JP2912016B2 - Selective call receiver with battery saving function in first and second modes and method therefor - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates generally to a selective call receiver, and more particularly to a selective call receiver with battery saving features in first and second modes, and therefor. About the method.

BACKGROUND OF THE INVENTION Communication systems use at least one transmitter to define the coverage area of the system. Each radio frequency (RF) transmitter has an associated geographic coverage area in which a communication device, such as a selective call receiver, tuned to the appropriate frequency, transmits the transmission from the RF transmitter. Can be received. However, as the distance between the selective paging receiver and the RF transmission increases, it becomes more difficult for the selective paging receiver to receive the transmitted signal at the assigned frequency, and eventually the selective paging receiver becomes Going out of the relevant geographical coverage of the RF transmitter. In this position, the selective paging receiver will be outside the coverage area of the system and outside the range of the RF transmitter, and will therefore be able to receive any further transmissions from the RF transmitter. Becomes impossible.

Currently, selective paging receivers that receive signals having a predetermined signaling protocol utilize the lack of detection of the predetermined signaling protocol to determine that the receiver is out of range. However, some communication systems having different signaling protocols may share a single RF channel or frequency, which, when received by the selective paging receiver, The receiver may erroneously generate an out-of-range signal, which means that the selective paging receiver, which receives the signaling protocol of another communication system, is out of the coverage area of the system because the predetermined signaling protocol was not received. Is determined erroneously.

Also, when the selective call receiver is carried into a shielded area, such as an elevator, a subway or the shadow of a building, the selective call receiver receives the predetermined signal protocol. In some cases, out of range signals may be generated. Therefore, a selective paging receiver will generally receive the predetermined signal periodically if there is sufficient distortion from other sources that the signal quality will be too low for the selective paging receiver to decode correctly. The out-of-range signal is generated even though the selective call receiver is still within the coverage area of the system.

Thus, what is needed is a selective call receiver that can increase the sensitivity of the receiver to determine that the selective call receiver is out of range and maintain battery saving features.

SUMMARY OF THE INVENTION A selective call receiver comprises means for receiving a paging signal including at least a synchronization codeword, and means coupled to the receiving means for obtaining synchronization with the paging signal. Means are provided for detecting at least the first and second baud rates and generating the first and second signals. The first signal is the first and second signals.
And the second signal is generated in response to the first and second baud rates not being detected. Means coupled to the receiving means perform a battery saving function in the first and second modes. Means responsive to the generation of the first signal initiates battery saving means for achieving a battery saving function in the first mode. A means responsive to the generation of the second signal detects a condition out of range. The out-of-range detection means coupled to the battery saving means starts the battery saving function in the second mode.

Also provided is a method for saving battery life in a selective call receiver capable of receiving a paging signal including at least a synchronization codeword, comprising: (a) receiving the paging signal; and (b) the paging signal. (C) detecting at least first and second baud rates; and (d) detecting that at least one of the first and second baud rates is detected by step (c). According to the first
And e) generating a second signal in response to the detection of the first and second baud rates not being detected, and (e) achieving a battery saving function in the first and second modes. (F) starting a battery saving function in the first mode in response to the generation of the first signal;
And (g) detecting an out-of-range condition in response to the generation of the second signal and starting a battery saving function in the second mode.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a signal diagram of a prior art POCSAG protocol signal.

FIG. 2 is an electrical block diagram of a paging system showing a paging transmitter and a selective paging receiver according to a preferred embodiment of the present invention.

FIG. 3 is an electrical block diagram of a microcomputer used in the selective call receiver of FIG.

FIG. 4 is a block diagram of a memory location used as a register to determine the quality of a received signal according to a preferred embodiment of the present invention.

FIG. 5 is an electrical block diagram of a code configuration for increasing receiver sensitivity in accordance with a preferred embodiment of the present invention.

6 and 7 are flowcharts illustrating the operation of the selective call receiver of FIG. 2 according to the preferred embodiment of the present invention.

