A new noncoherent radar pulse compression based on complementary sequences

Abstract

Noncoherent pulse compression (NCPC) is of interest to direct-detection laser ranging, and to simple radars that utilize noncoherent microwave power sources. In this technique, a unipolar sequence of pulses using on-off keying (OOK) modulation can be used in transmission. Bipolar binary complementary sequence pairs offer the possibility of perfect sidelobe cancellation, but in case of using unipolar codes, there is a severe degradation in the reflected echoes peak sidelobe level in compression filter response. Many techniques are suggested for sidelobe suppression. A recent technique used Manchester coding with a periodic autocorrelation of binary complementary pairs. This technique yields two large negative sidelobes response in addition to a broad bandwidth. In this paper, a new technique is proposed for NCPC via using a hybrid of two identical matched filters for each sequence. The output response is the sum of the complementary pair responses. This approach achieves a perfect correlation response with a peak of 2N (N is the length of each sequence) and a sidelobe level of zero without expanding the bandwidth in addition to implementation simplicity.