Channel Measurements and Characterizations for Long Range Air-to-Ground Communication Systems in the UHF Band

Abstract

In this paper, we consider long range air-to-ground (AG) communication systems which support aeronautical platforms including unmanned aerial vehicles (UAVs) in the ultra high frequency (UHF) band. For such a system, we present the measurement based path loss analysis and multipath characteristic results at the distance of hundreds of kilometers. To this end, the experimental AG channel measurement system is implemented at the aircraft with various ground station (GS) environments. Through realistic flight tests, we observe the path loss behaviors for long range UHF channels with sea and ground earth surface reflections. By comparing the measurement results with the empirical path loss model and the spherical earth two-ray model, we demonstrate that our measurement results match well with the model. Moreover, for the multipath channel characterization, we provide field test results on the occurrence probability, delay, and power of multipath components in hilly and mountainous environments with various altitudes of the aircraft.INDEX TERMS Air-to-ground, long range communication systems, channel characterization, UHF band

Application of Path-Based Multipath Component Tracking on Air-Ground Channel Measurement Data

“…is solved for α(b) i -again using the LS approach. Thus, the overall objective of the optimization problem is to minimize the residual (b) i returned by the LS algorithm applied to (14). Using the definition given in (11), this leads to…”

“…In [14], air-ground channel measurements with a bandwidth of 2 MHz in the Ultra High Frequency (UHF) band have been performed. The authors also provide a model on the path loss and discuss the observed effects of multipath propagation by a statistical evaluation of sets of Channel Impulse Responses (CIRs).…”