Main-lobe Deceptive Jammers with Array Radars Using Space-time Multidimensional Coding

With the rapid development of electronic technology, the electromagnetic environment is becoming increasingly complex. For instance, adaptive beamforming cannot suppress main-lobe jammers for traditional phased array radars; therefore, developing measures to tackle this common problem is an urgent need in radar technology. This study addresses the problem of main-lobe deceptive jammer suppression using space-time multidimensional coding. The first step is to design a three-dimensional phase coding scheme applicable across transmit channels, pulses, and subpulses. A Doppler division multiple access technique is employed at the receiver to separate the transmit signals. To solve the problem of waveform misalignment caused by high-speed moving targets, a novel approach is proposed to estimate the compensation index according to differences in beamforming energy. Subsequently, a dual-phase compensation method that leverages the phase differences between the main-lobe deceptive jammers and the target is proposed; this method can distinguish the true target, pulse-delayed jammers, and rapidly generated jammers in the transmit spatial frequency domain. Moreover, spatial filtering is applied to suppress all the main-lobe deceptive jammers by designing an appropriate transmit-receive weight vector. Additionally, an optimization problem aiming to maximize the output Signal-to-Interference-plus-Noise Ratio (SINR) is formulated to address the problem of performance degradation due to the Direction of Arrival (DOA) Errors. Further, to solve this problem, an alternating optimization method is utilized to obtain the optimized weight vector and transmit and receive coding coefficients iteratively to improve the SINR. Simulation results demonstrate that the proposed method suppresses the main-lobe deceptive jammers more effectively than other radar frameworks. Specifically, compared to the conventional multiple-input multiple-output radar, the proposed method achieves an SINR improvement of 34 dB in the presence of four main-lobe deceptive jammers.