With　the　rapid　development　of　the　Internet　of　Things　(IoT)　technology,　location-based　services　(LBSs)　are　gaining　significant　attention　for　their　potential　applications.　Among　the　various　LBS　methods,　angle　of　arrival　(AOA)　is　attracting　attention　due　to　its　simplicity　and　ease　of　implementation.　However,　in　practical　applications,　the　Bluetooth　low-energy　(BLE)-based　2-D　antenna　array　encounters　the　problem　of　constant　tone　extension　(CTE)　frequency　deviation　(FD),　which　introduces　phase　impairments.　Additionally,　the　support　of　periodical　advertising　(PA)　event　in　Bluetooth　poses　a　challenge　for　ensuring　excellent　angle　estimation　performance　in　periodic　physical　(PHY)　channels,　as　the　channel　overlaps　with　the　Wi-Fi　frequency　band.　To　address　these　challenges,　we　propose　a　hierarchical　angle　estimation　(HAE)　framework　based　on　the　phase　difference　of　single　reference　antenna.　The　framework　comprises　three　layers:　the　data　acquisition　layer,　the　phase　restoration　layer,　and　the　multichannel　estimation　layer　with　angle　collection　solver.　The　HAE　framework　enables　phase　correction　and　accurate　estimation　over　periodic　PHY　channels.　We　validate　the　proposed　method　on　a　real　hardware　system　and　demonstrate　that　it　achieves　a　high　level　of　precision　and　stability　in　the　estimation　of　angles,　which　makes　it　suitable　for　practical　LBSs　applications　in　challenging　environments.　©　1963-2012　IEEE.