Demodulation pa detection d'envelloppe

Bonjour,
Je suis entrain de réalisé un projet sur l’acquisition d'information sous labview, cela consiste à faire une démodulation d'un signal modulé afin d'extraire l'information.
D'après moi, le principe est de faire un redressement du signal, et de faire un détection d’enveloppe ou directement filtré en passe bas.Mais, je ne sais pas comment le mettre en pratique sous labview.
pourriez vous m'aidez svp?
cordialement

As a live sound engineer myself ( festivals a large scale gigs ) then the answer to your feedback question is that the rig was not properly rung out ( 31 bar graphic wise ) and the monitors were running too loud.
But that's a whole different subject than we cover in this help forum.
If the feedback is already all over your recording then I'm afraid you're going to have a job trying to remove it.
I've never heard of a post production feedback suppression plugin for Logic either. There is however a 31bar graphic equaliser that comes in the form of an Apple AU plugin as standard in Logic but I'm not sure this will help if the feedback is already on the recording. You can try notching out the problem frequencies and see I guess.

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FSK Demodulator and sync index found

Hello.
I am very much confused regarding understanding the in depth function of this block. i have following questions.
1) what is the purpose of FIFO in this FSK demodulator.vi? what is the length of these FIFO?
2) if i have a complete packet and data like below then what will be the output of this FSK demodulator block?
random arbitray data (8bits)+ gaurd bits (2bits)+sync bits (16bits)+data (60bits)+random arbitrary data(8bits)
what will be extracted exactly from this provided data and how?
3) how much data is buffered/queued by this FSK demodulator out of which it try to find the peak of correlation?
4) where is the process of finding peak correlation takin place in this vi.
5) can this FSK demodulator.vi be used for receiving bursty communication?
6) why is sync index found a decimal value? if it shows the start of sync SYMBOL then it should be some complete integer . i hope sync index found is related to extracting message bits (and is entirely a different process from max eye sub vi or symbol timing synchronization)
I would be thankfull if i get some detailed descriptive reply. thankyou so much.
i am working on FSK transceiver example present in labview 2012.

Hello Maria,
You can use the MT Generate Synchronization Parameters VI to tell the FSK Demodulator VI to look for a sequence of sync bits. You will have to embedded these sync bits in your bit stream yourself in the transmission side.
Beyond this, I don't think the demodulator VI does any "decoding" of your bit stream. It simply takes samples fetched IQ samples from the RFSA driver and converts them bits based on the FSK scheme. What you do with the demodulated bit stream is up to you.
The demodulator VI also doesn't detect bursts for you. You will either have to tell your VSA to aquire only bursts of data. Or detect the bursts in software.
I can't reveal much detail about the demodulator algorithm itself because its proprietary. However, since you can open up the VI, you can always use LabVIEWs debugging tools to get a better understanding of what its doing.
Wan L
Applications Engineer
National Instruments
http://www.ni.com/support

Windows no longer detecting my Audigy 4?(Non-P

Hey all. I've had my Audigy 4 (non-Pro) installed and working super for about 50 days, but it started giving me a weird problem. Windows was no longer detecting the card! It was weird. DX Diag, programs like EVEREST... they all report no sound card whatsoever.
Here are my PC specs:
XP Home Edition
Albatron K8X800 Pro
S754 3200+ ClawHammer
x 2 OCZ ELPE 52 MB(2-3-2-5)
Visiontek XTASY X850XT PE
x 80 GB SATA 2 Seagate, x 80 GB Maxtor
Some other things to note:
XP has been repaired. Went from Service Pack , updates, and all the way to Service Pack 2. The card requires XP w/SP2, yes, so I have that covered.
Onboard audio is disabled through the bios. I have AC'97 integrated audio on this.
My motherboard has fi've PCI slots - although I can only access 4 because my video card is in the way, and I have tried three of those and I get the same problem.
I have tried it in other PCs in my house, double-checked each time - so it is not ESD as I originally believed. It works just fine on those PCs. It is being not located only on MY PC.
So guys and gals, I do not know what to do... I am stumped. It's the weekend so I can't call Creative support until Monday. I don't want to request an RMA through my warranty because clearly it's just a problem with my PC. What should I do?!Message Edited by Celsius on -26-2005 07:36 PM

