Identification of propagation path for undesired electromagnetic wave using time domain measurement and array signal processing at ETC (Electronic toll collection system)

摘要

At ETC (Electronic toll collection system), it has been found that radio wave signal overreaches outside a specified area. This is due to multiple reflections of waves between the surface of the road and the canopy, which brought out communication error. This paper reports out trials of the identification of propagation paths for undesired electromagnetic wave using time domain measurement and array signal processing. We measured at the real tollgate and proved the effectiveness of the proposed scheme by comparing the measured DOA with the result calculated using ray tracing.