The electromagnetic spectrum is a finite resource that has become increasingly congested as the use of wireless communications and RF applications have expanded. With increased congestion, dynamic spectrum sensing and spectrum sharing techniques have been of increasing interest. However, dynamically accessing the spectrum on a pulse-by-pulse basis breaks traditional pulse assumptions that are used to inform range-Doppler processing. Additionally, even with a dynamic hopping scheme, more spectrum than is available may be needed to successfully carry out critical radar tasks, creating two unique challenges.

First, this work addresses pulse-by-pulse agility in two parts. This work presents a mismatched filter technique to reduce range-sidelobe modulation when processing a CPI of bandwidth agile pulses. Additionally, a modified backprojection technique enables Doppler processing of frequency agile CPIs. These two techniques work together effectively on CPIs of fully agile pulses, and real-world experimental data verifies their performance.

Second, this work develops a demodulation/remodulation estimation and extraction processing chain that actively cancels interference from orthogonal frequency division multiplexing sources and provides a 19 dB improvement in radar detection performance. When combining active interference cancellation and pulse agile processing, this work provides the tools to ensure radar systems can operate continually in an environment with a congested electromagnetic spectrum.