{'fraction_non_alphanumeric': 0.017735334242837655, 'fraction_numerical': 0.005457025920873124, 'mean_word_length': 5.327586206896552, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
MIMO channel characterization in subway tunnel for train-to-wayside applications

The demand for robust and high data rate wireless transmissions in tunnel leads to evaluate the impact of MIMO and diversity techniques over the channel performance in these types of environments. This paper presents a 4×4 MIMO channel sounding measurement campaign performed in the tunnels of the FGC (Ferrocarrils de la Generalitat de Catalunya) metro in Barcelona, at 5.8 GHz. Different configurations were tested with different antenna polarization and orientation in the tunnel. From these measurements, MIMO channel matrices are computed, in order to determine the correlation level of the channel and the MIMO channel capacity along the tunnel.