JP2000278197A - Relay broadcast system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To build up a relay broadcast network by means of a single frequency network SFN where the same channel is used for the transmission reception. SOLUTION: Occurrence of oscillation due to a sneak path is prevented by increasing power of a radio wave 52 received by a slave relay broadcast station 50 so as to make the power higher than power of a radio wave 60 through a sneak path. In order to increase the power of the received radio wave 52, a master transmission station 10 extracts part of a transmission radio wave and uses an auxiliary transmission antenna 18 prepared separately from a main transmission antenna 14 to transmit a relay transmission radio wave 21 to the slave relay broadcast station 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single frequency network (Single Frequ.) Using the same channel as a reception channel and a transmission channel of a relay station.
The present invention relates to a relay broadcast system, such as a TV and a radio, capable of constructing a broadcast relay network using an "encrypt network" (hereinafter referred to as SFN).

[0002]

2. Description of the Related Art FIG. 8 shows, for example, a document "Measurement of the amount of coupling between antennas transmitting and receiving at the same frequency in television broadcast wave relay-Feasibility of SFN" (IEICE Technical Report OSC9).
FIG. 6 is a block diagram showing a model of the configuration of a conventional relay broadcast system shown in FIG. 3 of the Institute of Electronics, Information and Communication Engineers (IEICE), 6-128 (1997-03). In general, TV broadcasts and FM radio broadcasts have similar relay broadcast system configurations, and therefore the configuration of TV broadcasts will be described here.

In the figure, reference numeral 10 denotes a TV transmitting station serving as a master station, 11 denotes a TV transmitting station building, 12 denotes a TV transmitting apparatus,
Reference numeral 13 denotes an antenna tower, 14 denotes a transmission antenna, 15 denotes a transmission power supply line connecting the TV transmitter 12 and the transmission antenna 14, and 16 denotes a transmission radio wave emitted from the transmission antenna 14. Also,
Reference numeral 50 denotes a TV relay broadcasting station as a slave station which receives and retransmits the transmission radio wave 16 from the TV transmission station 10 of the master station, and 51 denotes a TV relay station.
52 is a relay broadcasting station building, 52 is a radio wave received from the master station, 53
Is a receiving antenna, 54 is a TV relay broadcasting device, 55 is a receiving feed line connecting the receiving antenna 53 and the TV relay broadcasting device 54,
6 is an antenna tower, 57 is a transmission antenna, 58 is a transmission feed line connecting the TV relay broadcasting device 54 and the transmission antenna 57, 59
Is a transmission radio wave transmitted from the transmission antenna 57, and 60 is a diverted radio wave of the radio wave transmitted from the transmission antenna 57 which goes around the reception antenna 53.

Next, the operation will be described. The radio wave of the TV broadcast is emitted from the transmitting antenna 14 at the TV transmitting station 10. That is, in the TV transmitting station 10, a transmission signal to be broadcast by the TV transmission device 12 installed in the TV transmission station building 11 is created, and the created transmission signal is transmitted to the transmission power supply line 15.
To the transmitting antenna 14 attached to the upper part of the antenna tower 13, and the transmitting antenna 16
Fire as The radio waves emitted from the transmitting antenna 14 provide TV broadcasting to a wide area, but the transmitting radio waves 16 emitted from the TV transmitting station 10 which is the master station alone cannot cover a service area in a mountain shadow or a remote place. The area often remains. Therefore, in order to service the area where the transmission radio wave 16 from the TV transmission station 10 cannot provide service, the transmission radio wave 1 from the TV transmission station 10 is used.
6, a TV relay broadcasting station 50 is installed as a slave station for amplifying and retransmitting the received signal.

[0005] Various configurations are implemented as the TV relay broadcasting station 50. The TV relay broadcasting station 50 shown in FIG. Measurement-Feasibility of SFN-"
(IEICE Technical Report, OCS96-128
(1997-03)). That is, the TV relay broadcasting station 50 has a TV relay broadcasting station building 51, and a receiving antenna 53 is installed at a location near the TV relay broadcasting station 50 where radio waves 52 from the TV transmitting station 10 as a master station are easily received. The receiving antenna 53 and the TV relay broadcasting device 54 are connected by a receiving power supply line 55, and the received radio wave 52 is guided to the TV relay broadcasting device 54. The TV relay broadcasting device 54 performs channel conversion and amplification of the received TV broadcast signal, and outputs the output through a transmission feed line 58 to a transmission antenna 57 installed above the antenna tower 56.
Leading to.

The transmission antenna 57 emits a transmission signal received from the TV relay broadcasting device 54 through the transmission power supply line 58 as a transmission radio wave 59. At this time,
A part of 9 wraps around to the receiving side as a diverted radio wave 60 and is received by the receiving antenna 53. In such a configuration,
In the TV relay broadcasting station 50 as a slave station, radio waves from both the TV transmitting station 10 as the master station and the TV relay broadcasting station 50 are received, and the image quality is deteriorated due to the interference between these two radio waves. It is necessary to change the transmission channel of the TV relay station 50 from the reception channel.

