WO1994014286A1 - Recepteur d'appels selectif a fonction d'economie de piles pour les premier et deuxieme modes et sa methode d'utilisation - Google Patents

Recepteur d'appels selectif a fonction d'economie de piles pour les premier et deuxieme modes et sa methode d'utilisation

Info

Publication number
WO1994014286A1
WO1994014286A1 PCT/US1993/010944 US9310944W WO9414286A1 WO 1994014286 A1 WO1994014286 A1 WO 1994014286A1 US 9310944 W US9310944 W US 9310944W WO 9414286 A1 WO9414286 A1 WO 9414286A1
Authority
WO
WIPO (PCT)
Prior art keywords
signal
response
battery saving
receiving
generated
Prior art date
Application number
PCT/US1993/010944
Other languages
English (en)
Inventor
Von Alan Mock
Eric Thomas Eaton
David Jeffrey Hayes
Matthew Joseph Stanislawski
Original Assignee
Motorola, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Motorola, Inc. filed Critical Motorola, Inc.
Priority to AU56026/94A priority Critical patent/AU5602694A/en
Priority to JP6514171A priority patent/JP2912016B2/ja
Publication of WO1994014286A1 publication Critical patent/WO1994014286A1/fr

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/02—Power saving arrangements
    • H04W52/0209—Power saving arrangements in terminal devices
    • H04W52/0225—Power saving arrangements in terminal devices using monitoring of external events, e.g. the presence of a signal
    • H04W52/0229—Power saving arrangements in terminal devices using monitoring of external events, e.g. the presence of a signal where the received signal is a wanted signal
    • H04W52/0232—Power saving arrangements in terminal devices using monitoring of external events, e.g. the presence of a signal where the received signal is a wanted signal according to average transmission signal activity
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/02—Power saving arrangements
    • H04W52/0209—Power saving arrangements in terminal devices
    • H04W52/0225—Power saving arrangements in terminal devices using monitoring of external events, e.g. the presence of a signal
    • H04W52/0241—Power saving arrangements in terminal devices using monitoring of external events, e.g. the presence of a signal where no transmission is received, e.g. out of range of the transmitter
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
    • H04W88/02—Terminal devices
    • H04W88/022—Selective call receivers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