Device not recognized in iTunes

IPod Touch/Phone 4gens No Longer Detected in WINDOWS MY COMPUTER but OK in iTunes

Since I have not found help online regarding the above situation I'm looking for help accordingly. For most folks it's iTunes not detecting i-Devices, but my situation is unique.
It started last night after I was on the phone for hours with Norton regarding error messages I was getting with Internet Security. Those issues have been resolved.
Again: iTunes detects and interacts successfully with ALL my iDevices. Windows Vista > My Computer no longer does.
Please help.

Just now I performed the following:
Turned off and turned back on AMDS(Apple Mobile Device) Service.
Disabled Norton Internet Security, and tried checking if Windows would see my devices.
For anyone who has Windows Vista you are familiar with the notes that play when you plug in a USB device: "da-dunk!" Low-High note dadunk indicates connected. High-low indicates it was disconnected.
I can tell there is a problem because right after the Low-High dadunk in Vista I get a triple Low-note Du-du-dunk.
Please help!

Not detecting tv display when connected with Apple Mini-DVI to Video Adapte

I am connecting my macbook to my older tv using a Apple Mini-DVI to Video Adapter to an RCA (yellow video prong) and then into the tv. The red and white audio prongs hang loose, not hooked into anything on both ends. When I go into Displays there is no option for mirroring displays. I hit 'detect displays' but nothing happens. The Apple Mini-DVI to Video Adapter is brand new, just ordered it from apple. And I use the RCA cord all the time with other machines into my tv and it works fine.
Any help is really appreciated. Thanks!

Which generation MacBook do you have because at some point Apple dropped support for that adapter. Here is a link to a list of Apple adapters and compatible computer models:
http://support.apple.com/kb/HT3235

No TV detected using mini-DVI to S-VHS/Scart

In my old laptop, I have used the S-VHS output from the graphics card, and in order to see the monitor on my TV, I had to set the TV as default monitor. Now I recently purchased an iMac with a mini-DVI to video. I put my s-vhs cable into this adapter and at the other end I put the s-vhs cable into a scart adapter and then into the tv. When I push "Detect displays"-button, I see a short flicker (grey lines) on my TV and then it becomes black again. I have tried all possible resolutions, but I have a feeling that the TV is not properly detected. I have also tried all possible codecs like NTSC, PAL and SECAM on my TV ++, but it doesn't work?! I'm a total newbie, so hopefully there is a simple solution:) - maybe some settings on the iMac?

Okay you should connect your dvi to S-video and then the other end of the S-video small round 7 pin connector to the S-video port on your TV.
Then set your tv channel to input or video in sometimes listed as L1 or aux in.
Once this is set to same as what you would connect a DVD or VHS via rca round pin red/yellow/black or white cables to the channel / input then press detect.
The screen should go black and then after say 5+ secs. you should see a colorfull / background or something on the tv and on your Apple and it will also show the resolution settings for each screen on that screen itself.
Then you can choose either to mirror the screens = same size display and desktop on both or each one to be independent.
Maybe set your tv then to 800x600 to be safe and select what ever tv standard is available in your country. (ntsc/PAL)
PS: the S-video looks like the old PS2 mouse connectors from windows PC's from before usb was discovered.

Is there a way to detect two keys at the same time?

Is there a way to detect the keys if the user is holding two keys down at the same time?