Here, OFDM (Orthogonal Frequency Division Multiplexing)
In a digital TV broadcast or the like employing a modulation method, generally, a TV transmitting station 10 of a master station and a TV relay broadcasting station 50 of a slave station are generally used.
Image quality is not degraded by the interference of radio waves from both
A system configuration based on SFN in which the transmission channel of the V relay broadcasting station 50 is the same as the reception channel is possible. In addition, the above-mentioned document "Measurement of the amount of coupling between the same frequency transmitting and receiving antennas in television broadcast wave relay-feasibility of SFN-"
(IEICE Technical Report, OCS96-128
According to (1997-03)), in the TV relay broadcasting station 50 configured as shown in FIG. 8, the reception level of the wraparound radio wave 60 to the reception antenna 53 is determined by the transmission radio wave 59 emitted from the transmission antenna 57. The attenuation of the signal is about 70 dB as compared with the power of the receiving antenna 53.
The power is equivalent to or higher than the general received input power of the received radio wave 52 from the TV transmitting station 10 of the master station of 60 to 70 dBμV. That is, TV relay broadcasting station 5
At 0, if the transmission channel is the same as the reception channel, an oscillation phenomenon will occur due to the transmission of the transmission radio wave 59 of the own station.

[0008]

The conventional TV relay broadcasting system is configured as described above.
Even in a digital TV broadcast employing the OFDM modulation method, which enables a system to be constructed by N, the power of the transmitting radio wave 60 to the receiving side by the transmitting radio wave 59 of the local station increases in the local TV relay broadcasting station 50. Therefore, an oscillation phenomenon may occur in the TV relay broadcasting station 50 of the slave station itself, and in the TV relay broadcasting station 50 of the slave station, it is essential to change the transmission channel from the reception channel, and the SF
N has a problem in realizing the construction of a relay broadcast network, and in order to avoid this, the reception power of the received radio wave 52 from the TV transmitting station 10 of the master station is increased, and
9, it is necessary to obtain a reception power larger than the power of the diverted radio wave 60, but the TV relay transmitting station 50
Is generally installed in a place where the radio wave from the TV transmitting station 10 of the master station is weak. Therefore, it is difficult to obtain a large receiving power, and it is also necessary to increase the gain of the receiving antenna 53. There are problems such as difficulty in terms of location and installation cost, making it difficult to obtain power of the received radio wave 52 that is larger than the power of the diverted radio wave 60.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a relay broadcast system capable of constructing a relay broadcast network by SFN using the same channel for transmission and reception.

[0010]

A relay broadcasting system according to the present invention is provided with a relay signal extracting means at a transmitting station of a master station, and an auxiliary transmitting antenna different from a main transmitting antenna for emitting a broadcast radio wave. A part of the transmission signal generated by the transmitting device is extracted by the relay signal extracting means, and is emitted as a relay transmission radio wave from the auxiliary transmission antenna to the space. This enables reception of radio waves from the master station broadcasting station with power higher than the power of the transmission radio waves to the receiving antenna of the transmission radio waves.

[0011] The relay broadcasting system according to the present invention provides a transmission output signal emitted from a main transmission antenna as a transmission radio wave and a relay output signal emitted from an auxiliary transmission antenna as a relay transmission radio wave. A relay signal extracting means is formed by a power splitter that splits the signal into a power signal.

In a relay broadcasting system according to the present invention, a relay signal extracting means is formed by an auxiliary power amplifier for extracting a part of a transmission signal, amplifying the amplified signal, and supplying the amplified signal to an auxiliary transmission antenna as a relay output signal. It is.

In the relay broadcasting system according to the present invention, a plurality of auxiliary transmission antennas are provided in a master station transmitting station, and a transmission signal emitted from a main transmission antenna as broadcast transmission radio waves by a relay signal extracting means by a power splitter. The transmission signal is branched into an output signal and a plurality of relay output signals emitted as relay transmission radio waves from each of the auxiliary transmission antennas.

[0014] In the relay broadcasting system according to the present invention, as the relay signal extracting means, an auxiliary power amplifier for extracting and amplifying a part of the transmission signal, and a plurality of auxiliary transmission antennas for supplying the output to each of the plurality of auxiliary transmission antennas. A power distribution device for distributing to a relay output signal is used.

In the relay broadcasting system according to the present invention, as a relay signal extracting means, a distributor for extracting a part of the transmission signal generated by the transmitting device and distributing the extracted signal to a plurality of signals, and amplifying each of the distributed signals. Further, a signal formed by a plurality of auxiliary power amplifying units that supply each of the plurality of auxiliary transmission antennas as a relay output signal is used.