Definitions

  • This invention relates in general to selective call receivers, and more particularly to a selective call receiver with battery saving function in first and second modes and method therefor.
  • Communications systems utilize at least one transmitter to define a system coverage area. Every radio frequency (RF) transmitter has an associated geographical reception area within which communications devices, such as selective call receivers, tuned to the appropriate frequency can receive transmissions from the RF transmitter.
  • RF radio frequency
  • the selective call receivers are located outside a system coverage area, and will be out of range of the RF transmitters, and therefore will be unable to receive any further transmissions from the RF transmitters.
  • selective call receivers which receive signals having a predetermined signalling protocol use the lack of detection of the predetermined signalling protocol to determine when the receiver is out of range.
  • several communications systems having various signalling protocols may share a single RF channel or frequency which, when received by the selective call receiver, causes the selective call receiver to erroneously generate the out of range signal because the selective call receiver receiving the signalling protocols of other communications systems will erroneously determine that the selective call receiver is outside the system coverage area because the predetermined signalling protocol was not received.
  • the selective call receiver when the selective call receiver is carried into a shielded area, such as an elevator, subway or the shadow of a building, the selective call receiver may generate an out of range signal when the selective call receiver fails to receive the predetermined signalling protocol. Therefore, whenever there is enough distortion from other sources which results in a signal quality that is too low for the selective call receiver to accurately decode, the selective call receiver generally generates the out-of-range signal although the selective call receiver is still within the system coverage area because the predetermined signal is not periodically received.
  • a selective call receiver capable of increasing receiver sensitivity and conserving battery saving function for determining when the selective call receiver is out of range.
  • a selective call receiver comprises means for receiving paging signals which includes at least a synchronization codeword, and means, coupled to the receiving means, for obtaining synchronization to the paging signals.
  • Means, coupled to the receiving means performs battery saving functions in first and second modes.
  • Means, response to the second signal being generated detects an out-of range condition.
  • the out-of range detecting means coupled to battery saving means initiates battery saving function in the second mode.
  • a method for conserving battery life comprising the steps of:
  • step (c) detecting at least a first and second baud rates;
  • step (d) generating a first signal in response to step (c) detecting at least one of the first and second baud rates and generating a second signal in response to the absence of first and second baud rates being detected;
  • step (e) performing battery saving function in first and second modes;
  • FIG. 1 is a signaling diagram of a prior art POCSAG protocol signal.
  • FIG. 2 is an electrical block diagram of a paging system illustrating a paging transmitter and a selective call receiver in accordance with the preferred embodiment of the present invention.
  • FIG. 3 is an electrical block diagram of the microcomputer used in the selective call receiver of FIG. 2.
  • FIG. 4 is a block diagram of a memory location used as registers for determining the quality of the received signal in accordance with the preferred embodiment of the present invention.
  • FIG. 5 is an electrical block diagram of the decoding arrangement for increasing receiver sensitivity according to the preferred embodiment of the present invention.
  • FIGS. 6 and 7 are flow diagrams illustrating the operation of the selective call receiver of FIG. 2 according to the preferred embodiment of the present invention.
  • FIG. 1 a signaling diagram of conventional Post Office Code Standardization Advisory Group (POCSAG) protocol signal is shown which comprises a series of address and/or message information intended for individuals or groups of selective call receivers assigned to a paging system.
  • the series of addresses are assembled in accordance with requests and transmitted as a continuous transmission.
  • the transmission is of a digital format and starts with a preamble 102 of at least 576 bits, equivalent to the duration of a batch and one additional codeword.
  • the preamble 102 is followed by one or more batches of address and message codewords.
  • Each batch begins with a synchronization codeword (SC) 104 followed by eight frames 106, each frame having a duration equivalent to two codewords 108, 110, namely an address codeword and/or a message codeword.
  • SC synchronization codeword
  • the diagram of the POCSAG signalling protocol 100 is an example of one of the many signalling protocols which are applicable to the present invention.
  • the POCSAG signalling protocol 100 is a binary frequency shift keying (FSK) modulated signalling protocol originally proposed by British Telecom and an anagram for the Post Office Code Standardization Advisory Group.
  • the POCSAG protocol receivers perform separate bit and frame synchronization operations.
  • Bit synchronization is a process used to determine the presence of bit boundaries of a data transmission having bits transmitted at a predetermined baud rate, and thereafter to provide a clock to synchronously sample the bits.
  • Frame synchronization arranges the bits transmitted so that the data transmitted is in a form to be decoded for indicating the various word boundaries, for example, the first bit of address and data signals, etc.
  • the receiver With POCSAG signalling, once bit synchronization has been obtained, the receiver remains in synchronous communication with the transmitter until the signal is dropped, i.e., the sequence for initially establishing bit synchronization does not need to be repeated.
