KR20010004635A - Synchronous signal transceiver and synchronization acquisition method its in communication system - Google Patents

Abstract

PURPOSE: An apparatus for transceiving synchronous signals in a communication system is provided to obtain synchronization by using an optional communication medium while operating the CDMA base stations. CONSTITUTION: A synchronous signal generator(211) generates synchronous signals at predetermined time periods. A time information generator(212) supplies time information according to the synchronous signals. A modem(213) modulates the synchronous signals and the time information, and transmits the modulated signals and the time information to a communication medium. Each of synchronous signal receivers(220,230) comprises as follows. A modem(221) demodulates the synchronous signals received from the communication medium. A signal processor(222) inputs the demodulated synchronous signals and detects equalization synchronous signals, generated at a time point same with the synchronous signals of the transmitter(210). The signal processor(222) transmits the detected equalization synchronous signals to base stations, and predicts a synchronous signal generating time point by using the demodulated synchronous signals for a predetermined time, then supplies synchronous signals appropriate to the predicted time point to the base stations. A time information detector(223) inputs the equalization synchronous signals, and detects original time information supplied from the transmitter(210), then transmits the detected original time information to the base stations.

Description

Synchronization signal transmission and reception device and communication acquisition method in communication system {SYNCHRONOUS SIGNAL TRANSCEIVER AND SYNCHRONIZATION ACQUISITION METHOD ITS IN COMMUNICATION SYSTEM}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synchronization signal transmission and reception apparatus and a synchronization acquisition method thereof in a communication system, and more particularly, to a synchronization signal transmission and reception apparatus and a synchronization acquisition method for operating a base station of a code division multiple access (CDMA) scheme. It is about.

1 is a configuration diagram of a transmission and reception system for explaining a conventional method of obtaining a synchronization signal, including a base station (110, 111), a terminal 120, a GPS (Global Positioning System) receivers (130, 131) GPS satellites 140, 141, 142 and 143.

A conventional synchronization acquisition method will be described with reference to the transmission / reception system of FIG. 1 having such a structure as follows.

Domestic base stations (110, 111) using the CDMA scheme was absolutely dependent on foreign GPS satellites (140, 141, 142, 143).

And, the GPS receivers 130 and 131 on the ground can simultaneously view up to 5 to 8 GPS satellites, and provide highly accurate synchronization and time information (TOD) of tracking GPS satellites. Receive.

At this time, the GPS receiver on the ground receives the synchronization signal from the tracking GPS satellites and provides the synchronization signal with a very small error (that is, less than 0.8 msec) to the base station.

Then, since the base station transmits the CDMA signal in accordance with the provided synchronization signal, all the base stations are synchronized with each other, so that the terminal 120 has a soft / softer handoff between base stations or base station sectors. Becomes possible.

However, in the conventional synchronization acquisition method as described above, there is a problem that a domestic mobile communication service cannot be smoothly performed when a situation such as GPS satellite failure or the use of GPS satellites is paid.

Accordingly, the present invention has been made to solve the above problems, and transmits the synchronization signal necessary for the operation of the CDMA base station from the transmitting side to the communication medium and all the CDMA base stations in the remote area receive the synchronization signal from the communication medium. By analyzing the information on the synchronization signal and predicting the synchronization signal that is close to the original synchronization signal, an arbitrary communication medium (for example, a Korean Mugunghwa satellite, etc.) can be used without relying on a GPS satellite provided by a foreign country when operating a CDMA base station. It is an object of the present invention to provide a synchronization signal transmission and reception apparatus and a synchronization acquisition method thereof capable of acquiring synchronization.

1 is a block diagram of a transmission and reception system for explaining a conventional synchronization signal acquisition method.

2 is a block diagram of an embodiment of a synchronization signal transmission and reception device in a communication system according to the present invention.

3A and 3B are diagrams illustrating an operation process of a synchronization signal transmission and reception device and a synchronization acquisition method thereof in a communication system according to the present invention.

4 is a flowchart illustrating an embodiment of a synchronization acquisition method in a communication system according to the present invention.

5 is a flowchart illustrating an embodiment of a synchronization signal transmission method according to the present invention.

Figure 6 is a flow diagram of an embodiment of a synchronization signal receiving method according to the present invention.

