| The class of radar systems denoted as low probability of intercept (LPI) are designed to be covert, and when used successfully by enemy forces preclude our ability to accurately maintain battlefield awareness, posing a potential threat to friendly forces. Digital signal processing (DSP) is a powerful, reliable, and flexible tool that offers efficient software simulation of LPI signals and intercept algorithms that can be expanded to a hardware implementation as warranted. Several DSP algorithms are proposed to automatically detect low power signals emanating from non-cooperative LPI radar systems and embedded in additive white Gaussian noise (AWGN). All algorithms make use of the repetition in time of these signals to mitigate the effect of the noise, using either cyclostationary theory or time-frequency processing methods as their foundation. Performance is compared to the results of two published theses and is further illustrated with additional frequency-modulated continuous-wave (FMCW) and Frank modulated waveforms at lower signal to noise ratios (SNR). |
