JP2016039514A - Synchronization signal converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synchronization signal converter which allows for installation of a base station even in an environment where a GPS signal and a network signal cannot be received, while increasing the degree of freedom of system construction.SOLUTION: A broadcast wave synchronization signal extraction unit 110 acquires a broadcast wave synchronization signal from received broadcast waves, a synchronization signal conversion unit 120 converts a broadcast wave synchronization signal into a synchronization signal of pseudo GPS signal or pseudo network signal, and generates a pseudo GPS reception signal (pseudo GPS signal)including the converted synchronization signal, and a pseudo GPS signal transmission unit 130 outputs the GPS signal to a base station 5, where a reference clock can be generated from the pseudo GPS signal.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a synchronization signal conversion apparatus attached to a base station of a mobile communication system, and in particular, acquires a synchronization signal from a broadcast wave and synchronizes a pseudo GPS reception signal in accordance with a GPS (Global Positioning System) signal. The present invention relates to a synchronization signal conversion apparatus capable of increasing the degree of freedom of system construction by converting into a synchronization signal of a pseudo network reception signal according to a signal or a network signal.

[Conventional technology]
Conventionally, in a mobile communication system using a CDMA (Code Division Multiple Access) system or a WiMAX (Worldwide Interoperability for Microwave Access) system, an external clock is used as a synchronization signal between base stations.
A conventional base station apparatus receives a signal from a GPS system satellite as an external clock and extracts a synchronization signal, extracts time information and uses it as a synchronization signal, A synchronization signal may be used.

[Base station apparatus: FIG. 10]
The structure of the conventional base station apparatus is demonstrated using FIG. 10 and 11 are schematic configuration diagrams of a portion that acquires the synchronization signal of the base station apparatus. In FIGS. 10 and 11, portions other than those related to synchronization signal acquisition are omitted.
As shown in FIG. 10, the base station apparatus 5 includes a GPS antenna 50 that receives a GPS signal, a GPS receiver 51 that demodulates the GPS signal, and a GPS synchronization signal extraction unit 52 that extracts a synchronization signal from the GPS signal. I have.
Then, the GPS signal is received by the GPS antenna 50, the GPS receiving unit 51 converts it into a baseband signal, and is demodulated. The GPS synchronizing signal extracting unit 52 extracts the synchronizing signal and supplies it as a reference clock signal to each part of the apparatus. doing.

[Another base station apparatus: FIG. 11]
As shown in FIG. 11, another base station apparatus 6 includes a network interface 61 that connects to a network that conforms to IEEE 1588 and the like, and a network synchronization signal extraction unit 62 that extracts a synchronization signal from the network signal. .
A network signal complying with IEEE 1588 or the like is input through the network interface 61, a synchronization signal is extracted by the network synchronization signal extraction unit 62, and is supplied to each unit as a reference clock signal.

[Broadcast wave signal]
On the other hand, since terrestrial digital broadcasting requires time synchronization with high accuracy, a GPS signal may be used in a device on the broadcasting station side, and terrestrial digital broadcasting is operated with a synchronization signal conforming to GPS. .
Also, since satellite broadcasting requires synchronization between the broadcasting satellite and the ground station, the synchronization of the broadcast transmission signal is established with high accuracy using an Rb (rubidium) oscillator or Cs (cesium) oscillator with high frequency accuracy. ing.
Even in an environment where GPS signals cannot be received, an environment subject to interference, or an environment where connection to a network conforming to IEEE 1588 is not possible, broadcast wave signals of terrestrial digital broadcasts and satellite broadcasts are often receivable.

[Related technologies]
As a related prior art, there is "Inter-station phase synchronization system" (Patent Document 1) of Japanese Patent Application Laid-Open No. 07-030963.
Patent Document 1 discloses that in mobile communication, a frame synchronization signal to be transmitted from a base station to a mobile station is transmitted from the central station to the base station, and the base station receives a broadcast radio wave and extracts a pulse signal. In addition, an inter-station phase synchronization method that compensates the transmission timing of a frame synchronization signal based on a pulse signal is described.

Japanese Patent Laid-Open No. 07-030963

  However, in a base station of a conventional mobile communication system, a GPS reception signal is input from a provided GPS reception antenna, and a synchronization signal is extracted from the GPS reception signal and used as a reference clock. In an environment where the synchronization signal cannot be extracted from the mobile communication system, synchronization cannot be established in the mobile communication system, and the system cannot be constructed.

Specifically, the GPS signal is vulnerable to interference, and there is an environment where the synchronization signal cannot be extracted due to the interference, and there is an environment where the GPS signal cannot be received indoors.
Furthermore, some base stations may have an interface for receiving a synchronization signal from a network conforming to IEEE 1588 or the like, but the network environment in which the base station can receive this synchronization signal may not be realized.

