Wideband aeronautical channel sounding and modeling for C-band telemetry

A new aircraft-to-ground telemetry link in C-band, based on Orthogonal Frequency Division Multiplexing (OFDM), is currently being developed for Airbus. In order to parameterize this link adequately, information about the propagation channel is indispensable, in particular in terms of delay spread and Doppler spread. In order to identify these characteristics, a novel easy-to-use channel sounder was developed and successfully applied in multiple flight campaigns. With the channel sounding results, three typical environments could be clearly distinguished according to their specific charateristics: Parking & taxiing, take-off & landing and en-route. The measurement results are directly applicable as constant coefficients for tapped-delay line modeling. In contrast, classical approaches apply coefficients of stochastical nature, modeled as random variables. However, for a specific communication scenario, which we face here, the proposed approach yields much more accuracy and reliability, as it represents the exact real-world channels.