JP2008085636A - Signal transmission switching device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make the delay times of a signal to be switched and a signal to be bypassed be the same or approximate as to signals of two systems or more in a signal transmission switching device. <P>SOLUTION: A receiving means 21 receives a signal, a system distributing means 22 distributes the received signal to two systems or more, demodulating means 71 and 81 of the respective systems demodulate the distributed signals, switching and distributing means 91 and 92 input one branch signal obtained by branching the demodulated signals for two systems or more, switch a branch signal of one system and distributes the branch signal to two systems or more, delaying means 72 and 82 of the respective systems give a delay time being the same or approximate as to a delay time required for processing by the switching and distributing means to the other branch signal obtained by branching the demodulated signals, and switching and outputting means 93 and 94 of the respective systems switch and output one signal between the distributed signal of each system from the switching and distributing means and the delay signal of each system from the delay means of each system. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a signal transmission switching device that switches signals of two or more systems, and in particular, a signal transmission switching device in which the delay time of a signal to be switched and a bypassed signal is the same or approximate for these two or more signals. About.

  For example, in a broadcast system, an STL (Studio Transmitter Link) receiving device that receives a digital broadcast signal sent from a broadcast station (performance station) or the like to a broadcast station (transmitting station) is provided with a digital broadcast signal as a preliminary purpose. 2. Description of the Related Art A digital data transmission apparatus is used that includes a system switching device that receives signals from two or more receivers and selects one of the output signals from the receivers of each system.

FIG. 1 shows a configuration example of an operation mode of a digital data transmission apparatus in a broadcasting system. FIG. 1 is referred to in an embodiment described later, and is referred to here for convenience of explanation, but there is no intention to limit the present invention.
FIG. 4 shows a configuration example of the relay receivers 3 and 5, and a broadcast device 6 and a relay device 61 are shown as examples of output destinations. The relay device 61 includes, for example, a relay transmitter or a relay receiver.
Note that the demodulators 101 and 102 shown in FIG. 4 correspond to the demodulators 24 and 26 shown in FIG.

In system 1, two demodulated signals a1 and d1 obtained by branching (distributing) the demodulated signal demodulated by the demodulator 71 of the demodulator 101 are input to the switching distributor 27.
In the second system, two demodulated signals a3 and d2 obtained by branching (distributing) the demodulated signal demodulated by the demodulator 81 of the demodulator 102 are input to the switching distributor 27.
The switching distributor 27 receives the demodulated signals a1, d1, a3, and d2, and one of the two demodulated signals a1 and a3 is selected in accordance with an instruction from the control unit 95 in the switching unit 91, and the selected signal is selected. Is distributed by the distribution unit 92. Switching distribution output signals c1 and c2 that are distribution outputs from the distribution unit 92 are input to two relays (bypass relays) 93 and 94, respectively.

  Respective demodulated signals d1 and d2 are also input to the relays 93 and 94. The output signals d1 and d2 from the demodulating units 71 and 81 or the output signals c1 and c2 from the distributing unit 92 are input to the relays 93 and 94, respectively. Is switched and output to the broadcasting device 6 or the relay device 61. The system from the demodulation units 71 and 81 to the relays 93 and 94 ensures that the demodulated signals from the demodulation units 71 and 81 are reliably transmitted to the broadcasting device 6 and the relay device 61 even when the switching unit 91 and the distribution unit 92 fail. It is a detour provided for.

  However, in the configuration of the relay receivers 3 and 5 as shown in FIG. 4, for example, when the switching unit 91 or the distribution unit 92 fails in the broadcasting station B or the like, the demodulated signal d1 output from the demodulation units 71 and 81 , D2 can be selected, but in this case, since the processing by the switching unit 91 and the distributing unit 92 is bypassed, the signal transmitted to the output destination (in the example of FIG. 4, the broadcast device 6 or the relay device 61) The delay time will fluctuate. When the delay of the signal output to the output destination fluctuates, the relative time relationship between the signals transmitted wirelessly from the broadcast antennas 51 and 52 installed at the two broadcast stations A and B changes, and the two broadcasts In the case where an SFN (Single Frequency Network) is configured between the locations A and B, the failure of the SFN is caused. FIG. 1 shows an example of the overlapping area 8.

