KR0130629B1 - Signal receiving method during the failure of preamble capture in pager - Google Patents

Abstract

Disclosed is a method and apparatus to receive house data in state of mismatching preamble within a multi alarm receiver. The method comprises steps of sustaining, testing and detecting. In the sustaining step, a receiving part is sustained in a driving state without periodic operation if the first set code is not received during a time. In the testing step, receiving result for the second set code from the receiving part is tested. In the detecting step, the third set code is detected if the second set code is received.

Description

Method to Receive Call Data Even in Failure of Preamble Acquisition in Multi-Alarm Receiver

1 is an apparatus block diagram of a multi-alarm receiver according to the present invention.

2 illustrates a POCSAG signaling format applied to the present invention.

3 is a flow chart illustrating a calling procedure of a multi-alarm receiver in accordance with an embodiment of the present invention.

4 is a timing chart to help understand the present invention by showing the power saving signal according to the present invention together with that of the prior art.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiple alert receiver having a battery saving function. In particular, the present invention relates to its own calling data even when a predetermined type of code, such as a preamp, fails. It relates to a method that can receive.

In general, a multi-alarm receiver, such as a well-known pager (or radio call receiver) or the like, receives and processes a predetermined radio frequency code signal transmitted wirelessly to alert the user of the receiver multiplely.

In general, a multi-repair receiver includes a power saving circuit to optimize power consumption provided by batteries. This circuit supplies a power saving signal to the receiver circuit so that the receiver circuit for receiving the RF code signal can operate periodically.

On the other hand, the representative signal format of the RF code signal received by the multi-alarm receiver is the POCSAG signaling format that is widely used today. This format is also specified in CCIR Recommendation 584.

The power saving function of the multi-alarm receiver used a long time ago was performed according to the presence or absence of the code signal, which checks the signal and, if present, continuously supplies the power saving signal to the receiver circuit for a predetermined time. This was a poor initial method.

A more advanced conventional power saving method is to allow receiving their own calling data individually in accordance with the signal. One of these techniques is the United States of America invented by Edward L. Ehmke et al. It is disclosed under the title BETTERY SAVER FOR A TONE CODED SIGNALLING SYSTEM of patent no. 4,370,753. Edward's patent finds the first set code which is the preamp data of the POCSAG code under the operation of the power saving function, and subsequently finds the second set code which is the sync code which follows. After finding the second set code, the receiver circuit, which consumes a relatively large amount of power, is turned off by the power saving signal until its frame time period starts. When the receiver circuit is driven again, it receives a third set code which is an address code and a message code in its frame. After receiving the third set code, the receiver circuit discloses a method of reducing power consumption by turning off the second set code time interval of the next batch and then looking for the second set code.

However, if the receiver circuit for receiving the RF code signal does not detect the preamble located at the head of the RF code format during periodic operation, then the following second and third set codes cannot be found, so the multi-alarm receiver can call its own call. It is not possible to receive data. The detection of the preamble, which consists of a pattern of bit inversions, is often caused in areas with weak field strength, and is often caused by fading or the like.

Therefore, as described above, since the reception of the call data according to the conventional power saving method is achieved only by detecting the preamble, even if the code data following the detection of the preamble is normal data, it is not received. Therefore, a multi-repair receiver has a problem in that case necessarily involving a failure to acquire its call data.

It is therefore an object of the present invention to provide a call data reception method of a multi-alarm receiver which can solve the above-mentioned problems.

Another object of the present invention is to provide a method for receiving its own calling data even if a predetermined type of code such as a preamble is missed.

It is still another object of the present invention to provide a multi-alarm receiver and a calling signal processing method which can improve reception efficiency when a transmission error occurs in a predetermined code due to a weak field strength or fading phenomenon. Is in.

According to the present invention for achieving the above object, in the call reception method of a multi-alarm receiver having a receiver part that is periodically operated at a predetermined time interval for power saving, and operating in response to a predetermined signal code, Counting the time when the first set code is not received if the first set code is not received during the periodic operation of the receiver part, and initializing the counting value if the counting value matches the preset period. Re-starting the receiver part to search whether the second setting code has been received, and sequentially receiving the third setting code upon receiving the second setting code; and when the predetermined time when the receiver part is restarted has elapsed, the predetermined time. Driving the receiver part according to a section and repeatedly searching whether the first set code is received; It characterized by true.

The above steps may be configured in hardware in the decoder part in the multi-alarm receiver, preferably in software by implementing the above steps in a high level programming language such as general purpose C-language or the like. have.

