generation of AWGN

Started by maca in comp.dsp14 years ago 3 replies

hallo How can I generate a gaussian noise with : variance = SF/(2*EbN0); SF : spreading factor EbN0 : Eb/N0 Thanks a lot maca

hallo How can I generate a gaussian noise with : variance = SF/(2*EbN0); SF : spreading factor EbN0 : Eb/N0 Thanks a lot maca


Shannon's channel capacity with arbitrary noise!!

Started by santosh nath in comp.dsp14 years ago 14 replies

Hi all, It is not very common to discuss Shannon's channel capacity with an arbitrary noise. I guess we are more familiar with Shannon's...

Hi all, It is not very common to discuss Shannon's channel capacity with an arbitrary noise. I guess we are more familiar with Shannon's channel capacity perturbed by white Gaussian noise. I also think there had been lot of discussions with Shannon's limit,Shannon capacity etc. previously. My post is slightly different from those threads. Shannon, in his classic "A Mathematical Theory ...


Which noise?

Started by Manuel Tramontana in comp.dsp14 years ago 2 replies

Dear chaps, I have a problem. I have a signal recorded from a ultrasonic transducer of a chemical reaction. It is rich of noise, expecially...

Dear chaps, I have a problem. I have a signal recorded from a ultrasonic transducer of a chemical reaction. It is rich of noise, expecially the white one. I tried to filter with normal filter (butterworth band pass), but I did not obtained a lot of success. So, I thought was better delete the White gaussian noise with an adaptive filter. I used the demo of Simuling of LMS but I have probl...


noise..how to regulate it?

Started by Manuel Tramontana in comp.dsp14 years ago 1 reply

Dear chaps, I have a problem. I have a signal recorded from a ultrasonic transducer of a chemical reaction. It is rich of noise, expecially...

Dear chaps, I have a problem. I have a signal recorded from a ultrasonic transducer of a chemical reaction. It is rich of noise, expecially the white one. I tried to filter with normal filter (butterworth band pass), but I did not obtained a lot of success. So, I thought was better delete the White gaussian noise with an adaptive filter. I used the demo of Simuling of LMS but I have probl...


How to tell which channel the signal is transmitting

Started by Helen in comp.dsp14 years ago 3 replies

Hi Suppose I have a signal S=[s0 s1]^T both s0 and s1 are from the set of signal constellation C, the constellation C is known however S is not...

Hi Suppose I have a signal S=[s0 s1]^T both s0 and s1 are from the set of signal constellation C, the constellation C is known however S is not known. Now send the signal through some channel, we only know the channel model can be either H0 or H1 The receive signal could be expressed as Y=HS+N N is gaussian noise We get the receive signals R=[r0 r1]^T Is there an easy way that I ...


Power and variance of Gaussian White Noise

Started by Arjun Admirer in comp.dsp14 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...


Other Modulation Problem

Started by Texas Longhorns in comp.dsp13 years ago 1 reply

A baseband signal m(t) that has a Gaussian (amplitude) distribution frequency modulates a transmitter. Assume that the modulation has...

A baseband signal m(t) that has a Gaussian (amplitude) distribution frequency modulates a transmitter. Assume that the modulation has a zero-mean value and a peak value of Vp = 4*(sigma). The FM signal is transmitted over an additive white Gaussian noise channel. Let Beta = 3 and B = 15KHz. Find (S/N)out/(S/N)baseband when: A. No deemphasis is used. B. 75-u sec deemphasis is used. Again...


An Academic Detection Question

Started by Anonymous in comp.dsp13 years ago 19 replies

This has been a question I've had for a long time. I have simplified it to its basic components. You have a signal x(t) composed as x(t)...

This has been a question I've had for a long time. I have simplified it to its basic components. You have a signal x(t) composed as x(t) = u(t-t0) + n(t), where u(t) is the unit step function, t0 is unknown, and n(t) is stationary white Gaussian noise. You need to be able to detect the signal "reliably" (I'll leave the definition of that open for now) within t1 seconds of t0. No...


freq and phase estimation

Started by Michal Kvasnicka in comp.dsp13 years ago 7 replies

What is the most effective way to adaptive estimate freqs and phases of the mixture (superposition) of the signals: s_i(t) =...

What is the most effective way to adaptive estimate freqs and phases of the mixture (superposition) of the signals: s_i(t) = cos(2*pi*f_i*t+p_i)+n_i(t) , where i=1,2, ..., N and n_i is additive gaussian noise. Michal


simultaneous frequence and phase estimation

Started by Michal Kvasnicka in comp.dsp13 years ago 97 replies

I am looking for methods which are able to simultaneously estimate the frequency (f_i) and phase (p_i) of the mixture (superposition) the simple...

I am looking for methods which are able to simultaneously estimate the frequency (f_i) and phase (p_i) of the mixture (superposition) the simple "sinusoidal" signals with additive noise: s_i(t) = A_i*cos(2*pi*f_i*t+p_i)+n_i(t) , where i=1,2, ..., N and n_i is additive gaussian noise. Michal


Implementation of OQPSK-demodulator in matlab

Started by bamse in comp.dsp13 years ago 1 reply

Hello I have made a program in matlab that can demodulate an OQPSK-modulated signal with noise (additive white gaussian noise). The carrier...

