Experimental Evaluation of an OFDM Millimeter Wave System in an Underground Mine Channel Based on the IEEE802.15.3c Standard

In this paper, the time dispersion propagation measurements and the performance study of an OFDM system in a millimeter wave underground mine wideband wireless channel are addressed. Time dispersion and coherence bandwidth results are analyzed at both 40 m and 70 m levels of the mine. Different antenna configurations such as horn-horn and horn- omni in a line of sight (LOS) situation have been considered during the measurements. In contrast to conventional indoor millimetre wave channels, the channel in the underground mine is highly reflective, resulting in a rich scattering environment with significant RMS delay spread. Based on the obtained measurement results, the bit error rate (BER) performance is evaluated for a wideband orthogonal frequency division multiplexing (OFDM) system. Results show that the rough surface scattering, the directivity of the antenna and the gallery dimensions of the underground mine affect the performance of the system.