Programmed scanning pager receiver

• US 5,262,769 A
• Filed: 06/09/1992
• Issued: 11/16/1993
• Est. Priority Date: 04/23/1990
• Status: Expired due to Fees

• Current Assignee: Reach Electronics Incorporated
• Original Assignee: Reach Electronics Incorporated
• Inventors: Holmes, Roy L.
• Primary Examiner(s): Yusko, Donald J.
• Assistant Examiner(s): ZIMMERMAN, BRIAN A
• Application Number:
  US07/895,633
• Time in Patent Office: 525 Days
• Field of Search: 340/825.03, 340/825.44, 340/825.48, 455/185.1, 455/186.1, 455/161.1, 455/161.2, 455/165.1, 455/255, 455/71, 455/166.1, 455/166.2
• US Class Current: 340/7.42
• CPC Class Codes: H04W 88/022 Selective call receivers

Abstract

A pager receiver includes an addressable data memory for storing sets of digital frequency data for application to a frequency synthesizer which responds to each set of frequency data to tune the pager receiver to a channel or frequency identified by the frequency data, and a process controller which controls both the storing in the memory of the frequency data identifying a plurality of channels or frequencies and the reading out of the frequency data one set at a time in sequence in searching for a paging signal being transmitted to the paging receiver. The pager receiver is operable in a preprogrammed mode in which frequency data which identifies a plurality of channels is supplied to the pager receiver from an external source with the pager receiver scanning only those channels for which frequency data is stored in the memory or in an all channel scanning mode in which the pager receiver rapidly scans all available pager channels or frequencies and stores in the memory frequency data which identifies only those channels for which acceptable signal level and system code is detected, the pager receiver then scanning only those channels for which frequency data is stored in memory.

Claims

1. A pager receiver for receiving paging signals on a plurality of channels comprising signal receiving means including a local oscillator and tuning circuit means tunable to all of said channels and signal detecting means for detecting a paging signal on a channel to which said tuning circuit means is tuned;

tuning data generating means;

data memory means having a plurality of addressable data storage locations;

control means operable in a programming mode to enable said tuning data generating means to generate frequency data words identifying all of said channels in sequence, tuning signal generating means responsive to the frequency data words to cause said tuning circuit means to be tuned to all of said channels in sequence, said control means being responsive to said signal detecting means to select from said plurality of channels all of the channels on which a paging signal is detected and to store in said data memory means the frequency data words identifying the selected channels;

said control means thereafter being operable in a scanning mode to read out of said data memory means in sequence the frequency data words identifying the selected channels until a paging signal is detected;

said tuning signal generating means being responsive to each frequency data word read out of said data memory means for generating a control signal corresponding to a reference frequency indicated by the frequency data word, digital frequency compensation means for generating a digital frequency control signal to effect fine tuning of the local oscillator, analog frequency compensation means coupled to said signal receiving means for generating an analog frequency control signal, and signal combining circuit means responsive to said control signals to generate a control voltage for said local oscillator to establish the local oscillator frequency at the value needed for tuning said tuning circuit means to the selected channel identified by the frequency data word, said control means being responsive to the detection of a paging signal by said signal detecting means to cause said tuning circuit means to be maintained tuned to the selected channel identified by the data word being applied to said tuning signal generating means; and

signaling means responsive to the detected paging signal for providing an indication that a paging signal has been detected.

2. A pager receiver according to claim 1, including cycle timing means for defining operating cycles for the pager receiver, each operating cycle including an active period of a given duration and a low power period of a substantially greater duration.

3. A pager receiver according to claim 1 wherein said signal receiving means operates under the control of said control means to detect paging signals independent of system code.

4. A pager receiver according to claim 1, wherein said tuning signal generating means includes first and second digital to analog conversion circuits, said first digital to analog conversion circuit being responsive to each frequency data word read out of said data memory means to provide a first analog control signal corresponding to a reference frequency indicated by the frequency data word, and said second digital to analog conversion circuit being responsive to a digital frequency correction data word generated by said digital frequency compensation means to generate a second analog control signal corresponding to a compensation signal indicated by said digital frequency correction data word, said signal combining circuit means being responsive to said first and second analog control signals and to said analog frequency control signal to generate said control voltage for said local oscillator.

5. A pager receiver according to claim 4, wherein said tuning signal generating means includes modifying means for modifying the digital frequency correction data word to cause a corresponding change in the second analog control signal for fine tuning of said tuning circuit means to each channel.