  The present invention has been made in view of the above circumstances, and enables the base station to be reconstructed by allowing the base station to reproduce the reference clock even in an environment where GPS signals and network signals cannot be received, thereby increasing the freedom of system construction. It is an object of the present invention to provide a synchronizing signal converter that can be made to operate.

  The present invention for solving the problems of the above-described conventional example is a synchronization signal converter connected to a base station of a mobile communication system, which receives a broadcast wave and acquires a synchronization signal from the broadcast wave A wave synchronization signal acquisition unit, a synchronization signal conversion unit that converts the synchronization signal into a synchronization signal of a pseudo GPS reception signal based on the GPS signal, and a pseudo GPS reception signal including the converted synchronization signal is output. And a sending section.

  Further, the present invention is a synchronization signal conversion apparatus connected to a base station of a mobile communication system, which receives a broadcast wave and acquires a synchronization signal from the broadcast wave, and a synchronization signal A synchronization signal conversion unit that converts a pseudo network reception signal in accordance with a network signal into a synchronization signal, and a synchronization signal transmission unit that transmits a pseudo network reception signal including the converted synchronization signal It is characterized by.

  Also, the present invention is characterized in that, in the synchronization signal conversion apparatus, the synchronization signal acquired from the broadcast wave includes time information.

  Further, the present invention provides the above-described synchronization signal conversion apparatus, comprising a self-running counter that generates a clock for self-running, and determines whether or not a sync signal has been acquired from a broadcast wave by a broadcast wave sync signal acquisition unit. A self-running determination unit is provided that outputs a free-running clock from the free-running counter to the synchronization signal conversion unit when it is not possible.

  Further, according to the present invention, in the synchronization signal conversion device, the synchronization signal conversion unit, the synchronization signal of the pseudo GPS reception signal or the pseudo network reception signal from the broadcast wave synchronization signal acquired by the broadcast wave synchronization signal acquisition unit An adjustment unit is provided that adjusts the timing of the synchronization signal of the broadcast wave when converting to the synchronization signal.

  The present invention is also characterized in that, in the synchronization signal conversion apparatus, the broadcast wave is a terrestrial digital broadcast wave or a broadcast wave from a broadcast satellite.

  According to the present invention, a synchronization signal conversion apparatus connected to a base station of a mobile communication system, which receives a broadcast wave and acquires a synchronization signal from the broadcast wave, and a synchronization signal Signal conversion unit for converting a pseudo GPS reception signal to a synchronization signal based on the GPS signal and a transmission unit for outputting a pseudo GPS reception signal including the converted synchronization signal The base station can reproduce the reference clock by inputting a pseudo GPS received signal from the synchronous signal conversion device, and the base station can be used even in an environment where the original GPS signal cannot be received. It can be installed and has the effect of increasing the freedom of system construction.

  Further, according to the present invention, a synchronization signal converter connected to a base station of a mobile communication system, which receives a broadcast wave and acquires a synchronization signal from the broadcast wave, A synchronization signal conversion unit that converts a synchronization signal into a synchronization signal of a pseudo network reception signal according to a network signal, and a synchronization signal transmission unit that transmits a pseudo network reception signal including the converted synchronization signal The base station can reproduce the reference clock by inputting a pseudo network reception signal from the synchronization signal conversion apparatus, and cannot receive the original network signal. Also, there is an effect that a base station can be installed and the degree of freedom of system construction can be increased.

  In addition, according to the present invention, a self-running counter that generates a free-running clock is provided, and it is determined whether or not the synchronization signal can be acquired from the broadcast wave by the broadcast wave synchronization signal acquisition unit. Since the above-mentioned synchronization signal conversion device is provided with a self-running determination unit that outputs a free-running clock from the free-running counter to the synchronization signal conversion unit, even if a broadcast wave cannot be received due to a broadcast pause or the like, There is an effect that the accuracy of a typical synchronization signal can be maintained.

  Further, according to the present invention, in the synchronization signal conversion device, the synchronization signal conversion unit may generate a pseudo GPS reception signal synchronization signal or a pseudo network from the broadcast wave synchronization signal acquired by the broadcast wave synchronization signal acquisition unit. Since the above-described synchronization signal conversion device is provided with an adjustment unit that adjusts the timing of the synchronization signal of the broadcast wave when converting the received signal to the synchronization signal, the effect of being able to output a highly accurate pseudo synchronization signal There is.

