On Coexistence of In-Band UWB-OFDM and GPS Signals

Ultrawideband (UWB) radar sensor and location systems are finding extended use nowadays due to their inherent high resolution, robust performance in multipath conditions, good electronic counter-countermeasure (ECCM) and covert-operations potential. Orthogonal frequency-division multiplexing (OFDM) is a multi-carrier modulation technique which is being targeted for commercial UWB communications - however, it can potentially be also used in radar. The unique quality of UWB-OFDM waveforms is the dynamic spectrum allocation, which allows for increased pulse diversity, resistance to jamming and coexistence potential as compared to conventional short-pulse UWB signals. The goal of this initial study is to model a scenario under which GPS signals are received using the same UWB-OFDM radar/communication system. By adaptive nulling of UWB-OFDM sub-bands we can achieve low interference between the radar and GPS signals and, therefore, show coexistence potential.