A Bell 103 Demodulator

This was done as a class project and is the basic start to implementing a full Bell 103 modem. Currently, only the demodulating portion is implemented and is not fully featured.

It is currently capable of decoding 48,000 kilosample/s 16-bit single-channel WAV files in little-endian Microsoft PCM format. The file contents must be encoded using the answering frequencies of the 9N1 Bell 103 protocol at 300 bits per second. The bytes must also be packed tight with no lead-in or filtering.

There are options for changing the sampling rate, and filter length as well as using the origin frequencies instead of answering but these have not been tested.