## Forums More comp.dsp

## U.S. Television Polarization

inHey Folks, I did some googling on this and couldn't get a satisfying answer. 1. What polarization is used to transmit? 2. What...

Hey Folks, I did some googling on this and couldn't get a satisfying answer. 1. What polarization is used to transmit? 2. What polarization is used to receive? The answer to question 2 would seem to be horizontal since that is the orientation of the antennas I've seen. But most broadcast TV antennas are (I believe) vertical. If I've got it right, then why do the tx/rx polarizati...

## non-recursive fft

inIs there any info on how to implement fft and ifft algorithms that aren't recursive? I'd like to possibly calculate a really long on inside a...

Is there any info on how to implement fft and ifft algorithms that aren't recursive? I'd like to possibly calculate a really long on inside a signal chain so attempting to compute a 2 second fft in one function call would probably be disastrous. -Matt

## Watermark/fingerprint image for detecing transforms

inHi DSP people, I have a black-box system that ingests digital images, can perform a number of transformations on it, and later spits some of...

Hi DSP people, I have a black-box system that ingests digital images, can perform a number of transformations on it, and later spits some of them out in random order. My goal is to create an algorithm to generate digital images I sent into the system so that I can identify them when/if they come out, and tell which kind of transformations they have undergone. The images I put in have a n...

## Impulse invariance method

inI have a laplace transfer-function G(s)=k(1+sT)/s*2 which I need the discrete-time version G(z) using impulse invariance method. Using...

I have a laplace transfer-function G(s)=k(1+sT)/s*2 which I need the discrete-time version G(z) using impulse invariance method. Using partial fractions I get G(s) = c1/s + c2/s^2 c1=kT and c2=k However when I use Matlab c2d and select "impulse" it gives me a different version though the first term c1 is right. Matlabs second term c2 is negative. I assume for multiple pole...

## compress the orchestra

inOccasionally I attend recitals, where the student performs a concerto. It's a bit of a financial stretch for the music department to hire an...

Occasionally I attend recitals, where the student performs a concerto. It's a bit of a financial stretch for the music department to hire an orchestra, so a second pianist accompanies, acting as the orchestra. Thus someone has to condense the entire orchestral section down to a single instrument! A mighty job of compression indeed. How do they do that? The conductor isn't a mat...

## Flash website- end of an era

inOver 10 years ago I started a website ( www.fourier-series.com)in which I b= uilt interactive flash programs to teach various engineering...

Over 10 years ago I started a website ( www.fourier-series.com)in which I b= uilt interactive flash programs to teach various engineering concepts. I In= itially designed these programs to personally understand DSP and then to pa= ss along what I learned to others****. These topics were fourier series, di= screte fourier series, fourier transforms filtering I/Q modulation and also= some RF s...

## Doppler effect detection

inHi all, is it possible to know, without any prior, if an incoming signal has a Doppler effect? That's it, to know if the source is...

Hi all, is it possible to know, without any prior, if an incoming signal has a Doppler effect? That's it, to know if the source is moving to (or away from) the detector without any knowledge of the frequency. I can imagine that if the source is not moving directly towards (or away) the detector, but with an angle, the Doppler effect changes hence it is detectable. How about a dir...

## LOW SNR FFT

inHello, I am processing an audio signal with CS4244 codec at 24 bits and 48kHz. Every 2048 samples the FFT is calculated and its...

Hello, I am processing an audio signal with CS4244 codec at 24 bits and 48kHz. Every 2048 samples the FFT is calculated and its amplitude. Without input signal I get FFT values ââclose to 30dB. With maximum input values ââ(overflow) I get values ââof 90dB, with a scale of 0 to 120dB. Why not get a dynamic range of 100-110dB as is logical

## Naive question(s) about DTV

inIn the 60's I spent time as a BSEE student. Took a course using _Signals, Systems and Communication_ , Lathi , 1965 A generation later I found...

In the 60's I spent time as a BSEE student. Took a course using _Signals, Systems and Communication_ , Lathi , 1965 A generation later I found comp.dsp and obtained a copy of _Understanding Digital Signal Processing_ , Lyons, 2004 May I answers suitable for a bright high school student who reads eclectically {will account for what I've forgotten &/or never knew ;}. I've a germ of an ide...

## FFT zero analyzing pink noise

inIm doing the pink noise FFT. I calculate the frequency of 1kHz by adding the contribution of the corresponding bins. Is it possible that sometimes...

Im doing the pink noise FFT. I calculate the frequency of 1kHz by adding the contribution of the corresponding bins. Is it possible that sometimes the result is zero? Thanks.

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