  • the first word following the preamble is the synchronization codeword 104 which contains a predetermined binary sequence used for frame synchronization. Eight frames 106 or sixteen words of information 108, 110 follow thereafter before the synchronization codeword 104 is repeated.
  • the synchronization codeword 104 provides a means for achieving and maintaining frame synchronization.
  • FIG. 2 is an electrical block diagram of a paging system 150 illustrating a paging transmitter and a selective call receiver 200 in accordance with the preferred embodiment of the present invention.
  • the paging transmitter is coupled to an input device, for example, a telephone 256 for inputting messages or initiating pages via a paging controller 254.
  • the paging controller 254 generates, inter alia, pages to be transmitted to respective selective call receivers 200 according to the POCSAG signalling protocol, for example.
  • the paging controller 254 is coupled to the radio frequency transmitter /receiver 252 which transmits the pages via an antenna 250.
  • Information for example, pages, are preferably transmitted at a first baud rate and during a period when no information is being transmitted, a signal preferably comprising alternating "ones and zeros" is transmitted at a second baud rate.
  • the second baud rate is preferably lower than the first baud rate, for example, when the first baud rate is equal to either 512 or 1200 baud, the corresponding second baud rate is equal 300 or 750 baud, respectively.
  • the pages are received by the selective call receivers being addressed.
  • the selective call receiver 200 comprises an antenna 202 for intercepting transmitted radio frequency (RF) signals.
  • the antenna 202 is coupled to the input of a receiver 204.
  • the RF signals are preferably selective call (paging) message signals which provide, for example, a receiver address and an associated message, such as numeric or alphanumeric message.
  • paging paging
  • the receiver 204 processes the RF signal and produces, at the output, a data stream representative of a demodulated data information.
  • the demodulated data information is coupled into the input of a decoder /controller 206 which processes the information in a manner well known in the art.
  • a baud rate detector 224 coupled to the controller 206, is used to detect the baud rate of the received paging signal.
  • a power switch 210 coupled to the decoder /controller 206, is used to control the supply of power to the receiver 204, thereby providing battery saving functions in response to a battery save signal 260 generated from the decoder/controller 206 which operates the power switch 210.
  • a receiver sensitivity signal 262 is provided to the receiver 204 from the decoder/ controller 206 for increasing the receiver sensitivity, the operation of the receiver sensitivity signal 262 will be discussed further in detail below.
  • the battery save signal 260 and the receiver sensitivity signal 262 toggle the receiver 204 between off, on, weak signal mode and distortion mode as determined by the decoder /controller 206.
  • a code plug 222 is coupled to the decoder /controller 206 for storing a set of predetermined information, for example, the time required for the selective call receiver 200 to be out of range before the initiation of an out- of-range processing algorithm which will be discussed below.
  • the decoder/controller 206 activates the receiver 204 to detect the synchronization codeword 104 by providing an appropriate battery save signal 260 to the power switch 210.
  • the receiver 204 remains activated until the end of the transmission of the synchronization codeword 104 (FIG. 1) at which time the decoder/controller 206 provides a second battery save signal which turns-off power to the receiver 204.
  • the receiver 204 is subsequently activated to look in its assigned frame for address and information words 108, 110 transmitted to a group to which the selective call receiver is assigned.
  • the synchronization codeword 104 is again transmitted and the selective call receiver again operates in a similar fashion as described above.
  • the address is received by the decoder /controller 206, the received address is compared with one or more addresses stored in the codeplug (or code memory) 222, and when a match is detected, an alert signal is generated to alert a user that a selective call message, or page, has been received.
  • the alert signal is directed to an audible alerting device 214 for generating an audible alert or to a tactile alerting device 216 for generating a silent vibrating alert.
  • Switches 220 allow the user of the selective call receiver to, among other things, select between the audible alert 214 and the tactile alert 216 in a manner well known in the art.
  • the message information which is subsequently received is stored in memory 304 (FIG. 3) and can be accessed by the user for display using one or more of the switches 220 which provide such additional functions as reset, read, and delete, etc. Specifically, by the use of appropriate functions provided by the switches 220, the stored message is recovered from memory and processed by the decoder /controller 206 for displaying by a display 208 which enables the user to view the message.
  • the controller /decoder 206 of FIG. 2 can be constructed utilizing a microcomputer as shown in FIG. 3.
  • FIG. 3 is an electrical block diagram of a microcomputer based decoder/controller suitable for use in the selective call receiver of FIG. 2.
  • the microcomputer 206 is preferably an MC68HC05 microcomputer such as manufactured by Motorola, Inc., which includes an on-board display driver 314.
  • the microcomputer 206 includes an oscillator 318 which generates the timing signals utilized in the operation of the microcomputer 206.
  • a crystal, or crystal oscillator (not shown), is coupled to the inputs of the oscillator 318 to provide a reference signal for establishing the microcomputer timing.
  • a timer/counter 302 couples to the oscillator 318 provides programmable timing functions which are utilized in controlling the operation of the receiver or the processor.
  • a RAM (random access memory) 304 is utilized to store variables derived during processing, as well as to provide storage of message information which are received during operation as the selective call receiver.