In the relay broadcasting system according to the present invention, the slave relay station has a transmission signal splitter and a relay transmission antenna as relay signal extracting means, and the transmission signal splitter transmits the transmission signal. The output signal is branched into a transmission output signal emitted from the antenna as a broadcast transmission radio wave and a relay output signal emitted from the relay transmission antenna as a relay transmission radio wave.

According to the relay broadcasting system of the present invention, as a relay signal extracting means of a slave relay station, an auxiliary power amplifier for extracting and amplifying a part of a transmission signal and supplying it to a relay transmission antenna as a relay output signal. Is used.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a block diagram showing a modeled configuration of a relay broadcast system according to Embodiment 1 of the present invention. In FIG. 1, reference numeral 10 denotes a TV as a master station transmitting station.
A transmitting station 11 is a TV transmitting station building of the TV transmitting station 10. Reference numeral 12 denotes a T which is disposed in the TV transmission station building 11 and serves as a transmission device for generating a broadcast transmission signal.
V transmission device. Reference numeral 13 denotes an antenna tower installed in the TV transmission station building 11, and reference numeral 14 denotes a transmission output signal based on a transmission signal from the TV transmission device 12, which is attached to an upper portion of the antenna tower 13 as a broadcast transmission radio wave 16. It is the main transmitting antenna that launches into space. 15 is the TV transmission device 1
2 is a transmission feed line that connects the main transmission antenna 14 and transmits a transmission output signal to the main transmission antenna 14, and 16 is the above-mentioned broadcast transmission radio wave emitted from the main transmission antenna 14. These components correspond to the conventional components shown in FIG. 8 with the same reference numerals.

Reference numeral 17 denotes a relay signal extracting means for extracting a part of the transmission signal generated by the TV transmitting apparatus 12 as an output signal for relaying.
The transmission signal generated by the V transmitter 12 is transmitted to the main transmission antenna 1
4 uses a power splitter for splitting into a transmission output signal emitted as a broadcast transmission radio wave 16 and a relay output signal emitted as a relay transmission radio wave from an auxiliary transmission antenna described later. Reference numeral 18 denotes an auxiliary transmission antenna that emits the output signal for transmission and the output signal for relay branched by the power splitter 17 as the relay signal extracting means into space as a transmission radio wave for relay. 19 is a TV transmission device 12
A connecting cable connecting the power splitter 17 and the power splitter 20, a feeder line 20 for feeding the relay output signal branched by the power splitter 17 to the auxiliary transmission antenna 18, and a power transmission line 21 directed from the auxiliary transmission antenna 18 to the slave station This is the above-mentioned relay transmission radio wave emitted by the relay. The main output (output signal for transmission) of the power splitter 17 is supplied to the main transmission antenna 14 through the transmission power supply line 15 in the same manner as the conventional system shown in FIG.

Reference numeral 50 denotes a TV relay broadcasting station as a local station relay broadcasting station for receiving and retransmitting radio waves from the TV transmitting station 10, and 51 denotes a TV relay broadcasting station building of the TV relay broadcasting station 50. is there. Reference numeral 52 denotes a radio wave received from the main transmission antenna 14 and the auxiliary transmission antenna 18 of the TV transmitting station 10 of the master station, and 53 denotes a reception antenna for receiving the radio wave 52. Numeral 54 denotes a TV relay broadcasting device as a relay broadcasting device for amplifying the received radio wave 52 received by the receiving antenna 53 to generate a transmission signal, and 55 denotes a receiving power supply connecting the receiving antenna 53 and the TV relay broadcasting device 54. It is an electric wire. 5
Reference numeral 6 denotes an antenna tower installed in the TV relay broadcasting station building 51, reference numeral 57 denotes a transmission antenna mounted above the antenna tower 56, and reference numeral 58 denotes a transmission feed line connecting the TV relay broadcasting device 54 and the transmission antenna 57. . Reference numeral 59 denotes a broadcast transmission radio wave emitted from the transmission antenna 57, and reference numeral 60 denotes a diverted radio wave of the radio wave emitted from the transmission antenna 57 which goes around the reception antenna 53. These components are also equivalent to the conventional components shown in FIG.

Next, the operation will be described. As described above, when the transmission channel is set to be the same as the reception channel in the TV relay broadcasting station 50 of the slave station, the transmission radio wave 59 of the own station wraps around the reception antenna 53 as the looping radio wave 60, causing an oscillation phenomenon. Would. In order to avoid this, in the first embodiment, the reception power of the reception radio wave 52 from the TV transmission station 10 in the TV relay broadcasting station 50 is set to be higher than the level of the reception radio wave 60 of the local station, and Also, the TV relay broadcasting station 50 having the transmission channel of No. 3 can suppress re-transmission by suppressing the oscillation by the loop-in radio wave 60.