yes, but you'll have to check outside of the event loop (i.e. don't check for it in the keyPressed method).
just use an array of keys that keeps track of which keys are currently down and which are up. you could use a boolean array but I use an int array because... Im not sure I've just done it probably because of my C background. anyway, basic setup:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
public class MultiKey extends JFrame {
     int keys[];
     public MultiKey() {
          super();
          keys = new int[256];
          Arrays.fill(keys,0); // 0 = key is up
          enableEvents(AWTEvent.KEY_EVENT_MASK);
          show();
     public void processKeyEvent(KeyEvent e) {
          // the 0xff below binds the key code to below 256
          int key = (e.getKeyCode()&0xff);
          if (e.getID() == KeyEvent.KEY_PRESSED) {
               keys[key] = 1; // 1 = key is down
          else if (e.getID() == KeyEvent.KEY_RELEASED) {
               keys[key] = 0; // 0 = key is up
     protected boolean isKeyDown(int key) {
          return (keys[key] != 0);
     protected boolean isKeyUp(int key) {
          return (keys[key] == 0);
}so now at any time in your code you can check key state by using the isKeyUp and isKeyDown methods. this is about as close as you get to input polling in java unless you use LWJGL or something similiar ;)
you can try out a full executable example at my site here - just open up the jar and start holding keys down :)

IPod Touch, not detected in Windows or iTunes...

First of all, hello to everyone...
i want to say that i read a lot EVERYWHERE about my issue and still i couldnt find a solution...
the problem is easy, i have a 3rd gen ipod touch, OS 4.2.1 now fully working... but, it's not detected in windows or itunes, as simple as that, and as u all have read in lots of other posts...
my ipod is now working because i took it to an apple store and they charged it in a MAC and they had no problem at all. the MAC detected the ipod, with all its content and my ipod's name...
but when i took it home -this has been hapenning since maybe... 5 MONTHS!-, i plug it in my PC and nothing happens...
ok, first of all, my spec... win vista home premium 64 bits, last version of itunes...
i tried ALL the solutions provided in APPLE official support page, and nothing happens... that means:
1- completely uninstall itunes and then reinstalling it... i ALSO FORMATED my entire hard drive twice!!!!
2- tried all USB ports and even an entirely different PC and nothing happened
3- bought 3 different IPOD to USB cables and nothing happened
4- tried setting ipod to restore, that way itunes SOMETIMES detected the ipod but i coulnt restore because of different error codes, so i had to take it several times to apple store to "unblock" it...
the only way it works -detection and charge- is with MAC computers or dock systems such as an iHome my gf has thats the way im charging it now, but otherwise it wont work...
i would really appreciate any help, since idont know what else to do!!
thx in advance!!

HI I was having some other problems getting my itouch to restore because it was not being recognized in itunes and kept erroring out. Now it has finally restored after I updated all kinds of drivers and removed and reinstalled itunes and apple software a million times,(yes this is all after installing itunes 8.1 and paying for an itouch upgrade as well) Now itunes says it cannot do anything with the ipod because it is getting an invalid response from the device. So it won't put anything back on my itouch or even show that I have plugged it in. I emailed tech support, If I find anything out I'll let you know, will you do the same for me?

IPod Nano 4Gb (2nd Gen) not detected by Windows or iTunes

I am hoping someone can help me with this as I am at my wits end.
When I plug my iPod into the usb port, it begins the charging process, but neither windows, nor iTunes will detect any new devices. I have tried the 4 R's (the fifth needs a connection with iTunes), putting it into disc mode, and even on 3 different windows computers, but no dice. To save the no doubt normal questions, The usb ports are 2.0, and brand spanking new, which i have tested sucessfully with other usb devices, so I know it's not the usb port. I have the latest drivers & updates installed, and the latest version of iTunes also installed.
Other potentially useful info:
The model is iPod nano 4bg alu 2nd gen
It's not new, i was given it as a gift by a friend who upgraded to the video model.
Though I can't be sure, I suspect that the dock cable isn't an apple product. Given that *very few* places where I live sell official iPod accessories, it is difficult for me to check.
Like I said, i really hope someone can help me, I really don't know how long i can go listening to my friends rather dubious music tastes...

hi,
try the following article my friend...it will definitely resolve your problem..
http://docs.info.apple.com/article.html?artnum=302420
http://docs.info.apple.com/article.html?artnum=61711
Regards,
Sam

Error message "iTunes has detected an iPod that appears to be corrupted"

