Research And Implementation Of The Shortwave Relay Technology In Distributed Communication System

The main content of the topic is research and implementation of the shortwave relay technology in distributed communication system. The background of the paper is the distributed military communication system based on shortwave communication. It briefly discusses the shortwave communication and distributed communication system used in military aspects, and then it analyzes the digital signal processing technology——digital signal processing theory, DSP chips application and the CCS and DSP/BIOS development environment which are used in this paper. The disadvantages of traditional military communication systems with central switchings are discussed in this paper and it shows the necessity and significance of no-center switching system. It reveals the importance of the shortwave relay technology to the distributed military communication system and puts forward the meaning of this topic.The part of the shortwave relay is explained in the paper. The hardware design and software protocol and interface design of the platform of the shortwave relay technology which is used in studying this topic——DSP platform are described in detail. The paper introduces the voice communication process of the distributed communication system carefully and the working principle of the communication system is analyzed and demonstrated in the paper.The shortwave relay technology of the paper refers to the application of the polyphase processing technology to the shortwave relay. This results from the channelized characteristics of the distributed military communication system. The paper starts with the relationship between the shortwave relay and the polyphase processing technology and introduces the instructions about the application of polyphase processing technology in the subject. It focuses on the theory reasoning of the block diagram structure of the polyphase processing technology. The paper deduces the improved structure of the shortwave relay from the basic polyphase filter structure and gives the instructions of applying it to the shortwave relay. It carrys out the polyphase processing technology simulation based on MATLAB and the right result of the simulation demonstrates the feasibility of polyphase processing technology.In addition, the polyphase processing technology algorithm programming baesd on DSP platform is also illustrated in the paper, including the creation of the cross developing environment, the DSP/BIOS program creation and the hybrid programming method.At the end of the paper, it conducts the full digital Ethernet test of the system which can be finished by adjusting to different communication protocols according to different communication methods. The fully hardware TCP/IP stack chip is used in the test and the thought of fully hardware TCP/IP stack is drew forth.The polyphase processing technology has a mature theoretical basis. Applying it to the shortwave relay technology of the distributed military communication system can save a lot of cost and has certain marketing significance. Moreover, the polyphase processing module has many advantages. The polyphase module is designed from the point of view of the reasonable and practical aspects and decreases the complexity of the algorithm greatly which has high modular degree. It can be easily realized on the hardware platform and has practical applicable meaning.