Location estimation in CDMA systems: enhanced measurement on pilot channels

The location estimation of mobile telephones is of great current interest. One major technical challenge of CDMA cellular-based location systems has been recognized as the near-far (hearability) problem. In this paper, we propose a novel cellular-based location system, the enhanced measurement on pilots channels, to overcome this problem without affecting the capacity of the existing cellular communication systems. The basic idea is to enhance the hearability of pilots by increasing the integration time at the correlator. The limitation on the integration time is analyzed and the feasibility of the enhanced measurement system is demonstrated by a numerical example. It is shown that the location system performance is a tradeoff between the estimation accuracy, processing time, and the coverage area.