US 5,495,233 AGranted

Radio paging receiver capable of improving accuracy of frame synchronization

AssigneeNEC Corporation

InventorsShinichi Kawashima, Masayuki Kushita

Life of this patent

Estimating the term…

Loading patent…

Abstract

In a radio paging receiver for receiving a pager signal comprising a succession of frames each of which consists of a first through n-th group of signals, a first clock generating unit generates a first clock signal having a first clock rate. A synchronization clock generating unit generates a synchronization clock signal which is synchronized with digital word data derived from a receiving section and which has a synchronization clock rate equal to the first clock rate. A selecting circuit selects one of the first clock signals and the synchronization clock signal as a selected clock signal. A counter carries out a counting operation by the use of the selected clock signal and produces a counted signal. Responsive to the counted signal, a control circuit produces a control signal to make a battery saving switch have an "on" state and to make the synchronization clock generating unit have an active state. The selecting circuit selects the synchronization clock signal while the control circuit produces the control signal.

Claims14

Dependent claims

A radio paging receiver for use in responding to a pager signal comprising a succession of frames each of which has a frame period and which comprises first through n-th group signals where n represents a positive integer greater than unity, each of said first through said n-th group signals having a signal duration and comprising a call number signal representative of a call number,

said radio paging receiver having a preassigned call number which belongs to one of said first through said n-th group signals and comprising receiving means for receiving said pager signal to demodulate said pager signal into a digital signal which comprises a sequence of digital word data, switching means connected between a battery and said receiving means and having on and off states to supply electric power from said battery to said receiving means in said on state, and control means for controlling said switching means to put into said on state during reception of said one of the first through the n-th group signals, said control means comprising:
first clock signal generating means for generating a first clock signal having a first clock rate;
synchronization clock generating means for generating a synchronization clock signal synchronized with said sequence of digital word data, said synchronization clock signal having a synchronization clock rate equal to said first clock rate;
a selecting circuit connected to said first clock signal generating means and said synchronization clock generating means for selecting one of said first clock signal and said synchronization clock signal as a selected clock signal;
a counter connected to said selecting circuit for counting said frame period by the use of said selected clock signal to produce a counted signal indicative of a beginning and an ending of said one of the first through the n-th group signals;
and
a control circuit connected to said counter for producing a control signal which lasts from said beginning of the one of the first through the n-th group signals to said ending of the one of the first through the n-th group signals to make said switching means have said on state and to make said synchronization clock generating means generate said synchronization clock signal,
said selecting circuit being connected to said control circuit and selecting said synchronization clock signal as said selected clock signal while said control circuit produces said control signal.

5 more elements

A radio paging receiver for use with a power source and for use in responding to a pager signal comprising a succession of frames each of which has a frame period and which comprises first through n-th group signals where n represents a positive integer greater than unity, each of said first through said n-th group signals having a signal duration and comprising a call number signal representative of a call number,

said radio paging receiver having a preassigned call number which belongs to one of said first through said n-th group signals, said radio paging receiver comprising:
receiving means for receiving said pager signal to demodulate said pager signal into a digital signal which comprises a sequence of digital word data;
switching means connected between the power source and said receiving means and having on and off states to supply power from said power source to said receiving means in said on state;
and
control means for controlling said switching means to put into said on state during reception of said one of the first through the n-th group signals, said control means comprising:
first clock signal generating means for generating a first clock signal having a first clock rate;
synchronization clock generating means for generating a synchronization clock signal synchronized with said sequence of digital word data, said synchronization clock signal having a synchronization clock rate equal to said first clock rate;
a selecting circuit connected to said first clock signal generating means and said synchronization clock generating means for selecting one of said first clock signal and said synchronization clock signal as a selected clock signal;
a counter connected to said selecting circuit for counting said frame period by the use of said selected clock signal to produce a counted signal indicative of a beginning and an ending of said one of the first through the n-th group signals;
and
a control circuit connected to said counter for producing a control signal which lasts from said beginning of the one of the first through the n-th group signals to said ending of the one of the first through the n-th group signals to make said switching means have said on state and to make said synchronization clock generating means generate said synchronization clock signal.

8 more elements

Dependencies are inferred from the claim text.