Implementation of complementary codes pulse compression based on DMTD for compensating Doppler drift

The range sidelobe of phase-coded compression signals could induce the problem that the sidelobe of a large target might mask the presence of nearby smaller target, which reduce the ability of radar to detect the small target. Complementary codes in theory can solute this problem well, but, in practice, complementary codes have Doppler sensitivity problem: as the increase of Doppler frequency drift, complementarity of range sidelobe between the pair of complementary codes would reduce rapidly, which leads to the rise of sidelobe. To attack the problem above, a method of alternative transmit the complementary codes based on Digital Moving Target Detect (DMTD) is presented in this research. In processing, firstly, it should separately do MTD to positive code echo matrix and complementary code echo matrix. Then the phase difference would be compensated. At last, the pulse compression and superposition would be carried out to remove sidelobe. The presented method can effectively compensate the Doppler frequency shift and phase difference between the pair of complementary codes due to time division transmission, and maintain the complementarity of range sidelobe between the positive and complementary code echo. In addition, alternative emission of complementary codes could decrease the influence of echo energy fluctuation induced by angular glint.