A Generalized Framework Designing Monopulse Tracking of OFDM-aided Aircraft Communication

The upcoming non-terrestrial network communication system will comprise unmanned aerial vehicles (UAVs) and satellites as platforms providing broadband communication service in the future. The conventional UAV monopulse tracking technique at ground station tracking receiver requires dedicated signals which suffer from multipath effect in air-to-ground (A2G) link with low elevation angles. As an essential physical layer technique in 5G wireless networks, the orthogonal frequency division multiplexing (OFDM) under fading channel was not yet investigated well for target tracking in the UAV A2G link. In this paper, we propose a generalized nonlinearity-based angle detection method in tracking receiver of single-channel monopulse tracking (SCMT) system using OFDM signals. Then, we design a generalized framework of monopulse tracking system and evaluate the nonlinearity functions in terms of angle detection S-curve and detection range. Simulations results show that, the logarithmic nonlinearity detection functions exhibit smaller angle estimation root mean squared errors (RMSEs) than square- and absolute-nonlinearity detection functions by 0.03° under fading channels as well as additive white Gaussian noise (AWGN) channels.