Everything used to work just fine until recently. On my Windows XP Home SP3 laptop, with iTunes (version 9.0.2.25) already open, I connect my 5th Generation iPod Nano and get the following message in iTunes:
"iTunes has detected an iPod that appears to be corrupted. You may need to restore this iPod before it can be used with iTunes. You may also try disconnecting and reconnecting the iPod."
If I plug the iPod into the computer without first starting iTunes, the Windows ‘Auto Play’ message comes up immediately then disappears and then the following message appears:
"Your iPod needs to be formatted for use with Windows. Would you like to run iTunes to restore your iPod Now?"
Otherwise, the iPod functions normally when not connected in iTunes. I can play the music, videos, and record videos with no problems.
The troubleshooting steps I took were:
I performed a reset of the Nano by first sliding the hold switch on/off a few cycles, leaving switch off (no orange showing), then pressed and held the Menu + Select button until the Apple logo appeared. Then I tried it in iTunes again; no such luck, same error. I then did a reset again, this time with the iPod connected to an AC power source; still no luck. I tried the reset numerous times and it didn’t help.
Next, I ran the diagnostics by pressing and holding the Menu + Select buttons immediately followed by the Select + Reverse buttons. I stepped through all the diagnostics tests and all tests passed as far as I could tell (there was no errors reported).
After this, I tried it in iTunes again and still no luck.
I even tried the iPod on my Windows Vista Home Premium (32 bit) machine and it behaved the same way. The version of iTunes on that machine was at an earlier version when I first tried it there. I then upgraded iTunes to the latest version but that didn’t help either.
I can sync my iPod Touch and 2nd gen Nano without any problems.
Sorry about be long winded about this but I am wondering if anyone else may have other suggestions. I want to try and avoid a restore if possible because I have some videos I recorded that I would like to get off the iPod. I’m not concerned about my music files as I have them always backed up but didn’t get the videos off yet.

I am having this same problem with my brand new Mac Pro. It seems to be tied to the computer awaking from sleep (no I am not leaving the iPod connected while sleep... I am referring to waking the computer from sleep and then connecting iPod as opposed to restarting the computer and then connecting the iPod). In other words, if you are getting this error message, try ejecting the iPod, restart your computer, then connect the iPod and see if the error message goes away. For me it does, but I only get one shot at it, if I eject the iPod and then reconnect it, the error message returns. This happens on both iPods I have. I have rebooted (hold menu-select) and gone to disc mode (hold select-play) and the error message remains. The only way it goes away is to reboot the computer, then I get one shot at hooking up an iPod.
I NEVER had nor get this error message when I connect to the Windows PC that I started with. Perhaps the iPod does not like moving from PC to Mac?

My Ellipsis 8 can no longer detect my gym's wifi signal. Please help!

I used my Ellipsis 8 to watch Netflix over the open wifi signal at my gym for 2 months with no problem. One day I showed up and no signal was found. I went through all the trouble shooting steps all the way down to factory resets with no resolution. Called Verizon tech support and still nothing. They had me send them the tablet in a recovery box. One week later I have the tablet back and they said nothing was wrong with the unit. I went to the gym today and it still can not detect the signal. My Samsung phone picks up a very strong signal. No other people have reported a problem with wifi connection issues. Obviously Planet Fitness will not allow me to start messing with their router. Any suggestions would be GREATLY APPRECIATED!

I understand the importance of ensuring you are able to get connected to wifi michaeltatham. Allow us to get to the bottom of your tablet concerns. Have you recently installed any new software or new applications when it stopped connecting to the gym wifi? Have you tried to connect another device to your gym wifi?
Thank You,
MichelleS_VZW
Follow us on Twitter @VZWSupport
If my response answered your question please click the �Correct Answer� button under my response. This ensures others can benefit from our conversation. Thanks in advance for your help with this!!