For this reason, the T of the TV transmitting station 10 which is the master station is
The transmission signal to be broadcast generated by the V transmitter 12 is shown in FIG.
As shown in FIG.
7, the power splitter 17 converts the transmission signal into a broadcast output signal to the main transmission antenna 14 and an auxiliary transmission antenna 1
8 and a relay output signal to the relay signal 8. That is, the main output of the power splitter 17 is guided as a broadcast output signal to the main transmission antenna 14 via the transmission feeder line 15, and the branch output partially branched by the power splitter 17 is used as a relay output signal. It is guided to the auxiliary transmission antenna 18 via the power supply line 20.

The auxiliary transmitting antenna 18 is connected to the power splitter 17
Is output as a relay transmission radio wave 21 to a TV relay broadcasting station 50 of a slave station. Generally, the antenna directivity pattern of the main transmission antenna 14 is a broadband beam, but the auxiliary transmission antenna 18 has a TV pattern.
An antenna having an antenna directivity pattern with a large antenna gain, in which the transmission beam is narrowed toward the relay station 50, is used.

Here, in the conventional relay broadcasting system shown in FIG. 8, the reception power level Pr1 of the radio wave received from the TV transmitting station 10 as the master station in the TV relay broadcasting station 50 as the slave station is as follows. It is given by the following equation (1). Pr1 = Pt1 + Gt1 + Gr-Ld (1) Here, Pt1; transmission power of the TV transmitting station 10 Gt1; antenna gain of the main transmission antenna 14 Gr; antenna gain of the reception antenna 53 Ld; Propagation loss

On the other hand, in the relay broadcasting system according to the first embodiment shown in FIG. 1, radio waves emitted from auxiliary transmission antenna 18 of TV broadcasting station 10 of parent station in TV relay broadcasting station 50 of child station. Received power level Pr2
Is given by the following equation (2). Pr2 = Pt2 + Gt2 + Gr-Ld (2) where, Pt2; transmission power of radio waves emitted from the auxiliary transmission antenna 18 Gt2; antenna gain of the auxiliary transmission antenna 18 Gr; antenna gain of the reception antenna 53 Ld; auxiliary transmission antenna 18 and reception Propagation loss between antennas 53

Here, in the relay broadcasting system according to the first embodiment shown in FIG. 1, the reception power at the TV relay broadcasting station 50 is set to, for example, A (dB) compared to the conventional relay broadcasting system shown in FIG. Equation (3) shown below is satisfied in order to make it higher. Pt1-Pt2 = Gt2-Gt1-A (dB) (3)

The above-mentioned document "Measurement of the amount of coupling between antennas transmitting and receiving at the same frequency in television broadcast wave relay-Realization of SFN" (Technical Report of IEICE, OCS96-1)
28 (1997-03)), the TV relay broadcasting station 5
0, the wraparound power of the wraparound radio wave 60 due to the broadcast transmission radiowave 59 emitted from the own station is-
It is about 70 dB. Therefore, in a station having a transmission power of 10 W (TV relay broadcasting station 50), the sneak power becomes about 77 dBμV, and the TV transmission station 10 of the ordinary master station is used.
This indicates that the oscillation phenomenon is inevitable because the power becomes greater than the power (70 dBμV) of the received radio wave 52 from.

Here, as an example, the antenna gain difference (Gt2−G) between the auxiliary transmitting antenna 18 of the TV transmitting station 10 and the main transmitting antenna 14 in the direction of the receiving antenna 53 of the TV relay broadcasting station 50 is indicated.
Gt1) is 30 dB, and the transmission power of the auxiliary transmission antenna 18 is transmitted at 10 dB lower than the transmission power of the main transmission antenna 14 (Pt1−Pt2 = −10 dB).
= 20 dB, and in the case of the TV relay broadcasting station 50 having the above-described 10 W configuration, the received power of the received radio wave 52 is 90 dBμ.
V, which is larger than the power of the diverted radio wave 60, and the oscillation phenomenon can be suppressed. This means that the power splitter 17
If the branch output (relay output signal) is branched by 10 dB as compared with the main output (broadcast output signal), a normal broadcast relay system can be realized by avoiding the oscillation phenomenon caused by the loop-in radio wave 60. Is shown.

Embodiment 2 In the first embodiment, as the relay signal extracting means, a power splitter that splits a transmission signal into a broadcast output signal and a relay output signal is used, but a part of the transmission signal is extracted. An auxiliary power amplifying unit that amplifies the signal and generates a relay output signal may be used. FIG. 2 is a block diagram showing a modeled configuration of such a relay broadcast system according to the second embodiment of the present invention. The corresponding parts are denoted by the same reference numerals as in FIG. 1 and description thereof is omitted. In the figure, 22 is T as a master station.
A part of the transmission signal generated by the TV transmission device 12 arranged in the TV transmission station building 11 of the V transmission station 10 is amplified to generate a relay output signal, which is transmitted to the auxiliary transmission antenna 18 through the power supply line 20. An auxiliary power amplifying unit that supplies power and serves as a relay signal extracting unit. Reference numeral 23 denotes a connection cable that extracts a part of the transmission signal generated by the TV transmitter 12 and guides the extracted signal to the auxiliary power amplifier 22.

