Joint Design of Transmitting Waveforms and Receiving Filter for MIMO-STAP Airborne Radar

摘要

This paper addresses the joint design problems of transmitting waveforms and receiving filter for multiple-input multiple-output airborne radar, which employs space-time adaptive processing technique to detect target embedded in strong clutter. The joint optimization problems aim to maximize the output signal to clutter plus noise ratio (SCNR) of receiver, with the probing waveforms constrained by different constraints, i.e., energy constraint, constant modulus constraint and similarity constraint. Different from the existing cyclic algorithms, we first convert the joint optimization problem into an equivalent waveform optimization problem and iteratively find the optimal waveform based on minorization-maximization technique. The optimal filter is directly obtained according to the waveform optimization result. For each proposed algorithm, the output SCNR monotonically increases during iteration and finally converges to a stable value. Comparing with the existing algorithms, proposed algorithms require fewer iterations and lower computational complexities, while higher SCNRs can be obtained. Such improvement can be confirmed by comprehensive simulations. In addition, the effectiveness of designed waveform-filter pair to suppress clutter is also verified by spatial-temporal beampattern.