A CRLB Analysis of AoA Estimation Using Bluetooth 5

Angle of arrival (AoA) and angle of departure (AoD) are introduced in Bluetooth 5 to better support indoor localization and tracking. However, the performance of AoA estimation using Bluetooth 5 is not thoroughly understood at present. In this paper, a Cramér-Rao lower bound (CRLB) model, taking into account Constant Tone Extension (CTE) signals firstly adopted by Bluethooth 5, is proposed to theoretically analyze its performance given different uniform antenna arrays, such as linear, rectangular and circular arrays, and on these grounds, the effects of the number of antennas, inter antenna distance, incident angle, and CTE parameters on AoA estimation are carefully investigated. A simulation analysis is carried out and a comparison between different types of antenna arrays is reported as well.