Providing integrated communication and positioning services for smart terminals using widely deployed 5G infrastructure has been a promising way during the 5G standard evolution.Especially in an indoor scenario where the global navigation satellite system fails, high-accuracy localization services can be provided based on the 5G infrastructure, and thus, 5G integrated communication and localization will enable much vertical industry applications.However, there still exist many technical challenges for providing sub-meter-level 5G localization in practical applications.In addition, there is no unified testbed or platform to support the development of 5G localization.Firstly, the challenges that 5G positioning methods face in achieving indoor sub-meter accuracy were analyzed.Then the design of 5G positioning simulator focusing on 5G classical scenarios was introduced.Numerical results show that the uplink-angle-of-arrival-based approach can achieve sub-meter localization accuracy.Finally, the industrialization prospects of 5G indoor high-accuracy positioning technology were proposed.

Keywords： 5G localization ; high-accuracy positioning ; integrated communication and positioning ; simulator