A high speed DSP PSK modem for real time digital speech transmission

Describes the implementation of a coherent 9600 bps QPSK modem, which is fully realized using single TMS320C25 DSP systems, where all-digital phase locked loops are used for the baud timing and carrier recovery in the receiver. Due to the heavy computational burden in DSP modems and the speed restrictions of currently available devices, a new multimicroprocessing receiver is also presented which is shown to be able to support 32 Kbps data communication using coherent QPSK demodulation, and is suitable for use in ADPCM digital speech transmissions