JP2010220190A - Retransmission system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a broadcast wave signal retransmission system that requires no radio license, imposes no restriction on the arrangement or the shape of devices, and requires no change in frequency. <P>SOLUTION: The retransmission system includes a transmission unit 4 and a reception unit 8. The transmission unit 4 includes a plurality of retransmission antennas 7 and a transmitting-side device 5 for distributing a given broadcast wave signal into a plurality of signals, giving phase amounts different from each other to the plurality of distributed broadcast wave signals based on a given reference signal and supplying the plurality of broadcast wave signals, to which the different phase amounts have been given, respectively, to the plurality of retransmission antennas. The reception unit 8 includes a reception antenna 9 for receiving a plurality of broadcast waves retransmitted from the plurality of retransmission antennas 7 in the transmission unit 4, and an oscillator 20 for oscillating the reference signal to be transmitted from the reception antenna to the transmission unit. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a retransmission system for retransmitting a broadcast signal from a TV terminal indoors without directly connecting a cable between the TV terminal in the room and the antenna input terminal of the TV receiver.

  Conventionally, when viewing / recording TV broadcasts in buildings, apartment houses, detached houses, etc., generally, signals received from outdoor antennas and signals on CATV lines are connected to TV terminals provided on the walls of the room. , And the TV terminal and the antenna input terminal of the TV receiver are connected by a wired signal line such as a coaxial cable, so that the broadcast signal from the antenna is supplied to the TV receiver.

  However, routing a coaxial cable or the like from the TV terminal to the TV receiver imposes great restrictions on the indoor installation location of the TV receiver and the TV terminal, and the TV receiver and the room have become more thin and the back design has been emphasized. It is a factor that hinders its own beauty. In addition, the number of portable receivers that do not have broadcast signal input means other than built-in antennas such as one-seg compatible mobile phones has increased, and in portable environments where direct broadcast waves are difficult to reach, these portable devices allow TV viewing. I can't. On the other hand, various types of retransmission systems for supplying broadcast waves to a receiving apparatus have been proposed.

Patent Document 1 discloses an environment for indoor reception including correspondence to a portable receiving device by making a cable of a TV terminal and an antenna input terminal wireless by re-radiating a broadcast wave indoors by a broadcast wave indoor retransmission system. A re-transmission system that improves the performance is disclosed.
Patent Document 2 discloses a portable receiving device in which a cable of a TV terminal and an antenna input terminal is made wireless by re-radiating a broadcast wave indoors by a broadcast wave indoor re-transmission system for a room where radio waves do not reach. A re-transmission system that improves the environment of indoor reception including the correspondence to is disclosed.

Patent Document 3 discloses a retransmission system that performs frequency conversion processing in order to perform retransmission in a frequency band in which the restriction of electric field strength is relatively loose.
Patent Document 4 discloses a retransmission system provided with a dedicated reception environment for extremely shortening the transmission distance.

JP 2004-128719 A JP 2004-128720 A Japanese Patent Laid-Open No. 2005-12583 JP 2008-34898 A

  However, in Patent Document 1 and Patent Document 2, disordered radio wave radiation becomes a disturbing factor for other systems, and if TV viewing is taken as an example, it causes a reception failure for the neighborhood. Therefore, in Japan, the radio wave law regulates and manages conditions such as frequency, power, and usage of wireless devices. In the radio wave method, as will be described later with reference to FIG. 2, 322 MHz to 10 GHz, which is also a frequency band used for TV broadcasting, has an electric field strength of 35 μV / m (= 31 dBμV / m) at a transmission distance of 3 m, which is the most severe electric field strength tolerance. ). Therefore, in consideration of usage, there is virtually no wireless device other than a weak wireless station that can be used without permission / unlicensed in the same frequency band.