Description of the Preferred Embodiment Referring to FIG. 1, a traditional Post Office Code Stand
An ardization Advisory Group (POCSAG) protocol signal is shown, which includes message information directed to an individual or group of selective call receivers assigned to a range of addresses and / or paging systems. The series of addresses is assembled as required and transmitted as a continuous transmission. The transmitted signal is in digital format and starts with a preamble 102, which is equivalent to at least 576 bits, ie, one batch and one additional codeword period.
The preamble 102 is followed by one or more batch addresses and message codewords. Each batch begins with a synchronization codeword (SC) 104, which contains 8
Followed by a number of frames 106, each frame having a duration equivalent to two codewords 108, 110, an address codeword and / or a message codeword.

The diagram of the POCSAG signaling protocol 100 is one example of a number of signaling protocols applicable to the present invention. The POCSAG signaling protocol 100 is based on British Telecom
elecom), a binary frequency shift keying (FSK) modulated signal protocol originally proposed by
Anagram for the ost Office Code Standardization Advisory Group. The POCSAG protocol receiver performs separate bit and frame synchronization operations. Bit synchronization is a process used to determine the existence of bit boundaries in a data transmission having bits transmitted at a given baud rate, and then provide a clock to synchronously sample the bits. Frame synchronization arranges the transmitted bits so that the transmitted data is in a form to be decoded to indicate various word boundaries, such as the first bit of an address and data signal, and so on.

In operation, once bit synchronization is obtained by the POCSAG signal, the receiver remains in synchronous communication with the transmitter until there is no signal, i.e., the sequence for initially establishing bit synchronization is repeated. No need. The first word following the preamble is a synchronization codeword 104, which contains a predetermined binary sequence used for frame synchronization.
Eight frames 106 or 16 words of information 108, 110 follow 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 including a paging transmitter and a selective call receiver 200 according to a preferred embodiment of the present invention. The paging transmitter is coupled to an input device, such as telephone 256, for inputting a message or starting a page via paging controller 254. The paging controller 254 generates pages to be transmitted to the respective selective call receivers 200, for example, according to the POCSAG signaling protocol, among others. Paging controller 254 is a radio frequency transmitter / transmitting page via antenna 250
Coupled to receiver 252. The information, eg, the page, is preferably transmitted at a first baud rate and during a period during which no information is transmitted, and preferably a signal consisting of alternating "1s and 0s" is transmitted at a second baud rate. . The second baud rate is preferably lower than the first baud rate, for example, if the first baud rate is 512 or 120
The second baud rate corresponding to 0 baud is 300 or 750 baud, respectively. The page is received by the addressed selective call receiver.
Selective call receiver 200 includes an antenna 202 for capturing transmitted radio frequency (RF) signals. Antenna 202
Is coupled to the input of the receiver 204. The RF signal is preferably a selective call (paging) message signal, which provides, for example, an address and an associated message, such as a numeric or alphanumeric message. However, it will be appreciated that other well-known paging signal formats, such as tone-only signals or tone and voice signals, are suitable for use as well. Receiver 204 processes the RF signal and
At its output, a data stream representing the demodulated data information is generated. The demodulated data information is supplied to the decoder /
Coupled to an input of a controller 206, the decoder / controller 206 processes the information in a manner well known in the art. Baud rate detector 224, coupled to 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 generating a battery save signal from the decoder / controller 206 that operates the power switch 210. Provide battery saving function in response to 260. To increase the receiver sensitivity, the receiver sensitivity signal 262 is transmitted from the decoder / controller 206 to the receiver 20.
4, the operation of the receiver sensitivity signal 262 will be described in further detail below. The battery save signal 260 and the receiver sensitivity signal 262 cause the receiver 204 to toggle between on, off, weak signal mode and distortion mode as determined by the decoder / controller 206. Cord plug 222
Is coupled to the decoder / controller 206, a set of predetermined information, such as the time required for the selective paging receiver 200 to be out of range before the start of the out-of-range processing algorithm described below, Is stored.

For the purposes of this description, it is assumed that the POCSAG signaling protocol is used, but of course other signaling formats can be used as well. Decoder / controller 206 activates receiver 204 to detect synchronization codeword 104 by providing appropriate battery save signal 260 to power switch 210. Receiver 204 has sync codeword 10
4 (FIG. 1), remains active until the end of the transmission of the synchronization codeword 104, and at the end of the transmission of the synchronization codeword 104, the decoder / controller 206 issues a second battery save signal to turn off power to the receiver 204. provide. Receiving machine
204 is then activated so that the selective paging receiver looks at the assigned frame for the address and information words 108, 110 sent to the assigned group. After transmission of the sixteen words 108, 110, the synchronization code word 104 is transmitted again and the selective call receiver operates again in a manner similar to that described above.

