LFM hybrid-coding waveform design of MIMO SAR based on NSGA-II

The transmit signal with good performance is the precondition of the excellent multiple-input and multiple-output (MIMO) synthetic aperture radar (SAR). In order to obtain waveforms of MIMO SAR based on linear frequency modulation with higher tolerance of receiver noise, the improved non-dominated sorting genetic algorithm II (NSGA-II) with elite strategy is proposed. Application of orthogonal linear frequency modulation hybrid coding (LFMHC) signal to MIMO SAR is analyzed and waveform design is hence converted into multi-objective optimization problem. Objective function takes into account the signal-to-noise ratio (SNR) of the receiving signal after matched filtering. Orthogonal LFMHC waveform sets are designed. Comprehensive numerical simulation examples are performed. It is shown that the signal waveforms have more flexibility in encoding, with lower autocorrelation side-lobes and cross-correlation interference. They are desirable in separating targets and suppressing noise. The proposed method verifies the algorithm and enables MIMO SAR to operate efficiently in practical applications.