How can I read an audio file and brodcast it using NI RFSG?

[muslim]

Hi everybody,

I'm designing a wireless audio signal simulation system that will read an audio signal from a file and modulate the signal using NI 5671 RFSG, then broadcast it to be received at an NI 5660 RFSA. 

All I need is some guidance from you guys. Some related examples would be of great help since I'm a new user of NI hardwares and software.

Thanks in advance.

Muslim,

Communication Engineering Student,

International Islamic University Malaysia. 

[Paul_C.]

Hi Muslim,

First and foremost, what application development enviroment are you intending on using to program these two devices?  If you are using LabVIEW, I would highly recommend taking a look at the example finder (Help » Find Examples).  The examples for our RFSG and RSFA cards can be found in the example finder for labVIEW under Hardware Input and Output » Modular Instruments.  I would specifically take a look at the RFSG Write Waveform From File.vi found under Hardware Input and Output » Modular Instruments » NI-RFSG » Arbitrary Waveforms.  This example should help get you started on the generation side.  On the acquisition side there are various examples for getting started.  If you are using another application developement enviroment, please let me know and I will suggest some other examples.  The majority of the information for these devices and drivers is installed to the Start » Programs » National Instruments folder in windows.  Just navigate to the NI-RFSG or RFSA folder for examples and documentation on these devices.

Regards,
Paul C.

[Paul_C.]

Hey Muslim,

I found an example that was written as a demo that takes a wav file and transmits it using frequency modulation (FM).  You might want to take a look at it and see if it helps.

Regards,
Paul C.

[muslim]

Thanks Paul,

Basically, I'm using LabVIEW environment. The examples you attached are very helpful. I would appreciate more of those examples.

My project is quite simple, I need to acquire an analog signal from a sound file, then frequency-translate it to be ready for broadcating over a wireless environment. The signal will be then received and analyzed at an RFSA at a nearby station.

I will try the examples you provided and try FRSG Write to file then reply back to you..

Thanks a lot.

[Paul_C.]

Hi Muslim,

The examples I provided are a good place to get started.  Depending on if you are going to use modulation, there are quite a few more examples that can be found in the Modulation toolkit which we sell with the devices.  If you are looking for more specific examples, I would recommend searching our website and forums.  After you try the examples, let me know if you have any more trouble getting your program up and running.

Regards,
Paul C.

[muslim]

Hi Paul C,

I have attempted the examples you attached and advised. It was of a great help to me. What I did precisely, is that I combined some parts of the (fm-modulation) and the (generate FM signal from WAV file) examples into one design. The program did run. But, I'm still not very sure about the accuracy of my work. 

Frankly, I'm still stuck at the audio file reading part. I need to play the file at the RFSA. But,  the examples available do not show what I'm searching for.

one more thing, I need to do some analysis on the received audio signal. Any suggestions here?

Thanks a lot 🙂  

[hoffiz]

Hi,

I’m going to help here since Paul is out of the office, so far you have been able to use Paul’s example to generate a signal from a Wav File, right? I have a question: why did you combine some of the parts of the (fm-modulation) with the generate FM signal from WAV file if the example Paul attached is already modulating the signal?

I have another question on the part that you are stuck when reading the file, do you want to play it back through your speakers or you just want to be able to see the array of samples? Have you seen the example “MT niRFSA Demodulate FM.vi”? And if so why it does not help? Here is another example for FM modulation: Sound File Frequency Modulated Generation using NI-567x I would like to let you know that all those examples Paul and I are giving you are located at our website most are free and you may find them yourself; if you have the necessary drivers and toolkits installed you should be good to go. “The examples available do not show what I'm searching for” What are you searching for? What type of analysis do you need to perform?

Remember that in the RFSA part of your project what you are going to be receiving will be an array that contains all the points of your data not a WAV file. I will suggest trying to run both FM example the RFSG and RFSA with no modification for a better understanding of what is happening.

I hope it helps

[muslim]

Hi Jaime F,

Thanks for your help. I actually, spent one whole day trying those examples. non of them could detect my received signal. I'm using an NI 5660 signal analyzer.. my Digitizer is PXI-5620 which is a traditional device. Hence I could run NI 5660 examples only. Problem here is that I failed to detect any signal so far. my RFSG part is very ok now.

Why I combined two examples is because the generate a signal from a Wav File example doesn't run continuously, which makes my task very difficult as I want to analyze the audio signal. All I did was that I copied the VI's n functions that read the WAV file into the fm-modulation example. anyway, even when using the provided example of fm-modualtion of a sinusoidal signal, I still fail to detect the correct signal at the RFSA part. I only get some noise signal.

Any idea why detection fails?

[hoffiz]

Hi,

If you take a look at the pictures you can see the examples I’m using. This test was perform in through two different mediums, a SMA Cable from the RFSG to the 5660 and monopoles antennas connected to the RFSG and the 5660.

SMA Cable Test:

Antennas Test:

Let me know if you can perform this test?

[hoffiz]

SMA Cable Test:

Antennas Test:

Let me know if you can perform this test?, at least with the coaxial cable from on device to the other one.


Message Edited by Jaime F on 05-21-2008 03:55 PM