It is explanatory drawing which shows the state which connected the 1st synchronizing signal converter to the base station apparatus. It is a schematic block diagram of a 1st synchronizing signal converter. It is explanatory drawing which shows the outline | summary of the conversion operation | movement of a 1st synchronizing signal converter. It is a block diagram of the configuration of the first synchronization signal converter. FIG. 4 is a block diagram showing the configuration of a self-running determination unit 13. 3 is a block diagram illustrating a configuration example of a timing adjustment unit 14 and a synchronization signal conversion unit 15. FIG. It is explanatory drawing which shows the state which connected the 2nd synchronizing signal converter to the base station apparatus. It is a schematic block diagram of the 2nd synchronizing signal converter. It is explanatory drawing which shows the outline | summary of the conversion operation | movement when using time information. It is a schematic block diagram of the part which acquires the synchronous signal of a base station apparatus. It is a schematic block diagram of the part which acquires the synchronous signal of a base station apparatus.

Embodiments of the present invention will be described with reference to the drawings.
[Outline of the embodiment]
The synchronization signal conversion apparatus according to the embodiment of the present invention acquires a synchronization signal from a received broadcast wave, converts the synchronization signal of the broadcast wave into a synchronization signal of a pseudo GPS reception signal, and converts the converted synchronization signal Is generated and output to the base station apparatus, and the GPS signal is normally received using the base station apparatus that generates the reference clock using the synchronization signal of the GPS signal. Synchronization can be reliably established even in an environment where it is impossible.

  Further, the synchronization signal conversion apparatus according to the embodiment of the present invention acquires a synchronization signal from the received broadcast wave, and converts the broadcast wave synchronization signal into a pseudo network signal synchronization signal according to the network signal. An environment in which a pseudo network signal including the converted synchronization signal is generated and output to the base station, and the base station is configured to generate a reference clock from the synchronization signal of the network signal and cannot be connected to the network. Under certain circumstances, synchronization can be established with certainty, and the installation location of the base station apparatus can be set freely to increase the degree of freedom in system construction.

[First Embodiment]
First, the synchronization signal converter according to the first embodiment of the present invention will be described.
[Connection between first synchronization signal converter and base station: FIG. 1]
A state in which the synchronization signal conversion apparatus (first synchronization signal conversion apparatus) according to the first embodiment of the present invention is connected to the base station apparatus will be described with reference to FIG. FIG. 1 is an explanatory diagram illustrating a state in which the first synchronization signal conversion apparatus is connected to the base station apparatus.
As shown in FIG. 1, the first synchronization signal conversion apparatus 1 is connected to the base station apparatus 5 and supplies a pseudo GPS reception signal to the base station apparatus 5.

The base station apparatus 5 is substantially the same as the base station apparatus 5 shown in FIG. 10, but does not include a GPS antenna, and the GPS receiving unit 51 is connected to the first synchronization signal conversion apparatus 1.
The base station device 5 is configured to extract and use a synchronization signal from the GPS signal. The base station device 5 receives the pseudo GPS signal output from the first synchronization signal conversion device 1 and the GPS synchronization signal extraction unit 52 Similarly, the synchronization signal is extracted and used.

The first synchronization signal conversion device 1 receives a broadcast wave, converts the broadcast wave synchronization signal into a GPS synchronization signal, and generates a pseudo GPS reception signal (pseudo GPS signal) including the synchronization signal. Generate and output to the base station apparatus 5.
The pseudo GPS signal is a signal that is treated as a signal equivalent to the original GPS reception signal when input to the base station device 5.

  By connecting the first synchronization signal conversion device 1, the base station 5 that extracts and uses the synchronization signal from the GPS reception signal even in an environment where the GPS signal cannot be normally received, such as indoors or a place where interference is large. Can be installed, and the degree of freedom in constructing a wireless communication system can be increased.

[Schematic configuration of first synchronization signal converter: FIG. 2]
A schematic configuration of the first synchronization signal converter will be described with reference to FIG. FIG. 2 is a schematic configuration diagram of the first synchronization signal converter.
As shown in FIG. 2, the first synchronization signal conversion apparatus 1 includes a broadcast wave synchronization signal acquisition unit 110, a synchronization signal conversion unit 120, and a pseudo GPS signal transmission unit 130.
The broadcast wave synchronization signal acquisition unit 110 receives a broadcast wave and acquires a broadcast wave synchronization signal.
The synchronization signal conversion unit 120 converts the broadcast wave synchronization signal into a pseudo GPS reception signal synchronization signal, and generates a pseudo GPS signal including the synchronization signal.
The pseudo GPS signal sending unit 130 sends the pseudo GPS signal generated by the synchronization signal converting unit 120 to the base station 5. The pseudo GPS signal sending unit 130 corresponds to the sending unit described in claim 1.