  On the other hand, ARIB-STDB31 “Participation Material 3 Concept for Implementation of Digital Terrestrial Television Broadcasting Line Design” in Japanese standard ARIB-STDB31 states that the standard electric field strength of a terrestrial digital broadcast receiver is 60 dBμV / m. The standard input level of the receiver is about 46 dBμV when calculated based on the standard reception model in FIG. The minimum input level of the receiver is set to −75 dBm (= 34 dBμV) as a target value. Therefore, assuming digital terrestrial broadcast reception at a distance of 3 m below the field strength of a weak radio station, the field strength is about 30 dB below the standard reception model, and about 18 dB below the receiver minimum input level. There is a problem that practical broadcast reception is impossible in transmission.

  Patent Document 3 discloses a re-transmission system that converts the frequency of a signal to be re-transmitted into a frequency band in which the restriction on the electric field strength is relatively loose, as a re-transmission system in consideration of the limitations of the weak radio station. However, the method of converting the transmission frequency has to be an expensive system because the transmission / reception processing of the retransmission apparatus becomes complicated, and there are restrictions on the wave number and frequency arrangement to be retransmitted. There is a problem that a great burden is placed on the user for changing the broadcast frequency due to the frequency rearrangement.

Patent Document 4 discloses a retransmission system using a dedicated reception environment in which the transmission distance is extremely shortened. However, there are restrictions on the dimensions and functional arrangement of the TV receiver, and the advantages and convenience of the original portable type. There is a problem of sacrificing sex.
In addition, when the re-transmission system is provided, there is a problem that the broadcast wave directly incident on the room and the wave re-radiated in the room interfere with each other and are not necessarily in a desired reception state.

An object of the present invention is to provide a broadcast wave signal re-transmission system that does not require a radio license, has no restrictions on the arrangement of devices, the shape of the device, and the like, and does not change the frequency.
In addition, the present invention provides a retransmission system that can be controlled and coordinated so that a broadcast wave that is directly incident on a room and a wave that has been re-radiated indoors are in the most intensifying state at a desired reception point in the room without interfering with each other. The purpose is to provide.

One embodiment to solve the problem is:
In a retransmission system having a transmission unit that receives a broadcast wave signal and retransmits it as a broadcast wave, and a reception unit that receives the retransmitted broadcast wave,
The transmission unit (4)
A plurality of retransmission trust antennas (7);
A plurality of broadcast wave signals distributed to the plurality of broadcast wave signals, each having a different phase amount, and each of the plurality of retransmission wave antennas having the different phase amount Each having a distribution unit (5) for supplying to
The receiving unit (8)
A receiving antenna (9) for receiving a plurality of broadcast waves retransmitted from a plurality of retransmission trust antennas (7) of the transmission unit (4);
The re-transmission system includes an oscillation unit (20) that oscillates a reference signal transmitted from the reception antenna to the transmission unit.

Another embodiment for solving the problem is:
In a retransmission system having a transmission unit that receives a broadcast wave signal and retransmits it as a broadcast wave, and a reception unit that receives the retransmitted broadcast wave,
The transmission unit (4)
Based on the reception level information reported from the receiving unit, a variable phase section (32) for changing the phase of the broadcast wave to be retransmitted and transmitting from the retransmission credit antenna;
A controller (33) for controlling on / off of a broadcast wave retransmitted by the variable phase unit;
The receiving unit (8)
A level detection unit (37) that receives at least the broadcast wave transmitted from the retransmission trusted antenna and detects a reception level of the received broadcast wave;
A re-transmission system comprising: a communication unit (39) configured to transmit information based on a reception level of the broadcast wave detected by the level detection unit to the transmission unit.

  By distributing the broadcast wave signal to a plurality of retransmission trust antennas and suppressing individual antenna radiation levels, it is possible to retransmit the broadcast wave signal below the provisions of the Broadcasting Law. Further, the communication efficiency can be optimized by adjusting the phase each time the transmission unit and the reception unit are rearranged.

  In addition, when the retransmission system is installed in a room, the broadcast wave incident directly from the broadcast station into the room and the broadcast wave retransmitted from the transmission unit of the retransmission system cooperate at the desired indoor reception point. By performing phase control in this way, the strength of the reception level of the broadcast wave of the channel desired to be received can be optimized.

