Radio selective pager

Abstract

A radio selective pager capable of preventing an erroneous synchronization with received signals of different transmission rates to avoid an erroneous switch operation from a power saving mode to a continuous receiving mode, improving power saving efficiency and prolonging life of an internal battery. A bit synchronizer synchronizes bits of demodulation data output from a receiver with an internal reference clock. A preamble detector detects a preamble of demodulation data output from the bit synchronizer, and a frame signal detector detects a frame synchronizing signal. When an address number of the demodulation data is coincident with an individual address number stored in an address comparator, a controller controls an indicator to indicate a selective paging to a user. A bit rate detector detects leading and trailing change points of bits of the demodulation data, counts a detection number of at least ones of the leading and trailing change points held within change point detection windows, recognizes the received signal to be of a predetermined transmission rate when the count number is coincident with a predetermined value, and instructs the indicator to do the paging operation to the user.