Write software simple modem

Job ID: 33374510

Budget: $30 – $250 USD

It is necessary to make firmware on ready-made STM32 debug boards that will implement modem functions for an analog line. Block diagram attached. The flow rate is up to 20 kbps over an analog communication line.
Analog line: frequency band 400-3000Hz, data rate up to 20kbps
experience in writing QAM modulators / demodulators, signal equalizers, digital signal processing is required.