The block diagram which shows an example of the retransmission system which concerns on one Embodiment of this invention. The graph which shows an example of the electric field tolerance of the weak radio station which the said re-transmission system should observe. The block diagram which shows an example of a structure of the transmission side apparatus of the said retransmission system. The block diagram which shows an example of a structure of the receiving side apparatus of the said retransmission system. Explanatory drawing explaining an example of the operation | movement at the time of performing phase control from a receiving unit to a transmission unit in the said retransmission system. Explanatory drawing explaining an example of the operation | movement at the time of performing phase control from a receiving unit to a transmission unit in the said retransmission system. The block diagram which shows an example of 2nd Embodiment of the said retransmission system. The circuit diagram which shows the structure of the phase control part of other embodiment of the said retransmission system. The circuit diagram which shows the structure of the level measurement part of other embodiment of the said retransmission system. The block diagram which shows an example of 3rd Embodiment of the said retransmission system.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
First, a retransmission system according to an embodiment of the present invention is to solve the above-described problem.
(1) We want to make the system easy to handle without restrictions on users and places of use such as radio station licenses.
(2) We want to reduce the restrictions on the location of the re-transmission unit and make it easier to change the layout.
(3) We want to maintain the original frequency without changing the retransmitted frequency.
(4) We want to maintain the original functions and performance of the receiver by minimizing restrictions on the shapes and functions of various receivers.
Considering the configuration that can respond to such requests and issues.

(Constitution)
FIG. 1 is a block diagram showing an example of a broadcast wave signal retransmission system according to an embodiment of the present invention. In FIG. 1 in which a room 1 to be retransmitted is shown, it is assumed that a broadcast signal to be retransmitted is drawn into the TV terminal 3 by the TV home wiring 2 in the room 1. The output of the TV terminal 3 is normally adjusted so as to satisfy a range from a minimum of 34 dBμV (−75 dBm) to a maximum of 89 dBμV (−20 dBm) corresponding to the characteristics of the receiver.

  Further, the transmission unit 4 has a transmission side device 5 and N (N is an integer of 2 or more) retransmission credential antennas 7-1 to 7-N (referred to collectively as retransmission credential antennas 7). is doing. The transmission side device 5 receives the output of the TV terminal 3 through a coaxial cable. The signal processed by the transmission side device 5 is radiated from the retransmission trust antenna 7 via the retransmission trust antenna cable 6. Retransmission antennas 7-1 to 7-N can exhibit performance as independent antennas by arranging them at intervals equal to or greater than the wavelength of the frequency band to be retransmitted on the ceiling, wall surface, or floor of the room. Become.

  Then, the output level of the TV terminal 3 and the transmission are set so that the output of each antenna does not exceed the electric field strength of 35 μV / m (= 31 dBμV / m) at the transmission distance of 3 m, which is the allowable value of the electric field strength defined by the Radio Law. Set appropriately according to the number of distribution of the side device 5. This setting can be easily performed by adding a general attenuator (or amplifier) between the TV terminal 3 and the transmission side device 5.

On the other hand, the receiving unit 8 includes one receiving antenna 9 and a receiving side device 10. The receiver 11 is a receiver that is used for TV viewing.
The receiving antenna 9 is an arbitrary directional or omnidirectional antenna such as a commercially available indoor receiving television antenna or a simple rod antenna. The reception side device 10 is a device that makes a pair with the transmission side device 5, and is provided between the connection of the reception antenna 9 and the receiver 11. The phase control instruction device 12 is used by the user to instruct the transmission side device 5 and the reception side device 10 to perform phase control. The phase control instruction device 12 is connected to the infrared remote controller dedicated to the retransmission system of the present embodiment or the receiver 11. It is an attached remote control.