Next, the operation will be described. A part of the broadcast transmission signal generated by the TV transmitter 12 is taken out and guided to the auxiliary power amplifier 22 through the connection cable 23. The auxiliary power amplifier 22 is connected to the connection cable 23
The signal transmitted through the power transmission line 20 is amplified to a required power and supplied to the auxiliary transmission antenna 18 through the power supply line 20 as a relay output signal. The auxiliary transmission antenna 18 emits this relay output signal as a relay transmission radio wave 21 to the TV relay broadcasting station 50. On the other hand, the transmission signal output from the TV transmission device 12 is a transmission power supply line 1 as a broadcast output signal.
5 and transmitted to the main transmitting antenna 14 and emitted as broadcast transmission radio waves 16. The following operation is the same as in the first embodiment, and a description thereof will not be repeated.

As described above, in the relay broadcasting system according to the first embodiment shown in FIG. 1, power splitter 17 for handling large power is required for branching transmission power. In the relay broadcasting system according to mode 2, since the signal can be branched with low power by adopting the configuration as shown in FIG. 2, it can be realized by amplification of the auxiliary power amplifier 22 with relatively low power. . According to the example described in the first embodiment, in the relay broadcasting system of the second embodiment, the transmission output (Pt2) of the auxiliary power amplifier 22 is
An output that is 10 dB lower than the main transmission output (Pt1) is sufficient.

Embodiment 3 FIG. Further, in each of the above embodiments, the case where the TV station serving as the master station has one auxiliary transmission antenna has been described, but it is also possible to provide a plurality of auxiliary transmission antennas. FIG. 3 is a block diagram showing a model of the configuration of such a relay broadcast system according to Embodiment 3 of the present invention. Here, a case where two auxiliary transmission antennas are provided is shown. In this case as well, the corresponding parts are denoted by the same reference numerals as in FIG. 1 and the description thereof is omitted.

In the figure, reference numeral 24 denotes a new antenna tower 13
, An auxiliary transmission antenna similar to the auxiliary transmission antenna 18. 25 is a power supply line for guiding the relay output signal separated by the power splitter 17 to the auxiliary transmission antenna 24;
Reference numeral 26 denotes an auxiliary transmission antenna 2 based on the relay output signal.
4 is a relay transmission radio wave emitted from FIG. Reference numeral 70 denotes a TV relay station as a relay station for receiving and retransmitting the relay transmission radio wave 26 from the auxiliary transmission antenna 24,
The configuration is the same as that of the TV relay broadcasting station 50. Note that the power splitter 17 splits the transmission signal generated by the TV transmission device 12 into one broadcast output signal and two relay output signals, and is denoted by the same reference numerals in FIG. This is different from that of the first embodiment.

Next, the operation will be described. In order to secure a sufficient TV broadcasting service area, a plurality of TV relay broadcasting stations as slave stations are often required. FIG.
2 shows an example of a configuration in which two locations of TV relay broadcasting stations 50 and 70 are required. In order to transmit the relay transmission radio wave 26 from the TV transmission station 10 toward the TV relay broadcasting station 70, the transmission signal generated by the TV transmission device 12 is transmitted by the power splitter 17 in the TV transmission station 10 of the master station. , A broadcast output signal to the main transmission antenna 14, a relay output signal to the auxiliary transmission antenna 18, and a relay output signal to the auxiliary transmission antenna 24. That is, the main output of the power splitter 17 is guided as a broadcast output signal to the main transmission antenna 14 via the transmission feeder line 15 and partially branched by the power splitter 17. The signal is guided to the auxiliary transmission antenna 18 via the power supply line 25 and to the auxiliary transmission antenna 24 via the power supply line 25 as a relay output signal. The auxiliary transmission antenna 18 emits the relay output signal from the power supply line 20 to the TV relay broadcasting station 50 as a relay transmission radio wave, and the auxiliary transmission antenna 24 outputs the relay output signal from the power supply line 25 to the relay transmission radio wave. TV broadcast station 70
Fire at. The following operation is the same as in the first embodiment, and a description thereof will not be repeated.

In the above description, the power splitter 17 is used as the relay signal extracting means to obtain power for feeding the relay output signals to the auxiliary transmission antennas 18 and 24. It is not limited only to. In order to obtain power to feed the auxiliary transmission antennas 18 and 24, instead of the power splitter 17, for example, FIG.
Alternatively, a configuration as shown in FIG. 5 is also conceivable.

FIG. 4 is a block diagram showing another configuration example of the relay signal extracting means which is a main part of the relay broadcasting system according to the third embodiment. In this case, too, it is assumed that there are two auxiliary transmission antennas. ing. In the figure, 27 is a TV
An auxiliary power amplifying unit (relay signal extracting means) for amplifying a part of the transmission signal generated by the transmission device 12, and 28 is a TV signal
This is a connection cable that extracts a part of the transmission signal generated by the transmission device 12 and guides the extracted signal to the auxiliary power amplifier 27. 29 distributes the signal amplified by the auxiliary power amplifier 27 to generate two relay output signals,
(A relay signal extracting means).