When an address is received by the decoder / controller 206, the received address is compared to one or more addresses stored in the code plug (or code memory) 222 and a match is detected. At times, an alert signal is generated to alert the user that a selective call message, or page, has been received. The alarm signal is directed to an audible alarm 214 to generate an audible alarm or to a tactile alarm 216 to generate a silent vibration alarm. Switch 220
Enables the user of the selective call receiver to, among other things, make a selection between the audible alert 214 and the haptic alert 216 in a manner well known in the art.

The subsequently received message information is stored in the memory 304 (FIG. 3) and the switch 22 provides additional functions such as reset, read and delete, etc.
It can be accessed by a user for display using one or more of the zeros. In particular, by use of the appropriate functions provided by switch 220, the stored message or decoder / controller for display by display device 208 which is read from memory and allows the user to view the message Processed by 206.

The controller / decoder 206 of FIG. 2 can be configured using the microcomputer shown in FIG. FIG. 3 is an electrical block diagram of a microcomputer-based decoder / controller suitable for use in the selective call receiver of FIG. As shown, microcomputer 206 is preferably an MC68HC as manufactured by Motorola, Inc.
A 05-type microcomputer, which includes an on-board display driver 314.
The microcomputer 206 is the microcomputer 206
Includes an oscillator 318 that generates the timing signals used in the operation of. A crystal or crystal oscillator (not shown) is coupled to the input of oscillator 318 to provide a reference signal for establishing microcomputer timing. Timer / counter 302 coupled to oscillator 318 provides a programmable timing function used to control the operation of the receiver or processor. RAM (random accs
ess memory) 304 stores the variables obtained during the process,
As well as to enable storage of message information received during operation as a selective call receiver. A ROM (read only memory) 306 stores a subroutine for controlling the operation of a processor or a receiver, which will be described later. In many microcomputer configurations, the programmable ROM (PROM) memory area is EEPRO
It will be appreciated that it can be provided by M (Electrically Erasable Programmable Read Only Memory). The oscillator 318, timer / counter 302, RAM 304, and RO
M306 is coupled via an address / data / control bus 308 to a central processing unit (CPU) 310, which executes instructions and controls the operation of microcomputer 206.

The demodulated data generated by the receiver is input /
Microcomputer 206 via output (IO) port 312
Is combined with The demodulated data is processed by the CPU 310, and the received address is, for example, an I / O
If it is the same as the code plug memory coupled to the microcomputer through O port 313, the message, if any, is received and stored in RAM 304. Restoring stored messages and selecting a given destination address
Provided by a switch coupled to I / O port 312. The microcomputer 206 then restores the stored message and directs the information over a data bus 308 to a display driver 314,
Processes the information and formats the information for presentation by a display (not shown) such as an LCD (Liquid Crystal Display). When the address of the selective call receiver is received, an alarm signal is generated, which can be directed to an alarm generator 316 via a data bus 308;
The alarm generator 316 generates an alarm enable signal, which is coupled to the audible alarm described above. Alternatively, when the vibration alarm is selected as described above, the microcomputer generates an alarm enable signal, which is coupled to the I / O port 313 via the data bus 308 to provide a vibration or silent alarm. Can be generated. Battery saver operation provides a data bus to I / O port 312, which is coupled to the power switch by CPU 310.
It is controlled using a battery saving signal guided via 308. Power is periodically provided to the receiver to enable decoding of the received selective call receiver address signal and any message information intended for the receiver.

