JP2005286406A - Synchronization device between tdma radio stations - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a synchronization device between TDMA radio stations which is capable of synchronizing between radio stations by using a receiver with a simple configuration without providing a complicated receiver such as a GPS receiver, and eliminating the necessity of providing an independent synchronization reference station for synchronizing radio stations. <P>SOLUTION: In the TDMA radio system, each radio station 2 for performing radio communication on the basis of a TDMA system is provided with a transmission unit 23 for performing radio transmission according to a predetermined timing via a transmission antenna 21. In this system, each radio station 2 is provided with a synchronization device 1 between TDMA radio stations. This is provided with a receiver 12 for receiving the radio wave of a beacon including cell information to be regularly transmitted by an another existing radio ground station outside the TDMA radio system or a reference radio wave including a time code, and receiving a reception signal; a synchronization detector 13 for generating a synchronization signal on the basis of the reception signal; and a transmission control unit 14 for adjusting a transmission timing of the radio station 2 on the basis of the synchronization signal. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an inter-TDMA radio station synchronization apparatus that is provided in each radio station in a TDMA radio system in which each radio station performs radio communication based on a TDMA scheme, and synchronizes the radio stations.

  Conventionally, there is a TDMA (Time Division Multiple Access) system as one of the wireless communication systems. Since this TDMA system is a method of communicating in real time without collision by including a signal in a slot divided by a guard time in time, it is used in mobile phones and PHS that exchange voice and images. Yes.

  By the way, some conventional TDMA radio station synchronization apparatuses provided individually in each radio station in a TDMA radio system in which each radio station performs radio communication based on the above TDMA scheme, use a sequential transmission synchronization scheme. In this method, the delay time is corrected so that one of the other peripheral base stations establishes synchronization with the reference peripheral base station, and one of the other peripheral base stations is corrected based on the corrected peripheral base station. The delay time is sequentially corrected on a one-to-one basis such that the station establishes synchronization. However, such a sequential transmission synchronization method has a problem that the delay correction completion time increases in proportion to the number of neighboring base stations.

  In order to solve this problem, Patent Document 1 proposes a TDMA radio station synchronization apparatus that uses a GPS satellite to synchronize radio stations. According to this apparatus, even if various delay times occur when a call signal is transmitted from the central base station to each peripheral base station, it is synchronized with the period of the GPS clock generated by the GPS time received from the GPS satellite. Thus, since the neighboring base stations can simultaneously transmit the calling signal, the synchronization of the calling signal can be established instantaneously.

Note that Patent Document 2 discloses an asynchronous multiplex wireless communication device in which a receiver can reliably receive a signal transmitted from each transmitter regardless of the timing at which signals are transmitted from a plurality of transmitters. Has been.
JP-A-8-307932 JP 2002-319884 A

  However, in the TDMA radio station synchronization apparatus of Patent Document 1, for example, when a system that collects sensor information such as temperature, humidity, human detection, and alarm is configured with a TDMA radio system, a GPS receiver that uses a spread spectrum system, etc. Therefore, there is a problem in that the price of the TDMA radio system increases rapidly.

  The present invention has been made in view of the above circumstances, and it is possible to synchronize radio stations using a simple receiver without providing a complicated receiver such as a GPS receiver. Another object of the present invention is to provide a TDMA wireless station synchronization apparatus that does not require a separate synchronization reference station for synchronization between wireless stations.

  The invention according to claim 1 for solving the above-mentioned problem is a TDMA radio system in which each radio station that performs radio communication based on the TDMA scheme includes a transmission unit that performs radio transmission in accordance with a predetermined transmission timing. A TDMA inter-station synchronization device that is individually provided in each radio station and synchronizes the transmission timing of the radio station and the transmission timing of another radio station, and is another existing radio ground outside the TDMA radio system. A receiving means for receiving a received signal by receiving a beacon radio wave including cell information periodically transmitted by a station or a standard radio wave including a time code, and a synchronization signal based on the received signal received by the receiving means And a transmission control means for adjusting the transmission timing of the radio station based on the synchronization signal.

  In this configuration, a synchronization signal is generated based on a radio wave reception signal periodically transmitted by another existing wireless ground station outside the TDMA wireless system, and the transmission timing of the wireless station is adjusted based on the synchronization signal. Therefore, it is possible to synchronize each radio station using a receiver having a simple configuration without providing a complicated receiver such as a GPS receiver. Further, since radio waves from other existing radio ground stations outside the TDMA radio system are used, there is no need to separately provide a synchronization reference station for synchronizing the radio stations.