I cannot access or reinstall Itunes, and my ipod isn't being detected

So, sometime after the fall of 2010, which I suspect was after iTunes 10 was launched, I noticed I couldn't access iTunes.
It read error 2330.
I did some sleuthing for months, and now I get these error messages under the heading "iTunes + Quicktime" when I attempted a re-installation of iTunes:
"There's a problem with this Windows Installer package. A program required for this install to complete could not be run. Contact your support personnel or package vendor"
"An error occurred while attempting to create the directory: C:\Documents and Settings\All Users\Application Data\Apple Computer\iTunes"
In the past while attempting to re-install iTunes, I got error message 2330...STILL don't fully know what this means.
I currently have Bonjour, the iTunes folder, The iPhone Configuration Utility folder, and Quicktime on my desktop...The actual programs are also in my C:\ drive in Program Files...I can also see Apple software in the Add/Remove Programs section of the Control Panel on my PC.
I seem to be able to access iTunes/iTunes store via the executable file in the iTunes folder by clicking "iTunes.exe", but no other way...I also noticed that the software will run normally, but not detect my iPod or allow my computer access...So in other words, iTunes doesn't recognize my computer as being authorized for my account, and yet it displays my email address in the upper-right hand corner of iTunes.
It's like I can only access a "half version" of the full iTunes I once had by going through that folder...No clue what's happening or what files may be missing or corrupted.
Quite simply put, I need help...I want to be able to use iTunes and my iPod Touch (1st gen) like I was able to this past fall before the mysterious accident or corrupt files ruined everything.

For that 2330 error, run chkdsk on your C drive.
How to perform disk error checking in Windows XP
http://support.microsoft.com/?kbid=315265

IPad 3G no longer detected by iTunes (Win Vista), only charging when battery V. Low

This appears to be a software issue: my iPad 3G (32GB) is not detected by iTunes (yet my iPhone is), nor by Windows Vista. Furthermore, it does not charge from the wall charger until it shuts down in low battery, and only charges to 2%, after which it switches on again. Tried switching off and charging, which only causes it to switch back on again. Also tried cold resetting, but problem persists. Was working fine previously, no updates, additions or subtractions were made to either PC OS, iPad or iTunes immediately before problem started... and there doesn't seem to be any mention of this on the internets (including this forum). Any suggestions?

Soft boot, hold down top button and middle bottom button at the same time, with the iPhone connected to your computer and iTunes will recognize the phone on reboot.

Iphone is no longer detected on itunes/computer it is synched with.

One of my Iphones is no longer detected by the itunes/computer that it is synched with. The computer/itunes does detect other devices. The iphone in question is able to be detected on another computer/itunes.
I updated software oof iphone on another computer. I updated itunes on the computer that does not detect the phone. I rebooted both. I tried software conflict.
Does anyone have an idea how to resolve? I have all of my contacts, apps, photos, music etc on that computer.
When I updated phone software on another computer to see if that was the problem it wiped out all music,apps, photos etc on the phone. I have thee devices with one apple id and they are synched to different computers.

You should try another USB cable, charging and sending data through the cable is not completely the same, sending data is using other contacts inside the plug or docking connector.

IPod detected by Windows but not by ipod apps; installation freezes

Hello
As the installation CD felt out of the box I did not read the warning label that I first should install the drivers and then connect the ipod, probably this was a bad idea..
Now I cannot install the iPod nano software. The CD tries to detect the nano, does so and then wants to format it. This format lasts several hours and then reproducibly failes with "an error is occured" and after confirmation with "install script failure" or so.
The downloaded very last version of the updater does only waits for me to detect the nano but does not realize when I actually do it. It just freezes before showing me the serial number (I read that this should happen), so I cannot upgrade
or reformat the nano this way.
A normal nano reset by pressing those buttons until the apple logo comes does have no visible effect.
Rebooting Windows XP, trying to deinstall and reinstall in
various combinations neither.
When trying to install from the CD without connected nano, it works but itunes then does not recognize it. The list
of running daemons show the ipod service though.
The nano is though recognized by Windows as a USB hard drive and shown in the "my desktop" area as well as in the
task bar as removable media.
I connected the nano to serveral different USB 2.0 ports on the back of my computer.
Any idea?
thanks,
-christian-

i could do everything fine up until step 6), the installation of itunes. when i tried to, with the ipod updater window still open, it said it could not continue without closing the updater program. any suggestions?

Demodulation pa detection d'envelloppe

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