Explanation of symbols on the main parts of the drawings

210: sync signal transmitter 211: sync signal generator

212: visual information generators 213, 221: modem

220, 230: synchronization signal receiving unit 222: signal processor

223: visual information detector 240: satellite

250 and 251: base station 260: terminal

In order to achieve the above object, the present invention provides a synchronization signal transmission and reception device in a communication system, wherein the synchronization signal is generated at a predetermined time period and transmitted to a communication medium, and time information is transmitted to the communication medium according to the generated synchronization signal. Providing synchronization signal transmitting means; And detecting an equal synchronizing signal generated at the same time point as the synchronizing signal generated by the synchronizing signal transmitting means using the received signal received through the communication medium, and provided from the synchronizing signal transmitting means through the detected equal synchronizing signal. Detects the original time information and transmits it to the base station. The synchronization signal received through the communication medium for a predetermined time is used to predict the timing of occurrence of the synchronization signal in the synchronization signal transmitting means and synchronizes with the base station according to the prediction result. Synchronization signal receiving means for providing a signal.

In addition, the present invention provides a synchronization acquisition method in a communication system, comprising: a first step of generating a synchronization signal at a predetermined time period, modulating the generated synchronization signal and transmitting it to a communication medium; A second step of transmitting time information TOD according to whether or not the synchronization signal is generated in an even number of seconds, and transmitting a preamble signal of the synchronization signal to the communication medium after stopping a transmission operation for a predetermined time; And selectively predicting the timing of occurrence of the synchronization signal transmitted through the communication medium and the time information according to whether the signal received from the communication medium is a preamble signal of the synchronization signal. And providing a third step to the base station.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

2 is a block diagram of an exemplary embodiment of a synchronization signal transmission and reception device in a communication system according to the present invention. The synchronization signal transmission unit 210 and the synchronization signal transmission unit 210 for transmitting a synchronization signal are outputted as a communication medium. After receiving the synchronization signal transmitted through the satellite 240 to detect the equal signal, and the synchronization signal receiver 220, 230 for transmitting the synchronization signal to the base station (250, 251), respectively.

Here, the synchronization signal receivers 220 and 230 receive the transmitted information from the communication medium, detect the equal signal, and then provide the synchronization signals to the base stations 250 and 251 so that the terminal 260 receives the soft signal from the serviced base station. Softer handoff is enabled.

The synchronization signal transmitter 210 is a synchronization signal generator 211 for generating a synchronization signal at a predetermined time interval, and time information for providing time information TOD according to the synchronization signal transmitted from the synchronization signal generator 211. The generator 212 and the modem 213 which modulates and transmits the synchronization signal and time information transmitted from the time information generator 212 are comprised.

When the synchronization signal is generated every second from the synchronization signal generator 211, the synchronization signal transmitter 210 demodulates and transmits the synchronization signal and time information through the modem 213. At this time, the time information generator 212 determines whether the transmitted synchronization signal is an even second, and if it is an even second, there is time information (ie, year, month, day, hour, minute and second) after transmitting the synchronization signal. )

Each of the synchronization signal receivers 220 and 230 receives a modem 221 for demodulating a signal transmitted through the Mugunghwa satellite 240, which is a communication medium, and a signal demodulated by the modem 221. Detects an equal synchronization signal generated at the same time as the synchronization signal generated by the 210 and transmits it to the base stations 250 and 251, and uses the signals demodulated by the modem 221 for a predetermined time. A signal processor 222 for predicting the timing of occurrence of the synchronization signal of the < RTI ID = 0.0 >) < / RTI > and providing the synchronization signal to the base station and the synchronization signal detected by the signal processor 222. And a visual information detector 223 for detecting the original visual information transmitted from the mobile terminal and transmitting the original visual information to the base stations 250 and 251.

3A and 3B are explanatory diagrams illustrating an operation process of a synchronization signal transmission and reception device and a synchronization acquisition method thereof in a communication system according to the present invention, and the synchronization signal transmission and reception device of the present invention has the structure as described above with reference to this. The operation of the in detail is as follows.

First, the operation of the synchronization signal transmitter 210 will be described with reference to FIG. 3A.

The synchronization signal transmitter 210 first outputs one byte 'BB' of the ACSII method as a preamble of the synchronization signal, and informs that the synchronization signal 'AA' is soon transmitted.

After outputting the synchronization signal, the time information generator 212 determines whether the transmitted synchronization signal is an even-second synchronization signal, and transmits 16 bytes of time information after about 20 msec after the synchronization signal is transmitted.

As described above, after transmitting the time information TOD in the even-second synchronization signal, the transmission processor sleeps about 20 msec, and then transmits a preamble 'BB' of the synchronization signal again.

If the signal is not an even second synchronization signal, the processor sleeps about 40 msec and transmits a preamble 'BB' of the synchronization signal.

