Detection performance of phase-coded radar waveforms with various types of limiting

The detection performance of phase-coded radar waveforms is calculated for three types of limiting in the receiver and compared to the results when no limiting takes place. The loss in dB, which is the difference between the signal-to-noise ratio required for detection with and without limiting, is found to be a function of the required probability of detection P_d, false alarm probability P_fa, target radar cross-section fluctuation model, pulse code length N_c and number of pulses integrated noncoherently prior to detection M_p. Detection thresholds for a specified P_fa are determined analytically and the detection process is simulated using Monte-Carlo techniques. The least lossy limiting method of the three methods examined is that which quantises the I and Q quadrature components of the signal plus noise to three bits where two of these bits are allotted to noise excursions. The next more lossy case is hard limiting, or phase only, where signal phase is preserved but amplitude information is not utilised. The most lossy case is hard limiting with phase quantised to four values.