Research On Stratum Communication System Based On UWB Impulse Technology

How to communicate with miners is very important in case of undermine disaster, because only through communicating with those people trapped in coal mine, can we acquire the message that they are safe, and where are they located. But under this urgent environment, traditional communication technologies lost their function. wire communication meet with challenges mainly for the large attenuation through the rocks, and so is the traditional wireless communications. Hence, it is very necessary to develop a new way for emergency communication. In this paper we put forward a new method, based on an ultra-wideband spectrum spreading technologies, which could solve the problem perfectly, the main work of this paper is summarized as follows:1. The channel model of strata communication is restudied, actually there are two models here. The first model is based on electromagnetic wave, while the second is on the current field. The way of their transmission is analyzed, and we make a lot of tests to clarify them. It turns out that the system is based on the second model to transfer through rocks, because the transfer distance relying on the first model is restricted, thus confirms the application and development prospects of the system.2. We re-examine the present system's design correctness and superiority, based on pulse ultra wideband. The overall scheme of the sending and receiving system is made. The system is based on electrodes antennas, M-ary spectrum spreading method, ultra-wideband impulse waveform. And it has the advantage of high output voltage and good safety performance. Moreover, the reason why we use these technologies is given, which will help readers better understand the whole system.3. For synchronous capture sensitivity is a limitation of communicating distance, we propose a new synchronization header capture algorithm, which significantly improves the receiver sensitivity. Simulation results show that when Eb/N0 is 7 d B, the capturing probability is above 92%. And we adopt the old ways of the capturing structure, by replacing it with a parallel structure, which turns out to be correct, making the highest frequency half the original.4. The prototype is developed. Test is made outdoors, and this is the first time we make experiment indoors and outdoors, while the radio waves could not communicate. It turns out that text communication distance can be farther than 400 meters.