Space‐time matched filter design for interference suppression in coherent frequency diverse array

Abstract

By transmitting a single frequency-shifted waveform, coherent frequency diverse array (FDA) can provide a simple way to realize full spatial coverages with stable gains. Owing to the range-angle dependency in coherent FDA, the authors implement a two-dimensional angle-time matched filter to perform equivalent transmit beamforming and matched filtering simultaneously. However, such filter structures merely control main-lobes of equivalent transmit beams towards target directions. It fails to form nulls at interference directions. Moreover, traditional adaptive beamforming by designing adaptive weight vectors are no longer applicable. Additionally, they find that the range resolution scales linearly with the element number. To tackle these issues, a space-time matched filter (STMF) in combination with the hybrid coding technique is proposed. Aiming at mitigating interferences, the STMF is designed with a formulation of quadratically constrained quadratic programing. By relaxation of quadratic constraints, the hard non-convex problem can be turned into the second-order cone programing to obtain optimal filter parameters. Furthermore, the hybrid coding technique is devised to jointly improve the range resolution. Numerical experiments of both two-dimensional range-angle outputs and one-dimensional range profiles via filtering are provided, which demonstrate that the STMF with hybrid coding can effectively suppress sidelobe interferences with a range resolution enhancement.

Transmitting strategy with high degrees of freedom for pulsed‐coherent FDA radar

“…Note that as is discussed in Ref. [19, 24], the range resolution of coherent FDA radar will degenerate (larger than the theoretical value ) due to its intra‐pulse beam scanning (the equivalent range bandwidth will decline). As for Figure 5c when θ 0 = 25° (outside the ROI), the peak receive gain is −8.90 dB lower than others in spite of the received beamforming.…”

FDA-MIMO for target localization via multi-pulse tensor decomposition

“…The FDA-MIMO anti-jamming algorithm based on eigenvalue projection and block matrix processing was proposed in [18]. Based on the coherent frequency diversity array system, [19] designed a space-time filter for interference suppression. In [20], the simulated annealing algorithm of the FDA-MIMO system was proposed to combat the deception interference of the mainlobe range dimension.…”

Stability analysis of time-varying delay neural network for convex quadratic programming with equality constraints and inequality constraints

“…Convex quadratic programming(CQP) is a special class of nonlinear programming. It is an important and fundamental tool in many fields, such as risk assessment management [8,18,4], regression analysis [1], and image processing [25], etc, due to its concise form and ease of construction. Artificial neural networks are complex network systems that simulate the processing of information by the nerves of our brain.…”