JP2003110467A - Dual system wireless transmission method and dual system wireless transmission device - Google Patents

Abstract

(57) [Summary] A dual digital radio that does not receive a transmission clock from a device that supplies transmission data and does not require a means for supplying a transmission clock to a synchronization generator in a transmission device. A transmission device is provided, wherein both transmission systems of two systems supply a non-transmission data insertion synchronization signal generated inside each other, and a synchronization switching signal generator (9) transmits both synchronization signals to both transmission devices. A signal indicating which transmission system is used is supplied.
Then, the currently used transmission system is the master side,
By controlling the other transmission system to be the slave side so that the slave-side non-transmission data insertion timing follows the master-side non-transmission data insertion synchronization signal, the synchronization of the No. 1 and No. 2 systems is realized. .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital wireless transmission device having dual transmission systems, and more particularly to a digital wireless transmission device which operates by switching between two transmission systems.

[0002]

2. Description of the Related Art In recent years, with the digitalization of terrestrial broadcasting,
Digital wireless transmission equipment is being used, but especially for transmission equipment that requires high reliability for broadcasting applications, etc., the viewpoint of ensuring fault tolerance during actual operation and operability during maintenance work Therefore, in many cases, the signal transmission system is duplicated to provide redundancy. In such a digital radio transmission device, for example, a transmission device for broadcasting business, in addition to transmission data such as a broadcast signal, a reference signal for waveform equalization used for coping with the characteristic variation of the radio transmission line, etc. Non-transmission data is inserted and transmitted at fixed intervals.

Here, when switching the duplexed transmission system on the transmission side of the transmission device, it is conceivable that the data loss due to the switching does not occur by switching during the transmission period of non-transmission data. As an example of the specific method, there is the invention described in Japanese Patent Application No. 2001-166992.

An example of a conventional transmission device of a duplex transmission system will be described below with reference to FIGS. 3 and 4. FIG. 3 is a block diagram showing the configuration of the transmission side device of the dual digital wireless transmission system. FIG. 3 shows, as an example, for the same signal, the first system transmitter 1 from the input to the front of the antenna.
A block diagram is shown in the case where the transmitter 2 and the No. 2 system transmitter 2 are dual systems and the antenna 4 is common.

Signals having the same signal source are distributed as No. 1 system signals and No. 2 system signals to the No. 1 system transmitter 1 and No. 2 system transmitter 2, respectively. Further, the synchronization generator 12 generates a non-transmission data insertion signal, and a No. 1 system non-transmission data insertion unit 10 and a No. 2 system non-transmission data insertion unit 11
, And the synchronization switching signal generator 9. First, the system 1 signal input to the system 1 transmitter 1 is input to the system 1 non-transmission data insertion unit 10. The No. 1 non-transmission data insertion unit 10 uses the non-transmission data insertion signal supplied from the synchronization generator 12 to insert the input non-transmission data into the baseband transmission signal at a constant cycle to generate 1 as combined data. Output to No. system digital modulator 5.

FIG. 4 is a diagram showing waveforms of respective parts for explaining the system switching operation in the non-transmission data signal period. The horizontal axis shows the time axis, (a) shows the contents of data (transmission data and non-transmission data) transmitted as No. 1 transmission data, and (b) shows the data transmitted as No. 2 transmission data ( The contents of (transmission data and non-transmission data) are shown. (c) is a non-transmission data insertion synchronization signal, (d) is an RF switching control signal, (e)
Indicates the RF output switching synchronization control signal, and (f) indicates the content of the transmission data output from the RF output switching device.

As shown in FIG. 4, non-transmission data is periodically inserted between transmission data to form a data structure (combination data) in which transmission data portions and non-transmission data portions are alternately combined. There is. Note that such combination data is one of the typical data transmission methods in digital wireless transmission systems, and the non-transmission data that is inserted is used to perform waveform equalization according to the transmission path characteristics on the receiving side. Data such as a reference signal for waveform equalization.

The No. 1 system digital modulation section 5 digitally modulates the inputted combination data and outputs it to the No. 1 system transmission frequency conversion section 7. No. 1 system transmission frequency converter 7
The input signal is frequency-converted into an RF signal of a specified frequency and output to the RF output switch 3. On the other hand, the No. 2 system signal input to the No. 2 system transmitter 2 is processed in the same manner as the No. 1 system transmitter 1, and the No. 2 system non-transmission data insertion unit 11, No. 2 system digital modulation unit 6, No. 2 system An RF signal similar to that of the system 1 transmitter 1 is obtained through the system transmission frequency converter 8 and output to the RF output switcher 3.

