Analog to Information (A2I) Sensing for Software Defined Receivers

Radar Warning Receivers (RWRs) are an integral part of Tactical Aircraft Protection Systems and are used to quickly detect imminent threats so that countermeasures or other actions can be used to avoid attack. Threat Radar signals include pulsed Doppler signals with typical carrier frequencies from 2-40 GHz with the possibility to extend to even higher. An ideal RWR would be one based on the concept of a Software Defined Receiver (SDR), in which all key receiver algorithms are implemented in some form of programmable device. However, a significant limitation of a SDR based RWR is that the received RF signal must be sampled with an A/D converter which limits the usable bandwidth of a SDR to roughly 2 GHz. The relatively new field of compressive sensing is based on the notion that the information content of a signal may be much less than its instantaneous bandwidth, and that this signal “sparseness” can be exploited directly during the sensing operation. When applied to the sampling of wideband Radar signals, compressive sensing can allow Radar signals to be sampled well below the Nyquist rate, allowing COTS ADC devices to be used as a front end to a flexible software defined Radar Warning Receiver. This Phase 1 program will extend compressive sampling to the area of signal parameter estimation in order to detect and parameterize unknown received Radar signals over the entire Radar bandwidth from 1-100 GHz with a single ADC front-end receiver.