Technology And System Development Of Transmitting Voice And Text Signal Based On The Telephone Line

To enhance the function of the ordinary telephone, by which the user can communicate withothers in voice only, this system adds handwriting-test signal inputting and transmitting,besides the simultaneous voice. It is a type of multimedia communication equipment. Whenthe two talkers being from different areas speak in different accents, there always must be acondition that the two cannot know each other. While, using these functions, the users willavoide the embarrassing situation and misunderstanding. Additionally, if they want to discussthe figure, route, design on line, it also can meet their demands. What is more, it has canceledthe restriction on user effectively. In some special cases, it can be used to maintain secrecy.And the deaf-mutes, with the obstacle of the hearing and pronouncing, can use it freely.As requested, that is adding in the ordinary telephone hand-writing partly and revealingsome, and transmitting two signals of pronunciation and picture and text, in order to realizesoftware and hardware at the same time, the following works are finished:1 Based on the telephone line facsimile transmission function of the structure ofacoustic signals program, which TMS320C6713 digital signal processor as the core, with fastdata processing, and the expansion of powerful advantages.2 Application of DSP chips for signal processing, control, complete DSP with thetablet, liquid crystal display module connected to realize the handwriting input signal at thedisplay on LCD screen3 Using telephone lines as the common channel, for analog voice signal and datatransmission. And use the binary frequency shift keying modulation removal demodulation ofdata signals to higher frequencies . Simultaneously achieve two-way signal transmission byfrequency division multiplexing method.4 Through the public telephone network related knowledge study, DSP-based system in the network after the possible problems encountered and to give the corresponding solution.Preparation procedures and the design of circuits, to other similar applications can play a roleof inspiration and reference.