  • a ROM (read only memory) 306 stores the subroutines which control the operation of the receiver or the processor which will be discussed further. It will be appreciated that in many microcomputer implementations, the programmable-ROM (PROM) memory area can be provided by an EEPROM (electrically erasable programmable read only memory).
  • the oscillator 318, timer/counter 302, RAM 304, and ROM 306 are coupled through an address/data/control bus 308 to a central processing unit (CPU) 310 which performs the instructions and controls the operations of the microcomputer 206.
  • CPU central processing unit
  • the demodulated data generated by the receiver is coupled into the microcomputer 206 through an input/output (I/O) port 312.
  • the demodulated data is processed by the CPU 310, and when the received address is the same as the code-plug memory which couples into the microcomputer through, for example, an I/O port 313, the message, if any, is received and stored in RAM 304.
  • Recovery of the stored message and selection of the predetermined destination address is provided by the switches which are coupled to the I/O port 312.
  • the microcomputer 206 then recovers the stored message and directs the information over the data bus 308 to the display driver 314 which processes the information and formats the information for presentation by a display (not shown) such as an LCD (liquid crystal display).
  • the alert signal is generated which can be routed through the data bus 308 to an alert generator 316 that generates the alert enable signal which is coupled to the audible alert device that was described above.
  • the microcomputer when the vibrator alert is selected as described above, the microcomputer generates an alert enable signal which is coupled through data bus 308 to the I/O port 313 to enable generation of a vibratory, or silent alert.
  • the battery saver operation is controlled by the CPU 310 with battery saving signals which are directed over the data bus 308 to the I/O port 312 which couples to the power switch. Power is periodically supplied to the receiver to enable decoding of the received selective call receiver address signals and any message information which is directed to the receiver. Referring to FIG.
  • a memory arrangement for determining the signal quality according the the preferred embodiment of the present invention.
  • a quality factor of the received signal is calculated using the baud detector to analyze the frequency signature of the incoming limited data from the receiver section and forms the base for the quality calculation.
  • the quality calculation is stored in registers according to the preferred embodiment of the present invention and illustrated in RAM 304.
  • the signal is processed at least at four locations, preferably at one- quarter bit time intervals, and the results are stored in four baud detect registers 350, 352, 354, and 356. Each register is loaded with the accumulated number of transitions during the baud detect cycle.
  • the two highest numbers are added together to determine the quality at the selected gain state and also describes the opening of the eye pattern of the limited data input to the decoder controller.
  • the signal quality will be at its maximum value when all edges occur in only one quarter bit interval.
  • the present implementation of the quality calculation provides a resolution of a quarter bit error. Higher resolutions of eye pattern openings can be achieved by increasing the number of samples taken per bit period.
  • the identification of the signal environment and the proper receiver gain setting for a partial synchronous, synchronous or multiple signal baud rate system is achieved by conditional consecutive frequency analysis (referred to as baud detects) at selected gains.
  • Receiver sensitivity is increased by analyzing the frequency signature, or the eye threshold pattern, of the incoming signal for the correct baud rate at selective gain settings. For example, a low gain setting has the highest probability of being chosen over a high gain setting in an IM environment, and a high gain setting has the highest probability of being chosen over a low gain setting in a weak signal or fading environment.
  • Bit Error Rate (BER) is directly dependent upon the frequency signature (the eye pattern opening) of the limited data output from the receiver section.
  • the eye pattern provides a far superior indication of signal quality than algorithms based on the Bit Error Rate, since the eye pattern can give an earlier indication of a fading or IM environment with or without bit errors occurring.
  • the Eye Pattern Opening refers to the required time period for a limited data output from the receiver section to be determined a 1 or 0.
  • the BER will be minimal when the decision point for determining a 1 or 0 is centered within the eye pattern, and the BER will increase as the decision point for determining a 1 or 0 moves from the center of the eye pattern.
  • FIG. 5 a detailed electrical block diagram of the decoding arrangement for increasing receiver sensitivity according to the preferred embodiment of the present invention is shown.
  • the ROM stores subroutines for controlling the operations of the selective call receiver.
  • the receiver 204 of the selective call receiver 200 depicted in FIG. 2 comprises an RF front end 400 and a receiver back end 412.
  • a signal received by the antenna 202 is provided to the RF front end 400.
  • the response of the received signal is attenuated by a first attenuator 402 which may be optional and a second attenuator 406 in response to a signal 262 from the decoder/controller 206.
  • a diode switch 432 is controlled by the decoder/controller 206 to provide the necessary switching for operating the first and second attenuators and for operating the RF amplifier 404 in first and second states wherein the first state has a different RF gain from the second state.
  • the response of the received signal can be detuned by a varactor (not shown) which can substituted for the voltage diode switch 432.
