| 摘要 |
<p>A cellular/pager includes a cellular antenna (12) for receiving UHF cellular and paging signals. The cellular/pager also includes a VHF paging antenna (16). Every paging signal is sent to a paging receiver (18). The paging receiver (18) uses the same circuitry to process either the UHF or VHF page. This is accomplished by setting a voltage controlled oscillator (VCO) (106) to one of two frequency ranges. The chosen frequency is either added or subtracted to the incoming signal in order to match a constant intermediate frequency. The resultant signal is demodulated and a bit rate is selected by a decoder (110), under the control of a microprocessor (22). Cellular signals are sent to a cellular block (20). Cellular location information is utilized by the cellular/pager to form an internally updated roaming pager. The paging service then knows the location of the paging receiver, consequently the paging service can direct the pager to await for a page at a single frequency, thereby eliminating frequency scanning by the pager of manual updates by the user.</p> |