Here, the broadcast waves used by the first synchronization signal conversion device 1 include a broadcast wave of terrestrial digital broadcast and a broadcast wave of satellite broadcast, and the broadcast wave synchronization signal acquisition unit 110 uses the terrestrial digital broadcast. And / or a satellite broadcast receiving means. When both are provided, it is set to select and receive either the terrestrial digital broadcast or the satellite method according to the installation environment of the first synchronization signal converter 1.
The synchronization signal converter 120 is configured to appropriately convert the broadcast wave synchronization signal into a pseudo GPS reception signal according to the type of broadcast wave to be used.

[Overview of Conversion Operation of First Sync Signal Conversion Device: FIGS. 2 and 3]
Next, an outline of the conversion operation of the first synchronization signal converter will be described with reference to FIGS. FIG. 3 is an explanatory diagram showing an overview of the conversion operation of the first synchronization signal converter.
In the first synchronization signal converter 1, the broadcast wave synchronization signal acquisition unit 110 shown in FIG. 2 extracts a broadcast wave synchronization signal from the input broadcast wave signal.
As shown in FIG. 3, in the first synchronization signal conversion apparatus 1, a broadcast wave synchronization signal (broadcast wave synchronization signal) is used as a program reference clock.

Then, in the synchronization signal converter 120, based on the difference between the program reference clock of the broadcast wave and the synchronization signal of the original GPS reception signal, the frequency offset set in advance with respect to the program reference clock is adjusted, A frame timing signal of a pseudo GPS reception signal is generated.
Thus, the broadcast wave synchronization signal is converted into a pseudo GPS reception signal synchronization signal.
Then, a pseudo GPS signal including the frame timing signal (a pseudo GPS reception signal synchronization signal) is generated and sent from the pseudo GPS signal sending unit 130 to the base station 5.
In this way, the operation of the first synchronization signal converter 1 is performed.

[Specific Configuration of First Sync Signal Conversion Device: FIG. 4]
Next, a specific configuration of the first synchronization signal converter 1 will be described with reference to FIG. FIG. 4 is a block diagram showing the configuration of the first synchronization signal converter.
As shown in FIG. 4, the first synchronization signal conversion apparatus 1 includes a broadcast wave receiving antenna 10, a broadcast wave receiving unit 11, a broadcast wave synchronization signal extracting unit 12, a self-running determination unit 13, and a timing adjustment unit. 14, a synchronization signal conversion unit 15, and a GPS signal transmission unit 16.

Each part of the 1st synchronizing signal converter 1 is explained.
The broadcast wave receiving antenna 10 is an antenna that receives terrestrial digital broadcasts and satellite broadcasts, and includes either or both of terrestrial digital broadcast and satellite broadcasts.
The broadcast wave receiving unit 11 demodulates the broadcast wave signal input from the broadcast wave receiving antenna 10.
The broadcast wave synchronization signal extraction unit 12 extracts the program reference clock from the broadcast wave signal as a broadcast wave synchronization signal.
The free-running determination unit 13 determines whether to use a broadcast wave synchronization signal or an internally generated frequency signal (self-running signal) based on the state of the broadcast wave, Select one of the free-running signals and output. The self-running determination unit 13 will be described later.

The timing adjustment unit 14 stores an offset value for correcting a difference between the synchronization signal of the GPS reception signal and the synchronization signal included in the broadcast wave, and outputs the offset value to the synchronization signal conversion unit 15.
The synchronization signal conversion unit 15 adjusts the timing of the broadcast wave synchronization signal or the free-running signal output from the free-running determination unit 13 with the offset value stored in the timing adjustment unit 14, and the synchronization signal of the pseudo GPS reception signal Is converted to a GPS frame timing signal.
Further, the synchronization signal conversion unit 15 generates a pseudo GPS signal including the converted synchronization signal.
The GPS transmission unit 16 outputs the generated pseudo GPS signal to the base station device 5.

[Operation of First Sync Signal Conversion Device: FIG. 4]
Next, the operation of the first synchronization signal converter will be described with reference to FIG.
The broadcast wave received by the broadcast wave receiving antenna 10 is demodulated by the broadcast wave receiving unit 11, and the broadcast wave synchronization signal extracting unit 12 extracts the broadcast wave synchronization signal.
Then, the extracted broadcast wave synchronization signal is input to the free-running determination unit 13, and the free-running determination unit 13 determines whether to use the broadcast wave or the free-running signal from the state of the broadcast wave, and the reception state is If normal, the broadcast wave synchronization signal is selectively output, and if not normal, the free-running signal is selectively output.

