Complementary Waveforms for Range-Doppler Sidelobe Suppression Based on a Null Space Approach

Abstract

While Doppler resilient complementary waveforms have previously been considered to suppress range sidelobes within a Doppler interval of interest in radar systems, their capability of Doppler resilience has not been fully utilized. In this paper, a new construction of Doppler resilient complementary waveforms based on a null space is proposed. With this new construction, one can flexibly include a specified Doppler interval of interest or even an overall Doppler interval into a term which results in range sidelobes. We can force this term to zero, which can be solved to obtain a null space. From the null space, the characteristic vector to control the transmission of basic Golay waveforms, and the coefficients of the receiver filter for Golay complementary waveform can be extracted. Besides, based on the derived null space, two challenging non-convex optimization problems are formulated and solved for maximizing the signal-to-noise ratio (SNR). Moreover, the coefficients of the receiver filter and the characteristic vector can be applied to fully polarimetric radar systems to achieve nearly perfect Doppler resilient performance, and hence fully suppress the inter-antenna interferences.

Doppler Resilient Waveforms Design in MIMO Radar via a Generalized Null Space Method

“…When the transmit antennas number is D = 2, the method proposed in this paper is also applicable to fully polarimetric radar. In other words, the proposed method can take the waveform transmission scheme proposed in [18] for fully polarimetric radar as a special case.…”

“…The optimization problem (6) can be converted to a unconstrained optimization problem [18] (Due to the page limitation, we omitted the detailed steps):…”

“…The development in [17] was to propose a new class of sequence pairs, called "quasi-orthogonal Z-complementary pairs (QOZCPs)", which could be applied to fully polarimetric radar systems. In [18], a null space ap-Copyright c 2022 The Institute of Electronics, Information and Communication Engineers proach for designing Golay complementary waveforms with Doppler resilience was proposed, and the range sidelobes were cleared in a specified Doppler interval of interest or even an overall Doppler interval.…”

“…Motivated by the work of Wang et al [18], we extend the fully polarimetric radar scene to MIMO radar and propose a generalized null space method to jointly design the transmission of the transmit pulse train and the receive pulse weights. The received pulse weights in the proposed method are complex-valued.…”