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!

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...

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, 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...

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.

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...

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

Hi, The number of symbols is usually a power of 2 in constellation . Any specific reason for that ? Or Are there scenarios in which it will...

Hi, The number of symbols is usually a power of 2 in constellation . Any specific reason for that ? Or Are there scenarios in which it will not be power of 2 also ? Thx in advans, Karthik Balaguru

I have a simple question regarding equivalent complex and real sequences. I know that by sampling in quadrature (I and Q complex samples) you...

I have a simple question regarding equivalent complex and real sequences. I know that by sampling in quadrature (I and Q complex samples) you can satisfy the Nyquist criteria at the sample rate (fs) and if I took real samples only and sampled at 2fs, then I should get equivalent power spectra in the bandwidth 0

Hi, I'm trying to use the "Gaussian Noise Generator" under Simulink 6.3(R14SP3). There are something I dont understand. 1. Is there any...

Hi, I'm trying to use the "Gaussian Noise Generator" under Simulink 6.3(R14SP3). There are something I dont understand. 1. Is there any mathematic formula to calculate the "Noise Power Density" from the parameters "mean value(I set this to zero)", "variance", and "sample time"? 2. What's the sample rate mean? Should it be the same with the sample rate of signal, or the sample rate of ...

Hi all, I have a problem which I can't find any way to go: X is an Wide Sense stationary process. Its power spectral density S(w) is zero...

Hi all, I have a problem which I can't find any way to go: X is an Wide Sense stationary process. Its power spectral density S(w) is zero outside [-wmax, wmax]. They ask to prove R(0)-R(t) < 0.5 *wmax^2 *t^2 *R(0). where R(t) is autocorrelation of X. The question is a hint |sin(x)|

A friend and I have been analyzing a signal x(t) containing both random and known-period deterministic variations. So, I wrote a simple Matlab...

A friend and I have been analyzing a signal x(t) containing both random and known-period deterministic variations. So, I wrote a simple Matlab DFT algorithm for calculating the periodogram of x(t). My friend asked me to scale the calculated power and plot my results as an "Amplitude Spectrum", in order that one could read off the amplitudes of the underlying sinusoids. Following Parseval's Theo...

What other methods can be used to analyse power system oscillations from phasor measurements besides FFT and Wavelet?

What other methods can be used to analyse power system oscillations from phasor measurements besides FFT and Wavelet?

I want to compute an M point DFT of a sequence x(n)where M is not a power of 2. One way to do this would be: 1. Pad (N - M) zeros and compute...

I want to compute an M point DFT of a sequence x(n)where M is not a power of 2. One way to do this would be: 1. Pad (N - M) zeros and compute an N point DFT where N = power of 2 & N > = M. 2. Find the (continuous) DTFT (discrete time fourier transform) of x(n) from the N DFT samples by interpolating the DFT with the sinc function. X(w) = Summation {Y(k)* sinc[N/2 * (w - 2*pi

I want to compute an M point DFT of a sequence x(n)where M is not a power of 2. One way to do this would be: 1. Pad (N - M) zeros and compute an...

I want to compute an M point DFT of a sequence x(n)where M is not a power of 2. One way to do this would be: 1. Pad (N - M) zeros and compute an N point DFT where N = power of 2. 2. Find the (continuous) DTFT (discrete time fourier transform) of x(n) from the N DFT samples by interpolating the DFT with the sinc function. X(w) = Summation {Y(k)* sinc[N/2 * (w - 2*pi*k/N)] } ...

hi, I have created a random binary noise using 2 methods. My main aim is to create a random binary noise whose auto power spectrum rolls of at...

hi, I have created a random binary noise using 2 methods. My main aim is to create a random binary noise whose auto power spectrum rolls of at 1Hz(cut off) and the attenuation should be sharp which is my spectrum pass band should end near 2Hz. first method: I used a random gaussian noise by a sampling frequency 40Hz and compared it with sinusoidal signal whose frequency is 0.3Hz with an a...

"Jerry G." wrote: > > Reverse video to give higher transmission power during black was chosen, > because noise is more visible to the eye...

"Jerry G." wrote: > > Reverse video to give higher transmission power during black was chosen, > because noise is more visible to the eye in the black levels of video. > With the whites, noise is less visible to the eye. Therefore the higher > transmission power levels in black levels allow for less visible noise > due to any RF carrier signal loss. > > It has nothing to do with sync pul

I'm using pwelch to estimate power spectrum. Since a window is used by pwelch, then 1. if I should make the window size long enough or...

I'm using pwelch to estimate power spectrum. Since a window is used by pwelch, then 1. if I should make the window size long enough or equivalently the window mainlobe narrow enough to give an accurate estimate? 2. if I make the window size as long as 131072, the mainlobe width is less than 100Hz. How many sections are needed to make the estimate reasonably smooth? 8 or 16 sections seem to b...

Hi, I'm investigating power saving techniques with the F2811 and have an issue with the dsp crashing after executing an IDLE instruction...

Hi, I'm investigating power saving techniques with the F2811 and have an issue with the dsp crashing after executing an IDLE instruction after the flash is set to sleep.. from the TI doc the flash is supposed to power up and execution continue.. but my system crashes periodically.. inspection of flash contents on the emulator show all zero's as if the flash has "disappeared".. LOL resett...

This is my first forray into hardware DSP. I must confess to being a programmer, though I've worked a fair bit with...

This is my first forray into hardware DSP. I must confess to being a programmer, though I've worked a fair bit with microcontrollers (particularly the atmels). I'm trying to get a lay-of-the-land esp. vis-a-vis power consumption, and good DSPs to consider for hobbyist use. For my first project, I'm trying to make an extremely low-power high- quality audio recorder that can record continuou...