Study On Digital Wireless Voice Transmit System Based On AMBE Vocoder

Two-way radio, an important branch of mobile communication, is widely used in many fields. It will be continue used in the future for its market position is different from other wireless mobile communication tool such as mobile phone and can not replace each other. At present, common two-way radio still uses analog commnication technology except trunked transceivers use digital control signals in China. However, with the development of society and technological progress, frequency resource are becoming more and more precious, users require higher performance two-way radio. Therefore, in oder to improve the research of digital two-way radio in China, the state administration of radio published related technical indexes in September 2007.Provided unreliable voice and easy to be interfered was one of analog system's faults. In order to solve this problem, this paper adopted on a low data rate, superior voice quality speech compression chips based on AMBE algorithm, combined with TDMA/TDD technology, micro-controller technology, designed and implemented a digital wireless voice transmission system.This paper firstly discussed the communication protocol the system used,defi-ned the physical layer, designed the two-slot frame solution. Then demonstrated the hardware circuit terminal solution of digital wireless voice transmission system, finished chip selection and circuit designed of micro-controller module, voice processing module which based on AMBE-1000 vocodec, and power supply module. Then designed software system, followed top-down strategy, divided task into three module: initialize module, data control module and communication module.Then used assembler language, bottom up finish programming of initialize module and data control module. Then introduced the process of realization and debugging of hardware and software using iterative model.The digital wireless voice transmission system studied in this paper working in the bit rate of 4.8kb/s with high speech quality, changeable bit rate, full-duplex communication, provided another resolvent for the Trunked communication system. Moreover, if taking low cost, low power as a starting point, the system, which function has been perfected, is wieldy, reliable, and has well performance enough to satisfy demand on daily telephone conversation, the system also may be generalized in more areas.