  • the decoder /controller 206 When the receiver 204 is turned on by the power switch 210 in response to the signal 260 from the decoder/controller 206, power from a power source, e.g., a battery (not shown), is provided to a voltage switch/regulator 424 which powers the RF front end 400 and a current source 426 which powers the receiver back end 412.
  • a power source e.g., a battery (not shown)
  • the decoder /controller 206 determines whether to operate the receiver in a high gain state or a low gain state. This determination will be discussed in detail below.
  • a signal is applied to the input of the voltage diode switch 432 which generates a signal 262 which turns off the first and second attenuators 402, 406, and sets the operating state of the RF Amplifier 404 to the first state, for example, its normal operating gain.
  • Control of the first attenuator 402, second attenuator 406 and the RF amplifier 404 can be provided by signals simultaneously applied, as well as by signals independently applied.
  • the decoder/ controller 206 determines whether to operate the receiver in a high or a low gain state.
  • the selective call receiver 200 When the selective call receiver 200 is within close proximity to the RF transmitter, the selective call receiver will receive a "strong" signal, and as a result, the decoder /controller can preserve battery life by operating the receiver 206 at a low gain state because the receive signal is strong and therefore, can be easily received and decoded at low power.
  • the selective call receiver 200 is further away from the RF transmitter, the receiver signal will be "weak", therefore, the decoder /controller 206 will cause the receiver to operate at the high gain (usually, the normal power setting) in order to receive the weaker signal.
  • the selective call receiver can optimize its battery life by operating the receiver at the low gain state and therefore exacts a lesser burden on the battery or power supply.
  • the RF amplifier 404 biasing status is also controlled by the decoder/ controller 206 which switches the amplifier from high gain state to low gain state and vice versa.
  • the output of the RF amplifier 404 via the second attenuator 406 is provided a first mixer 408 which receives a second input from a first oscillator 410 which provides an intermediate frequency (IF) to a second mixer 420 by techniques well known to one of ordinary skill in the art.
  • the frequency of the signal from the first oscillator 410 determines the assigned frequency or channel upon which the selective call receiver operates.
  • the output signal from the first mixer 408 is provided to conventional circuitry of the receiver back end 412 comprising the second mixer 420, a second oscillator 422, an amplifier 418, a demodulator 416 and an audio limiter 414 for processing the signal received in a manner well known in the art.
  • the circuitry of the receiver back end 412 eliminates signals on adjacent channels and demodulates the received signal to provide an output to decoder/controller 206 for further processing.
  • the battery save signal 260 and receiver sensitivity signal 262 are provided from the decoder /controller 206 to the voltage switch/ regulator 424 and the current source 426 of the receiver 204 to control the operation of the receiver to achieve optimum battery life.
  • an out- of-range signal processing routine allows the controller/decoder 206 via the battery save signal 260 and a sensitivity control 430 to operate the receiver 204 in a super battery saver mode, e.g., increases the ratio of the time the receiver 204 is OFF to the time the receiver 204 is ON while alternating the sensitivity of the selective call receiver each time the unit turns on when it is determined that the selective call receiver is "out of range”.
  • the alert generator 316 receives a signal to provide a predetermined alert, for example, displaying the words, for example, "OUT OF RANGE".
  • the selective call receiver powers up and initializes all variables to begin to receive transmissions.
  • the gain of the receiver is selected from at least two gain states as discussed above in reference to FIG. 4.
  • an initialization bit is set which determines the gain state that is chosen in the next receiver operation.
  • the receiver circuitry turns on to receive the predetermined signalling protocol on its assigned frequency channel, step 500, and the gain state is selected. In this fashion, the gain state the receiver uses as its first gain can be either the first or second gain state depending on the prior operation of the receiver.
  • a baud detect is performed on the received signal, and a quality of the received signal is determined at the first selected gain state, step 502.
  • a time-out flag is set when the receiver times-out before detecting a valid baud rate.
  • the received signal may either be transmitted in a first or second baud rate, which results in a baud rate detection being perform in step 502 to detect when either the first or the second baud rate is being transmitted.
  • a quality factor is assigned to the received signal at the first selected gain state. When the baud rate detect fails, the quality assigned to the signal is zero.
  • the quality of the signal is calculated at the first gain state.
  • the quality of the signal is calculated by selecting preferably two registers of at least four registers of the baud detect circuitry having the maximum number of recorded transitions. The summation of the numbers of transitions of the two registers having the maximum number of recorded transitions equates to the quality of the signal being received at the first gain state.
  • a determination is done to determine whether a valid baud rate was detected.
  • step 506 determines if the second baud rate (e.g., 300 baud rate) signal was detected. If so, the receiver turns off, step 508, and the battery save option, the first battery saving mode, is initiated for a predetermined time period. Beginning at step 506, when the second baud rate is not detected and the first baud rate being detected in step 504, the next gain state is selected, and another baud rate detect is performed to determine whether the first or second baud rate is being transmitted, step 510.
  • the second baud rate e.g., 300 baud rate