6. A pager receiver according to claim 4, wherein said tuning signal generating means includes signal level detecting means deriving from said signal receiving means a signal for updating said digital frequency correction data word.

7. A pager receiver according to claim 4, including sensing means for sensing ambient temperature and providing a temperature signal representing the temperature sensed, said control means being responsive to said temperature signal for adjusting said digital frequency correction data word to thereby adjust the fine tuning of said local oscillator in correspondence with temperature variation.

8. A pager receiver according to claim 7, wherein said sensing means comprises a device having a resistance that varies as a function of temperature and a capacitor connected in circuit with said device across inputs of said control means.

9. A pager receiver for receiving paging signals on a plurality of channels comprising signal receiving means including tuning circuit means tunable to all of said channels and signal detecting means for detecting paging signals on a channel to which said tuning circuit means is tuned;

tuning data generating means;

data memory means;

control means operable in a programming mode to enable said tuning data generating means to generate data words identifying all of the said channels in sequence, tuning signal generating means responsive to the data words as they are generated to cause said tuning circuit means to be tuned to all of said channels in sequence, said control means being responsive to said signal detecting means to select from said plurality of channels all of the channels on which a paging signal is detected and to store in said data memory means the data words identifying the selected channels, said control means thereafter being operable in a scanning mode for controlling said data memory means to read out of said memory means in sequence the stored data words identifying the selected channels for application to said tuning signal generating means to cause said tuning circuit means to be tuned to the selected channels in sequence, said control means being responsive to said signal detecting means to stop reading out the data words when a paging signal is detected on one of said selected channels; and

signalling means responsive to the detected paging signal for providing an indication that a paging signal has been detected, said control means including reference means for indicating the total number of active selected channels that are identified by data words stored in said memory means, scan count means for storing a count indicating the total number of active selected channels that have been scanned during a given operating sequence for the pager receiver and means responsive to said reference means and said scan count means for indicating when all of said active selected channels have been scanned during said given operating sequence.

21. A pager receiver according to claim 9, including means responsive to said missed search means for preventing said control means from reading the data word out of said memory means for a channel for which a paging signal failed to be detected for a predetermined number of tuning cycles.

10. A self-programming pager receiver for receiving paging signals on a plurality of channels comprising signal receiving means including tuning circuit means tunable to all of said channels and signal detecting means for detecting paging signals on a channel to which said tuning circuit means is tuned;

tuning data generating means;

data memory means;

control means responsive to the application of power to the pager receiver, and independent of externally generated programming command signals which preselect channels to be scanned, to automatically begin operating in a programming mode to enable said tuning data generating means to generate data words identifying all of said channels in sequence, tuning signal generating means responsive to the data words as they are generated to cause said tuning circuit means to be tuned to all of said channels in sequence, said control means being responsive to said signal detecting means to select from said plurality of channels all of the channels on which a paging signal is detected and to store in said data memory means the data words identifying the selected channels, said control means thereafter being operable in a scanning mode for controlling said data memory means to read out of said memory means in sequence the stored data words identifying the selected channels for application to said tuning signal generating means to cause said tuning circuit means to be tuned to the selected channels in sequence, said control means being responsive to said signal detecting means to stop reading out the data words when a paging signal i detected on one of said selected channels and signalling means responsive to the detected paging signal for providing an indication that a paging signal has been detected.

11. A pager receiver according to claim 10, wherein said tuning signal generating means comprises a digital to analog converter responsive to each data word as it is read out of said memory means for generating an analog tuning signal for causing said tuning circuit means to tune to the channel identified by said data word.

12. A pager receiver according to claim 10, wherein said tuning signal generating means comprises a phase locked loop.

13. A pager receiver according to claim 10, including cycle timing means for defining operating cycles for the pager receiver, each operating cycle including an active period of a given duration and a low power period of a substantially greater duration.

22. A pager receiver according to claim 10, including external programming means for overriding said control means, and wherein said control means responds to programming data identifying preselected channels provided by said external programming means and controls said tuning data generating means in the generation of data words identifying said preselected channels and stores the data words identifying said preselected channels in said memory means.