  According to a second aspect of the present invention, in the inter-TDMA radio station synchronization apparatus according to the first aspect, the transmission control of the synchronization signal is performed with an accuracy that an error with respect to the synchronization signal generated by the synchronization detection means is within a predetermined period. A timing means for repeatedly outputting to the means, and an operation for receiving the received signal by the receiving means in a period before or after the predetermined period by using the predetermined period periodically, and synchronization by the time measuring means While the operation of repeatedly outputting a signal to the transmission control unit is prohibited, the operation of receiving the reception signal by the reception unit is prohibited during the predetermined period, and the synchronization signal by the timing unit is repeatedly transmitted to the transmission control unit. Receiving control means for repeating the control to allow the output operation. In this configuration, the operation of receiving the reception signal by the reception unit is prohibited within a predetermined period that is used periodically, and the operation of repeatedly outputting the synchronization signal to the transmission control unit by the timing unit is allowed. In addition to synchronization between radio stations, the receiving means can be operated intermittently, and the power consumed for reception can be reduced.

  According to a third aspect of the present invention, in the inter-TDMA radio station synchronization apparatus according to the first or second aspect, each of the radio stations in the TDMA radio system is divided into a plurality of groups, and a signal having a different frequency for each group. It is characterized by wireless communication. With this configuration, even if the number of radio stations increases, the degree of decrease in responsiveness of the TDMA radio system can be reduced.

  According to the present invention, it is possible to synchronize radio stations using a simple receiver without providing a complicated receiver such as a GPS receiver, and synchronize radio stations. There is no need to provide a separate synchronization reference station.

(Embodiment 1)
1 is a configuration diagram of a TDMA radio station synchronization apparatus according to a first embodiment of the present invention, FIG. 2 is a diagram illustrating a TDMA radio system including radio stations including the TDMA radio station synchronization apparatus, and FIG. It is a figure which shows the operation timing of the synchronization apparatus between TDMA radio stations.

  As shown in FIGS. 1 and 2, the TDMA radio station synchronization apparatus 1 according to the first embodiment is configured such that each radio station 2 that performs radio communication based on the TDMA scheme has a predetermined transmission timing via a transmission antenna 21. In the TDMA radio system A including a transmission unit 23 that wirelessly transmits a signal including data from the input unit 22 according to the signal, each of the radio stations 2 is provided individually.

  In FIG. 1, illustration of other components such as a reception unit corresponding to the transmission unit 23 is omitted. As for the form of the TDMA wireless system A, as shown in the examples of FIG. 1 and FIG. 2, even if the wireless stations 2 do not include the moving body and wirelessly communicate with each other, A configuration may be employed in which wireless communication is performed with each wireless station 2. In short, the TDMA radio system of the present invention may be configured so that each radio station that performs radio communication based on the TDMA scheme includes a transmission unit that performs radio transmission in accordance with a predetermined transmission timing.

  The TDMA radio station synchronization apparatus 1 synchronizes the transmission timing of the radio station 2 and the transmission timing of another radio station 2, and includes an antenna 11, a receiver 12, a synchronization detector 13, and a transmission. And a control unit 14.

  The receiving unit 12 demodulates the radio wave of the beacon including cell information periodically transmitted by the radio ground station B in another existing TDMA radio system outside the TDMA radio system A after receiving it by the antenna 11. A beacon reception signal is received and the beacon reception signal is output to the synchronization detection unit 13. Here, as the radio ground station B, for example, a radio station in a system such as a mobile phone or a PHS is used. In such a case, the beacon periodically transmitted by the radio ground station B includes cell information such as base station ID and communication quality. The antenna of the radio station 2 may be a common antenna.

  The synchronization detection unit 13 generates a synchronization signal based on the beacon reception signal received by the reception unit 12. The synchronization signal is generated at the rising or falling time of the waveform corresponding to the predetermined information in the beacon by, for example, level determination.

  The transmission control unit 14 adjusts the transmission timing of the wireless station 2 based on the synchronization signal generated by the synchronization detection unit 13. For example, one cycle composed of a slot and a guard time is matched with the synchronization signal generated by the synchronization detection unit 13, and the transmission timing of the radio station 2 is set to the start time of the slot assigned to the own station (the radio station 2). Adjustments are made so that

  Next, operations that characterize the first embodiment will be described. A radio wave of a beacon including cell information is periodically transmitted from the radio ground station B in another existing TDMA radio system outside the TDMA radio system A. When the radio wave of the beacon is received by the antenna 11, the reception unit 12 receives a beacon reception signal. When the beacon reception signal is output from the reception unit 12 to the synchronization detection unit 13 as illustrated in FIG. 3, the synchronization detection unit 13 generates a synchronization signal based on the beacon reception signal. When the synchronization signal is output from the synchronization detection unit 13 to the transmission control unit 14, the transmission timing of the wireless station 2 is adjusted based on the synchronization signal, and the adjusted transmission timing signal is transmitted to the transmission control unit 14. To the transmitter 23.

