Based On Ultrashort Wave Radio Frequency-hopping Voice Communications Research

Frequency Hopped communication system develops fast and deeply both in civil and military use because its ability in anti-interference, anti-fading and the realization of multi-address for networking. But the frequency hopped system is composed of multi-function and multi-processing algorithm. How to coordinate the different parts is the important and difficulty point of the whole system design.Based on the specific design practice about VHF band frenquency hopping radio, the pratical design proposal was advanced. The thesis summarizes the working process and equipment of the VHF band frequency hopping radio. Then expatiates on the reason why uses CVSD for encoding while the radio frequency hopping communites and the process and result of performance testing. Third, explains how to realize the synchronizd design of frequency hopped system and software and hardware of the specific module. Forth, introduces the MSK modulation process of how to receive and send the radio signal under frequency hopping and elaborates on the key step. Finally, lists the results of module and the radio testing and the problem solving process in testing.We emphasizes the strictly synergic design of software and hardware during the developing process of frequency hopping system. The design of software is based on the hareware, while considering the software runnig at the beginning of the design of hardware.The elaborated discussed modules hareware are all mainly base on FPGA+processor. The FPGA give the maximum freedom about logic design about hardware, and provide the synchronization of the whole frenquency hopping system. The processor guarantees the rigorous of complex algorithm design, realizes the mutability of frequency hopping, makes the two supplementay to each other and provides the space for system expansion and function perfection.I participate in demonstration of the whole plan, subdivision of the functional indexes and vercification of the test during the project, and in charge of the terminal module hardware design and the frequency hopping processing module. After one year's systemic program developing test, realizes the verification of frequency hopping function both in module and in the radio. The system has already tested in Egypt and received the satisfactionary reaction from the customers.