RF Planning for 3D coverage in Cellular LTE Range Telemetry

Abstract

Initial analysis and lab experiments have provided positive confirmation of the viability of 4G LTE Cellular Technology for Aeronautical mobile telemetry. COTS LTE equipment is deployed for the test range frequency bands. The high speeds of test articles (TAs) can be addressed with a UE add-on applique’ customized to compensate for the Doppler shifts. The applique has worked effectively with the LTE physical layer. To achieve spectrum efficiency, a multi-cell network is planned. Mobility is managed with native LTE handovers. To address extreme Doppler cases, additional support is provided to mobility management via a central entity that estimates the TA’s trajectory and issues handover commands. Within this framework, we present aspects of an RF planning study that characterizes the dependence of coverage on such design parameters as base station density, antenna orientation, and altitude of the user device. We also quantify the Doppler shifts that can result under the standard strategy of connecting the user device to the strongest cell, and show how, with an alternative, threshold-based strategy, one can achieve a substantial reduction in Doppler shifts at the expense of a loss in user rates.