In this thesis work, we implement a DSVD modem protocol for simultaneous voice and data transmission following the standard of ITU Recommendation V.dsvd.
Digital data and digitally encoded voice signals are multiplexed using a V.42 LAPM based multiplexing techique described in V.gmux. The multiplexed bit stream is transmitted using the modulation techniques defined in recommendations V.34 and V.32 bis for duplex communication over a single general switched telephone network(GSTN) connection or over a 2-wire leased point-to-point telephone-type circuit.
For DSVD modem protocol for simultaneous voice and data transmission, we implemented of the CELP speech coding algorithm for voice processing function and the V.42 error-correcting protocols for data processing function.
At voice and data integration, compressed speech is multiplexed with the user's data stream and send over the phone line using a null modem with an RS232C interface.
The speech coder and decoder are implemented in real time using an T.I. TMS320C32 DSP chip. The function of error recovery and data compression for user's data is implemented following V.42 and V.42 bis protocol procedures.
This implementation fulfills the technical requirements for a digital simultaneous voice and data (DSVD) terminal.