That is, the synchronization signal transmitter 210 repeats the cycle (Cycle) as described above every second.

Next, the operation of the synchronization signal receivers 220 and 230 will be described with reference to FIG. 3B.

First, when the synchronization signal receivers 220 and 230 receive the preamble 'BB' of the synchronization signal, the reception processor recognizes that the synchronization signal 'AA' is soon received and the synchronization signal is in a ready state. Wait.

If it is not the preamble 'BB' of the synchronization signal, it recognizes the time information TOD, receives 16 bytes of time information, transmits the time information TOD at 9600bps to the base station, and then preambles the preamble of the synchronization signal. Wait for BB '

Upon receiving the synchronization signal 'AA', the processor finds a time difference between the synchronization signal reception time and the synchronization signal (that is, the prediction synchronization signal) provided to the base station by the synchronization signal receivers 220 and 230.

At this time, since the synchronization signal transmitted from the Mugunghwa satellite 240, which is a communication medium, is transmitted as serial data, the lower the transmission baud rate, the larger the synchronization error of the synchronization signal, and the maximum 1 / board sec. Error will occur.

In order to solve this problem, the signal processor 222 is required in the synchronization signal receivers 220 and 230. In the signal processor 222, by calculating an average of the time difference between the synchronization signal 'AA' input time and the predicted synchronization signal for a predetermined time, an error caused by a low transmission baud rate can be reduced.

In this way, with the time difference obtained through the uniform signal detection, the processor may control the prediction synchronization signal generation time to provide a stable synchronization signal to the base station.

4 is a flowchart illustrating an embodiment of a synchronization acquisition method in a communication system according to the present invention.

Referring to FIG. 4, a synchronization signal is generated at approximately one second period, and the generated synchronization signal is modulated into a one-byte signal called 'AA' and transmitted to a transmission communication medium (401).

Subsequently, the transmitting processor determines whether the synchronization signal is generated in even or odd seconds (402), and if it occurs in even seconds, 20 msec passes, and then transmits 16 bytes of time information TOD, and again stops the transmission operation for 20 msec. (403). At this time, the 16-byte time information TOD is provided using a protocol provided from the base station to the terminal.

If the synchronizing signal is generated in an odd number of seconds in the process of determining the generation time of the synchronizing signal, the transmission operation is stopped for 40 msec without transmitting the time information TOD (404).

In this way, as in the transmission stop process (403, 404), the transmission is stopped for a predetermined time, and then the preamble 'BB' of the synchronization signal is transmitted to the communication medium (405). In the present invention, a synchronization signal is generated after approximately 10 msec after the preamble is generated.

Through this process, it is determined whether the signal received from the communication medium is a preamble 'BB' of the synchronization signal (406). If the synchronization signal is a preamble, the internal processor of the synchronization signal receivers 220 and 230 is ready. After waiting for the synchronization signal 'AA' for a predetermined time, and receiving the synchronization signal 'AA', the time difference detected by detecting the time difference between the predicted synchronization signal generation time and the reception time of the synchronization signal 'AA' is used. In step 407, the equal synchronization signal is detected, the time differences detected are accumulated for a predetermined time, the average value of the accumulated time values is taken, and the prediction synchronization signal generation time is changed according to the average value (407).

If the preamble 'BB' of the synchronization signal is determined in step 406, the synchronization signal receivers 220 and 230 receive and receive 16 bytes of time information TOD when the received signal is not the preamble 'BB' of the synchronization signal. The time information TOD is transmitted to the base station (407).

5 is a flowchart illustrating an embodiment of a synchronization signal transmission method according to the present invention.

Referring to FIG. 5, the synchronization signal transmitter 210 generates a synchronization signal at a period of about 1 second (501), and modulates the generated synchronization signal through the modem 213 to a 1-byte signal called 'AA' for transmission communication. Transmit with the medium (502).

Subsequently, the transmission processor inside the synchronization signal transmitter 210 determines whether the synchronization signal is generated in even or odd seconds (503), and if generated in even seconds, stops the transmission operation for 20 msec (504), and then 16 bytes. Time information TOD is transmitted (505), and the transmission operation is further stopped for 20 msec (506).

If the synchronizing signal is generated in an odd number of seconds in the process of determining the occurrence time of the synchronizing signal, the transmission operation is stopped for 40 msec without transmitting the time information TOD (507).

Thus, as in the transmission stop process (506, 507), the transmission is stopped for a predetermined time, and then the preamble 'BB' of the synchronization signal is transmitted to the communication medium (508).