  In this way, in the configuration of the relay receivers 3 and 5 as shown in FIG. 4, when the received signal is demodulated into two systems for the purpose of backup, and the two demodulated signals are switched and output. In consideration of the failure of the switching unit 91 and the like, a bypass path is provided for the switching unit 91 and the like, but switched to the normal operation (switching by the switching unit 91) and the bypass path. Since the delay time differs depending on the time of operation, there is a problem that the SFN is broken when the SFN is configured.

  The present invention has been made in view of such conventional circumstances, and when switching two or more signals, the delay time of the signal to be switched and the bypassed signal is the same for these two or more signals. Alternatively, it is an object to provide a signal transmission switching device that can be approximated.

In order to achieve the above object, the present invention has the following configuration in a signal transmission switching device that switches two or more signals obtained by distributing received signals.
That is, the receiving means receives a signal. A system distributing unit distributes the signal received by the receiving unit into two or more systems. The demodulating means for each system demodulates the signal for each system distributed by the system distributing means. The switching distribution means inputs one branch signal obtained by branching a signal demodulated by the demodulation means for each system for the two or more systems, and one of the two or more systems of the branched signals input. The branch signal is switched, and the switched branch signal is distributed to the two or more systems. The delay means for each system has a delay time that is the same as or approximate to the delay time required for the processing by the switching distribution means for the other branched signal obtained by branching the signal demodulated by the demodulator for each system. give. The switching output means for each system inputs a distribution signal for each system from the switching distribution means, and also inputs a delay signal for each system from the delay means for each system, and among these two input signals To switch and output one signal.

  Therefore, when switching two or more signals obtained by distributing received signals, a signal for outputting the two or more signals without bypassing the signal is output together with a path for performing such switching (bypassing). ) When a path is provided, a delay that matches or approximates the time required for switching is given to the bypassed signal. Therefore, for these two or more signals, the signal to be switched and the bypassed signal The delay time can be the same or approximate, and, for example, even when the SFN is configured in the broadcasting system, the failure of the SFN can be avoided.

Here, as the two or more systems, for example, two systems of an active system and a standby system can be used, but three or more systems may be used.
Various modes may be used as the mode of control to switch to one system signal among the two or more systems signals by the switching distribution means.
Various delay times may be used as the delay time given to the signal by the delay means for each system. For example, a practically effective value is set based on the delay time required for processing by the switching distribution means. It only has to be done.
Various modes may be used as a mode of control to switch between the signal switched from the switching distribution unit by the switching output unit and the bypassed signal from the delay unit.

  As described above, according to the present invention, a path for switching two or more signals obtained by distributing received signals, and outputting (bypassing) the two or more signals without performing such switching. In the signal transmission switching device provided with a path, a delay that matches or approximates the time required for the switching is given to the bypassed signal, so that these two or more signals are bypassed with the signal to be switched. For example, even when the SFN is configured in a broadcasting system, the failure of the SFN can be avoided.

Embodiments according to the present invention will be described with reference to the drawings.
FIG. 1 shows a configuration example of a broadcast system according to an embodiment of the present invention.
In the broadcasting system of this example, a transmission signal source 1 and a relay transmitter 2 are provided in a broadcasting station (performance place).
The relay transmitter 2 includes a modulator 11, a frequency converter 12, and a transmission antenna 13.
In the broadcasting system of this example, a broadcast receiver (transmitting station) A is provided with a relay receiver 3, a relay transmitter 4, and a broadcasting device 6.
The relay receiver 3 includes a receiving antenna 21, a distributor 22, a first frequency converter 23 and demodulator 24, a second frequency converter 25 and demodulator 26, and a switching distributor 27. It has.
The relay transmitter 4 has the same configuration as that of the relay transmitter 2 and includes a transmission antenna 31 and the like.
The broadcast device 6 includes a broadcast antenna 51.

