Study On The Near-ground Propagation Characteristics Of IR-UWB Signal Between Landmine Nodes

In the future information-based and high technological war, the smart landmine and minefield with intelligence and informational are the emphases in our army landmine equipment research. The impulse radio ultra wideband (IR-UWB) is one of the newest technologies with advantages such as low power consumption, low complexity and anti-interference ability etc. It is very suitable for the wireless data transmission and accurate self-localization between landmine nodes in the minefield environment and can satisfied the requirements of the future landmine weapon system’s informationization and network connections. In recent years, the studies on the IR-UWB mainly focus on the indoor wireless communication, localization and radar detection both at home and abroad. The minefield is normally in the outdoor field environment. The mine node is small and mainly laid on the ground. The mine’s antenna is very near the ground. So, study on the propagation characteristics of the IR-UWB signal in the minefield condition are the key issues of the mine weapon’s practical application. The research results can provide great significance in the development of our landmine equipment in the future.In this paper, aiming at the characteristics of the minefield environment and smart mine and minefield’s technical and tactical requirements, the feasibility of the IR-UWB system are analyzed theoretically and experimentally. Based on the wireless radio propagation fundamental theory, the near-ground propagation characteristics of the IR-UWB signal between landmine nodes are studied. The primary rules of the waveform distortion are given. The IR-UWB propagation channel model that fit the minefield environment is established. The applications of the IR-UWB in the minefield are also discussed. The work in this paper can provide technological support for the relative research and the system design of the smart mine and minefield. The main work and results are summarized as follows:Firstly, the principles of the wireless radio propagation are studied. According to the analysis of the characteristics of the minefield environment and mine node, the technological parameters are put forward with the demands of the minefield network. The3D model of the minefield environment is established. These can provide references for the IR-UWB signal’s propagation characteristics research and channel modeling.Based on the radio ground reflection theory, the IR-UWB near-ground link performance budget model is established. The relationships of the transmit power, antenna height, transmission distance and data rate are analyzed. The IR-UWB system’s transmission capability between landmine nodes is studied. Combined with the outdoor field experiment measurement and testing data analysis, the link budget model is testified to be correct. It is also shows that the IR-UWB technology can be used in the mine weapon obviously.According to the characteristics of the minefield environment, the waveform distortion reasons are analyzed when the IR-UWB signal transmit between mine nodes. Due to the huge bandwidth of the IR-UWB signal, the frequency domain (FD) sub-band method is raised to cope with the signal’s properties in waveform distortion. In different grazing angle and soil conditions, the IR-UWB reflection waveforms are studied and the near-ground reflection rules are obtained. Based on the uniform theory of diffraction (UTD), the IR-UWB diffraction model in the minefield environment is established. Then the IR-UWB diffraction waveform is studied from two aspects of the signal’s amplitude and phase.Through the analysis of the wireless channel modeling theory, the modeling method combined with stochastic theory and deterministic analysis is determined. With the channel model, the path-loss properties and multi-path effect of the IR-UWB signal near-ground propagation are studied and the results are received.Finally, researches on the applications of the IR-UWB technology in the landmine are carried out. The IR-UWB signal’s design principles and primary parameters are put forward. The self-localization method of the landmine node base on the time of arrival (TOA) ranging algorithm is studied. With the results of the near-ground propagation characteristics, the location and ranging error are analyzed, then the method of improving the self-localization precision are given.