Referring to FIG. 4, a memory configuration for determining signal quality according to a preferred embodiment of the present invention is shown.
The quality factor of the received signal is calculated using a baud detector to analyze the frequency signature of the incoming restricted data from the receiver section and forms the basis of the quality calculation. The quality calculations are stored in registers and shown in RAM 304 in accordance with a preferred embodiment of the present invention. The signal is processed in at least four locations, preferably in quarter-bit time intervals, and the result is stored in four baud detection registers 350, 352, 354 and 356. Each register is loaded with the accumulated number of transitions during the baud detect cycle. The two largest numbers, usually adjacent registers (eg, registers 352, 354), are added together to determine quality at the selected gain state and also to
Describes the opening of the eye pattern for limited data input to the controller. The signal quality is at its maximum when all edges occur in only one quarter-bit interval. This configuration of the quality calculation provides a quarter-bit error resolution. High resolution of the eye pattern aperture can be achieved by increasing the number of samples taken per bit period.

Identification of the signal environment and appropriate receiver gain settings for a partial synchronization, synchronization or multi-signal baud rate system is achieved by conditional continuous frequency analysis at selected gains (referred to as baud detection). This technique increases receiver sensitivity to an Inter-Modulation (IM) environment without increasing the average current drain of the pager. Receiver sensitivity is increased by analyzing the frequency response of the incoming signal, or eye threshold pattern, for the correct baud rate at the selective gain setting. For example, in an IM environment, a low gain setting has the highest probability of being selected over a high gain setting, and in a weak signal or fading environment, a high gain setting has the highest probability of being selected over a low gain setting. . The bit error rate (BER) is directly dependent on the frequency characteristics (eye pattern aperture) of the limited data output from the receiver section. Although eye patterns provide a much better indication of signal quality than algorithms based on bit error rates, eye patterns can provide an earlier indication of fading or IM environments with or without bit errors. Because it can be given. Eye Pattern Openin
g) refers to the time required for the limited data output from the receiver section to be determined as one or zero. The BER is minimized when the decision point for determining 1 or 0 is at the center of the eye pattern, and the BER increases as the decision point for determining 1 or 0 moves from the center of the eye pattern. I do.

Referring to FIG. 5, there is shown a detailed electrical block diagram of a decoding configuration for increasing the sensitivity of a receiver according to a preferred embodiment of the present invention. As mentioned earlier, RO
M stores a subroutine for controlling the operation of the selective call receiver. However, it will be appreciated that the operation of the selective call receiver can also be controlled by hardware circuitry. According to a preferred embodiment of the present invention, the receiver 204 of the selective call receiver 200 shown in FIG.
412 is provided. The signal received by antenna 202 is
Supplied to RF front end 400. The response of the received signal is optionally responsive to a signal 262 from the decoder / controller 206 for a first attenuator 402 and a second attenuator 406.
Attenuated by Diode switch 432 is controlled by decoder / controller 206 to provide the switching necessary to operate the first and second attenuators and to operate RF amplifier 404 in the first and second states. The first state has a different RF gain than the second state. Alternatively, the response of the received signal can be detuned by a varactor (not shown) that can replace the voltage diode switch 432.

Receiver 204 receives signal 26 from decoder / controller 206.
When turned on by the power switch 210 in response to 0, power from a power source, eg, a battery (not shown), is provided to the voltage switch / regulator 424, which switches the RF front end 400 and current Power source 426, which powers receiver backend 412. The decoder / controller 206 determines from the received signal whether to operate the receiver in a high gain state or a low gain state. This determination will be described later in detail. If the decoder / controller 206 determines that the receiver should operate in the high gain state, a signal is provided to the input of the voltage diode switch 432, which generates a signal 262, which is the first and second signals. Second attenuator 402,4
06 is turned off, and the operation state of the RF amplifier 404 is set to the first state.
, For example, the normal operation gain is set. Alternatively, if the decoder / controller 206 determines that the receiver should operate at low gain, a signal is sent to the voltage diode switch 432,
Generates a signal 262, which turns on first and second attenuators 402,406, which attenuate RF
The signal is attenuated and the operating state of the RF amplifier 404 is set to a second state, for example, a 10 dB lower operating gain. The control of the first attenuator 402, the second attenuator 406 and the RF amplifier 404 can be performed by simultaneously applied signals and by independently applied signals.

