Data Transmission using Audio Channel - repost

Hi Gang, there is a interesting project : [login to view URL] offers a kind of data-transmission over a audio channels. There are also smartphone Apps available - see [login to view URL] So basically you are able to transfer short messages between smartphones using the microphone + loudspeaker over a short distance. The scope of the project is to built a similar think (just the audio transmission solution, not all the other rest). We are looking for a smartphone-to-smartphone audio communication over the audio channel that sounds like "birds tweeting" while transmitting. Pls try the above smartphone Apps to see what I;m talking about. Technically considered this is a : - FSK modulation (but I;m open for other ideas) - 50 Bits of data (in general only few bytes should be transmitted, maximim transmission time just a few seconds) - Reed-Solomon Codes - See for details [login to view URL] - The parameters does not need 1:1 like chirp.io. We are not looking for a "copy", just a kind of inspiration. The real challenge on this task is to make the transmission sound like birds tweeting. One aspect that also [login to view URL] has used is to use "puretones" that are known from the "music" notes - [login to view URL] But there is more. The delivery goal would be : - A working code for transmitting of arbitrary data using a audio interface (one way, A to B, B to A is not required) - Nice would be a Java Code that runs on Android, but I;m open for other solutions. - The usage of Reed-Solomon Codes for error corrections (e.g. [login to view URL]) - Signal/Noise consideration (evtl. some Matlab Code for simulations ?) Please bid only when you know what would be required. This means you are potentially a export in the high-frequency domain, you know about topics like DSP, FFT, digital filtering, etc. The goal is not to have a "only" a FSK based transmission using from A to B, but while transmitting the user has the impression that some birds are tweeting.. :-) Cheers, jj Some another useful links : [login to view URL] [login to view URL]