A Novel Smeared Synthesized LFM TC-OLA Radar System: Design and Performance Evaluation

This paper introduces a novel smeared synthesized LFM (SSLFM) time compression overlap-add (TC-OLA) radar system. The new system allows us to control the signal to noise ratio level, and, therefore, obtain a higher processing gain compared to the traditional LFM-PC radar systems. In addition, it allows us to control the signal spectrum spreading, making it more immune to noise jamming. The new SSLFM signal is obtained by either multiplying the LFM waveform with a complex unit signal with the random phase or by encoding the time compression signal with the random phase at the transmitter. A denoising processor, placed either before or after the OLA processor, is used to remove the random phase from the SSLFM and forward the resulted LFM signal to the rest of the conventional LFM-PC radar receiver system. The new SSLFM TC-OLA radar system enjoys a better low probability of intercept feature while maintaining the LFM time sidelobe and Doppler tolerance properties. Moreover, the additional modules in the new radar system do not require changing the core LFM radar components. Using TC-OLA and denoising requires a synchronization system (SS) to properly recover the LFM signal. We, therefore, offer three SSs. The performance evaluation of the new radar system shows its superiority over the traditional LFM, the wideband LFM, and the TC-OLA-based LFM radars, especially under powerful noise jamming. The synchronization system is implemented and tested experimentally using software-defined radar.