Thus, depending on the received signal, decoder / controller 206 determines whether to operate the receiver in a high gain state or a low gain state. If the selective paging receiver 200 is very close to the RF transmitter, the selective paging receiver will receive a "strong" signal, and as a result, the decoder / controller will operate the receiver 206 in a low gain state. This can save battery life because the received signal is strong and can therefore be easily received and decoded with low power. On the other hand, if the selective paging receiver 200 is further away from the RF transmitter, the received signal is "weak", and thus the decoder / controller 206 changes the receiver to high gain (generally, Operate at normal power setting). Thus, based on analysis of the received signal, the selective paging receiver can optimize its battery life by operating the receiver in a low gain state and thus require less burden on the battery or power supply. Become. The bias state of RF amplifier 404 is also controlled by decoder / controller 206 which switches the amplifier from a high gain state to a low gain state and back. The output of the RF amplifier 404 via the second attenuator 406 is supplied to a first mixer 408, which
Accepts a second input from first oscillator 410 and provides an intermediate frequency (IF) to second mixer 420 by techniques well known to those skilled in the art. The frequency of the signal from the first oscillator 410 determines the assigned frequency or channel at which the selective paging receiver operates. Therefore, the first
The output signal from the mixer 408 is provided to a traditional circuit receiver backend 412, which receives a second signal to process the received signal in a manner well known in the art. Mixer 420, second oscillator 422, amplifier 41
8. It has a demodulator 416 and an audio limiter 414. The circuitry of the receiver back end 412 removes adjacent channel signals and demodulates the received signal and provides the output to the decoder / controller 206 for further processing.

As previously mentioned, the battery save signal 260 and the receiver sensitivity signal 262 are transmitted from the decoder / controller 206 to the receiver 204 voltage switch / regulator 424 and current source 42.
6 supplied to control the operation of the receiver to achieve optimal battery life. In operation of the preferred embodiment of the present invention, further described, the out-of-range signal processing routine allows the controller / decoder 206 to operate the receiver in the super-battery saver mode via the battery save signal 260 and the sensitivity controller 430. The sensitivity of the selective paging receiver is switched each time the unit is turned on if the selective paging receiver is determined to be "out of range",
Increase the ratio of the time that the receiver 204 is off to the time that the 204 is on. In operation, if the controller / decoder 206 determines that the selective paging receiver is out of range, an alarm generator 316 may generate a predetermined alert, eg, a word, eg, “OUT OF RANGE”.
RANGE) is received to provide a predetermined alert.

Referring to the flowchart of FIG. 6, the preferred operation of the selective call receiver is shown. During startup, the selective call receiver powers up and initializes all variables to begin receiving the transmitted signal. During initialization,
The gain of the receiver is selected from at least two gain states described above with reference to FIG. Based on the previous operation of the receiver, an initialization bit is set, which determines the gain state selected in the next receiver operation. Steps
At 500, a receiving circuit is turned on to receive a predetermined signal protocol by the assigned frequency channel, and the gain state is selected. In this way, the gain state used by the receiver as its initial gain can be the first gain state or the second gain state depending on previous operation of the receiver. In step 502, baud detection is performed on the received signal, and the quality of the received signal is determined at the first selected gain state. During step 502, a timeout flag is set when the receiver times out before detecting a valid baud rate. As mentioned above, the received signal is transmitted at either the first or second baud rate, and consequently at step 502 a baud rate detection is performed and either the first or second baud rate is being transmitted. Detect that. During the baud rate detection,
A quality factor is assigned to the received signal in the first selected gain state. If baud rate detection is not successful, the quality factor assigned to the signal is zero. However, if a valid baud rate is detected, or if baud detection is not successful due to a predetermined timeout period before the baud rate of the received signal is determined, the signal quality factor Is calculated in the first gain state. According to a preferred embodiment of the present invention, the signal quality is calculated by selecting preferably two of the at least four registers of the baud detection circuit having the largest number of recorded transitions. The sum of the number of transitions of the two registers with the maximum number of recorded transitions will be equal to the quality of the signal being received in the first gain state. At step 504, a determination is made to determine whether a valid baud rate has been detected. In step 506, if the code plug is programmed with an option to detect a second baud rate, for example, 300 baud rate for a 512/300 baud rate system, the second code plug option is selected, It is determined whether a baud rate (for example, 300 baud rate) signal is detected. If so, in step 508, the receiver is turned off and a battery saving option, a first battery saving mode, is initiated for a predetermined time.

