In this paper, a Direction of Arrival (DOA) based system is proposed. This method searches the direction relative to the array to find where the signal source is located. The proposed system can achieve sub-meter level accuracy with a near real-time update rate. Also, we introduced several refinement methods including a compact tracking system that is compatible with small items, a DOA accuracy prediction function, a method based on linear prediction to expand antenna array to create a virtual antenna matrix, and a novel method for multipath effect cancellation. Overall, the proposed system achieved sub-meter level accuracy, and the functionality of the refinement methods has been approved in the simulation.