In the relay broadcasting system configured as described above, a part of the transmission signal is extracted from the TV transmitter 12 and the signal is connected to the auxiliary power amplifier 27 via the connection cable 28.
, And amplifies the required power in the auxiliary power amplifier 27. The power distributor 29 distributes the output of the auxiliary power amplifier 27 to generate two relay output signals for the TV relay broadcast station 50 and the TV relay broadcast station 70. The generated relay output signal for the TV relay station 50 is supplied to the auxiliary transmission antenna 18 via the power supply line 20 and the TV relay station 7.
The relay output signal for 0 is supplied to the auxiliary transmission antenna 24 through the power supply line 25, respectively. The following operation is the same as in the above description.

FIG. 5 is a block diagram showing still another configuration example of the relay signal extracting means according to the third embodiment. In this case, too, it is assumed that there are two auxiliary transmission antennas. In the figure, reference numeral 30 denotes a distributor (relay signal extracting means) for distributing a part of the transmission signal generated by the TV transmission device 12 into two signals, and 31 denotes a part of the transmission signal generated by the TV transmission device 12. This is a connection cable that is taken out and led to the distributor 30. 32 and 33 amplify each of the two signals distributed by the distributor 30 to generate two relay output signals, which are then fed to the feeder line 20 or 25.
The auxiliary power amplifier (relay signal extracting means) that outputs the signal to the auxiliary power amplifier.

In the relay broadcasting system configured as described above, a part of the transmission signal is extracted from the TV transmission device 12 and the signal is guided to the distributor 30 by the connection cable 31.
Distribute into two signals. One of the signals distributed by the distributor 30 is input to the auxiliary power amplifier 32 and amplified to a required power, and is output to the auxiliary transmission antenna 18 through the power supply line 20 as a relay output signal for the TV relay broadcasting station 50. Powered. The other of the signals distributed by the distributor 30 is input to the auxiliary power amplifier 33 and amplified to a required power, and is output as a relay output signal for the TV relay broadcasting station 70 through the power supply line 25 and the auxiliary transmission antenna 24. Power is supplied to The following operation is the same as in the above description.

Embodiment 4 FIG. In each of the above embodiments, the description has been given of the case where the relay transmission radio wave is emitted only from the TV station serving as the master station and the relay transmission radio wave is not transmitted from the TV relay station serving as the slave station. It is also possible to emit a relay transmission radio wave from a TV relay broadcasting station. FIG. 6 shows such a fourth embodiment of the present invention.
FIG. 1 is a block diagram showing a modeled configuration of a relay broadcasting system according to the first embodiment. In this case as well, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In the figure, 9
Numeral 0 denotes a TV relay broadcasting station as a slave station relay broadcasting station having a function of receiving and retransmitting the relay transmission radio wave 21 from the TV transmission station 10 and emitting the relay transmission radio wave. Reference numeral 50 denotes a TV relay broadcasting station configured to receive and retransmit a transmission wave for relaying from the TV relay broadcasting station 90 and having the same reference numerals in FIG. 1, and in this case, It functions as a grandchild bureau.

Further, in the TV relay broadcasting station 90 of the slave station, reference numeral 61 denotes a transmission output signal emitted from the transmission antenna 57 as a broadcast transmission radio wave 59 from the transmission signal generated by the TV relay broadcasting device 54, A transmission signal splitter that splits a signal into a relay output signal emitted as a relay transmission radio wave from the auxiliary transmission antenna. Reference numeral 62 denotes a relay transmission antenna that emits a transmission output signal and a relay output signal branched by the transmission signal splitter 61 into space as a relay transmission radio wave to be described later. Reference numeral 63 denotes a power supply line for feeding the relay output signal branched by the transmission signal splitter 61 to the relay transmission antenna 62. Reference numeral 64 denotes the above-mentioned relay transmission emitted from the relay transmission antenna 62 to the grandchild station. Radio waves.

Next, the operation will be described. Some TV relay broadcasting systems amplify a relay transmission radio wave received at a TV relay broadcasting station of a slave station and retransmit it to another TV relay broadcasting station (TV relay broadcasting station of a grandchild station), thereby providing a broadcast service area. May be secured. In the relay broadcasting system shown in FIG. 6, in a local TV relay broadcasting station 90, the TV relay broadcasting device 54 converts a transmission signal generated from a received radio wave 52 from the TV transmitting station 10 into a transmission signal splitter 61.
To the transmission antenna 59 from the transmission antenna 57.
Output signal for transmission, which is launched as
2 branches into a relay output signal emitted as a relay transmission radio wave 64. The relay output signal branched by the transmission signal splitter 61 is transmitted through a feeder 63 to a relay transmission antenna 62.
, And a relay transmission radio wave 64 from the relay transmission antenna 62.
And is launched toward the TV relay broadcasting station 50 of the grandchild station.
Note that, within the TV relay broadcasting station 50, the TV relay broadcasting station 90
To amplify the received radio wave 52 from the Internet and retransmit it as a broadcast transmission radio wave 59;
The operation of amplifying the received radio wave 52 from the V transmitting station 10 and retransmitting it as the broadcast transmitting radio wave 59 is the same as that of the TV relay broadcasting station 50 in the first embodiment.

