| dc.description.abstract | This dissertation mainly focuses on the research of direction-of-arrival (DOA) estimation with micro-UAV swarm-based (MUSB) arrays, including signal model formulation, closed-form asymptotic mean square error (AMSE) derivation, Cramer-Rao bound (CRB) derivation in the presence of receiving antenna gain, phase, and position errors, system performance analysis with the derived equations, performing numerical simulation and practical experiments to verify the theoretical expectations.
This dissertation firstly reports on the DOA estimation with MUSB arrays. This work presents the mathematical model of MUSB array data collection system and introduces the iterative multiple signal classification (iterative-MUSIC) algorithm for MUSB arrays. System convergence of the MUSB array is examined by simulation and experiment to verify that the iterative-MUSIC algorithm works for the three-dimensional (3D) time-varying arrays based on UAV swarm.
Then statistical performance of iterative-MUSIC for the MUSB array is investigated by AMSE formulas and system limitation is examined by the derived CRB. This work also examines the applications of AMSE formula, such as studying the asymptotic efficiency and analyzing the asymptotic performance statistically. The CRB associated with DOAs in the presence of sensor gain and phase errors is also derived to reveal some direction-finding properties such as the global convergence, the impact of snapshots and the number of the arrays. Performance analysis with one-emitter case is also given to describe the CRB. A successive DOA refinement procedure with iterative-MUSIC algorithm is provided based on the reconstructed arrays and spectrum from swarming UAVs to meet the requirement of high-precision DOA estimation.
Finally, the system performance analysis in the presence of small sensor gain, phase, and position errors is given. We firstly introduce the signal model with deterministic unknown location errors, and then extend the model to the cases when the location error is stochastic (Gaussian case). We also derived the joint CRB of DOAs, sensor gain, sensor phase, and sensor location errors for MUSB arrays, which can be applicable even if the number of sources exceeds the number of initial UAVs. Both numerical simulations and practical experiments will be given to verify the theoretical results. | en |
