Study On Wireless Network Indoor Positioning Technology

With the help of the new technology, policy and the need of the market, communication technology is heading to higher uplink and downlink transporting rate, safer in the private, smarter, more flexibility, better signal quality and better service quality. At the same time, owing to the improvement of whole network level, the interact of the users and the network is getting more and more frequently and in all kinds of ways, they prefer to access in the network in there handset whenever they want to, which cause to the improvement of the network from the simply connecting of equipment to multi-service bearer platform. Among with all kinds of wireless network services, the position information of the users is the key point for the carriers to push their telecom value-added service, and the certain service of indoor scenario is ceratainly the most important one among above, which cause the indoor positioning become the hottest researching point in recent years.This paper firstly introduces the common indoor positioning technology in LTE-A system, especially the Wi-Fi and DOP combining positioning method; secondly researched the RFPM indoor positioning method; lastly adopts the CSI-RS instead of CRS aiming at the characteristic of RS to measure RSRP in CoMP scenario. According to the LTE-A protocols, system level and link level simulations on the proposed algorithm are made.Regard to the current Wi-Fi indoor positioning algorithm, this paper introduce DOP into the algorithm, the positioning needed node are re-filtered. Detailed analysis the simulation method, including transmit module, receiver module and the filtering method. According to the simulation results, the proposed method can largely improve the efficiency of Wi-Fi nodes, and improve the positioning accuracy.Regard of the method, positioning accuracy depends largely on the RSRP measuring accuracy. Currently CRS is used to calculate RSRP and RSRQ for non-CoMP scenario. But in some typical CoMP scenarios where the CRS signals transmitted from different TP are the same, the UE cannot distinguish the TPs just based on CRS signal. In this scenario CSI-RS will be transmitted from different TPs for distinguishing them. This paper investigates the side conditions and the corresponding measurement accuracy based on CSI-RS using system and link level simulation, illustrates the side condition of SINR and gives the results at the same time. The simulation results show that the measurement accuracy of CSI-RS based RSRP can achieve similar performance as R8CRS RSRP and satisfy the need of CoMP operation.