bit of reading and I've got some idea of what I want to do but I'm not really sure how to go about implementing things. For example, I've read that I can model a rayleigh fading channel as two gaussian noise sources, X and Y, and then if I just sum them as phasors, Z = sqrt(X.^2 + Y.^2), then Z will be a rayleigh distri...

## Image filtering using Low Pass Hamming filter

Started by in comp.dsp14 years ago 23 replies

Hello all, I am trying to remove gaussian noise from a 2-D gray scale image using low pass hamming filter. I know I can generate the...

Hello all, I am trying to remove gaussian noise from a 2-D gray scale image using low pass hamming filter. I know I can generate the 1-D hamming filter using the equation. How do I use that on the 2-D image. I really need some help for this. Thanks in advance.

Started by in comp.dsp14 years ago 3 replies

Hi, I am very excited to be a freshman here, I am interested in DSP,but my DSP knowledge is really not so good. Here I want to ask you...

Hi, I am very excited to be a freshman here, I am interested in DSP,but my DSP knowledge is really not so good. Here I want to ask you a question: How to add the noise to the clean speech?For instance ,how to add Gaussian noise to the clean speech? Can you list them with main procedures for me or give a summary for this problem , so that I have an intuition for them and can have a practic...

## Audio jamming using white noise (Matlab code)

Started by in comp.dsp14 years ago

Hi anybdy have any idea how can a baseband audio sound can be supressed or jammed using a white gaussian noise and how the result can be shown...

Hi anybdy have any idea how can a baseband audio sound can be supressed or jammed using a white gaussian noise and how the result can be shown in Matlab. any help will be appreciated. -Shruti

## Audio jamming using white noise (Matlab code)

Started by in comp.dsp14 years ago 2 replies

Hi anybdy have any idea how can a baseband audio sound can be supressed or jammed using a white gaussian noise and how the result can be shown...

Hi anybdy have any idea how can a baseband audio sound can be supressed or jammed using a white gaussian noise and how the result can be shown in Matlab. any help will be appreciated. -Shruti

## Relationship between noise dB level and sigma

Started by in comp.dsp14 years ago 3 replies

I have a noise generator which gives me N(0, 1) Gaussian noise. I wish to add the noise to a signal of known dynamic range. What is the scaling...

I have a noise generator which gives me N(0, 1) Gaussian noise. I wish to add the noise to a signal of known dynamic range. What is the scaling such that the noise dB is 3. My approach was this: Since I need upto 3 dB, 3 = 10 log10(Vt/Vs)^2, which means Vt/Vs = 1.4142 where Vt is the noisy signal and Vs is the noiseless signal. The noise Vn is then 41% of Vs (approx). I scale the Vn samp...

## Speech detection (Formulation Problem)

Started by in comp.dsp14 years ago 12 replies

Hi all, i am currently doing speech detection in white gaussian noise. I would take fft of a frame of noisy speech and if the maximum value...

Hi all, i am currently doing speech detection in white gaussian noise. I would take fft of a frame of noisy speech and if the maximum value is above a certain threshold, i can say that speech is detected. Of course, there is another part of the algorithm that does a more thorough check. My question is, i need to come up with a formula for this threshold. meaning threshold=x^2 + y for example, r...

## Superposition of Signal from three equiphase sources peturbed by Gaussian noise

Started by in comp.dsp14 years ago

Hi all, This is my first post on here, so please forgive me for any mistakes I make. Currently I'm working with simulating a system...

Hi all, This is my first post on here, so please forgive me for any mistakes I make. Currently I'm working with simulating a system consisting of a three radar horns mounted on a spherical back-plane, with an observation point placed at the focus. What I'm looking at is simulating the effect of Gaussian noise, which is being radiated from the horns with the orignal signal, on the direction o...

## Interpolation and the additive white gaussian noise

Started by in comp.dsp14 years ago 20 replies

Dear all, The following problem recently came up in one of my simulations. I have a PSK modulated RRC filtered signal that I have to transmit...

Dear all, The following problem recently came up in one of my simulations. I have a PSK modulated RRC filtered signal that I have to transmit over the AWGN channel. Before RRC filtering, I interpolate the IQ signal to twice the Nyquist rate. Now consider the two setups: The first one transmits the RRC filtered signal at twice the Nyquist rate, and adds white Gaussian noise to it. The secon...

## LPC coding doubt

Started by in comp.dsp14 years ago 6 replies

Hi I was reading about LPC coding, and I have a doubt. What i read is that the way we find the coeffecients of a filter is by using an energy...

Hi I was reading about LPC coding, and I have a doubt. What i read is that the way we find the coeffecients of a filter is by using an energy eqn, minimize it wrt the coeff, and later find out (by backtracing) if the input function is closer to a white gaussian noise or a periodic impulse train. While I can figure out how this works out in the end, I can't understand why we chose to minim...

## Effect of Additive White Gaussian Noise (AWGN) on the Transmitted Data

Started by in comp.dsp14 years ago 1 reply

Hello i need to investigate the effect of additive white noise on the transmitted data using based-band simulation under different value...

Hello i need to investigate the effect of additive white noise on the transmitted data using based-band simulation under different value of signal-to-noise (SNR) ratio. here are the 2 programs Both files allow you to calculate the bite error rate (BER) depending on: i. the noise amplitude Pn & ii. the signal amplitude Ps i;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; cl...

## Noise distribution of phase of complex signal

Started by in comp.dsp12 years ago 21 replies

I have read in this newsgroup that the distribution of the phase of complex Gaussian noise is uniform. I have no doubt this is true but I would...

I have read in this newsgroup that the distribution of the phase of complex Gaussian noise is uniform. I have no doubt this is true but I would like to find an "authoritative" referernce for this that I can quote, rather than "Some guy on the Internet said..." ;) Can anyone help? Thanks.

## Volterra filter _ State Variable form

Started by in comp.dsp13 years ago 1 reply

Hi, How can I make a 2nd order Volterra filter for input of sine wave (with gaussian noise). i.e. I need to get the filter coefficients...

Hi, How can I make a 2nd order Volterra filter for input of sine wave (with gaussian noise). i.e. I need to get the filter coefficients and represent that filter in a state variable form. Might seem a dumb exercise or something; but I will really appreciate the help. Thanks

## Matlab seems not to be easy for me .im just beginning.

Started by in comp.dsp13 years ago 3 replies

to simulate a radiopropagation channel,(clarke model),which signal is E(t)=I(t)cos(2*pi*f*t)-Q(t)sin(2*pi*f*t) with I(t) and Q(t) 2...

to simulate a radiopropagation channel,(clarke model),which signal is E(t)=I(t)cos(2*pi*f*t)-Q(t)sin(2*pi*f*t) with I(t) and Q(t) 2 independant gaussian signal of spectral S(f)=K/sqrt(1-(f/fd)^2) ,-fd

## wavelet based method for removing Gaussian Noise

Started by in comp.dsp13 years ago

Dearl all: Hi all, I need to use wavelet based method to remove Gaussian white noise on an image. I have some confusion and would like to ask...

Dearl all: Hi all, I need to use wavelet based method to remove Gaussian white noise on an image. I have some confusion and would like to ask you: 1. What wavelet basis I should choose for decomposing the image? I intend to use Haar , DB2, db3, db4 to test the SNR to see what is the best. However I am considering for Gaussian Noise, if there are some best wavelet bases for this task, if...

## Single Channel Adaptive Noise Cancellation algorithm for Speech Enhancement

Started by in comp.dsp13 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...