Improved detector for continuous wave radar waveforms exploiting phase information

By transmitting multiple copies of an arbitrary (frequency modulated) continuous wave radar signal, phase information in target echoes can be exploited for detection. The phase information is gained by calculating the sample variance of phase spectra of the multiple echoes. In this manner, phase and amplitude information is available at the detector. The optimal detector decides based on two-dimensional decision regions in the amplitude/phase-variance space. Suboptimal detectors combine two one-dimensional decisions. It is shown, that the proposed method improves detection performance especially at low signal to noise ratios. The optimal detector achieves a gain in detection rate compared to the conventional square law detector of nearly 10% at a signal to noise ratio (SNR) of 3 dB. The performance gain reduces to about 3% at a SNR of 9 dB. One of the suboptimal detectors also outperforms the conventional detector, but achieves lower gains in detection rates than the optimal detector.