The synchronization switching signal generator 9 is used by the operator of the equipment when switching the transmission from the system No. 1 to the system No. 2 or from the system No. 2 to the system No. 1 when a failure occurs or during maintenance work. The RF switching control signal generated by another generator (not shown) is applied by a predetermined operation of. Further, the synchronization switching signal generator 9 is supplied with a non-transmission data insertion synchronization signal from the synchronization generator 12. Synchronous switching signal generator
9 indicates, for example, when the RF switching control signal is input at time t _o in FIG. 4 and there is an instruction to switch from the 1st system to the 2nd system, the RF output switching operation synchronization control signal is generated, and the following The non-transmission data synchronization signal is output to the RF switch 3 at a timing delayed by a predetermined time τ from the time t ₁ .

Since the RF switch 3 receives the RF output switching operation synchronization control signal, the RF switch 3 switches from the No. 1 system to the No. 2 system at the approximate center in the transmission period of the non-transmission data.
The output of switch 3 is switched, and until now, the 1st system receiver
The signal input from 1 was output to the transmitting antenna 4, and the signal input from the No. 2 receiving device 2 is output to the transmitting antenna 4. Transmitting antenna 4
Transmits the input signal. As a result, a switching operation without interruption that avoids the loss of transmission data is realized.

[0011]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In order to realize the system switching operation during the non-transmission data transmission period so that the transmission data is not lost, the 1st system signal and the 2nd system signal by the non-transmission data synchronization signal generated by the synchronization generator are used. Synchronization is essential. For that purpose, it is necessary to output the non-transmission data synchronization signal in synchronization with the transmission data, and it is necessary to separately supply the timing synchronized with the transmission data, that is, the transmission clock, to the synchronization generator. However, a device that supplies transmission data, such as a broadcasting device, does not always have a transmission clock signal for a synchronization generator, and in that case, the transmission clock is synchronized in the digital wireless transmission device. There is a drawback that the system configuration becomes difficult because a means for supplying to the generator is required. The object of the present invention is to eliminate the above-mentioned drawbacks and not to input a transmission clock from the device side that supplies transmission data.
Another object of the present invention is to provide a dual type digital wireless transmission device that does not require a means for supplying a transmission clock to a synchronization generator within the transmission device.

[0012]

In order to achieve the above object, the dual system wireless transmission device of the present invention has a non-transmission data contained in each transmitter when used in one system. Is used, that is, a non-transmission data insertion synchronization signal is used. Therefore, in the dual-system wireless transmission device of the present invention, both of the two-system transmission devices supply the non-transmission data insertion synchronization signal generated internally to each other, and both of them from the synchronization switching signal generator. To the transmitter,
It provides a signal indicating which transmission system is being used. Then, by controlling the transmission system currently used as the master side and the other transmission system as the slave side, by controlling the slave side non-transmission data insertion timing to follow the master side non-transmission data insertion synchronization signal, It is intended to realize synchronization of signals of No. 1 system and No. 2 system.

Further, the duplex wireless transmission method of the present invention comprises a first transmission device and a second transmission device for respectively transmitting transmission data, and the first transmission device and the second transmission device. In the dual-system wireless transmission device for transmitting either one of the output signals, the first transmission device and the second transmission device respectively supply internally generated synchronization signals to each other, Is used to synchronize the timing of another transmission device with the synchronization signal supplied by the transmission device that is currently being transmitted. Further, according to the dual wireless transmission method of the present invention, non-transmission data is periodically inserted into transmission data to form combination data, and the combination data is transmitted first.
And a second transmission device, wherein the first transmission device is a dual-system wireless transmission device that transmits an output signal of either the first transmission device or the second transmission device. And the second transmission device respectively supply the internally generated non-transmission data insertion synchronization signal to each other, and based on the signal indicating which transmission system is being used, the transmission device currently being transmitted is It is characterized in that the non-transmission data insertion synchronization signal supplied is synchronized with the non-transmission data insertion timing of another transmission device.

Furthermore, the duplex wireless transmission apparatus of the present invention comprises a non-transmission data insertion section for inputting transmission data and periodically inserting non-transmission data into the transmission data to generate combination data. A first transmission device and a second transmission device, each of which is provided with a wireless means for converting the combination data into a transmission signal, and which mutually supply a synchronization signal internally generated, and the first transmission device. An output switching device that is coupled to the transmission device and the second transmission device and outputs any one of the transmission signals of the first transmission device and the second transmission device, and a switching control signal. A synchronous switching signal generator that outputs a control signal to each of the first transmission device, the second transmission device, and the output switching device based on the input switching control signal; Transmission device and the second transmission The device is characterized by synchronizing with a synchronization signal of either the first transmission device or the second transmission device based on the control signal output from the synchronization switching signal generator. .