14. A pager receiver for receiving paging signals on a plurality of channels comprising signal receiving means including tuning circuit means tunable to all of said channels and signal detecting means for detecting a paging signal on a channel to which said tuning circuit means is tuned;

tuning data generating means including digital signal counting means for generating data words identifying all of said channels;

data memory means having a plurality of addressable data storage locations;

control means operable in a programming mode for incrementing said digital signal counting means to generate data words identifying each channel of said plurality of channels in sequence;

tuning signal generating means responsive to each data word as it is generated for generating a control signal for tuning said tuning circuit means to the channel identified by the data word;

said control means being responsive to said signal detecting means to select from said plurality of channels all of the channels on which a paging signal is detected and to store in said memory means the data words identifying, the selected channels and said control means thereafter being operable in a scanning mode to cause the stored data words to be read out from the memory means in sequence for application to said tuning signal generating means, said tuning signal generating means responding to each data word as it is read out of said memory means to tune the pager receiver to the selected channel identified by the data words read out from said memory means; and

signalling means responsive to the detected paging signal for providing an indication that a paging signal has been detected.

15. A pager receiver according to claim 14, wherein said signaling means includes signal decoding means for decoding a detected paging signal for a given channel identified by a data word stored in said memory means, said control means when operating in said scanning mode being responsive to said decoding means to cause a sequentially higher channel of all of said channels to be scanned for the presence of a paging signal, and said control means being responsive to the detection of a paging signal on said sequentially higher channel to determine whether or not said sequentially higher channel is one of said selected channels and to store in said memory means, the data word identifying said sequentially higher channel upon determining that said sequentially higher channel is not one of said selected channels.

16. A pager receiver according to claim 15, which includes means for comparing the data word identifying said sequentially higher channel generated by said tuning data generating means with each data word stored in said memory means prior to storing in said memory means the data word identifying said sequentially higher channel to determine whether or not said sequentially higher channel is one of the selected channels.

17. A pager receiver comprising signal receiving means including signal detecting means for detecting paging signals in a plurality of channels;

tuning circuit means for determining the receiving frequency in accordance with an analog control signal applied thereto;

tuning data generating means for generating digital frequency data words identifying all of the channels;

data memory means having a plurality of addressable locations for storing digital frequency data words for identifying selected ones of the channels, and addressing means for selectively addressing said storage locations in said memory means in sequence to effect readout of the frequency data words stored therein;

digital to analog converting means for converting each digital frequency data word read out of said memory means into an analog signal for application to said tuning circuit means for establishing the receiving frequency for the pager receiver during a given operating cycle;

frequency control means for modifying each frequency data word to compensate for variations in a frequency value represented by each frequency data word relative to the receiving frequency.

18. A pager receiver for receiving paging signals on a plurality of channels comprising signal receiving means including tuning circuit means tunable to all of said channels and signal detecting means for detecting paging signals on a channel to which said tuning circuit means is tuned;

tuning data generating means;

data memory means;

control means operable in a programming mode to enable said tuning data generating means to generate data words identifying all of the said channels in sequence, tuning signal generating means responsive to the data words as they are generated to cause said tuning circuit means to be tuned to all of said channels in sequence, said control means being responsive to said signal detecting means to select from said plurality of channels all of the channels on which a paging signal is detected and to store in said data memory means the data words identifying the selected channels, said control means thereafter being operable in a scanning mode for controlling said data memory means to read out of said memory means in sequence the stored data words identifying the selected channels for application to said tuning signal generating means to cause said tuning circuit means to be tuned to the selected channels in sequence, said control means being responsive to said signal detecting means to stop reading out the data words when a paging signal is detected on one of said selected channels; and

signaling means responsive to the detected paging signal for providing an indication that a paging signal has been detected, said signaling means including signal decoding means for decoding a detected paging signal for a given channel identified by a data word stored in said memory means, said control means when operating in said scanning mode being responsive to said decoding means to cause a sequentially higher channel of all of said channels to be scanned for the presence of a paging signal, and said control means being responsive to the detection of a paging signal on said sequentially higher channel to determine whether or not said sequentially higher channel is one of said selected channels and to store in said memory means the data word identifying said sequentially higher channel upon determining that said sequentially higher channel is not one of said selected channels.

19. A pager receiver according to claim 18, which includes means for comparing the data word identifying said sequentially higher channel generated by said tuning data generating means with each data word stored in said memory means prior to storing in said memory means the data word identifying said sequentially higher channel to determine whether or not said sequentially higher channel is one of the selected channels.

20. A pager receiver according to claim 18, which includes missed search means for indicating the number of times that said signal detecting means failed to detect a paging signal on a given one of said selected channels while said tuning circuit means is tuned to that channel.