  • the quality of the signal is also calculated at the second gain state in step 510. Subsequent to the baud detect in step 510, step 512 determines if a valid baud rate was detected. If so, the absolute value of the difference between the quality of the signal at the first gain state and the quality of the signal at the second gain state is calculated (Qdelta), step 514. The calculated Qdelta is checked to determine when it is greater-than-or-equal-to a Quality maximum (Qmax) stored in memory, step 516. If so, the gain of the receiver is set to Low gain state, step 518, and the selective call receiver continues to receive transmitted signals in the first battery saving mode.
  • Qmax Quality maximum
  • the calculated quality at the second gain state is compared to determine if it is greater than the calculated quality at the first gain state, step 520. If so, then the receiver selects the gain associated with calculation of the second quality, that is, the second gain state, step 522. However, when the quality at the first gain state is lesser than or equal to the quality at the second gain state, the receiver selects the first gain state, step 524.
  • step 512 when an invalid baud rate is detected, the receiver again selects the first gain state to ensure that an error was not made when the valid baud rate was determined to have been detected at the first gain state and performs another baud rate detect at the first gain state, step 526.
  • step 528 a determination is done on whether a valid baud rate was detected, and if so, the gain is set the first gain state, step 524. However, if the valid baud rate was not detected, the receiver turns off, step 528.
  • the selective call receiver checks for a second time if the valid baud rate was correctly detected at the first gain state before the receiver is set to operate at the first gain state.
  • step 504 when the valid baud rate is not detected, the processor determines if the time-out period occurred before the baud rate was detected, step 530.
  • the gain of the RF amplifier is set to the second gain state, and a baud rate detection is performed, and the quality of the received signal is calculated as discussed above, step 532.
  • step 534 a determination is done on whether a valid baud rate was detected.
  • step 536 determines if the second baud rate (e.g., 300 baud rate) signal was detected. If so, the receiver turns off, step 538, and the battery save option in the first battery saving mode is initiated. Alternately, when the second baud rate is not detected in step 536, the signal quality at the second gain state previously calculated in step 532 is checked to determine if it is greater than a quality threshold value (Qthreshold) which is preferably stored in the code plug to determine if a high quality signal or a low quality signal was detected, step 540. If the signal quality is greater that Qthreshold than the high quality signal was detected, the receiver RF amplifier is set to the second gain state, step 546.
  • Qthreshold quality threshold value
  • step 540 when the signal quality is determined to be the low quality signal in step 540, another baud rate detect is performed at the second gain state to ensure that the valid baud rate found at step 534 was not in error, step 542.
  • step 544 a determination is done on whether a valid baud rate was detected, and if so, the gain is set the second gain state, step 546. However, if the valid baud rate was not detected at either steps 544, 534, 530 or 528, the receiver turns off, step 548.
  • a time-out timer is incremented which was initialized in the initialization step, step 550, and the timer is checked to determined if the time-out value has expired, step 552.
  • the first (e.g., normal) battery save option is initiated for a predetermined time period.
  • a super battery saving routine (the battery saving in the second mode) is initialized for an out-of-range battery save, step 554.
  • a baud rate detection is performed at the first and second baud rates, step 556.
  • Step 558 determines if a valid baud rate was detected, and if so, the process continues to block A. Alternately, when a valid baud rate is not detected, the gain state is changed, step 560, and the process repeats from step 556 by continuing the super or second battery saving mode routine until the selective call receiver is within range of the transmitters.
  • the selective call receiver checks for a second time if the valid baud rate was correctly detected at the second gain state before the receiver is set to operate at the second gain state.
  • a second baud detect is performed at the next gain state except when the first baud detect had a higher signal quality than the predetermined threshold quality.
  • a third baud rate detect is performed to decrease the falsing rate and is generally performed at the same gain at which a valid baud rate was previously detected.
  • the third baud rate detect is performed when the first baud detect failed to reveal a valid baud rate, and when the second baud rate detect had detected a valid baud rate with a signal quality lower than a quality threshold value, or when the first baud rate detect failed to detect a valid baud rate, and the second baud rate detect detected a valid baud rate.
  • the processor will go into a modified battery save mode after a preset amount of time has elapsed. This would consist of longer off-to-on ratios and alternating receiver sensitivities which increase battery life while the receiver sensitivity is being varied.
  • the out-of-range technique is used to insure a quick response time without reducing battery life on receivers by switching the sensitivity of the receiver each time the selective call receiver turns on after the selective call receiver had determined it is out of range.
  • a selective call receiver comprises means receiving paging signals having at least a synchronization codeword.
  • the receiving means has a variable gain control means for enabling the receiving means for receiving a paging signal in at least first and second gains.
  • Means, coupled to the receiving means, obtains synchronization to the paging signals.
  • Means determining a quality of the received paging signal.
  • the out-of-range detecting means coupled to battery saving means initiates battery saving function in the second mode.
  • Means for maintaining the battery saving function in the second mode in response to the second signal is being generated.