According to the present invention described above, when the first setting code corresponding to the preamble is normally received during the periodic operation of the receiver part within a predetermined time, a procedure for processing a general ho data is performed. If the first set code is not received through the receiver part, the receiver part is forcibly operated to find a second set code corresponding to the sync code. Thus, even if the first set code has an error due to weak field strength or fading phenomenon, it is possible to receive its own call data in the batch or the next batch.

In practice, the preamble is transmitted wirelessly from the paging transmission station at least once within a few tens of seconds. The basic concept of the present invention is to provide a calling signal processing method of a multi-alarm receiver that can receive its own call data even when an error occurs in the preamble in consideration of such a situation.

Hereinafter, the structure of a method and a multi-alarm receiver according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following description, detailed descriptions of the type of such structures and the like are provided to aid a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details. In addition, well-known circuit features and functions have not been described in detail in order not to obscure the present invention.

Referring to FIG. 1, which illustrates a device structure of a multi-alarm receiver applied to the present invention, the receiver includes an antenna 100 for capturing a modulated RF signal at a multi-alarm transmission side, and the angina ( A receiver part 110 demodulating the RF signal received from the receiver 100 and outputting the logic signal as logic level data, a decoder part 130 receiving the logic level data from the receiver part 110, and processing the received logic level data; A code memory 190 embedded in a frame code as a cap code and entangled by access of the decoder part 130, an address code in the cap code stored in the code memory 190, and the receiver part ( When the data output from 110 is compared and checked by the decoder part 130 and an appropriate calling signal is found, the data is received from the decoder part 130 and the liquid crystal is received. LCD 120 for displaying on the image, and the data in the decoder part 130 (actually, the decoder part 130 consists of a gate array 131 and the MPU 132, a 4-bit one-chip processor And an internal memory for storing in the MPU 132). In addition, the receiver has a configuration in which the decoder part 130 drives the allot 170 or the vibrator 180 in accordance with the received data. In addition, the call-indicator 150 is operated according to the on / off period of the allot signal, and the backlight lamp 160 is provided for back-lighting the LCD 120.

In addition, the decoder part 130 is connected to a memory / normal mode selection switch 240 and a lead key switch 230. Here, the memory mode refers to a silent mode in which the vibrator 180 is driven without driving the alert 170 even when a calling signal is detected. The operation of the mode is performed by a user selecting the selection switch 240. Is selected. The reed key switch 230 may be configured to forcibly stop the driving of the allot 170 or the vibrator 180 or to recall a received message stored in the internal memory of the decoder part 130. It is a user switch. In addition, a rechargeable battery 200 having a limited power capacity is embedded in the receiver, and includes a DC-DC converter 220 that generates power to be used for the decoder part 130 as the power of the battery 200. The battery 200 is provided with a switch 210 for the user to operate the power on / off.

In FIG. 1, line A is a line of received data which is the logic level data supplied to the decoder part 130 through the receiver part 110, and line B is the receiver part 110 from the decoder part 130. It is a line of power saving signal supplied. The power saving circuit built into the decoder part 130 periodically supplies the power saving signal to the receiver part 110.

Referring to FIG. 2 to describe the POCSAG signaling format applied to the present invention, the POCSAG signaling format is composed of a number of batches and preamble signals. The preamble signal 21 is for informing the multi-alarm receivers that a call is currently being sent. The signal causes the multi-alarm receivers to synchronize clock bits. In the present invention, the preamble will be referred to as a first set code. In this arrangement, the sync code 22, which is called a word sync or sync code word, is intended to synchronize the following code word signals (address and message code words), which is referred to as a second set code in the present invention. The codeword signal formatted after the second setup code, that is, its frame data (including addresses, messages, and idle codewords) will be referred to as a third setup code.

Here, the first set code is a 01010 type periodically inverted signal having a rate of 512 or 1200 bits per second, and according to the POCSAG standard (CCIR 584) according to the POCSAG standard (CCIR 584) to enable the power saving function of the multi-alarm receiver. Is sent out. Accordingly, the decoder part 130 may optimally maintain power consumption by supplying a power saving signal having a cycle of 64-bit on and 512-bit off to the receiver part 110.

