The Improvement And Implementation Of Digital Voice Baseband System Based On PIC

Today,as the mobile phone has become the necessities to people, a low-cost point-to-point wireless communication system is in increasing development, it is a required communication equipment for policing, security personnel and field staff, it is different from mobile phones, Without charging according to talk time, and will not have the problem of network congestion, it can be used to guarantee the communication of major task and kinds of sudden emergencies. In the process of design speech communication system, the method of speech signal processing have relation to the performance of the system , with the more and more high quality requirement, people need to use less code-rate to obtain the better quality of synthetic speech as far as possible.For the huge market of domestic civil digital interphone , this thesis introduces a digital interphone with low cost,low powe dissipation and designs the frequency-hopped voice communications system based on PIC chips and RF transceiver chip CC1100. The scheme using DSP+MCU architecture as baseband processor. In the software of design information interaction adopts the DMA transmission,improve the transmission rate; using a plan that Microchip chip replace the special speech compress chip adopted by existing digital interphone to realize speech processing, it makes the temporal distribution of baseband module by its resources, reducing cost of production; the system realize frequency-hopping communication through controller changing the carrier frequency of CC1100, protects the security of communication.Digital wireless voice communications system which this thesis studies also provides a feasible scheme for realizing digital terminals in digital trunking communication system. Communication more safe and reliable, voice more clearly by digital processing. The abundant PIC peripherals resources and flexible periphery connection circuit can provide a common platform for the algorithms research. In addition, as the country has not unified standards and regulations, system also retain expansion and spaces to adapt to the new changes and to further research needs.