Research On The UHF Radio Wave Propagation And Location Algorithms In Mine Tunnels

In the future decades, coal will still be the main energy source in China, and the energy structure with the coal as the main component will not change, so the problem of safe production in mine corporations is and will be an important issue at present and a quite long period from now on. And miner locating is one of the key technologies of the security program in mining tragedies. Therefore, governments and researchers pay much attention to this issue. The main work of this thesis is to analyze the UHF(ultra high Frequency) propagation characteristics in mine tunnels and make an in-depth research on miner locating algorithms suitable for tunnels underground. The work in this dissertation accords with the development tendency of mine corperations and was supported by the youth scientists awarding fund of Shandong province: Research on the Key Technologies about the Underground Information Digitization for Digital Mines(02BS011). Major work of this dissertation includes four parts as the following:1. research on UHF Propagation characteristics in mine tunnels Mine tunnels were modeled as hollow dielectric waveguides, and the propagation characteristics about the near field and far field was analyzed differently by image theory of geometrical optics and mode theory of waveguides, based on which a relatively more complete prediction theory of the UHF propagation was set up. And the TOA(time of arrival) technology is used in the miner locating issue.2. research on time domain TOA and frequency domain IFT-TOA in mine tunnels Problems of the time domain wideband TOA method when applied in multi-path environments were discussed in detail. IFT-TOA, the frequency domain method based on IFT(inverse Fourier transform), was studied. To the case of IFT-TOA in single-path channel, the interpolation algorithm for error correction was deduced as the length of the frequency sample window is not the integral multiple of the fundamental period. To IFT-TOA in multi-path channel, the frequency domain windowed interpolation algorithm was studied.3. research on super-resolution TOA algorithms based on MUSIC algorithm and OFDM technology The frequency domain channel response was modeled as a broad sense harmonic process, and the super-resolution spectrum estimation theory based on eigen-decomposition was applied to the TOA estimation problem. MUSIC(multiple signal classification) algorithm has the super-resolution capability, and the OFDM(orthogonal frequency division multiplexing) technology offers the reliable frequency channel response. So the super-resolution TOA algorithms based on MUSIC algorithm and OFDM technology, that is, MO-TOA, was proposed. The performance of the MO-TOA algorithm was analyzed in theory, and validity simulation was also carried out.4. MO-TOA in band-limit conditions and noisy background...