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  • Mobile Radio Communication Systems (AREA)

Abstract

Récepteur d'appels sélectif (200) comprenant un récepteur (204) recevant les signaux d'appel individuels, mettant en ÷uvre au minimum un mot de code (104) de synchronisation, et un chronométreur (302), couplé au récepteur, réalisant la synchronisation par rapport aux signaux d'appel individuels. Un circuit de détection de cadence télégraphique (224) capte au moins la première et la seconde cadence télégraphique et produit un premier et un deuxième signal. Le premier signal est produit en réponse à la première ou à la deuxième cadence télégraphique captée tandis que le deuxième signal est produit en réponse à l'absence des première et deuxième cadences télégraphiques captées. Un système de commande (206), couplé au récepteur, assure les fonctions d'économie de piles dans les premier et deuxième modes. Un commutateur de courant, qui réagit au premier signal produit, met en ÷uvre le circuit d'économie de piles pour réaliser la fonction d'économie de piles dans le premier mode. Le circuit de détection de cadence télégraphique (224), en réponse à la production du deuxième signal, identifie une situation où la source est hors de portée. Ce circuit couplé au dispositif d'économie de piles, met en ÷uvre la fonction économie de piles dans le deuxième mode.
PCT/US1993/010944 1992-12-08 1993-11-15 Recepteur d'appels selectif a fonction d'economie de piles pour les premier et deuxieme modes et sa methode d'utilisation WO1994014286A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AU56026/94A AU5602694A (en) 1992-12-08 1993-11-15 Selective call receiver with battery saving function in first and second modes and method therefor
JP6514171A JP2912016B2 (ja) 1992-12-08 1993-11-15 第１および第２のモードでのバッテリセイビング機能を備えた選択呼び出し受信機およびそのための方法