In addition, the synchronization signal transmitter 210 repeatedly performs the above-described transmission process, and determines whether an operation stop command is transmitted from the outside through an internal processor (509), and if the operation stop command is not transmitted, the synchronization signal. The process proceeds to the generation process 501, and if the operation stop command is transmitted, the synchronization signal transmission ends.

On the other hand, the synchronization signal transmitter 210 repeats the above-described process (501 to 508) every second.

In addition, the synchronization signal transmitter 210 provides a pulse per second (1pps) synchronization signal and a preamble every second, and provides time information TOD every two seconds.

6 is a flowchart illustrating a method of receiving a synchronization signal according to the present invention.

Referring to FIG. 6, the synchronization signal receivers 220 and 230 determine whether the signal received from the communication medium is a preamble 'BB' of the synchronization signal (601), and if the synchronization signal is a preamble of the synchronization signal, In order to receive the signal 'AA', the internal processor of the synchronization signal receiver 220 or 230 waits for reception of the synchronization signal 'AA' for a predetermined time in a ready state (602).

Subsequently, when the synchronization signal 'AA' is received, a time difference between the predicted synchronization signal generation time (that is, the synchronization signal 'AA' is the time generated by the synchronization signal transmitter) and the reception time of the synchronization signal 'AA' are detected. An equal synchronization signal is detected using the detected time difference (603). Here, the detected equal synchronization signal is a synchronization signal generated by the synchronization signal receivers 220 and 230 at the same time when the synchronization signal is generated by the synchronization signal transmitter 210.

At this time, after accumulating the detected time differences for approximately 20 seconds, the average value of the accumulated time values is taken, and the synchronization signal receivers 220 and 230 according to the average value accurately generate the 1pps synchronization signal at the synchronization signal transmitter 210. In operation 604, an accurate synchronization signal is provided to the base stations 250 and 251 according to the prediction result.

Thus, the 1pps sync signal provided to the base station is a reference clock in the base station, which is used to generate a system clock in the base station.

Meanwhile, one terminal may communicate with two or more base stations, where each base station is provided with a 1 pps synchronization signal generated at the same time.

If the preamble 'BB' of the synchronization signal is determined in step 601, the synchronization signal receivers 220 and 230 receive a 16-byte time information TOD when the received signal is not the preamble 'BB' of the synchronization signal (605). The received time information TOD is transmitted to the base station (606).

The synchronization signal receivers 220 and 230 repeatedly perform the reception process as described above, and determine whether the operation stop command has been transmitted from the outside through the internal processor (607). The process proceeds to the synchronization signal receiving process 601, and if the operation stop command has been transmitted, the synchronization signal reception ends.

Although the technical idea of the present invention has been described in detail according to the above preferred embodiment, it should be noted that the above-described embodiment is for the purpose of description and not of limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention.

As described above, the present invention provides an arbitrary communication medium between a transmitter and a receiver by acquiring a synchronization signal using an arbitrary communication medium without relying on a GPS satellite provided abroad when the CDMA base station is operated. For example, it is possible to provide a stable synchronization signal to a CDMA base station outside the use of GPS satellites in other countries by using the Korean Mugunghwa satellite and transmission paths), and also to use domestic satellites in situations where foreign GPS satellites are unavailable or difficult to use. Only by using a stable synchronization signal necessary for the communication system has the effect of ensuring the stability of the communication.

Claims (9)

