Radar and GPS System Inter-Operability with UWB-OFDM Signals

Ultra-wideband (UWB) signals and systems find increasing use in the fields of high-resolution radar, communication and networking, precision navigation, and others. There is a valid concern, however, that these systems may impose undesirable interference on other services used in airborne platforms, e.g., GPS. This potential disadvantage complicates and even prohibits use of in-band UWB and GPS systems. To mitigate this limitation, it is proposed to use an UWB-orthogonal frequency-division multiplexing (OFDM) system concept which allows for dynamic spectrum adjustments. An OFDM signal model is derived, and a system model with a single antenna and analog front-end (AFE) for both UWB-OFDM radar and a GPS receiver is analyzed. It is shown that such a system would permit inter-operability of in-band OFDM and GPS for OFDM signals, given that the OFDM signal power does not exceed a critical level determined by the GPS receiver implementation. Conclusions regarding potential benefits and system implementations of the proposed concept are also discussed.