In the broadcast system of this example, a broadcast receiver (transmitting station) B is provided with a relay receiver 5 and a broadcast device 7.
The relay receiver 5 has the same configuration as the relay receiver 3 and includes a reception antenna 41 and the like.
The broadcast device 7 includes a broadcast antenna 52.
In the broadcasting system of this example, the SFN is configured by the two broadcasting devices 6 and 7. FIG. 1 shows an example of the overlapping area 8.

An example of the operation performed in the broadcast system of this example is shown.
The transmission signal source 1 is, for example, a broadcast program produced at a performance room or the like, and is modulated by the modulator 11 in the relay transmitter 2. This modulation processing includes error correction coding processing and interleaving processing. The modulated signal is frequency-converted (up-converted) by the frequency converter 12 and then transmitted wirelessly from the transmitting antenna 13 to the receiving antenna 21 of the broadcasting station A.

At the broadcasting station A, a signal received by the receiving antenna 21 is distributed to two systems, a working system and a standby system, by a distributor 22 in the relay receiver 3. The distributed received signals are frequency-converted (down-converted) by frequency converters 23 and 25 and demodulated by demodulators 24 and 26, respectively. The demodulated broadcast program is selected and distributed by the switching distributor 27. One signal distributed by the switching distributor 27 is input to the broadcasting device 6 and broadcast (transmitted) from the broadcasting antenna 51 by radio.
On the other hand, the other signal distributed by the switching distributor 27 is input to the relay transmitter 4, processed in the relay transmitter 4, and then transmitted from the transmission antenna 31 to the reception antenna 41 of the next broadcasting station B. And transmitted by radio. At the broadcasting station B, the signal received by the receiving antenna 41 is subjected to the same processing at the relay receiver 5 as the relay receiver 3 at the broadcasting station A. The output from the relay receiver 5 is input to the broadcasting device 7 and broadcast (transmitted) from the broadcasting antenna 52 by radio.

FIG. 2 shows a configuration example of the relay receiver 3 of this example, and shows a broadcast device 6 and a relay device 61 as examples of output destinations. The relay device 61 includes, for example, a relay transmitter or a relay receiver. Note that the relay receiver 5 has the same configuration as the relay receiver 3.
In the relay receiver 3 of this example, each demodulator 24, 26 includes a demodulator 71 and delay units 72, 82.
The switching distributor 27 includes a switching unit 91, a distribution unit 92, two relays (bypass relays) 93 and 94, and a control unit 95.
Here, the delay units 72 and 82 provided in each demodulator 24 and 26 give the signal a delay corresponding to the processing time by the switching unit 91 and the distribution unit 92 in the switching distributor 27.

An example of the operation performed in the relay receiver 3 of this example is shown.
In the first system, the demodulated signal demodulated by the demodulator 71 of the demodulator 24 is branched (distributed) into two, and the demodulated signal a1, which is one of the branched signals, is directly input to the switching distributor 27 and the other branched The demodulated signal, which is a signal, is delayed by the delay unit 72, and the delayed demodulated signal a 2 is input to the switching distributor 27.
In the second system, the demodulated signal demodulated by the demodulator 81 of the demodulator 26 is branched (distributed) into two, and the demodulated signal a3 which is one of the branched signals is directly input to the switching distributor 27 and the other branched The demodulated signal, which is a signal, is delayed by the delay unit 82, and the delayed demodulated signal a 4 is input to the switching distributor 27.

  The switching distributor 27 receives these demodulated signals a 1, a 2, a 3, a 4, and for the two demodulated signals a 1, a 3 not passing through the delay units 72, 82 in the demodulators 24, 26, In 91, one is selected by an instruction from the control unit 95, and the selected signal is distributed into two by the distribution unit 92. Switching distribution output signals c1 and c2 which are distribution outputs from the distribution unit 92 are input to the two relays 93 and 94.

