Hi all, I heard we can obtain the phase difference between two signal from cross power spectrum. If someone knew, could you show me how to...

Hi all, I heard we can obtain the phase difference between two signal from cross power spectrum. If someone knew, could you show me how to obtain the phase difference ? I mean the algorithm. I read the cross power spectrum is defined as FFT (A) FFT*(B) / N^2, so we have real and imaginary components. Thanks, Titi

Dear All, How to find a random signal vector whose power spectral density is known?? As we know FFT of auto correlation of any signal gives...

Dear All, How to find a random signal vector whose power spectral density is known?? As we know FFT of auto correlation of any signal gives its power spectrum. If I go in the reverse direction, one solution could be, calculating IFFT and then reverse process of auto correlation. but I have no idea on how to find the reverse of auto correlation in matlab. any suggestions????? Kind reg...

Hi guys, Does anyone know how to solve this problem: A zero mean stationary signal having a correlation matrix R is applied to a FIR filter...

Hi guys, Does anyone know how to solve this problem: A zero mean stationary signal having a correlation matrix R is applied to a FIR filter with coefficient vector w. Show that the average power of the filter output is given by w'Rw. Find also an expression for the output power spectrum using the elements of w and R. What would be the output power spectrum if the FIR filter coefficients are s...

hi I need to do an analysis on computation power spent in sensor networks (general architectures) for computation of certain...

hi I need to do an analysis on computation power spent in sensor networks (general architectures) for computation of certain mathematical functions for certain number of times, in individual motes/over the network. I need some good references. Any links? (i dont want those who just discuss their computation constraints, rather, give some actual data of power consumed per computation, e.g pow...

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

Found this board, and hopefully someone can give me a helping hand. Background: I'm using labview with a DAQ. It's acquiring a signal and I...

Found this board, and hopefully someone can give me a helping hand. Background: I'm using labview with a DAQ. It's acquiring a signal and I take a power fft with peak hold averaging on. In this spectrum, there are atmospheric noise, some other signals with large BW about 250 hz, and signals that have FSK modulation with smaller BW. I'm trying to detect FSK signals in that I want the able to...

Recursive least squares is suggestted to be initialized with delta*I where delta is a small positive number of the order of...

Recursive least squares is suggestted to be initialized with delta*I where delta is a small positive number of the order of 0.01*sigma_x^2, sigma_x^2 is the signal power and I is the identity matrix. But for a multi-channel problem and if the signal power of these channels are not identical, then how to initialize RLS? Thanks.

Hi, Signal in digital domain: Centre at 10Mhz, with bandwidth of 10Mhz. The signal is sampled by a DAC at the rate of 80Mhz. Analog...

Hi, Signal in digital domain: Centre at 10Mhz, with bandwidth of 10Mhz. The signal is sampled by a DAC at the rate of 80Mhz. Analog output: Fundamental at 10Mhz and many images following that, one of image is the signal of interest which is located at 90Mhz. The signal will be preserved by applying a suitable band pass filter, Problem: the power level of the signal is many magnitude l...

Hello, I am new to this group, and I have a question on the Sun forums that it seems this group would be able to help with. The question...

Hello, I am new to this group, and I have a question on the Sun forums that it seems this group would be able to help with. The question is posted at: http://forums.sun.com/thread.jspa?messageID=10391494 If you use that forum, I am awarding Duke points to anyone that answers/helps. For people who may be able to help here, this is my question: I am trying to compute the power (in db) o...

Hi all, I have the following problem: a snapshot of a signl s[n], n=0.....N-1. I compute signal power like this: P=1/n*sum(abs(s[n])^2)...

Hi all, I have the following problem: a snapshot of a signl s[n], n=0.....N-1. I compute signal power like this: P=1/n*sum(abs(s[n])^2) n=0,...,N-1. After this I make S=fft(s) and P'=sum(abs(S)^2). Missing out a normalization parameter (depending from fft definition) I have the same result. Suppose noe that I want to use a window function with fft like hanning (for example) my n...

Hi there, I calculate SINR for OFDM system as: (TP. pathloss.|CG|^2)/(cov + TP_ou. pathloss_ou.|CG_ou|^2) where, TP: Transmit...

