BIT SYNCHRONIZER

摘要

A paging receiver capable of bit synchronizing to one of two data rates. The receiver has a digital phase locked loop integrated onto a single integrated circuit clocked by a single frequency crystal. The paging receiver receives and synchronizes to a POCSAG signal which may be transmitted at either 512 bits per second or 1200 bits per second. The digital phase locked loop bit synchronizes to either data rate using a single crystal frequency of 76.8 kHz. The data rate is selected by a bit in the code paging receiver's code plug. The digital phase locked loop is constructed to have a substantially constant frequency to bandwidth ratio at both data rates.