The timing of the broadcast wave synchronization signal or the free-running signal is adjusted by the synchronization signal conversion unit 15, and a pseudo GPS signal including the synchronization signal is generated and output from the GPS transmission unit 16 to the base station 5.
In this way, the operation of the first synchronization signal converter is performed.

[Configuration of self-running determination unit 13: FIG. 5]
Next, the configuration of the self-running determination unit 13 will be described with reference to FIG. FIG. 5 is a configuration block diagram of the self-running determination unit 13.
As shown in FIG. 5, the free-running determination unit 13 includes a free-running counter 131, a selection unit 132, and a broadcast wave reception determination unit 133.
Since the broadcasting station may suspend broadcasting for maintenance or the like, the first synchronization signal conversion apparatus 1 includes a self-running determination unit 13 so that the accuracy of the synchronization signal can be maintained even during broadcasting suspension. I have to.

The free-running counter 131 is a frequency generation circuit including a VCXO (Voltage Controlled Crystal Oscillator), a TCXO (Temperature Compensated Crystal Oscillator), and the like. Run clock).
Here, although not shown, the free-running counter 131 periodically acquires and synchronizes the broadcast wave synchronization signal output from the broadcast wave synchronization signal extraction unit 12, and is equivalent to the broadcast wave synchronization signal. Generate a self-running signal.

  The selection unit 132 inputs the broadcast wave synchronization signal from the broadcast wave synchronization signal extraction unit 12 and the self-running signal from the free-running counter 131, and in accordance with an instruction from the broadcast wave reception determination unit 133, One of the free-running signals is selected and output to the synchronization signal converter 15.

The broadcast wave reception determination unit 133 monitors the reception state of the broadcast wave and outputs an instruction to the selection unit 132 as to whether to select a broadcast wave synchronization signal or a free-running signal.
For example, the broadcast wave reception determination unit 133 instructs to select a broadcast wave synchronization signal if the signal strength is larger than a preset threshold based on the signal quality such as the signal strength of the input broadcast wave synchronization signal. If the signal strength is less than the threshold value, an instruction to select a free-running signal is output.

  Alternatively, when the broadcast wave reception determination unit 133 receives the identification information using specific identification information (information indicating a broadcast wave) included as control information in the broadcast wave, An instruction to select a broadcast wave synchronization signal is output on the assumption that the broadcast wave has been normally received. If the identification information is not received, an instruction to select a free-running signal is output.

The operation of the free-running counter 13 will be briefly described.
In the free-running counter 13, the free-running counter 131 generates a free-running signal according to the broadcast wave synchronization signal from the broadcast wave synchronization signal extraction unit 12, and the broadcast wave reception determination unit 133 determines the reception state of the broadcast wave. When the selection unit 132 normally receives the broadcast wave in accordance with the instruction from the broadcast wave reception determination unit 133, the selection unit 132 selects the broadcast wave synchronization signal and outputs it to the synchronization signal conversion unit 15 for normal reception. If not, select and output a free-running signal.
As a result, the first synchronization signal conversion unit 1 can accurately maintain the synchronization signal of the pseudo GPS signal even when the broadcast wave cannot be received due to the broadcast suspension or the like.

[Configuration of Timing Adjustment Unit 14 and Synchronization Signal Conversion Unit 15: FIG. 6]
Next, the configuration of the timing adjustment unit 14 and the synchronization signal conversion unit 15 will be described with reference to FIG. FIG. 6 is a block diagram illustrating a configuration example of the timing adjustment unit 14 and the synchronization signal conversion unit 15.
As shown in FIG. 6, the timing adjustment unit 14 stores an offset value (frequency offset value) for correcting a timing difference between the synchronization signal of the GPS reception signal and the broadcast wave synchronization signal in a register. The signal is output to the signal converter 15.
The offset value is measured in advance before the start of operation, and is set by writing to a register from the outside.

In addition, the synchronization signal conversion unit 15 includes an addition unit 151 and a pseudo GPS signal generation unit 152.
The adding unit 151 adjusts the broadcast wave synchronization signal or the free-running signal input from the free-running determination unit 13 based on the offset value, and sets the timing of the broadcast wave synchronization signal to the timing of the synchronization signal of the original GPS reception signal. Match.
The pseudo GPS signal generation unit 152 generates a pseudo GPS signal as a pseudo GPS reception signal including the timing-corrected synchronization signal and outputs the pseudo GPS signal to the GPS transmission unit 16.
As a result, a pseudo GPS signal including a synchronization signal whose timing coincides with that of the original GPS signal is output from the synchronization signal conversion unit 15 to prevent a deviation from other base stations using the original GPS signal. It is something that can be done.

