Orthogonal sparse frequency waveforms design for mimo radar via alternating projection

With developments in the field of radar and communications, spectrum is a scarce resource nowadays. Multiple-input multiple-output (MIMO) radars, especially those operating in UHF and HF bands, are increasingly influenced by narrow band interferences. Sparse frequency waveform with narrow notches sparsely located among a wide frequency band is a preferred solution to this problem. This paper deals with the orthogonal sparse frequency waveforms design for MIMO radar. The optimal waveforms are determined according to the following criteria: matching the demanded power spectrum density (PSD) and minimizing the cross-correlation energy and off-peak auto-correlation energy. In addition, the constraints of the finite transmitting energy and low peak-to-average power ratio (PAPR) which are highly desirable in practice are also taken into consideration. An efficient two-stage alternating projection algorithm is proposed to solve the optimization problem. The optimal frequency spectrums satisfying the PSD and correlation property (CP) requirements are figured out in Stage 1. And then the optimum waveforms are fitted under the transmitting energy and PAPR constraints in Stage 2. Simulations are performed to verify the effectiveness and superiority of the proposed approach.