Joint Multitarget Detection and Tracking in Multipath Environment Using Expectation Maximization Algorithm

Joint detection and tracking is fundamentally important in signal processing, navigation, and radar applications. Especially, multitarget detection and tracking in multipath environments is a promising issue and broadening range for joint detection and tracking. However, its wide adoption in real-world systems is challenged by the unknown data association, complex and changeable motion environment, and data mutual coupling. To address those problems, we propose a joint detection and tracking scheme based on expectation maximization (EM) algorithm. By alternately computing the complete likelihood function and optimizing it with respect to target existence state (detection) and target kinematic state (tracking), the proposed scheme iteratively optimizes estimation and data association. Furthermore, we provide a hybrid forward and backward algorithm during the M-step to deal with the coupling of the target existence state and target kinematic state. We also provide a convergence speed-up algorithm based on K-means method and stochastic initialization method to accelerate convergence speed. Finally, we verify the effectiveness of the proposed joint detection and tracking scheme by conducting extensive simulations with different tracking scenarios. The simulation results show that the proposed algorithm not only improves the detection and tracking performance, but also stays stable performance in complex and changeable motion environment and high noise background.