Design And Implementation On The Data Link Layer Protocol Of The HF Data Transmission

HF communication, as an important means of long distance communication, has advantages of high flexibility, strong anti-destroying ability, low cost and easy to rebuild, so it has important application in military communication. This paper is derived from the research topic of short-wave frequency selection and link establishment system. In order to provide efficient, reliable data transmission services for users, the short-wave frequency selection and chain building system is put forward in our laboratory, which has the advantages of needing short time to build chain, fast frequency selection and large amount of data transmission. The data transmission module of the link layer is studied in this paper. The author’s major contributions are outlined as follows:1. The data link layer protocol of the HF data transmission is studied. It focused on the business management protocol and high-speed data transmission protocol. The content and frame format of each protocol unit is determined in this paper. Error control technology, adaptive transmission technology and initial rate adaptation technology is studied in data transmission at the same time.2. Design and implementation on the data link layer protocol of the HF data transmission is studied. The LM3S9B96 chip produced by TI company is selected in this paper. Combining with the data manual and the bare computer development practice of ARM processor, as well as the studies of interrupt mechanism of the serial port interrupt, network port interrupt, timer interrupt in data transmission based on bare computer, the general design scheme of data transmission module based on ARM processor is given. Besides, in Keil4.5 development environment on the Windows operating system, the software realization of data transmission module is completed, which is based on LM3S9B96 with C language.3. The performance of the data transmission on link layer is studied. In the room, the channel simulator is used to simulate Gauss channel by setting different parameters, and the data transmission module is tested through transmitting different size files under different SNR in the channel. The throughput is calculated when the different files in diverse size is transmitted in the system. Through the above test and analysis, we conclude that the data transmission module of the HF link layer can not only ensure efficient data transmission but also has a strong anti-jamming property.