Rate-Maximizing OFDM Pilot Patterns for UAV Communications in Nonstationary A2G Channels

TL;DR

This paper introduces an adaptive pilot configuration scheme for UAV OFDM communications that maximizes data rate by adjusting pilot spacing and power based on changing channel conditions, improving throughput with low complexity.

Contribution

It presents a novel rate-maximization approach for pilot design in UAV OFDM systems that adapts to nonstationary A2G channels with explicit feedback.

Findings

Enhanced throughput in UAV communications demonstrated.

Low computational complexity and feedback overhead.

Effective adaptation to time-varying channel statistics.

Abstract

In this paper, we propose and evaluate rate-maximizing pilot configurations for Unmanned Aerial Vehicle (UAV) communications employing OFDM waveforms. OFDM relies on pilot symbols for effective communications. We formulate a rate-maximization problem in which the pilot spacing (in the time-frequency resource grid) and power is varied as a function of the time-varying channel statistics. The receiver solves this rate-maximization problem, and the optimal pilot spacing and power are explicitly fed back to the transmitter to adapt to the time-varying channel statistics in an air-to-ground (A2G) environment. We show the enhanced throughput performance of this scheme for UAV communications in sub-6 GHz bands. These performance gains are achieved at the cost of very low computational complexity and feedback requirements, making it attractive for A2G UAV communications in 5G.