Voice signal to bits

[jrmonagas]

Hello. 

I have a problem. I want to modulate a voice signal (WAV format) in 8PSK modulation. My problem is that I want to take the voice signal to a bit stream, having it quantized in 256 levels, and I don't know how. I just get to receive the voice signal but I don't know how to start to get to this quantization and then to the bit stream.

Thank you very much.

Jose Rafael Monagas

[cschneider]

you cant simply read your signal by the "sound file read.vi" and use the data output, which is a simple waveform (cluster) and do all your calculations on this cluster?

[jrmonagas]

It is not what I am trying to do. I need to record the sound right there in the VI and then see how it is being modulated and demodulated. So I start with an analogic voice signal and have to do everything to have it modulated. which includes quantize it. This is where I have problems. I need to have it quantized to 256 levels. 

Thank you very much anyways

[jrmonagas]

I am sorry cschneider, I didn't understand well what you tried to say. I do now. I am trying to work with that waveform. It is what I was trying to do since I started the project. But my problem is that I don't know how to take that waveform all the way to a bit stream to modulate it PSK, and then demodulate it and try to listen to it again. My problem is really that I need to maintain as much information as I can so at the other side it keeps sounding alike. 

Thank you very much. 

I hope I can get suggestions or answers very soon because I am running out of time. 

[cschneider]

it will work like this for you? i am not familiar with your calculation, but this is a way, you can modify your waveform...

[Coq_Rouge]

This should be it. Then working with sound file data the range is +/- 1 

[jrmonagas]

I am sorry coq rouge I don't get your diagram very well.. where should I plug the sound waveform?

And cschneider, my problem is that at the end of the diagram I need to have a bit stream.. a 0,1 type of data.. 

thank you very much

[Coq_Rouge]

Please look to the example from cschneider. Then replace the constant array with data from the sound card.

[jrmonagas]

Hello. Good afternoon. 

I have done what you recommended me. What you showed on the diagram. It works perfectly fine. Thank you very much. But I have another problem now, and it is that I don't know how to reverse the process at the other side of the mod-demod so I can play the sound waveform again.

Again thank you very much for your help Coq Rouge and cschneider.

Jose Rafel Monagas.

[Coq_Rouge]

I do not mean to be rude, but I think I have given you a push in the correct direction, and to bring balance in the account it is time for you to present some code for further discussion. If you reverse engineer what I have done, and read up on AD/DA conversion it should be a breeze 😉