A digital method for obtaining high accurate clock reference using GPS-disciplined VCXO [articol]

Abstract

This paper will preset the digital part of a GPS based synchronization scheme developed for WiMAX base stations. The PPS obtained from the GPS receiver will discipline the VCXO oscillating frequency. The accuracy of the clock reference will be bounded by the PPS jitter. A digital method for reducing the PPS jitter will be described. Also a controlling algorithm of the VCXO when the PPS signal is lost will be presented. The digital part of the scheme will be implemented on FPGA.