  Note that the control unit 95 controls the switching unit 91 based on, for example, signals indicating the states of the demodulator 24 and 26 input from the two demodulators 24 and 26. For example, the control unit 95 demodulates the active system. When the demodulator (eg, demodulator 24) is in a normal state, the switching unit 91 is controlled to select the demodulated signal (eg, demodulated signal a1) from the active demodulator, and the active demodulator is selected. When the detector is in an abnormal state, the switching unit 91 is controlled to select a demodulated signal (for example, demodulated signal a3) from the standby demodulator (for example, demodulator 26).

  Respective demodulated signals a2 and a4 via the delay devices 72 and 82 in the demodulator 24 and 26 are also input to the relays 93 and 94, respectively. One of the output signals (demodulated signals) a2 and a4 from the delay units 72 and 82 or the output signals (switched distribution output signals) c1 and c2 from the distributing unit 92 is switched and output to the broadcasting device 6 and the relay device 61. . The system from the delay units 72 and 82 in the demodulator 24 and 26 to the relays 93 and 94 ensures that the demodulated signals from the demodulating units 71 and 81 are transmitted to the broadcasting device 6 even when the switching unit 91 or the distributing unit 92 fails. Or a detour provided for transmission to the relay device 61.

  In the relays 93 and 94, for example, when the switching unit 91 and the distribution unit 92 are operating normally, the switching distribution output signals c1 and c2 from the distribution unit 92 are selected and output to the output destination. When the switching unit 91 or the distribution unit 92 fails, the demodulated signals a2 and a4 from the demodulators 24 and 26 are switched to be output to the output destination.

  In this example, in the relay receivers 3 and 5, the delay units 72 and 82 for the two demodulated signals a2 and a4 output from the demodulators 24 and 26 correspond to the processing time by the switching unit 91 and the distributing unit 92. For example, even when the switching unit 91 or the distribution unit 92 of the relay receiver 5 breaks down at the broadcasting station B because of the delay, wireless transmission is performed from the broadcasting antennas 51 and 52 of the two broadcasting devices 6 and 7. It is realized that the relative time relationship between the signals does not change, and as a result, it is possible to continue broadcasting without causing SFN failure.

In FIG. 3, two signals a1 and a2 output from the first demodulator 24, two signals a3 and a4 output from the second demodulator 26, the switching unit 91 of the switching distributor 27, and An example of the temporal relationship is shown for the signals c1 and c2 input to the relays 93 and 94 via the distributor 92. Each of the signals a1 to a4, c1, and c2 includes a stream of data (DATA1, DATA2, DATA3,...).
As shown in the figure, the demodulated signals a1 and a3 output from the demodulating units 71 and 81 of the two demodulators 24 and 26 are switched after these signals are processed by the switching unit 91 and the distributing unit 92. The distributed output signals c1 and c2 have a delay (time Δt) due to the processing. In this example, a delay corresponding to the same time Δt as this delay is set in advance in the delay units 72 and 82 of the respective demodulators 24 and 26, for example, so that the input signals a2, c1, and a4 in the relays 93 and 94 are set. , C2 falls within a predetermined range, and as a result, the failure of SFN can be avoided.

  As described above, in the broadcasting system of this example, the signal switching unit (this example) selects one system from a plurality of data streams obtained by distributing the same received signal to two or more systems and demodulating each system. Then, in a signal transmission switching device (in this example, a digital data transmission device) constituted by a receiving device (in this example, the relay receivers 3 and 5) provided with the switching distributor 27), the demodulator 24 of the receiving device. 26, in addition to the demodulating units 71 and 81 for outputting the data stream obtained by the demodulation, delay units 72 and 82 for delaying the data stream are provided, and the delayed data with a predetermined delay is provided. In addition, the signal switching unit is provided with a path for bypassing signal switching, and the data stream input to the signal switching unit (in this example, the delayed data stream) is directly output. It has become possible.