Hello I have made a program in matlab that can demodulate an OQPSK-modulated signal with noise (additive white gaussian noise). The carrier is phase-shifted with an arbitrary constant between 0 and 2*pi. Here is what I do to demodulate the signal: When the signal is received at time t=0 I know the following will happen for the first T seconds: 1) If there is no or little noise and t...


question about white gaussian noise

Started by bamse in comp.dsp13 years ago 1 reply

does additive white gaussian noise only change the amplitude of a signal or does it change both amplitude and phase?

does additive white gaussian noise only change the amplitude of a signal or does it change both amplitude and phase?


Noise and Signal Subspace

Started by Ra?l Gonz?lez in comp.dsp13 years ago 7 replies

I have a file with the values associated to the electric field for 32 different frequencies at a fixed point. Due to the RootMUSIC...

I have a file with the values associated to the electric field for 32 different frequencies at a fixed point. Due to the RootMUSIC requierements, white gaussian noise is added to original vector, obtaining the noisy_matrix. After that I calculate the covariance matrix and then I get its eigenvalues. The problem is that I don?t see any meaningful difference between eigenvalues that let me id...


How to set the parameter value for Rayleigh fading Simulation

Started by Tang in comp.dsp13 years ago 1 reply

When calcualate BER for certain modulation scheme, under Rayleigh fading, exact theoretical valuse is available from books and...

When calcualate BER for certain modulation scheme, under Rayleigh fading, exact theoretical valuse is available from books and publications. But how to do set Rayleigh parameters in the simulation? For example, received signal is r(t) = Alpha * exp(-j*Phi) * s(t) + z(t) ( By Proakis 's book) And s(t) transmitted signal z(t) Gaussian noise ~ N ( 0, Sigma) ...


BER dependence on SINR

Started by Vimal in comp.dsp13 years ago 8 replies

Hello, In case of r(t) = s(t) + i(t) + n(t) where r(t) - received signal s(t) - desired signal i(t) - interference...

Hello, In case of r(t) = s(t) + i(t) + n(t) where r(t) - received signal s(t) - desired signal i(t) - interference signal n(t) - additive Gaussian noise then does the BER depend on Signal-to-{Interference + Noise} Ratio (SINR) directly For e.g. if s(t) is Binary PSK, can I use the Q-function directly by replacing the SNR by SINR to estimate the BER. Cheers...


capacity of multi-antenna channel - channel matrix unknown at receiver

Started by roy in comp.dsp13 years ago 2 replies

Consider the memoryless, discrete time, matrix channels with additive Gaussian noise of the form Y = HX + Z, where H is the channel matrix, X is...

Consider the memoryless, discrete time, matrix channels with additive Gaussian noise of the form Y = HX + Z, where H is the channel matrix, X is the original signals, and Y is the received signals. There is a growing body of literature discussing the capacity of such channel when H is known at the receiver. However, I didn't find any paper studying the problem when H is NOT known at the rec...


does WGN(white Gaussian noise) imple zero mean?

Started by kiki in comp.dsp13 years ago 18 replies

Hi all, I read through several books but did not get clarification on whether WGN(white Gaussian noise process) imply zero mean or...

Hi all, I read through several books but did not get clarification on whether WGN(white Gaussian noise process) imply zero mean or not... Another confusion I have is that the definition of WGN is it has flat power spectrum density, let's say S(f)=1, then Rx(t)=delta(t) is its autocorrelation function, I don't see how people say the power of this noise process is E((x(t))^2)=sigma_x, ...


Non-uniform Sampling of White Gaussian Noise??

Started by mimo in comp.dsp13 years ago 8 replies

Hi there, I have modelled a system that non-uniformly samples a bandpass signal. Unfortunately I am not allowed to transform to the...

Hi there, I have modelled a system that non-uniformly samples a bandpass signal. Unfortunately I am not allowed to transform to the equivalent bandpass. Now I have the problem that I should also model the samples, when bandpass filtered White Gaussian Noise is sampled. For uniform sampling, the variance of the Gaussian Variable of each tap equals N_0B. How can I evaluate the variance of t...


Adding Noise

Started by gouq...@gmail.com in comp.dsp13 years ago 1 reply

Hi, Is there some quick ways or software tools to add kind of noise, for example gaussian noise etc to each tuple in a...

Hi, Is there some quick ways or software tools to add kind of noise, for example gaussian noise etc to each tuple in a vector. Thanks, Richard


Basic Question about Additive White Gaussian Noise

Started by Your Name Heres in comp.dsp12 years ago 17 replies

When we talk about an AWGN signal, n(t), which parameter(s) has the Gaussian distribution? Is it the amplitude, power, or phase of the signal??...

When we talk about an AWGN signal, n(t), which parameter(s) has the Gaussian distribution? Is it the amplitude, power, or phase of the signal?? Also is the parameter linear or logarithmic under the Gaussian distribution? For example, are we to assume that AWGN describes a power signal with a mean and variance on a logarithmic scale versus time? Any help understanding this will be appreci...