DME signal power from inlay LDACS1 perspective

L-band digital aeronautical communications system type 1 (LDACS1) is a multicarrier transmission system proposed to cope with the increasingly growing demand in the aeronautical communications. LDACS1 offers the possibility to operate as an inlay system in the frequency "gaps" between adjacent distance measuring equipment (DME) channels. Therefore, DME signals are interference signals from the perspective of an LDACS1 receiver. The estimation of the DME signal power in the adjacent LDACS1 channels is important for a successful inlay implementation of LDACS1. This includes among others, interference mitigation, cell planning and adaptive coding and modulation. In this paper, we investigate the power of a DME signal in the adjacent LDACS1 channels. Closed-form expressions have been obtained. In the worst case, we found out that the DME signal interference power in the adjacent LDACS1 channel is 32 dB below the DME transmit power.