[Operation of base station 5]
Then, the base station 5 connected to the first synchronization signal conversion device 1 inputs the pseudo GPS signal from the first synchronization signal conversion device 1, and synchronizes from the pseudo GPS signal in the same manner as in the case of the original GPS signal. A signal is acquired and used as an internal reference clock.

[Effect of the first embodiment]
According to the synchronization signal conversion apparatus (first synchronization signal conversion apparatus) according to the first embodiment of the present invention, the broadcast wave synchronization signal extraction unit 12 acquires a broadcast wave synchronization signal from the received broadcast wave. The synchronization signal converter 15 converts the broadcast wave synchronization signal into a pseudo GPS signal synchronization signal by adjusting the timing, and converts the pseudo GPS reception signal (pseudo GPS signal) including the converted synchronization signal. Since the GPS transmitter 16 generates and outputs the pseudo GPS signal to the base station device 5, the base station device 5 regenerates the reference clock based on the pseudo GPS signal from the first synchronization signal converter. It is possible to install a base station device 5 of a type that uses a GPS signal to extract a synchronization signal even in an area where it is difficult to use the original GPS signal due to interference or the like. There is an effect that can increase.

  Further, according to the first synchronization signal conversion device, the free-running determination unit 13 includes the free-running counter 131 that generates a free-running signal that is synchronized with the broadcast wave synchronization signal, and the broadcast wave reception determination unit 133 has received. Based on the reception intensity of the broadcast wave, etc., it is determined whether or not the broadcast wave is normally received. If it is received, the broadcast wave synchronization signal is output to the synchronization signal conversion unit 15 and is not received. In such a case, since the free-running signal is output to the synchronization signal converting unit 15, even if the broadcast wave cannot be received due to the broadcast stoppage or the like, the high-precision synchronization signal is supplied by switching to the free-running signal. There is an effect that can continue.

[Second Embodiment]
Next, a synchronization signal conversion apparatus (second synchronization signal conversion apparatus) according to a second embodiment of the present invention will be described.
[Connection between Second Synchronization Signal Conversion Device and Base Station Device: FIG. 7]
A state in which the second synchronization signal conversion apparatus is connected to the base station apparatus will be described with reference to FIG. FIG. 7 is an explanatory diagram illustrating a state in which the second synchronization signal conversion apparatus is connected to the base station apparatus.
As shown in FIG. 7, the second synchronization signal conversion device 2 is connected to the conventional base station device 6 shown in FIG. 11, and supplies a pseudo network signal to the base station device 6. It is.

The second synchronization signal converter 2 receives a broadcast wave, converts the broadcast wave synchronization signal into a network synchronization signal in accordance with a network signal such as IEEE 1588, and includes a pseudo signal including the converted synchronization signal. A network signal (pseudo network signal) is generated and output to the base station 6.
The base station device 6 includes a network interface 61 and a network synchronization signal extraction unit 62, extracts a synchronization signal from the pseudo network signal input from the second synchronization signal conversion device 2, and uses it as a reference clock.
When the pseudo network signal is input to the base station 6, it is treated as a signal equivalent to a network signal conforming to a network signal such as IEEE 1588.

  By connecting the second synchronization signal conversion device 2, the base station 6 that extracts and uses the synchronization signal from the network signal can be used even in an environment where a network signal conforming to the network signal such as IEEE 1588 cannot be received. It can be installed.

[Schematic Configuration of Second Sync Signal Conversion Device: FIG. 8]
A schematic configuration of the second synchronization signal converter will be described with reference to FIG. FIG. 8 is a schematic configuration diagram of the second synchronization signal converter.
As shown in FIG. 8, the second synchronization signal conversion device 2 includes a broadcast wave synchronization signal acquisition unit 210, a synchronization signal conversion unit 220, and a pseudo network signal transmission unit 230.

As with the first synchronization signal converter 1, the broadcast wave synchronization signal acquisition unit 210 receives a broadcast wave and acquires a broadcast wave synchronization signal. As a broadcast wave, one or both of a terrestrial digital broadcast wave and a satellite broadcast wave are received. The broadcast wave synchronization signal is a program reference clock.
The synchronization signal conversion unit 220 converts the broadcast wave synchronization signal into a synchronization signal of a pseudo network reception signal, and generates a pseudo network reception signal (pseudo network signal) including the converted synchronization signal.
The pseudo network signal transmission unit 230 transmits the pseudo network signal generated by the synchronization signal conversion unit 220 to the base station 6. The pseudo network signal transmission unit 230 corresponds to the transmission unit described in claim 2.