Beginning at step 506, if the second baud rate has not been detected and the first baud rate has been detected at step 504, the next gain state is selected at step 510 and the first or second baud rate is selected. Another baud rate detection is performed to determine which one is being transmitted. In step 10, the signal quality factor is also calculated in the second gain state. Following the baud detection at step 510, step 512 determines whether a valid baud rate has been detected. If so, in step 514, the absolute value of the difference between the quality of the signal in the first gain state and the quality of the signal in the second gain state is calculated (Qdelta). The calculated Qdelta is checked at step 516 to determine that it is above the maximum quality (Qmax) stored in memory. If it is greater than or equal to Qmax, then in step 518, the gain of the receiver is set to the low gain state and the selective paging receiver is set to the first
In the battery saving mode. Alternatively, if Qdelta is not greater than or equal to Qmax in step 516, the calculated quality in the second gain state is compared in step 520 to determine whether it is greater than the calculated quality in the first gain state. Is done. If it is greater than the calculated quality in the first gain state, the receiver selects the gain associated with the second quality calculation in step 522, ie, selects the second gain state. However, if the quality in the first gain state is less than or equal to the quality in the second gain state, the receiver selects the first gain state in step 524.

Alternatively, if an invalid baud rate is detected in step 512, the receiver again selects the first gain state in step 526 and determines that a valid baud rate is detected in the first gain state. In such a case, the first gain state is selected to ensure that no error has occurred, and another baud rate detection is performed in the first gain state. At step 528, a determination is made as to whether a valid baud rate has been detected, and if so, at step 524 the gain is set to the first baud rate.
Is set to the gain state. However, step 52
At 8, if no valid baud rate is detected, the receiver is turned off. In this way, if a valid baud rate is determined in the first gain state and is not detected in the second gain state, the selective paging receiver sets the receiver to operate in the first gain state a second time. Before the operation, it is checked whether a valid baud rate is correctly detected in the first gain state.

Still referring to the flowchart of FIG. 7, the preferred operation of the selective call receiver is shown. If a valid baud rate is not detected at step 504, the processor determines at step 530 whether a timeout period has occurred before the baud rate is detected. If an invalid baud rate is detected, but not due to a timeout period, then in step 542 the gain of the RF amplifier is set to the second gain state and baud rate detection is performed and the quality of the received signal is reduced. It is calculated as described above. At step 534, a determination is made as to whether a valid baud rate has been detected. If the code plug is programmed with an option to determine whether a second baud rate has been detected, for example, a 300 baud rate for a 512/300 baud rate system, step 536 may include the second baud rate (eg, It is determined whether a signal of 300 baud rate) is detected. If so, in step 538 the receiver turns off and the option of battery saving in the first battery saving mode is initiated. Alternatively, if the second baud rate is not detected in step 536, then in step 540 the signal quality is checked in the second gain state previously calculated in step 532 to detect a high or low quality signal. In order to determine whether or not it has been performed, it is preferably determined whether or not the quality threshold (Qthreshold) stored in the code plug is greater than the threshold value. If the signal quality is greater than Qthreshold and a high quality signal is detected, the RF amplifier of the receiver is set to the second gain state in step 546.

Alternatively, if it is determined in step 540 that the signal quality is low, then in step 542 the second gain state is set to ensure that the valid baud rate detected in step 534 is not an error. Performs another baud rate detection. Step 54
At 4, a determination is made as to whether a valid baud rate has been detected and, if detected, step
At 546, the gain is set to a second gain state. However, if no valid baud rate is detected in steps 544, 534, 530 or 528, step 54
At 8, the receiver turns off. In step 550, the timeout timer initialized in the initialization step is incremented, and in step 552 the timer is checked to determine if the timeout value has elapsed. If the timeout period has not elapsed, a first (eg, normal) battery save operation is initiated for a predetermined period. However, if the timeout period has elapsed, at step 554, the super-battery saving routine (battery saving in the second mode) is initialized for out-of-range battery saves. In step 556, baud rate detection is performed at the first and second baud rates. Step 558 determines whether a valid baud rate has been detected, and if so, processing proceeds to block A.
followed by. Alternatively, if a valid baud rate is not detected, the gain state is changed at step 560 and processing continues from step 556 until the selective call receiver is within range of the transmitter. Is repeated by continuing the routine. In this way, the effective baud rate is
And if not detected in the first gain state, the selective paging receiver corrects the second effective baud rate before the receiver operates in the second gain state. Check if the status is detected.