Here, in the above description, the transmission signal splitter 61
Is used to feed a relay output signal to the relay transmission antenna 62. However, the present invention is not limited to this. Instead of the transmission signal splitter 61, for example, a transmission signal An auxiliary power amplifier that extracts a part of the signal and amplifies it to generate a relay output signal may be used. FIG. 7 is a block diagram showing another example of the configuration of the main part of the relay broadcasting system according to the fourth embodiment, showing the internal configuration of the TV relay broadcasting station building 51 in the TV relay broadcasting station 90 of the slave station. . In the figure, reference numeral 65 denotes an auxiliary power amplifier that amplifies a part of the transmission signal generated by the TV relay broadcasting device 54 to generate a relay output signal and supplies the output signal to the power supply line 63. 66 is the TV relay broadcasting device 54
Is a connection cable for taking out a part of the transmission signal generated by the above-described method and guiding it to the auxiliary power amplifier 65.

In the relay broadcasting system configured as described above, a part of the transmission signal is extracted from the TV relay broadcasting device 54 at the TV relay broadcasting station 90 of the slave station, and the signal is connected to the auxiliary power amplifying unit via the connection cable 66. The power is then amplified to the required power in the auxiliary power amplifier 65. The signal amplified by the auxiliary power amplifier 65 is supplied to the relay transmission antenna 62 through the feeder 63 as a relay output signal.
The following operation is the same as in the above description.

[0045]

As described above, according to the present invention, the relay signal extracting means and the auxiliary transmitting antenna are provided in the master station transmitting station,
A part of the transmission signal generated by the transmitting device is extracted by the relay signal extracting means, and the signal is emitted from the auxiliary transmission antenna to the space as a relay transmission radio wave. Reception of broadcast transmission radio waves Because it is possible to receive radio waves from the master station with higher power than the power of the diverted radio wave to the antenna, oscillation phenomena caused by the sneak in of the transmission signal of the own station at the slave station relay station Can be avoided, and there is an effect that a relay broadcast system that can be constructed by SFN can be obtained.

According to the present invention, the transmission signal is branched into a transmission output signal emitted from the main transmission antenna as a transmission radio wave and a relay output signal emitted from the auxiliary transmission antenna as a relay transmission radio wave. By power splitter,
Since the relay signal extracting means is formed, there is an effect that it is possible to suppress the oscillation phenomenon due to the routed electric wave with a simple device configuration.

According to the present invention, the relay signal extracting means is formed by the auxiliary power amplifying section which extracts and amplifies a part of the transmission signal and supplies it to the auxiliary transmission antenna as a relay output signal. There is an effect that the operation can be performed with low power and can be realized by a low-power power amplification unit.

According to the present invention, a relay signal extracting means for providing a plurality of auxiliary transmission antennas at a master station transmitting station and generating a plurality of relay output signals emitted from each of the auxiliary transmission antennas as relay transmission radio waves. As a power splitter that splits a transmission signal into a broadcast output signal and a plurality of relay output signals, or an auxiliary power amplifier that amplifies a part of the signal extracted from the transmission signal, A power divider that distributes the output to multiple relay output signals, or a divider that extracts a part of the transmission signal and distributes it to multiple signals, and amplifies each distributed signal to generate a relay output signal Since the configuration is such that a plurality of auxiliary power amplifiers are used, it is possible to retransmit radio waves from the master station transmitting station at a plurality of slave station relay broadcasting stations, and to sufficiently cover a wider service area. There is an effect that can be coercive.

According to the present invention, the relay station for relay station is provided with a relay signal extracting means and a relay transmitting antenna, and as the relay signal extracting means, the transmission signal from the relay broadcasting apparatus is used as a broadcast output signal and a relay output signal. A power splitter that branches to an output signal, or a part of the transmission signal is extracted and amplified,
Since the auxiliary power amplifier that generates the relay output signal is used, it passes through the slave station relay station even to the grandchild station relay station where relay transmission radio waves do not directly reach from the master station transmitter station. As a result, it is possible to deliver a radio wave from the master station transmitting station, and it is possible to construct a more flexible system.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a relay broadcasting system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a relay broadcast system according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a relay broadcasting system according to a third embodiment of the present invention.

FIG. 4 is a block diagram showing another configuration example of a main part of the relay broadcast system according to the third embodiment.

FIG. 5 is a block diagram showing yet another configuration example of a main part of the relay broadcast system according to the third embodiment.