As shown in FIG. 2, it can be seen that one arrangement structure of the POCSAG format is composed of a 32-bit word sync code (second set code) and eight frames. Message Codeword There are two codewords with 32 bits. That is, one arrangement structure is composed of 17 codewords in 32-bit units (16 second setup codes + 16 frames). In addition, one codeword is the same as 21 bits of information bits (both word sync, address, message, and idle codewords), 10 bits of BCH parity bits obtained by BCH encoding the 21 bits of data, and 31 bits (21). The total of one bit for even parity of +10) data is 32 bits. The algorithm of BCH encoding is specified in POCSAG [31. 21 BCH + PARITY]. It is processed by Codeword Generation. The simple processing of this equation is as follows. Each 32-bit codeword has 21 bits of information, which is related to the polynominal coefficients from X ³¹ to X ¹¹ . The polynominal coefficients are divided by a modulo-2 method by a predetermined syndrome generating polynominal (X ¹⁰ + X ⁹ + X ⁸ + X ⁶ + X ⁵ + X ³ + 1). To produce Thus, the calculation of the syndrome table corresponding to each of the 21 bits of information bits is derived. Therefore, the multi-alarm transmission side adds 21 bits of information bits BCH encoded using the syndrome table and 10 bits of parity bits generated at the time of encoding to generate 31 bits of data. The 31-bit data is used to make even parity 1 bit. Accordingly, it can be seen that each 32-bit codeword is transmitted in a structure as shown in FIG.

Accordingly, the multi-alarm receiver on the receiving side generates BCH parity again by performing BCH decoding on the codeword received through the receiver part using the syndrome table, and compares and checks the parity bit and the received parity bit. Here, the BCH decoding method proceeds in the reverse order of BCH encoding, and is largely processed by two methods, one of which is a software decoding method, and the other of which is a hardware decoding method. Since the hardware decoding method increases the memory capacity and peripheral devices, a decoding method using a 4-bit one-chip microprocessor (eg, HD40L4808H) is generally known.

The calling procedure of a multi-alarm receiver in accordance with an embodiment of the present invention is shown in FIG. 3, and the timing chart of the power saving signal for the understanding of the present invention is shown in FIG. Referring to FIG. 3, the reception standby start of step 300 is performed by the user of the receiver turning on the switch 210 of FIG. 1 and selecting the switches 230 and 240 appropriately. In step 302, the MPU 132 in the decoder part 130 supplies the power saving signal, such as 4B of FIG. 4, to the receiver part 110 via line B. FIG. Here, the on section of the power saving signal corresponds to the operation section of the receiver part 110. The on period T1 from time points 50 to 52 of 4B has a 64-bit time interval, and the off period T2 from time points 52 to 54 has a 512 bit time interval. Time point 54 is the start of a new on-interval period and maintains a 576-bit time interval from time point 50. The time interval from the time points 54 to 56 is the same as the on period T1. In step 304 the MPU 132 checks whether a preamble is received over line B. The check is substantially performed during the on period T1. If the preamble is normally detected, the MPU 132 extends the section T1 of 4B by a section of time points 40 to 42 of 4A to detect the second set code which is a word sync in step 306. That is, in the standby state in which the preamble is not received, a signal such as 4B is applied through line B. When the preamble is received at time point 40 of 4A, the operation period of the receiver part is 4A time point to detect the second set code. It will last up to 42. If the second set code is detected in step 308, step 312 is performed. Time points 42 to 44 of 4A indicate that the receiver part 110 is turned off and restarted after its detection of the second set code for power saving. In this embodiment, it is assumed that its frame data is the fourth frame in the batch, that is, named frame number 3. Thus, on time intervals from time points 44 to 46 are maintained to perform steps 314,316. If the address codeword in the third set code is detected in step 314, the processing of the message code with continues in step 316. In addition, the receiver part is turned off to save power. Step 318 proceeds when the address code is not detected or after performing 316 steps. When the next batch time, that is, the time when the second batch is started, step 320 is performed and then returned to step 308 again. The time points 46 to 48 of the 4A time interval are generated as the steps 318 and 320 are performed. Time point 50 corresponds to time point 42 and time points 52 to 54 are repetitions of time points 44 to 46. However, the above steps alone do not achieve the object of the present invention. That is, 4A is a power saving signal that is normally performed after the preamble is normally received, and 4B is a periodic power saving signal in the standby state when the preamble is not received.

In order to aid the complete understanding of the present invention, once again referring to the conventional problem, the fact that the preamble is not received for more than a few hundred seconds in areas with weak field strength is better understood by time points 60 to 62 of 4C. Can be. That is, in the related art, when the preamble is not transmitted wirelessly but the preamble is not received during the time period, the decoder part recognizes that there is no preamble and provides a 4B or 4C signal to the receiver part. Thus, the reception of the call fails.