The specific configuration of the second synchronization signal converter 2 is basically the same as that of the first synchronization signal converter 1 shown in FIG.
However, in the second synchronization signal conversion device 2, a pseudo network signal generation unit that generates a pseudo network signal is provided instead of the pseudo GPS signal generation unit 152 provided in the synchronization signal conversion unit 15 of FIG. This is different from the first synchronization signal converter 1 in that point.
The offset value in the timing adjustment unit 14 stores not the difference between the timing of the broadcast wave and the GPS signal, but the difference between the timing of the broadcast wave and the network signal.
Further, a network signal transmission unit is provided instead of the GPS transmission unit 16 of FIG.
Other components are the same as those of the first synchronization signal converter 1.

  Accordingly, the second synchronization signal conversion device 2 converts the broadcast wave synchronization signal included in the broadcast wave into a network signal synchronization signal in accordance with a network signal such as IEEE 1588, and generates a pseudo network signal to generate a base station. It can output to the device 6.

[Effect of the second embodiment]
According to the synchronization signal conversion apparatus (second synchronization signal conversion apparatus) according to the second embodiment of the present invention, the broadcast wave synchronization signal is acquired from the received broadcast wave, and the timing of the broadcast wave synchronization signal is adjusted. Thus, a network received signal (pseudo network signal) conforming to a network signal such as pseudo IEEE 1588 including the converted sync signal is converted into a network signal synchronizing signal conforming to a pseudo network signal such as IEEE 1588. Is generated and output to the base station apparatus 6, so that the base station apparatus 6 can regenerate the reference clock based on the pseudo network signal from the second synchronization signal conversion apparatus, and the original network Even in environments where signals cannot be received, this type of base station equipment extracts synchronization signals based on network received signals. 6 can be installed, there is an effect that can increase the degree of freedom of the system configuration without changing the configuration of the base station apparatus 6.

  In addition, the second synchronization signal conversion device also includes a self-running determination unit, similar to the first synchronization signal conversion device, so that even when a broadcast wave cannot be received due to a pause in broadcasting or the like, the second synchronization signal conversion device is switched to a free-running signal. Thus, there is an effect that a pseudo network signal including a highly accurate synchronization signal can be generated.

[When using time information]
Next, a case where time information included in a broadcast wave is used as a synchronization signal will be described.
Some base station apparatuses 5 extract time information from a GPS reception signal and use it as a synchronization signal.
Similarly, some base station apparatus 6 takes out time information from a network reception signal conforming to a network signal such as IEEE 1588 and uses it as a synchronization signal.
When connecting to such a base station, the first and second synchronization signal converters described above generate a pseudo GPS signal or a pseudo network signal including time information and send it to the base station apparatus.

[First Sync Signal Conversion Device Using Time Information: FIGS. 4, 5, and 6]
Since the configuration in the case of using time information is basically the same as that in the case of using the above-described synchronization signal, the operation when the time information is used as the synchronization signal in the first synchronization signal converter is shown in FIGS. 5 and FIG.
When the time information is used, the broadcast wave synchronization signal extraction unit 12 in FIG. 4 extracts the broadcast wave time information (time date information).
In the free-running determination unit 13 shown in FIG. 5, the free-running counter 131 counts based on a free-running signal (free-running clock) synchronized with the time information of the broadcast wave, and time information that conforms to the time information of the broadcast wave. Is generated and held as a counter value.
Then, the broadcast wave reception determination unit 133 selects either the broadcast wave time information or the counter value of the free-running counter 131 (counter value information corresponding to the time information) based on the broadcast wave reception state. An instruction is output to the selection unit 132 so as to output.

In the timing adjustment unit 14 shown in FIG. 6, the difference between the time information of the broadcast wave and the time information of the original GPS reception signal is set as an offset value.
The synchronization signal conversion unit 15 adds the offset value to the time information of the broadcast wave (or the counter value of the free-running counter 131) and converts it into time information of a pseudo GPS system, and the pseudo GPS signal generation unit 152 Thus, a pseudo GPS reception signal (pseudo GPS signal) including the converted time information is generated.
Then, a pseudo GPS signal including time information is output from the GPS transmission unit 16 to the base station 5, and the base station device 5 extracts the time information from the pseudo GPS signal and uses it as a synchronization signal.
In this way, the operation when using time information is performed.

[Overview of conversion operation when using time information: FIG. 9]
Here, an outline of the conversion operation when using time information will be described with reference to FIG. FIG. 9 is an explanatory diagram showing an overview of the conversion operation when using time information. FIG. 9 shows a case in which broadcast wave time information is converted into GPS time information.
As shown in FIG. 9, the broadcast wave includes time date information as time information.
The GPS time information is managed in units of one week, and includes week number information that identifies which week it is and Z count that is information indicating the elapsed time from the beginning of the week. The Z count is time information representing the head position of the subframe.

