Pulse compression waveform for complementary codes based on minimum shift keying

Pulse compression waveform techniques are recognized as a means of obtaining sufficient average power on targets for detection, while retaining a desired range resolution with peak-power limited radars. Complementary-coded pulse radar waveform implementation is introduced in many publications based on using the quadrature phase shift keying (QPSK) as a modulation technique. The problem, QPSK can return sidelobes non-cancellation because of imbalance correlation in detection for the two coded signals. This drawback because the abrupt phase changes can create amplitude variations in the waveform. Nonlinearity in traveling wave tube (TWT) or in class C solid-state radar amplifiers increases the distortion in the fluctuant waveform envelope. This paper proposed using pulse compression waveform for complementary codes based on minimum shift keying (MSK) modulation. In MSK the output waveform is constant envelope and continuous in phase hence there are no abrupt changes in amplitude. This achieves a perfect correlation response in detection and hence a perfect zero sidelobs.