In order to solve this conventional drawback, in the embodiment of the present invention, power saving signals such as 4D and 4E are provided to the receiver part separately from the period shown in the signal of 4B. The generation of such signals is achieved by the combination of the above-mentioned steps and steps 322, 324, 326 to be described below.

If no preamble has been received, then at step 322 the MPU 132 drives a preamble counter. The preamble counter is a counter for counting the time when the preamble is not detected. The counting of the MPU 132 may be performed by an internal watch dog, and may operate by installing a timer externally. If the counting value matches a predetermined time value in step 324, then the preamble counter is initialized in step 326 and step 306 proceeds. Therefore, the receiver part is forcibly driven after the period T3 from 72 to 74 even if the preamble is not checked at the time intervals 70 to 72 of 4D. Time points 74 to 76 are sections for detecting the second set code, and 4D time points 78, 80, 82, 84, 86, and 88 are 4A time points 44, 46, 48, 50, 52, and 54, respectively. Corresponds to. The time period T3 may be shortened by T2 and vice versa. That is, the setting can be made for a time corresponding to a maximum of several hundred seconds. Section T7 plus T5 and T6 of 4E is a section forcibly turning on the receiver part and searching for a second set code. Time points 77, 79, 81, 83, 85, 87, and 89 correspond to the time points 78, 80, 82, 84, 86, and 88, respectively. The signal of 4E is also provided when the preamble is not received in the time points 71 to 73. Although not shown, in the worst case the receiver part will be able to find the second set code of the next batch 2B.

Referring to the operation of the present embodiment as shown in FIG. 3, when a first setup code corresponding to a preamble is normally received during a periodic operation of the receiver part within a predetermined time, a procedure for processing general call data is performed. When the first setting code is not received through the receiver part within the predetermined time, it can be seen that the receiver part is forcibly operated to find the second setting code corresponding to the synchronization code. Thus, even if the first set code has an error due to weak field strength or fading phenomenon, it is possible to receive its own call data in the batch or the next batch.

As described above, the present invention has been illustrated and described in accordance with the embodiments, but the same is not limited to the present invention without departing from the lofty basic concept of the present invention, and various changes and modifications having ordinary knowledge in the art are possible. It will be clear.

For example, the procedure may be changed to detect the preamble again without looking for the second set code when the preamble is not detected for a certain period of time, and it may be possible to freely change the value of the preamble counter from hundreds of seconds to several tens of minutes. . In addition, it will be apparent to those skilled in the art that the BCH coding can be directly performed from the second configuration code of the next batch instead of performing the BCH coding from the reception of the third configuration code.

In the present invention, the POCSAG code is illustrated and described, but it is possible to receive its own frame data when the preamble is missed even by another method change even in the case of another predetermined code.

As described above, according to the present invention as described above, even when the preamble is missed due to weak field strength or fading or the like, it is possible to receive its own data, thereby greatly improving the call achievement rate. have.

Claims (6)

In a call reception method of a multi-alarm receiver having a receiver part periodically operated at a predetermined time interval for power saving and operating in response to a preset signal code, a first setting code is applied during periodic operation of the receiver part. If not received, counting the time when the first set code is not received, and if the counting value is equal to the preset time, initializes the counting value and restarts the receiver part to receive the second set code. Searching whether the second setting code is received and sequentially receiving the third setting code; and when the receiver part is restarted, when the preset time elapses, driving the receiver part according to the predetermined time interval to set the first setting. Multi-alarm receiver characterized in that it consists of a process of repeatedly searching for the reception of the code Call receiving method. The method of claim 1, wherein the preset signal code is in POCSAG format. 2. The method of claim 1 wherein the first set code is preamble. 4. The method of claim 3, wherein the second set code is a 32-bit sync code. 5. The method of claim 4, wherein the third set code is an address and a message codeword. In the call reception method of a multi-alarm receiver having a receiver part periodically operated at a predetermined time interval for power saving and operating in response to a preset signal code, the receiver part periodically operated within a prescribed time period A first step of counting the time when the preamble is not received; and resetting the receiver part and re-starting the receiver part when the counting value coincides with a preset time, and searching for the reception of the sync code. In step 2, when the sync code is received, the receiver part is turned off and restarted until its frame time interval starts, and the address and message codeword are received while the sync code is not received during the preset time. Characterized in that the third process to return to the first process Call reception method of a multi-alarm receiver.