And in the synchronous signal converter using time information, a week is specified based on time date information included in a broadcast wave, and week number information is calculated from a GPS time reference.
Also, the elapsed time from the beginning of the week is obtained from the acquired time date information, converted into a subframe (subframe time is calculated), and used as Z count information.
In this way, when time information is used as a synchronization signal, conversion from time information of a broadcast wave to time information of a pseudo GPS reception signal is performed. This operation is performed in the synchronization signal converter 220 in FIG.

Here, the first synchronization signal conversion device has been described as an example, but the handling of time information is the same in the second synchronization signal conversion device.
In the second synchronization signal conversion device, the time information of the broadcast wave is converted into the time information of the network signal in accordance with the network signal such as pseudo IEEE 1588, and the pseudo IEEE 1588 including the converted time information is used. A network signal (pseudo network signal) conforming to the network signal is generated and output to the base station apparatus 6.
Then, the base station device 6 extracts time information of the pseudo network signal and uses it as a synchronization signal.
When the time information is used, there is an effect that it is possible to provide a pseudo synchronization signal with high accuracy by simple processing.

  In the above example, the time information of the pseudo GPS pseudo network signal is generated from the time information of the broadcast wave. However, a synchronization signal indicating timing other than the time information may be generated from the time information of the broadcast wave.

  The present invention can acquire a synchronization signal from a broadcast wave, convert it into a pseudo GPS reception signal synchronization signal according to a GPS signal or a pseudo network reception signal synchronization signal according to a network signal, and output the GPS signal. The base station can be installed even in an environment where signals and network signals cannot be received, and it is suitable for a synchronous signal converter that can increase the degree of freedom of system construction.

  DESCRIPTION OF SYMBOLS 1 ... 1st synchronizing signal converter, 2 ... 2nd synchronizing signal converter, 5,6 ... Base station apparatus, 10 ... Broadcasting wave receiving antenna, 11 ... Broadcasting wave reception , 12 ... broadcast wave synchronization signal extraction unit, 13 ... self-running determination unit, 14 ... timing adjustment unit, 15 ... synchronization signal conversion unit, 16 ... GPS transmission unit, 51 .. GPS reception unit 52 ... GPS synchronization signal extraction unit 61 ... Network interface 62 ... Network synchronization signal extraction unit 110,210 ... Broadcast wave synchronization signal acquisition unit 120,220 .. Synchronous signal conversion unit, 130 ... Pseudo GPS signal transmission unit, 131 ... Self-running counter, 132 ... Selection unit, 133 ... Broadcast wave reception determination unit, 151 ... Addition unit, 152. ..Pseudo GPS signal generator, 230 ... Pseudo network signal transmitter

Claims (6)

A synchronization signal converter connected to a base station of a mobile communication system,
A broadcast wave synchronization signal acquisition unit that receives a broadcast wave and acquires a synchronization signal from the broadcast wave;
A synchronization signal conversion unit that converts the synchronization signal into a synchronization signal of a pseudo GPS reception signal based on the GPS signal;
A synchronization signal conversion apparatus comprising: a transmission unit that outputs the pseudo GPS reception signal including the converted synchronization signal. A synchronization signal converter connected to a base station of a mobile communication system,
A broadcast wave synchronization signal acquisition unit that receives a broadcast wave and acquires a synchronization signal from the broadcast wave;
A synchronization signal conversion unit that converts the synchronization signal into a synchronization signal of a pseudo network reception signal based on the network signal;
And a synchronization signal transmitting unit that transmits the pseudo network reception signal including the converted synchronization signal.   The synchronization signal conversion apparatus according to claim 1 or 2, wherein the synchronization signal acquired from the broadcast wave includes time information.   A self-running counter that generates a self-running clock is provided. The broadcast wave synchronization signal acquisition unit determines whether or not the synchronization signal can be acquired from the broadcast wave. 4. The synchronization signal conversion device according to claim 1, further comprising a self-running determination unit that outputs a running clock to the synchronization signal conversion unit.   When the synchronization signal conversion unit converts the broadcast wave synchronization signal acquired by the broadcast wave synchronization signal acquisition unit into a pseudo GPS reception signal synchronization signal or a pseudo network reception signal synchronization signal, 5. The synchronization signal converter according to claim 1, further comprising an adjustment unit that adjusts the timing of the synchronization signal.   6. The synchronous signal converter according to claim 1, wherein the broadcast wave is a terrestrial digital broadcast wave or a broadcast wave from a broadcast satellite.

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