Noncoherent pulse compression with complementary coded direct sequence signaling

Noncoherent pulse compression (NCPC) can be obtained by the correlation of received unipolar binary complementary coded pulses with reference bipolar binary sequences. For improving the peak sidelobe level (PSL), a recent technique suggested obtaining NCPC from Manchester coding with a periodic autocorrelation of binary complementary pairs. This technique yields two large negative sidelobes around the mainlobe. In addition, the transmitted signal is 4N coded pulses in the duty cycles (N is the length of each complementary code). This leads to bandwidth broadening due to Manchester coding. In this paper, a new technique is proposed for NCPC based on coding only N transmitting pulses in the duty cycles using the direct sequence (DS) technique and on-off keying (OOK) modulation. In compression, a hybrid of two identical matched filters for each sequence is used for correlations. The output response is the sum of the two sequence responses. This technique achieves a perfect correlation with a peak of 2N while transmitting only N pulses and sidelobe levels of zero with only a half of the required bandwidth compared with Manchester coding based techniques besides implementation simplicity.