Design of Complementary PCFM Waveform Set for Smearing Spectrum Jamming Suppression in MIMO Radar Systems

The smeared spectrum (SMSP) jamming technique generates dense comb-shaped false targets at the receiver, making it difficult to detect the target of interest. Waveform design introduces greater flexibility at the transmitter, offering the potential for active antijamming strategies. This article investigates countermeasures to SMSP jamming in multiple-input–multiple-output radar systems by designing phase-coded frequency-modulated (PCFM) waveforms. Moreover, the complementary PCFM waveform design scheme is considered to further expand the design freedom, utilizing the coherence between multiple pulses to achieve improved performance. Specifically, we first formulate the complementary waveform design as a multiobjective optimization problem, by unifing the SMSP jamming levels, the waveform sidelobes, and the waveform orthogonality after the matched filter processing at the receiver into a set of fractional terms. Subsequently, the optimal complementary PCFM waveforms are obtained by employing the iterative algorithm based on the approximated Hessian matrix of the objective functions. Numerical simulations are conducted to demonstrate that the designed complementary PCFM waveforms significantly improve SMSP jamming suppression and enhance target detection performance.