  In this example, in an STL transmission / reception apparatus that receives digital broadcast signals sent from a broadcast station (performer) or the like to broadcast stations A and B, two or more receivers provided with a large number of digital broadcast signals for backup purposes are used. When performing digital data switching processing for receiving (demodulating in this example) and selecting one of the receiver output signals of each system, the bypass outputs of the demodulating units 71 and 81 in the demodulators 24 and 26 Delay units 72 and 82 that give a delay corresponding to the processing delay (time Δt) by the switching unit 91 and the distributing unit 92 are provided in advance, so that when the switching unit 91 and the distributing unit 92 fail, Even when switching from the normal operation to the operation of the bypass path, the delay time can be set within a predetermined range, and the failure of the SFN can be avoided.

  Note that, in the signal transmission switching device configured by the relay receiver of this example (in this example, the relay receiver 3 or the relay receiver 5), the receiving means is configured by the function of the receiving antenna 21, and the distributor 22 The system distribution means is configured by the functions of the above, the demodulation means for each system is configured by the functions of the demodulation sections 71 and 81 for each system, and the switching distribution means is configured by the functions of the switching section 91 and the distribution section 92. The delay means for each system is configured by the functions of the delay devices 72 and 82 for each system, and the switching output means for each system is configured by the functions of the relays 93 and 94 for each system. ing.

Here, the configuration of the system and apparatus according to the present invention is not necessarily limited to the configuration described above, and various configurations may be used. The present invention can also be provided as, for example, a method or method for executing the processing according to the present invention, a program for realizing such a method or method, or a recording medium for recording the program. It is also possible to provide various systems and devices.
The application field of the present invention is not necessarily limited to the above-described fields, and the present invention can be applied to various fields.
In addition, as various processes performed in the system and apparatus according to the present invention, for example, the processor executes a control program stored in a ROM (Read Only Memory) in hardware resources including a processor and a memory. A controlled configuration may be used, and for example, each functional unit for executing the processing may be configured as an independent hardware circuit.
The present invention can also be understood as a computer-readable recording medium such as a floppy (registered trademark) disk or a CD (Compact Disc) -ROM storing the control program, and the program (itself). The processing according to the present invention can be performed by inputting the program from the recording medium to the computer and causing the processor to execute the program.

It is a figure which shows the structural example of the broadcast system which concerns on one Example of this invention. It is a figure which shows the structural example of the relay receiver which concerns on one Example of this invention. It is a figure which shows an example of the timing of a signal. It is a figure which shows the structural example of a relay receiver.

Explanation of symbols

  1 .... Transmission signal source, 2, 4 .... Relay transmitter, 3, 5 .... Relay receiver, 6, 7 .... Broadcast equipment, 8 .... Overlapping area, 11 .... Modulator, 12, 23, 25 .. Frequency converter 13, 31 .. Transmitting antenna 21, 41 .. Receiving antenna 22 .. Divider 24, 26, 101, 102 .. Demodulator 27 .. Switching distributor 51, 52・ ・ Broadcast antenna 61 ・ ・ Relay device 71, 81 ・ ・ Demodulation unit 72, 82 ・ ・ Delay unit 91 ・ ・ Switching unit 92 ・ ・ Distribution unit 93, 94 ・ ・ Bypass relay 95 ・Control unit, a1, a3, d1, d2,... Demodulated signal, a2, a4, demodulated delay signal, b1, b2, .. alarm detection signal, c1, c2, .. switching distribution output signal,

Claims (1)

In a signal transmission switching device that switches between two or more signals obtained by distributing received signals,
Receiving means for receiving a signal;
System distribution means for distributing the signal received by the reception means into two or more signals;
Demodulation means for each system for demodulating the signal for each system distributed by the system distribution means;
One branch signal obtained by branching the signal demodulated by the demodulating means for each system is input for the two or more systems, and one of the two or more system branch signals is switched over. Switching distribution means for distributing the switched branch signal to the two or more systems;
Delay means for each system that gives a delay time that is the same as or approximate to the delay time required for the processing by the switching distribution means for the other branch signal branched from the signal demodulated by the demodulating means for each system;
The distribution signal for each system is input from the switching distribution means, and the delay signal for each system is input from the delay means for each system, and one of the two input signals is switched and output. Switching output means for each system;
A signal transmission switching device comprising:

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