An apparatus for transmitting and receiving synchronization signals in a communication system, Synchronizing signal transmitting means for generating a synchronizing signal at a predetermined time period and transmitting the synchronizing signal to the communication medium, and providing time information to the communication medium according to the generated synchronization signal; And Detecting an equal synchronizing signal generated at the same time point as the synchronizing signal generated by the synchronizing signal transmitting means using the received signal received through the communication medium, and the original signal provided from the synchronizing signal transmitting means through the detected equal synchronizing signal. Detects and transmits the time information to the base station, predicts the timing of occurrence of the synchronization signal in the synchronization signal transmission means using the synchronization signals received through the communication medium for a predetermined time, and synchronizes the synchronization signal to the base station according to the prediction result. Synchronization signal receiving means for providing a Synchronous signal transmission and reception device in a communication system comprising a. The method of claim 1, The synchronization signal transmission means, Synchronizing signal generating means for generating a synchronizing signal at the predetermined time period; Time information generating means for providing time information according to the synchronization signal; And Modulation means for modulating the synchronization signal and time information and transmitting the same to the communication medium Synchronous signal transmission and reception device in a communication system comprising a. The method according to claim 1 or 2, The synchronization signal receiving means, Demodulation means for demodulating a received signal received from the communication medium; Receives a signal demodulated by the demodulation means, detects an equal synchronization signal generated at the same time point as the synchronization signal generated by the synchronization signal transmission means, transmits the signal to the base station, and demodulates the demodulation means during the predetermined time. Signal processing means for predicting a synchronization signal generation point in the synchronization signal transmission means using the received signals and providing a synchronization signal suitable for the prediction point to the base station; And Visual information detecting means for receiving the equal synchronizing signal detected by the signal processing means and detecting the original visual information provided from the synchronizing signal transmitting means and transmitting it to the base station. Synchronous signal transmission and reception device in a communication system comprising a. The method of claim 3, wherein The synchronization signal transmission means, And generating the synchronization signal substantially every second and providing the time information every even second. The method of claim 4, wherein The synchronization signal receiving means, And a synchronization signal transmission / reception apparatus for a communication system, wherein the synchronization signal transmission means predicts the timing of the synchronization signal generation using the synchronization signals received through the communication medium for substantially 20 seconds. In the synchronization acquisition method in the communication system, A first step of generating a synchronization signal at a predetermined time period, modulating the generated synchronization signal and transmitting the same to a communication medium; A second step of transmitting time information according to whether or not the synchronization signal is generated in an even number of seconds, transmitting a preamble signal of the synchronization signal to the communication medium after stopping a transmission operation for a predetermined time; And According to whether the signal received from the communication medium is a preamble signal of the synchronization signal, the synchronization signal and the time information corresponding to the occurrence time predicted by predicting the occurrence time of the synchronization signal transmitted through the communication medium selectively; Third step provided to the base station Synchronization acquisition method in the communication system made, including. The method of claim 6, The first step is, Generating a synchronization signal at substantially '1' second intervals; And A fifth step of modulating the generated synchronization signal into a predetermined byte signal and transmitting the same to the communication medium; Synchronization acquisition method in the communication system made, including. The method of claim 6, The second step, A fourth step of determining whether the synchronization signal is generated in even or odd seconds; A fifth step of stopping transmission operation substantially for 20 msec if it is determined that the synchronization signal is generated in even seconds in the fourth step; A sixth step of transmitting the time information to the communication medium after stopping the transmission operation for substantially 20 msec; A seventh step of stopping the transmission operation for substantially 20 msec after transmitting the time information TOD; An eighth step of stopping transmission operation substantially for 40 msec, if it is determined in the fourth step that the synchronization signal is generated in an odd number of seconds; A ninth step of transmitting a preamble signal of the synchronization signal to the communication medium after stopping the transmission operation for a predetermined time in the seventh or eighth step; A tenth step of determining whether an operation stop command has been transmitted from the outside after transmitting the preamble signal of the synchronization signal; An eleventh step of terminating transmission of the synchronization signal when it is determined that the operation stop command is transmitted in the tenth step; And If it is determined that the operation stop command is not transmitted in the tenth step, the twelfth step goes to the fourth step. Synchronization acquisition method in the communication system made, including. The method according to any one of claims 6 to 8, The third step, A thirteenth step of determining whether a signal received from the communication medium is a preamble signal of the synchronization signal; If it is determined in step 13 that the received signal is a preamble signal of the sync signal, receiving a sync signal modulated into a predetermined byte signal through the communication medium; The time difference generated between the predicted generation time by predicting the generation time of the synchronization signal and the reception time of the synchronization signal received through the communication medium is detected, and the synchronization signal of the transmitting side is generated using the detected time difference. A fifteenth step of detecting an equal synchronization signal generated at a receiving side at the same time as the viewpoint; After accumulating the time differences detected in the fifteenth step for substantially 20 seconds, taking an average value of the accumulated time values, predicting the precise occurrence time of the synchronization signal at the transmitting side according to the average value, and matching the estimated occurrence time to the A sixteenth step of providing a synchronization signal to the base station at a receiving side; A seventeenth step of receiving the time information from the communication medium when it is determined that the received signal is not a preamble signal of the synchronization signal in the thirteenth step; An eighteenth step of transmitting the received time information to the base station; A 19th step of determining whether an operation stop command has been transmitted from the outside after changing the prediction synchronization signal generation time or transmitting the received time information to the base station; A 20th step of terminating reception of the synchronization signal if it is determined that the operation stop command is transmitted in the 19th step; And If it is determined in step 19 that the operation stop command has not been delivered, step 21 goes to step 13 above. Synchronization acquisition method in the communication system made, including.