A study on the accuracy of a CDMA-based location system

Recently, positioning of the handset from which the calls occur has been required for public safety. For emergency services, USA wireless carriers have been obligated to provide a position location at the handset and the services are called Enhanced 911 (E911). We have developed a IS-95-based location system which uses forward link trilation (FLT) techniques. Performance evaluations in various environments through simulations are often required and the evaluation technique is the key issue for efficient development of such location systems. In this paper, the simulation model proposed here is verified with a field trial. The simulation results and the trial results show good agreement. The results show that the proposed scheme could give the ability to evaluate the performance of the location system. Then, this paper shows simulation results of the location accuracy in typical environments with actual geometric configuration of the handset and the base stations. The results show that the location system achieves positioning accuracy which satisfies the E911 requirements.