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US98694892A 1992-12-08 1992-12-08
US07/986,948 1992-12-08

Publications (1)

Publication Number Publication Date
WO1994014286A1 true WO1994014286A1 (fr) 1994-06-23

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1993/010944 WO1994014286A1 (fr) 1992-12-08 1993-11-15 Recepteur d'appels selectif a fonction d'economie de piles pour les premier et deuxieme modes et sa methode d'utilisation

Country Status (4)

Country Link
JP (1) JP2912016B2 (fr)
CN (1) CN1032509C (fr)
AU (1) AU5602694A (fr)
WO (1) WO1994014286A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997036372A1 (fr) * 1996-03-27 1997-10-02 Motorola, Inc. Recepteurs d'appels selectifs a commande de gain variable pas a pas avec hysteresis
GB2315896A (en) * 1996-08-01 1998-02-11 Nec Corp Radio selective calling receiver
EP0868100A2 (fr) * 1997-03-26 1998-09-30 Nec Corporation Récepteur radio d'appels sélectifs à zones multiples avec procédé de resynchronisation répété entrecoupé par un procédé de balayage de fréquences
SG82573A1 (en) * 1997-04-28 2001-08-21 Motorola Inc Selective call receivers for receiving signals in synchronous communication systems

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4816820A (en) * 1986-10-21 1989-03-28 Motorola, Inc. Radio communication receiver with apparatus for altering bit rate of the receiver
US4818987A (en) * 1985-12-18 1989-04-04 Nec Corporation Selective paging receiver with message display
US5001776A (en) * 1988-10-27 1991-03-19 Motorola Inc. Communication system with adaptive transceivers to control intermodulation distortion

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4818987A (en) * 1985-12-18 1989-04-04 Nec Corporation Selective paging receiver with message display
US4816820A (en) * 1986-10-21 1989-03-28 Motorola, Inc. Radio communication receiver with apparatus for altering bit rate of the receiver
US5001776A (en) * 1988-10-27 1991-03-19 Motorola Inc. Communication system with adaptive transceivers to control intermodulation distortion

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997036372A1 (fr) * 1996-03-27 1997-10-02 Motorola, Inc. Recepteurs d'appels selectifs a commande de gain variable pas a pas avec hysteresis
GB2315896A (en) * 1996-08-01 1998-02-11 Nec Corp Radio selective calling receiver
US5977881A (en) * 1996-08-01 1999-11-02 Nec Corporation Radio selective calling receiver having battery saving function
GB2315896B (en) * 1996-08-01 2000-06-14 Nec Corp Radio selective calling receiver
EP0868100A2 (fr) * 1997-03-26 1998-09-30 Nec Corporation Récepteur radio d'appels sélectifs à zones multiples avec procédé de resynchronisation répété entrecoupé par un procédé de balayage de fréquences
EP0868100A3 (fr) * 1997-03-26 2000-02-09 Nec Corporation Récepteur radio d'appels sélectifs à zones multiples avec procédé de resynchronisation répété entrecoupé par un procédé de balayage de fréquences
US6057783A (en) * 1997-03-26 2000-05-02 Nec Corporation Multi-area radio pager with repeated resynchronizations interposed by frequency scanning process
SG82573A1 (en) * 1997-04-28 2001-08-21 Motorola Inc Selective call receivers for receiving signals in synchronous communication systems

Also Published As

Publication number Publication date
JPH08504311A (ja) 1996-05-07
JP2912016B2 (ja) 1999-06-28
CN1091872A (zh) 1994-09-07
AU5602694A (en) 1994-07-04
CN1032509C (zh) 1996-08-07

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