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This paper investigates the problem of the spectrally compatible waveform design for multiple-input multiple-output (MIMO) radar in the presence of multiple targets and signal-dependent interference. Unlike the existing approaches to designing the waveform for a single target via output signal-to-interference-plus-noise ratio (SINR) maximization, a new method is proposed to deal with a more general problem, i.e., designing a spectrally compatible waveform for multiple targets, by minimizing the waveform energy of the overlayed space-frequency bands under constraints of waveform similarity and individual SINR requirements. Due to the existence of signal dependence, the formulated optimization problem is NP-hard. Toward this end, an iterative algorithm is developed. Concretely, at each iteration, the receive filter is first obtained with the aid of the minimum variance distortionless response method, then the transmit waveform is optimized by employing the dual ascent method. Both the convergence and asymptotic optimality of this algorithm are discussed. Numerical simulations are provided to demonstrate the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

This paper focuses on the robust transmitter–receiver design to improve the detectability of an extended target embedded in signal-dependent interference. Specifically, we allow uncertainties for both the interference and target impulse responses. An iterative algorithm is proposed to sequentially improve the worst-case Signal-to-Interference-plus-Noise Ratio (SINR) under the constant modulus constraint. Each iteration involves two max-min problems, which can be efficiently solved by generalized eigenvalue decomposition and the Dinkelbach’s procedure, respectively, to obtain the optimized receive filter vector and unimodular transmit sequence. The effectiveness of the proposed method is confirmed numerically in terms of the optimized SINR. We also highlight the improvements of the worst-case SINR compared to nominal designs without robustness considerations. [ABSTRACT FROM AUTHOR]

We propose a novel robust design method to jointly optimize the radar transmit code and receive filter, exploiting the Signal-to-Interference plus Noise Ratio (SINR) at the receiver end as design figure of merit. We confer robustness to our method against uncertainties on the target impulse response (TIR) using a worst-case optimization approach based on two different uncertainty sets. The former is composed of a finite collection of TIRs, obtained by sampling the actual TIR at some aspect angles; the latter is a spherical uncertainty set. We further enforce a peak-to-average power ratio (PAR) constraint to the transmit code, which is very important for radar applications where the transmitter operates close to saturation. The design problem is tackled using a sequential optimization procedure alternating between two semi-definite programming (SDP) problems, followed by randomization steps. Our numerical results highlight the robustness and applicability of the proposed method in different scenarios. [ABSTRACT FROM PUBLISHER]

The problem of robust transmitted waveform and received filter design for cognitive radar in a signal-dependent interference environment is considered. When estimate errors of the target impulse response (TIR) and clutter impulse response (CIR) exist, in order to improve the worst signal-to-clutter ratio (SCR) and signal-to-interference-and-noise ratio (SINR), a robust transmitted waveform and received filter are designed based on the minimax criterion by using the information fed back from the receiver. Using deterministic and random models, the waveform and filter design problem is divided into three optimization problems. The robust waveform and filter are then obtained by solving these problems. In the deterministic model, we prove that the robust waveform and filter impulse response can be generated by a pseudorandom code. In the random model, the robust waveform and filter impulse response can be obtained by an alternative projection algorithm. Numerical results indicate that the worst SINR of the robust waveform and filter is higher than that of the traditional waveform and filter. [ABSTRACT FROM AUTHOR]

The problem of signal detection for cognitive radar (CR) is considered, and a closed‐loop detection system is proposed to detect the extended target in the presence of signal‐dependent interference. In the system, the estimator of target impulse response (TIR) and waveform design are used to improve the detection performance of CR, and the estimate of TIR is also used for designing the matched waveform. In addition, in order to improve the reliability of detection, the two‐step process which is called estimation before detection is proposed. Simulation results indicate that the proposed system performs better than the traditional radar system which used the fixed waveform. [ABSTRACT FROM AUTHOR]