Study Of Wireless Controling And Guiding With CDMA Technology For A Portable Anti-Tank Missile

This dissertation is an exploration for the technology of CDMA applied on missile controlling and guiding. It is involved with the theory of spread spectrum communication, the theory of missile controlling and guiding, and corresponding practical digitized technology. The key techniques and problems to realize the hardware of CDMA wireless missile controlling and guiding are studied in theory and practice, while the realization of the hardware of CDMA wireless missile controlling and guiding is the aim of the research. This thesis mainly consists of the following parts.Firstly, the actuality of portable anti-tank missile in the world is introduced. The related fundamental theories and key techniques to the study are elaborated. The applications of CDMA techniques being used in military and popularity are presented. The application of CDMA used on missile controlling and guiding is proposed. All of the above works are the basis for the following research.Secondly, the circumstance of a battlefield is analyzed. The results show that most of the matured techniques of CDMA are not all meet the demand of the missile controlling and guiding. The manner of modulation, the spread spectrum codes, and the manner of the acquisition and tracking are discussed. Barker codes, DPSK and match filter with the ability of rapid acquisition are concluded as the appropriate manner for CDMA missile controlling and guiding.Thirdly, the potential interference on a anti-tank missile from its working environment is analyzed. It is pointed out that the anti-interference and anti-capture are the important demands for CDMA wireless instruction transporting. CDMA anti-interference capability is studied in theory, and it is concluded that many kinds of interference can be restrained by CDMA technique. Other techniques for anti-interference and anti-capture are also studied.Fourthly, the practical techniques of CDMA such as programming, miniaturization and so on are studied. The digital base-band CDMA transmitting and receiving scheme is put forward. The scheme uses a technique called as zero medium frequency without the need of PN codes synchronously are resumed. The related issues to zero mediumfrequency including digital match filter and orthogonal sampling are studied. The research makes a basis for the development and realization of CDMA hardware system.The realization process of the developed CDMA base-band transmitting and receiving system is elaborated. Based on the developed system, and equipped with module for wireless transmitting and receiving, the experimental validation for the functions of CDMA techniques are carried through. Corresponding experimental data is presented.It can be concluded that CDMA system can realize the correct receiving, meanwhile CDMA system will not interference with another receiver in the system and other receivers will not capture the signal from the working system. This shows that the developed system used as controlling and guiding instructions transporting is feasible.