A NEW CLASS OF PRECISION UTC AND FREQUENCY REFERENCE USING IS-95 CDMA BASE STATION TRANSMISSIONS

Abstract

A new class of precision timing and frequency reference is introduced that indirectly receives GPS timing and frequency information via TIA/EIA Standard IS-95 Code Division Multiple Access (CDMA) mobile telecommunications base station transmissions. Like cell phones, these products operate indoors without external antennas and provide accuracy, low cost and ease of installation. The technology fits particularly well in IP network synchronization and quality-of-service monitoring applications where rooftop antenna installation is often impossible. The salient characteristics of the IS-95 CDMA signals that make them suitable for this purpose and a general CDMA timing receiver architecture are described. Performance data versus similar references that use conventional GPS reception are also presented.