Robust transceiver design for wideband MIMO radar utilizing a subarray antenna structure

Abstract

In this paper, we investigate the possibility to suppress interference in wideband multiple-input multiple-output radar. The idea is to employ tunable filters at the transmitter and the receiver sides, and to derive filter coefficients that result in optimal transmitted signals from a system performance point of view, for a given radar scenario. The system performance is measured in signal-to-interference-and-noise ratio (SINR) at the receiver output, from which the filter properties are derived. The focus is to suppress active jamming interference, and especially deceptive jamming interference. We discuss two ways to derive the transmit and the receive filters. Each procedure utilizes two different power constraints related to the transmit filters. To incorporate imperfections in the given scenario, a robust extension to the design problem is proposed. Two different robust methods are evaluated: one that utilizes a Taylor series expansion of the SINR, and one that exploits a worst-case SINR maximization. Numerical validation illustrates the possibility to suppress interference without actually forming a spatial null in the direction towards interference, and the necessity to design transmit filters that are robust to uncertainties in the given scenario.