The Design And Study Of Multimedia Telephone Terminal Based On DSP

The realization way of digital signal communicate in the telephone lines and the chosenof micro controller are analyzed in this paper, and a new multimedia telephone terminal isdesigned based on the fully research of current situation home and abroad of multimediafixed telephone, in order to make up the shortage of traditional fixed telephone in the form ofcommunication and to meet the needs of every person more convenient and quick. Thegraphic input and display module are taken into the telephone terminal on the basis of voicecommunication. This makes the telephone communicates by voice and graphic display at thesame time.The hardware circuit design and software programming of each function module areintroduced in detail in this paper. DSP is used to manage the liquid crystal display module,A/D conversion module and graphic signal modulation-demodulation. The speech signal andgraphic can transmit in the telephone lines at the same time by using frequency divisionmultiplexing technology. In addition, the key technologies, problems and solutions occurredduring debugging stage Which are touch screen coordinates transform and error handling,realization of the difference detection demodulation and filtering of digital signals beforeenter the phone channel are particularly discussed. Finally the reliability of multimediatelephone communication is confirmed through the test of whole system.This project makesboth sides of communication can not only speak and listen, but also see and write. Thismakes better exchange and communication.The development of this multimedia phone not only can effectively get rid ofmisunderstandings between different areas and different dialects during communication, butalso can play a more intuitive display in remote teaching and counseling. It providesconvenient for deaf-mutes in communication. And in some special occasions which are notallowed to have another person in the call can make efforts to confidentiality.