Hi there, I calculate SINR for OFDM system as: (TP. pathloss.|CG|^2)/(cov + TP_ou. pathloss_ou.|CG_ou|^2) where, TP: Transmit Power TP_ou: Transmit Power of other users CG: Channel Gain CG_OU: Channel Gain of other users cov: Covariance of AWGN Then, how can I calculate SINR for OFDMA systems. What will be the effect of multiple access on SINR? Thank you!

How to do the multiplication of two polynomials over Galois field when the most power of the result exceeds the most big power of the filed it...

How to do the multiplication of two polynomials over Galois field when the most power of the result exceeds the most big power of the filed it self? Example: let's be A(x) and B(x) defined over GF (2^4) with the primitive polynomial p(x) = 1+x+x^4. All coefficients of A(x) and B(x) belong in GF (2^4). A(x) = 1 + x + x^2 B(x) = 1 + x + x^2 + x^14 result C(X) = 1 + x^2 + x^4 + x^14 + x^15...

Dear All, I have built an OFDM transmitter with 0dbm output power. If my receiver needs 20 db of SNR to work properly, what would be the...

Dear All, I have built an OFDM transmitter with 0dbm output power. If my receiver needs 20 db of SNR to work properly, what would be the range of my transmitter. The noise figure of the receiver is 5 dB. (In my experiments, the range is roughly 2 feet. So i want to know if it is a valid figure). Thank you, Aitezaz

OK, I?m stumped. I?ve been trying to calculate the power spectrum of a particular random waveform, and I?m not making much progress. Help! Let...

OK, I?m stumped. I?ve been trying to calculate the power spectrum of a particular random waveform, and I?m not making much progress. Help! Let w(t) be a random signal with a white spectrum. If we integrate this signal we obtain a random walk, r(t). That is, r(t) = Int[0..t] w(y) dy, for t > 0. As well known, the expectation of the amplitude of r(t) increases with the square root of

hi, Is there a way to generate a random signal which has a prescribed power spectral density, psd? I have analytic formula for the broadband...

hi, Is there a way to generate a random signal which has a prescribed power spectral density, psd? I have analytic formula for the broadband power spectral density, and I need to generate a random time signal that is supposed to model acoustic pressure, p(t), as a function of time, having given psd. Phase is not important, so I think it should be possible to generate a signal somehow? Tha...

I'm getting a puzzling result from trying to look at the spectral content of noise and am wondering if someone could shed some light. I'm...

I'm getting a puzzling result from trying to look at the spectral content of noise and am wondering if someone could shed some light. I'm probably missing something very simple. Suppose I take a length N stationary signal and look at the normalized power at the lowest non-zero frequency, f=1/N, of the dft. By normalized, I mean using Parseval's relation and also dividing by the length of th...

Hi, I have a question concerning the exact definition of the one-sided Power Spectral Density (PSD): Usually it is defined as 2 times the...

Hi, I have a question concerning the exact definition of the one-sided Power Spectral Density (PSD): Usually it is defined as 2 times the two-sided PSD, but only for frequencies f > = 0. Then I found one definition which said that the one-sided PSD is 2 times the two-sided, but for f > 0 only ! For f = 0, this definition said, that the one-sided PSD equals the two-sided PSD. Intuitively

I'am studying robust methods for processing power electrical signals in non-Gaussian noise. I know the mostly used method is M-Estimator and...

I'am studying robust methods for processing power electrical signals in non-Gaussian noise. I know the mostly used method is M-Estimator and have already implemented an algorithm to analyze power harmonics. But how can I evaluate it and compare it with other non-robust methods. Besides impulsive noise, is there any other non-Gaussian noise? How can I simulate them? Thanks in advance!!!!!...

Okay, I have a Matlab exercise I've been working on. I've been stuck on something peripheral to the main problem. It gives two channels, each...

Okay, I have a Matlab exercise I've been working on. I've been stuck on something peripheral to the main problem. It gives two channels, each with its own attenuation coefficient in dB/km. As well, there are repeaters with a minimal signal power requirement, given in dBm. Basically, for this part of the problem, we have to figure out which channel gets the signal across 100 km with the least ...

I plotted the power spectrum density of a signal and I am trying to get a conversion scale that will give the magnitude(amplitude) of the...

I plotted the power spectrum density of a signal and I am trying to get a conversion scale that will give the magnitude(amplitude) of the original signal in time domain. I am entirely new to this.