Position location of LTE femtocells deployed in a cluster

A femtocell (femto for short) is a small cellular base station, typically designed for use in a home or small business. A femto allows service providers to extend service coverage indoors, especially where access would otherwise be limited or unavailable. Contrary to macro base stations which have fixed known locations, femtos are usually deployed by the users. The location of femtos are usually not immediately known to the network operator and users may move the femtos within their homes, or may carry the femtos with them e.g., when relocating. The knowledge of femto location may be needed to support location-based applications or to satisfy applicable requirements. Conventional positioning methods that use navigation satellite or macrocell signals have their limitations in positioning devices that are located deep indoors. In this paper, we describe a positioning method that uses Relative Time Difference of Arrival (RTDOA) measurements between femtos deployed in a cluster. We show simulation results of the RTDOA method for different channel models.