Further, the non-transmission data insertion section of the dual type wireless transmission device of the present invention includes a selector that outputs either a reset signal generated by each of them or a synchronization signal supplied from another transmission device. The selector is configured to output either the reset signal or the synchronization signal supplied from the other transmission device based on the control signal supplied from the synchronization switching signal generator.

As a result, the transmission periods of the non-transmission data of the transmitters of the two systems can be made to coincide with each other without the synchronization generator, and the switching operation without interruption can be realized while avoiding the loss of the transmission data. become able to.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing a configuration of an embodiment of a transmission side device of a digital wireless transmission device of the present invention. In FIG. 1, almost the same as in the prior art shown in FIG. 3, for the same signal, from the input to the front of the antenna, a dual system of a No. 1 transmitter 1'and a No. 2 transmitter 2 ', The configuration is such that the antenna 4 is common. No. 1 transmitter 1 '
Signals having the same signal source are distributed to the No. 1 and No. 2 system transmitters 2'as the No. 1 system signal and No. 2 system signal, and the No. 1 system non-transmission data insertion section 10 'and No. 2 system signal non-transmission data insertion. Part 1
Input to 1 '. The No. 1 signal non-transmission data insertion unit 10 'and the No. 2 system signal non-transmission data insertion unit 11' mutually generate the No. 1 system generated by the non-transmission data insertion synchronization signal generation unit (described later). Or it transmits and receives the No. 2 system non-transmission data insertion synchronization signal and the synchronization switching signal generator 9 '
Supply to each.

The synchronization switching signal generator 9'provides a No. 1 system selection signal to the No. 1 system signal non-transmission data insertion section 10 'to indicate which system is used for each transmitter. A No. 2 system selection signal is supplied to the No. system signal non-transmission data insertion unit 11 '. For example, when the No. 1 system is currently used, the synchronization switching signal generator 9'sets the No. 1 system selection signal to the selection side and the No. 2 system selection signal to the non-selection side. In this case, the No. 1 transmitter 1'is positioned as the master side,
No. 1 signal non-transmission data insertion section 10 '(non-transmission data insertion synchronization signal generation section 13 (described later)) Non-transmission data is inserted at the timing of the No. 1 system non-transmission data insertion synchronization signal generated by itself. The No. 2 system transmitter 2'is positioned as the slave side and the No. 1 system signal non-transmission data insertion unit 10 '
Non-transmission data is inserted by the No. 2 system signal non-transmission data insertion unit 11 'at the timing of the No. 1 system non-transmission data insertion synchronization signal supplied from On the contrary, when the No. 2 system is used, the No. 2 system signal non-transmission data insertion unit 1
1 '(non-transmission data insertion synchronization signal generator) Inserts both non-transmission data at the timing of the No. 2 non-transmission data insertion synchronization signal generated by itself.

Next, an embodiment of the asynchronous data insertion unit of the present invention will be described with reference to FIG. FIG. 2 is a block diagram showing an embodiment of the configuration of the No. 1 signal non-transmission data insertion section 10 '. The No. 1 system signal non-transmission data inserting section 10 'is composed of a non-transmission data insertion synchronizing signal generating section 13, a non-transmission data signal generating section 14, a selector 15 and a selector 16. The non-transmission data signal generator 14 generates non-transmission data and outputs it to the input terminal a of the selector 15. Also, 1
The No. 1 system signal input to the No. system signal non-transmission data insertion unit 10 'is input to the input terminal b of the selector 15. The non-transmission data insertion synchronization signal generator 13 generates the non-transmission data insertion synchronization signal and outputs it to the control input terminal d of the selector 15.
Output as a switching signal. The selector 15 inserts the non-transmission data input from the input terminal b between the No. 1 system signal input to the input terminal a according to the switching signal, and outputs the combined data from the output terminal c to the No. 1 system digital modulator. Output to 5.

The input terminal a of the selector 16 is supplied with the reset signal generated inside the No. 1 system signal non-transmission data insertion section 10 ', and the input terminal b of the selector 16 is
2 supplied from No. 2 system signal non-transmission data insertion section 11 '
The system-based non-transmission data synchronizing signal is input, and the control system input terminal d of the selector 16 is supplied with the system 1 selecting signal supplied from the synchronization switching signal generator 9 '. Selector 16
Selects the system of the transmitter used by the No. 1 system selection signal, and if No. 1 system is selected, the input terminal
The reset signal from a is output from the output terminal c to the non-transmission data insertion synchronization signal generator 13, and if the second system is selected, the second system non-transmission data synchronization signal from the input terminal b is output to the output terminal c. To non-transmission data insertion sync signal generator
Output to 13. Non-transmission data insertion sync signal generator 13
Resets the internal counter circuit by the signal input from the selector 16. As a result, the No. 1 system signal non-transmission data inserting section 10 'can perform the switching operation during the non-transmission data transmission period.