Except when the first baud detection has a signal quality higher than a predetermined threshold quality, the second baud detection is performed in the next gain state. Transmission of two separate baud rates achieves improved battery life. That is, during a quiescent period, a selective paging receiver in which a random signal pattern is transmitted and does not check for the presence of this signal will severely reduce battery life, but it will cause the selective paging receiver to be out of range. This is because it is not possible to properly determine that they have entered. Thus, a third baud rate detection is performed to reduce the wrong rate, and a generally valid baud rate is performed at the same gain previously detected. The third baud rate detection may be performed when the first baud detection does not find a valid baud rate, and when the second baud rate detection detects a valid baud rate with a signal quality lower than the quality threshold, or This is performed when the first baud rate detection does not detect a valid baud rate and the second baud rate detection detects a valid baud rate. This process eliminates possible erroneous conditions and improves battery life by providing a second battery saving mode in the event that the receiver is determined to be out of range, allowing the receiver to be out of range. Eliminate routines that consume unnecessary current until returning.

From the foregoing, there is provided an improved and more reliable signal processing technique that can enable a selective paging receiver to quickly recover from out-of-reach situations without the consequence of using large battery capacity. It should be understood that If the selective paging receiver determines that it is outside the reception coverage area, the processor will enter a modified battery saving mode after a preset amount of time has elapsed. This consists of longer off-to-on ratios and alternating receiver sensitivities that increase battery life while changing the sensitivity of the receiver. Out-of-range technology does not reduce battery life for the receiver by switching the receiver sensitivity each time the selective call receiver turns on after the selective call receiver determines that it is out of range. Used to guarantee quick response time.

In short, the selective paging receiver comprises means for receiving a paging signal having at least a synchronization codeword. The receiving means has variable gain control means for enabling the receiving means to receive a paging signal with at least first and second gains. Means coupled to the receiving means obtain synchronization with the paging signal. Detecting valid and invalid baud rates at least in the first and second baud rates;
A means for generating the signal of The first signal is generated in response to at least one valid baud rate being detected at the first and second baud rates;
The second signal is generated in response to detection of an invalid baud rate for the first and second baud rates. Means for determining the quality of the received paging signal are used. Means for controlling the gain of the receiving means in response to the determination of the quality of the received paging signal is used. Means for performing a battery saving function in the first and second modes coupled to the receiving means is used. Means for initializing the battery saving means to achieve a battery saving function in a first mode in response to the generation of the first signal, and in response to the generation of the second signal. Means for detecting out-of-range conditions is used. The out-of-range detection means coupled to the battery saving means starts the battery saving function in the second mode. Means for maintaining a battery saving function in the second mode in response to the generation of the second signal are used.

Continuing the front page (72) Inventor Hayes David Jeffrey Heathley Drive, Lake Worth, 33467, Florida, USA 7379・ Marie Cycle 8083 (56) References JP-A-4-304043 (JP, A) JP-A-3-239024 (JP, A) JP-A-1-502870 (JP, A) US Patent 5001776 (US, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) H04B 7/24-7/26 H04Q 7/00-7/38

Claims (10)

