Wideband time-variant air-to-ground radio channel measurements at 5 GHz

We report on the results of an air-to-ground radio channel measurement campaign that we performed at 5120 MHz with 20 MHz bandwidth (within the extension band currently allocated to the microwave landing system). In particular, the measurements addressed the channel corresponding to transmission between a passenger aircraft and a fixed terrestrial ground station, e.g. for telemetry purposes. Time-variant transfer functions were measured in a number of different scenarios regarding transmitter-receiver range, aircraft altitude, and aircraft attitude. Results are given for the direct path gain, in particular with respect to the influence of shadowing caused by wings and engine. Furthermore, results for the r.m.s. delay spread are presented.