The same operation as described above is performed for the No. 2 system transmitter 2 ', and the No. 2 system signal non-transmission data insertion unit 1
1'is supplied with either the reset signal generated therein or the No. 1 system non-transmission data synchronization signal from the No. 1 system non-transmission data insertion unit 10 'from the synchronization switching signal generator 9'. The switching operation is performed in the non-transmission data transmission period by the No. 2 system selection signal. With the configuration and control as described above, the transmission periods of the non-transmission data of the two transmission devices are the same, and when switching, the RF output is switched at the same timing as the conventional technique shown in FIG. It becomes possible to realize the switching operation without interruption without avoiding the loss of the.

[0022]

As described above, according to the present invention, by utilizing the circuit signal which the transmitting device itself should have in advance, that is, the asynchronous data insertion synchronizing signal, two systems can be provided without providing an external synchronization generator. It is possible to provide a digital wireless transmission device capable of synchronizing the transmission data of the above and capable of switching control for suppressing the loss of the transmission data.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of a transmission side device of a digital wireless transmission device of the present invention.

FIG. 2 is a block diagram showing an embodiment of a non-transmission data insertion unit of the present invention.

FIG. 3 is a block diagram showing a configuration of a transmission side device of a conventional dual digital wireless transmission system.

FIG. 4 is a waveform chart of each part for explaining a system switching operation in a non-transmission data signal period.

[Explanation of symbols]

1, 1 ': No. 1 transmitter, 2, 2': No. 2 transmitter,
3: RF output switcher, 4: Transmission antenna device, 5: 1 digital modulation section, 6: 2 digital modulation section, 7:
No. 1 system transmission frequency conversion unit, 8: No. 2 system transmission frequency conversion unit, 9, 9 ': Synchronous switching signal generator, 10, 10': No. 1 system signal non-transmission data insertion unit, 11, 11 ': 2 No. system signal non-transmission data insertion unit, 12: synchronization generator, 13: non-transmission data insertion synchronization signal generation unit, 14: non-transmission data signal generation unit, 15 and 16: selector.

Claims (4)

[Claims] 1. A first transmission device and a second transmission device for respectively transmitting transmission data, wherein two output signals of one of the first transmission device and the second transmission device are transmitted. In a heavy-duty wireless transmission device, each of the first transmission device and the second transmission device supplies internally generated synchronization signals to each other, and based on a signal indicating which transmission system is used. A dual-system wireless transmission method, characterized in that the timing of another transmission device is synchronized with a synchronization signal supplied by the transmission device currently being transmitted. 2. A first transmission device and a second transmission device for transmitting combination data by periodically inserting non-transmission data into transmission data to form combination data, and the first transmission device. And a second wireless transmission device for transmitting an output signal of one of the second wireless transmission device, wherein each of the first wireless communication device and the second wireless communication device inserts non-transmitted data internally generated. The non-transmission data insertion timing of other transmission devices is added to the non-transmission data insertion synchronization signal supplied by the transmission device currently being transmitted, based on the signal that supplies the synchronization signals to each other and indicates which transmission system is used. A dual-type wireless transmission method characterized in that the two are synchronized. 3. A non-transmission data insertion section for inputting transmission data, periodically inserting non-transmission data into the transmission data to generate combination data, and a wireless means for converting the combination data into a transmission signal. A first transmission device provided with the first synchronization signal and the second synchronization signal supplied internally to each other;
And a second transmission device, and the first transmission device and the second transmission device,
An output switching device that outputs one of the transmission signals of the first transmission device and the second transmission device; and a switching control signal that is input, and based on the input switching control signal, the first switching device Transmission device, the second transmission device, and a synchronization switching signal generator that outputs a control signal to the output switching device, respectively, wherein the first transmission device and the second transmission device include the synchronization switching device. A dual-system wireless transmission device, characterized in that it synchronizes with a synchronization signal of either the first transmission device or the second transmission device based on the control signal output from a signal generator. 4. The dual type wireless transmission device according to claim 3, wherein the non-transmission data insertion unit outputs either a reset signal generated by each of them or a synchronization signal supplied from another transmission device. A selector for outputting the reset signal or the synchronization signal supplied from the other transmission device based on the control signal supplied from the synchronization switching signal generator. Dual system wireless transmission device.