(57) [Claims] 1. A selective paging receiver, comprising: receiver means for receiving a paging signal having at least first and second baud rates, coupled to the receiver means for obtaining synchronization with the paging signal. A baud rate detector for detecting the at least first and second baud rates of the received paging signal, wherein the decoder / controller detects that the first baud rate has been detected. Generating a first signal responsively and generating a second signal in response to the second baud rate being detected, and generating a third signal in response to the first and second baud rates not being detected. Generating a signal, and activating the battery saving function in the first mode in response to the generation of the first signal. And the second
A power switch for starting the battery saving function in the second mode in response to the generation of the third signal, and for starting the battery saving function in the third mode in response to the generation of the third signal. A selective call receiver comprising: 2. The selective call receiver of claim 1, wherein said baud rate detector detects paging signals for valid and invalid baud rates of said first and second baud rates. 3. The selective call receiver according to claim 2, wherein said receiver means further comprises means for changing the gain with at least first and second gains for receiving a paging signal. 4. The selective call receiver according to claim 1, further comprising means for maintaining the battery saving function, wherein the power switch maintains the battery saving function until another signal is generated. . 5. A method for conserving battery life in a selective call receiver capable of receiving paging signals having at least first and second baud rates, comprising: (a) setting the at least first and second baud rates; Receiving the paging signal having: (b) detecting the at least first and second baud rates of the received paging signal; (c) detecting the first baud rate in the step (b) Generating a second signal in response to detecting the second baud rate in step (b), and generating a second signal in response to detecting the second baud rate in step (b);
Generating a third signal in response to no baud rate being detected, and (d) providing a battery saving function in a first battery saving mode of operation in response to the generation of the first signal. Perform the second battery saving mode operation in response to the generation of the second signal, and perform the operation in the third battery saving mode in response to the generation of the third signal. Performing a method for conserving battery life. 6. A selective paging receiver for receiving a paging signal having at least a first baud rate and a second baud rate, the receiver comprising at least a first and a second power. A baud detector for determining that paging signals at the first and second baud rates are being received at the first power level; and a paging signal coupled to the baud detector. A decoder / controller processing the paging signal at the first and second baud rates to determine a quality of the paging signal, the decoder / controller storing information indicative of a quality of the received paging signal. A plurality of registers for comparing information of the plurality of registers with information exceeding a certain threshold Means for determining a register of the plurality of registers; a central processing unit for determining the baud rate and calculating the quality of the paging signal; and the paging for any of the first and second baud rates. Means for selecting a first power level of the receiver in response to a signal quality exceeding the threshold, and a first in response to the first baud rate. Starts battery saving in the second operation mode according to the second baud rate, and starts third battery operation in the second operation mode according to the absence of the first and second baud rates. A power switch for initiating battery saving with the selective call receiver. 7. The means for selecting the second power level of the receiver in response to the baud detector detecting an invalid baud rate for the first and second baud rates. Wherein the receiver receives the paging signal at the second power level in response to the means for selecting, and the central processing unit sends the paging signal to the baud rate detector. Initiating detection of first and second baud rates, and the means for comparing compares the information with the threshold value in response to the baud detector, and detects first and second paging signals. 7. The selective call receiver according to claim 6, wherein it is determined whether any of the two baud rates has been received. 8. The selective call receiver according to claim 6, further comprising a timer for periodically checking information in said register according to said threshold value. 9. A method for changing the power level of a receiver in a selective call receiver, the method comprising: (a) receiving a paging signal having at least a first baud rate and a second baud rate; Receiving the paging signal at first and second power levels; and (b) processing the paging signal so that the paging signals at the first and second baud rates are at the first power level. (C) detecting a transition of the paging signal, wherein the detecting detects a baud rate of the paging signal; and (d) detecting a transition of the paging signal at each baud rate. Determining the quality, wherein: (e) the pager at the first and second baud rates; Storing the number of detected transitions of the signal; and (f) comparing the sum of contents of first and second registers storing the maximum number of detected transitions for the first and second baud rates. (G) calculating the quality of the paging signal received at the first and second baud rates; (h) a threshold value for the quality of the paging signal for any of the first and second baud rates Selecting the first power level in response to exceeding the threshold, and selecting the second power level in response to the quality of the paging signal not exceeding the threshold. And (i) starting battery saving in a first operation mode according to the first baud rate, and battery saving in a second operation mode according to the second baud rate The method was initiated and the first and second initiating a third battery Say Bing in an operation mode in response to a lack of baud rate comprises a changing in the selective call receiver, the power level of the receiver. 10. The number of detected transitions of said first register in response to the sum of the number of detected transitions in said first and second registers being less than said threshold value. The second
(K) selecting the first power level in response to the content of the first register being greater than the content of the second register; and 10. The method of claim 9, comprising: (l) selecting the second power level in response to the content of the second register being greater than the content of the first register.