Dominant Pilot Recovery in Is-95 Cdma Systems Using Repeaters

We investigate the use of repeaters to combat the problem of pilot pollution in IS-95 CDMA systems. For the purpose, we have formulated the problem into a manageable optimization model and suggested a greedy-type algorithm that determines the number and locations of repeaters needed. Simulation studies have been carried out by applying the algorithm to an actual CDMA network in which pilot pollution was present. The simulation results have been veri ed by eld trials performed on the same area. They indicate that, by recovering a dominant pilot, repeaters are able to cope with the pilot pollution problem, thus improving call quality. Since the cost of installation and eld maintenance for repeaters is relatively low, our results show that the repeater is is a very e cient and cost-e ective way to mitigate the e ects of pilot pollution in IS-95 CDMA systems.