FIG. 6 is a block diagram showing a relay broadcast system according to a fourth embodiment of the present invention.

FIG. 7 is a block diagram showing another configuration example of a main part of the relay broadcasting system according to the fourth embodiment.

FIG. 8 is a block diagram showing a conventional relay broadcasting system.

[Explanation of symbols]

10 TV transmitting station (master station transmitting station), 12 TV transmitting apparatus (transmitting apparatus), 14 main transmitting antenna, 16, 59 broadcast transmission radio wave, 17 power splitter (relay signal extracting means),
18, 24 Auxiliary transmission antenna, 21, 26, 64 Relay transmission radio wave, 22, 27, 32, 33 Auxiliary power amplifier (relay signal extracting means), 29 power distributor (relay signal extracting means), 30 distributor ( Relay signal extraction means),
50, 70, 90 TV relay station (slave station relay station), 52 received radio wave, 53 received antenna, 54 TV
Relay broadcasting device (relay broadcasting device), 57 transmitting antenna, 6
1 transmission signal splitter, 62 relay transmission antenna, 65 auxiliary power amplifier.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Junya Koyama 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Inventor Masanori Abe 2-3-2 Marunouchi, Chiyoda-ku, Tokyo 3 F term in Ryo Denki Co., Ltd. (reference) 5K022 DD01 DD12 DD21 5K072 AA04 BB14 BB25 BB27 CC33 DD16 DD17 EE19 GG02 GG12 GG21 GG22

Claims (8)

[Claims] A transmitting device for generating a transmission signal to be broadcast; a main transmitting antenna for emitting a transmission output signal based on the transmission signal generated by the transmitting device to a space as a broadcast transmission radio wave; A relay signal extracting means for extracting a part of the transmission signal generated as a relay output signal, and emitting the relay output signal extracted from the transmission signal by the relay signal extracting means to a space as a relay transmission radio wave. A base station transmitting station having an auxiliary transmitting antenna for receiving, a receiving antenna receiving radio waves transmitted from the base station transmitting station, and a relay broadcast for amplifying a radio wave received by the receiving antenna to generate a transmission signal. A relay station having a transmitting antenna for transmitting a transmission signal generated by the relay station as a transmission radio wave for broadcasting. Stem. 2. A relay signal extracting means in a master station transmitting station transmits a transmission signal generated by a transmitting device as a transmission radio wave for broadcasting from a main transmission antenna, and a relay transmission signal from an auxiliary transmission antenna. 2. The relay broadcast system according to claim 1, wherein the power splitter is a power splitter that splits a signal into a relay output signal emitted as a radio wave. 3. A relay signal extracting means in a master station transmitting station is an auxiliary power amplifier for extracting and amplifying a part of a transmission signal generated by a transmitting device and supplying the amplified signal as a relay output signal to an auxiliary transmission antenna. The relay broadcast system according to claim 1, wherein: 4. The master station transmitting station includes a plurality of auxiliary transmitting antennas, and the relay signal extracting means outputs a transmitting signal generated by the transmitting device as a transmitting radio wave for broadcasting from the main transmitting antenna. 2. The relay broadcast system according to claim 1, wherein the power splitter is a power splitter for splitting a signal and a plurality of relay output signals emitted as relay transmission radio waves from each of the auxiliary transmission antennas. 5. The master station transmitting station includes a plurality of auxiliary transmission antennas, and the relay signal extracting means extracts a part of the transmission signal generated by the transmitting device, amplifies the extracted signal with an auxiliary power amplifier, and amplifies the auxiliary power. 2. The relay broadcasting system according to claim 1, wherein an output of the amplifier is distributed to a plurality of relay output signals by a power divider and supplied to each of the auxiliary transmission antennas. 6. The master station transmitting station includes a plurality of auxiliary transmitting antennas, and the relay signal extracting means extracts a part of the transmitting signal generated by the transmitting device and distributes the signal to a plurality of signals by a distributor. ,
2. The relay broadcasting system according to claim 1, wherein the signals distributed by the distributor are amplified by an auxiliary power amplifier, and supplied to the auxiliary transmission antennas as relay output signals. 7. A relay transmission antenna for emitting a relay output signal based on a transmission signal generated by the relay broadcasting device to a space as a relay transmission radio wave, wherein the relay station relay station generates the relay transmission antenna. A transmission output signal emitted from the transmission antenna as a transmission radio wave for broadcasting,
2. The relay broadcasting system according to claim 1, further comprising: a transmission signal splitter that splits a signal into a relay output signal emitted from the relay transmission antenna as a relay transmission radio wave. 8. A relay transmission antenna for emitting a relay output signal based on a transmission signal generated by the relay broadcast device to a space as a relay transmission radio wave, wherein the relay relay station generates the relay transmission device. 2. The relay broadcast system according to claim 1, further comprising: an auxiliary power amplifier for extracting and amplifying a part of the transmission signal, and supplying the amplified output signal to the relay transmission antenna as a relay output signal.