Outlier-Robust Three-Element Non-Uniform Linear Arrays Design Strategy for Direction of Arrival Estimation in MIMO...

Area of Science:

• Signal Processing
• Radar Systems Engineering
• Array Signal Processing

Background:

• Direction of Arrival (DoA) estimation in Multiple-Input Multiple-Output (MIMO) radar systems is crucial for target tracking.
• Maximum Likelihood (ML) based DoA estimation methods are susceptible to outliers caused by likelihood function local maxima.
• Array configuration significantly impacts the accuracy and robustness of DoA estimation.

Purpose of the Study:

• To develop a novel design strategy for outlier-robust, three-element non-uniform linear array (NULA) configurations.
• To optimize NULA placement for Multiple-Input Multiple-Output (MIMO) radar systems to enhance target Direction of Arrival (DoA) estimation.
• To minimize outlier probability while maximizing estimation accuracy in DoA estimation.

Main Methods:

• Investigated the impact of transmitter and receiver positioning on outlier occurrence and ML DoA estimation accuracy.
• Utilized theoretical prediction of DoA Mean Squared Error (MSE) to guide array design.
• Proposed a joint optimization strategy for NULA element positions within a subspace ensuring low outlier probability.

Main Results:

• Achieved superior estimation accuracy compared to single-transmitter NULA configurations.
• Demonstrated enhanced robustness against outliers due to reduced sidelobes in optimized arrays.
• Validated the approach for practical implementation in low-cost 3x3 or 2x3 MIMO radars, considering physical constraints.

Conclusions:

• The proposed design strategy effectively mitigates outliers in DoA estimation for MIMO radar systems.
• Optimized three-element NULA configurations offer improved accuracy and robustness.
• The method is practical for real-world, cost-sensitive radar applications.