BEM Reference Signal Estimation for an Airborne Passive Radar Antenna Array

In this paper, we consider an airborne passive radar using digital video broadcasting—terrestrial OFDM signals. In such an application, the channel composite nature and the mobility of the receiver deeply alter the signal and, therefore, degrade the decoding processing. Classic methods experience difficulties in dealing with such channel impacts. In order to reconstruct a proper reference signal, we propose here a channel estimation method that exploits both antenna diversity and a basis expansion model modeling the channel time variations. The application of this method to experimental in-flight recorded data demonstrates the performance improvement provided by the proposed method over the classic demodulation and other methods developed to cope with intercarrier interferences.