Quantization Effects on Cognitive Waveforms for Spectral Coexistence

The radio frequency electromagnetic spectrum faces unprecedented demand from diverse applications, creating a critical need for the use of spectrally-shaped waveforms that enable coexistence within crowded frequency bands. Within this context, this paper focuses on the impact of the quantization involved in the digital-to-analog conversion (DAC) on radar and jamming waveforms designed for spectral coexistence with frequency-overlaid emitters, with a particular focus on the spectral shaping alterations resulting from reduced DAC resolution. Analysis is conducted numerically considering both a cognitive radar and a selective jamming applications. The results indicate that DAC with a small number of bit may significantly affect the depth of spectral notches in the designed cognitive waveforms, leading to potential impairments to friendly emitters and thereby compromising effective spectrum sharing.