I'm making a soft demodulation/decoding to communicate a microphone and a speaker in short range. I have to calculate the LLR using my constellation and the airborne sound channel probability density function (pdf). I have searched a lot about airborne sound or acoustic channel model, and I just found out some considerations about the attenuation depending on the frequency. My questions are:
- Wich book can I read, so i can learn more about soft demodulation examples: BPSK, QPSK, QAM, FSK?
- If I use a pdf estimator of the channel, how can I use the estimation to find the LLR of my received symbols?
- Can I use another model to aproximate the airborne acoustic channel (it could be related to AWGN), or which book can I read to learn about how to model a communication channel?