Orthogonal Waveform Design Based on LFM-PC Hybrid Modulation Signal

The use of Phase Coded (PC) signal in high-speed motion platforms and high-speed target detection has Doppler sensitivity problem, which restricts its application in wide Doppler tolerance orthogonal waveform. This paper studies a wide Doppler tolerance signal form based on hybrid modulation of Linear Frequency Modulation (LFM) signal and PC signal—LFM-PC signal, and deduces the discrete expression of the ambiguity function of its interpulse signal. Within the Doppler tolerance, an optimal design model is established by minimizing the sum of the side lobes of the normalized auto ambiguity function and the cross-ambiguity function, and a low-complexity signal optimization method based on the Alternating Direction Method of Multipliers (ADMM) is proposed. The simulation results show that the optimized LFM-PC signal based on ADMM has better waveform diversity gain and waveform isolation within the Doppler tolerance, and the optimized algorithm has the characteristics of fast convergence speed and low computational complexity.