  At this time, in FIG. 3, since there is no data to be transmitted from the input unit 22 such as the above-described sensor, the transmission unit 23 does not perform wireless transmission according to the transmission timing signal. After this state continues three times, data to be transmitted is input, but since there is no transmission timing signal from the transmission control unit 14, the data is temporarily held (accumulated) in the buffer. When the transmission timing signal is input from the transmission control unit 14, the wireless transmission of the signal including the data that is temporarily held is performed via the transmission antenna 21.

  As described above, according to the first embodiment, the synchronization signal is generated based on the beacon reception signal of the radio wave of the beacon periodically transmitted by the radio ground station B in the other existing TDMA radio system outside the TDMA radio system A. Since the transmission timing of the radio station 2 is adjusted based on the synchronization signal, a simple receiver can be used between each radio station 2 without providing a complicated receiver such as a GPS receiver. Can be synchronized. Further, since radio waves from other existing radio ground stations B outside the TDMA radio system A are used, there is no need to separately provide a synchronization reference station for synchronizing the radio stations 2.

  In the first embodiment, a wireless station in a system such as a mobile phone or a PHS is used as the wireless ground station B. However, the present invention is not limited to this, and a standard radio wave including a time code is transmitted. A configuration in which a radio station is used may be used. In the case of this configuration, the synchronization detection unit 13 may generate the synchronization signal in accordance with the rising or falling time of the waveform corresponding to the predetermined information of the time code, for example, by level determination. Specifically, the second is defined by the rising edge of the pulse signal, and the 55% value of the rising edge of the pulse is synchronized with the 1-second signal at the standard time, so that the synchronization signal can be generated based on the 1-second signal. .

  Needless to say, the transmission unit 23 may or may not be included in the TDMA radio station synchronization apparatus 1. In short, the present invention receives a received signal by receiving a beacon radio wave including cell information or a standard radio wave including a time code periodically transmitted by another existing radio ground station outside the TDMA radio system. Means, a synchronization detection means for generating a synchronization signal based on the reception signal received by the reception means, and a transmission control means for adjusting the transmission timing of the radio station based on the synchronization signal Good.

(Embodiment 2)
FIG. 4 is a configuration diagram of the TDMA radio station synchronization apparatus according to the second embodiment of the present invention, and FIG. 5 is a diagram illustrating operation timing of the TDMA radio station synchronization apparatus.

  As shown in FIG. 4, the TDMA radio station synchronization apparatus 1 according to the second embodiment is different from the first embodiment in that an error with respect to the synchronization signal generated by the synchronization detection unit 13 is within an allowable range for a predetermined period ( The internal timer 15 that repeatedly outputs to the transmission control unit 14 a synchronization signal that is substantially equal to the synchronization signal generated by the synchronization detection unit 13 within a predetermined time, that is, within a predetermined time; A reception control unit 16 for controlling the operation of the internal timer 15 is further provided.

  Next, a specific configuration of the reception control unit 16 will be described together with an operation that is a feature of the second embodiment. As shown in FIGS. 4 and 5, the reception control unit 16 periodically uses the predetermined period T2 in the period before or after the predetermined period T2 (the previous period T1 in FIG. 5). For example, the beacon reception control signal for the internal timer 15 is set to the high level to allow the reception unit 12 to receive the reception signal, and the timer control signal to the internal timer 15 is set to the low level, for example. The operation of repeatedly outputting to the transmission control unit 14 is prohibited. Thereby, the receiving part 12 performs the operation | movement which receives a received signal according to the beacon reception control signal which changed to the High level, for example. The internal timer 15 stops the operation of repeatedly outputting a synchronization signal to the transmission control unit 14 in response to, for example, a timer control signal that has changed to the Low level. The internal timer 15 may synchronize the timing at which the internal timer 15 outputs the synchronization signal with the timing of the synchronization signal output from the synchronization detection unit 13 during the period T1 during which the operation is stopped.

  The reception control unit 16 sets the beacon reception control signal to the reception unit 12 to, for example, a low level within the predetermined period T2 after the period T1, and prohibits the operation of receiving the reception signal by the reception unit 12, The timer control signal to the internal timer 15 is set to a high level, for example, and the operation of repeatedly outputting the synchronization signal by the internal timer 15 to the transmission control unit 14 is permitted. Thereby, the receiving part 12 stops the operation | movement which receives a received signal according to the beacon reception control signal which changed to the Low level, for example. The internal timer 15 operates to repeatedly output a synchronization signal to the transmission control unit 14 in accordance with a timer control signal that has changed to a high level, for example. Further, the above series of control is repeatedly executed.

  As described above, according to the second embodiment, the operation of receiving the reception signal by the reception unit 12 is prohibited within the predetermined period T2 used periodically, and the synchronization signal by the internal timer 15 is repeatedly transmitted to the transmission control unit 14. Since the output operation is allowed, the radio stations 2 can be synchronized, and the receiving unit 12 can be operated intermittently, so that the power consumed for reception can be reduced.

  In addition, in the period T1 in which the internal timer 15 stops the operation of repeatedly outputting the synchronization signal to the transmission control unit 14, the timing at which the internal timer 15 outputs the synchronization signal is the timing of the synchronization signal output from the synchronization detection unit 13. In this case, the synchronization signal can be repeatedly output to the transmission control unit 14 with the accuracy that the error with respect to the synchronization signal generated by the synchronization detection unit 13 is within the allowable range within the predetermined period T2 in each period T2. it can.

  In the first and second embodiments, the synchronization signal is configured to be used in the transmission control unit 14, but is used in a reception control unit (not shown), and the reception control unit is included in the TDMA radio system A. A receiving unit that receives a radio wave from the radio station 2 or the moving body and receives a reception signal may be configured to adjust the reception timing based on the synchronization signal.

  As a modification of the first and second embodiments, as shown in FIG. 6, each radio station 2 in the TDMA radio system A is divided into a plurality of groups G1,..., Gn, and different frequencies f1 for each group. ,..., Fn may be used for wireless communication. According to this configuration, even if the number of radio stations 2 increases, the degree of decrease in responsiveness of the TDMA radio system A can be reduced.

It is a block diagram of the TDMA radio station synchronizing apparatus of Embodiment 1 by this invention. It is a figure which shows the TDMA radio system comprised by each radio station including the same TDMA radio station synchronizer. It is a figure which shows the operation | movement timing of the same TDMA radio station synchronizing apparatus. It is a block diagram of the TDMA radio station synchronizing apparatus of Embodiment 2 by this invention. It is a figure which shows the operation | movement timing of the same TDMA radio station synchronizing apparatus. It is a figure which shows the modification of Embodiment 1,2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 TDMA radio station synchronizer 11 Antenna 12 Receiving part 13 Synchronization detection part 14 Transmission control part 15 Internal timer 16 Reception control part 2 Radio station 21 Transmitting antenna 22 Input part 23 Transmitting part

Claims (3)

In a TDMA radio system in which each radio station that performs radio communication based on the TDMA system includes a transmission unit that performs radio transmission in accordance with a predetermined transmission timing, each radio station is individually provided with a transmission timing of the radio station. And a TDMA radio station synchronization device that synchronizes with the transmission timing of other radio stations,
Receiving means for receiving a reception signal by receiving a radio wave of a beacon including cell information periodically transmitted by another existing radio ground station outside the TDMA radio system or a standard radio wave including a time code;
Synchronization detecting means for generating a synchronization signal based on the received signal received by the receiving means;
And a transmission control means for adjusting the transmission timing of the radio station based on the synchronization signal. A timing unit that repeatedly outputs a synchronization signal to the transmission control unit with an accuracy that an error with respect to the synchronization signal generated by the synchronization detection unit is within a predetermined period within an allowable range;
Periodically using the predetermined period, an operation of receiving a reception signal by the reception unit is permitted in a period before or after the predetermined period, and a synchronization signal by the time measurement unit is repeatedly output to the transmission control unit On the other hand, during the predetermined period, the operation of receiving the reception signal by the reception unit is prohibited, and the control for allowing the operation of repeatedly outputting the synchronization signal to the transmission control unit is repeated. The TDMA radio station synchronization apparatus according to claim 1, further comprising: a reception control unit.   3. The TDMA radio station synchronization apparatus according to claim 1, wherein each radio station in the TDMA radio system is divided into a plurality of groups and performs radio communication using signals having different frequencies for each group.

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