  Next, the configuration of the transmission side device 5 of the transmission unit 4 will be described with reference to FIG. The transmission side device 5 includes a path switcher 13 that switches a signal flow at the time of retransmission operation and phase control, a distributor 14 that distributes a broadcast wave signal that is connected and input to the number of retransmission credit antennas, A plurality of variable phase shifters 15 connected to this and varying the signal phase to the retransmission trust antenna 7, a level detector 16 for detecting the level of the reference signal radiated from the receiving antenna during phase control, and level detection A control unit 17 that controls the phase to each retransmission trust antenna 7 based on the signal from the receiver 16; a light receiving unit 18 that receives an instruction from the user's infrared remote controller; and a power source (not shown) such as an AC adapter or a battery. have. The path switch 13 guides the signal from the TV terminal 3 to the distributor 14 during retransmission operation, and guides the signal from the distributor 14 to the level detector 16 during phase control. The path switcher 13 preferably switches to the path for the retransmission operation when the power supply is interrupted. The variable phase shifter 15 is, for example, a voltage control phase shifter using a variable capacitor or the like, and is provided by a number one less than the number N of retransmission trust antennas. The level detector 16 is preferably capable of detecting the level of only the reference signal, and, as an example, is a combination of a narrow band pass filter and a diode detector.

Further, as shown in FIG. 4, the receiving side device 10 of the receiving unit 8 includes a path switch 19 for switching the signal flow during the retransmission operation and the phase control, and the source of the phase control reference signal on the transmitting side. An oscillator 20, a light receiving unit 21 that receives an instruction from the user's infrared remote controller, a control unit 22 that controls the overall operation, and a power source (not shown) such as an AC adapter or a battery.
The path switch 19 guides the signal from the receiving antenna 9 to the receiver 11 during retransmission operation (and power off), and guides the signal from the oscillator 20 to the receiving antenna 9 during phase control. The reference signal may be an unmodulated signal (tone signal) that can be easily processed as long as the frequency band substantially matches the frequency band of the broadcast to be retransmitted. As an example, the frequency is fixed to the frequency of the gap between adjacent channels in the vicinity of the frequency where there are many broadcast wave channels, or the frequency is set according to the frequency of the viewing target channel according to the instruction of the phase control instruction device 12 ( ) Can be set. As a power source for the reception side device 10, DC15V superimposed on the satellite broadcast reception converter from the antenna terminal of the receiver 11, a battery built in the reception side device 10, or the like is used.

(Operation)
The retransmission system having the above-described configuration performs phase control processing and broadcast wave retransmission processing as follows. FIG. 5 is an explanatory diagram for explaining an example of the operation when performing phase control from the receiving unit to the transmitting unit in the retransmission system, and FIG. 6 is when performing phase control from the receiving unit to the transmitting unit in the retransmission system. It is explanatory drawing explaining an example of this operation | movement.

  That is, in FIG. 5, the user instructs the phase control with the phase control instruction device 12 after installing the receiving unit 8 in the vicinity of the receiver 11. When an instruction to start phase control is given, the control unit 22 in the receiving-side device 10 switches the path of the path switcher 19 to a path connecting the oscillator 20 and the receiving antenna 9, and the receiving antenna 9 A reference signal is emitted.

Then, as shown in FIG. 6, the receiving antenna 9 functions as a reference signal transmitting antenna during phase control, and the radiated reference signal has the same distance and path as the retransmitted wave during retransmission operation. Thus, at the time of phase control of the transmission unit 4, it reaches each of the retransmission trust antennas 7-1 to 7 -N serving as reception antennas. Here, in order to consider the phase of each propagation path, the reference phase adjustment point 25 is placed at a position immediately before distribution of the distributor 14. If the frequency of the broadcast wave and the reference signal substantially match, the distance between the reference retransmission trusted antenna 7-1 and the receiving antenna 9 (including the retransmission trusted antenna cable) is L ₁ , and the distance is the phase according to L ₁ . The phase at the phase adjustment point 25 obtained by adding (L1 · ω / c) and the phase of the distributor 14 is φ ₁ (−π ≦ φ ₁ ≦ π), and φ ₂ is similarly set for the retransmission trust antenna 7-2. up when you defined, by controlling the phase of the variable phase shifter 15-2 such that _{φ 1 = φ 2 + φ VA} , the received signal level from the receiving unit reaches the level detector 16 via the route switch 13 become.

After that, if the number of retransmission trust antennas is N, the control unit 17 sequentially controls the phase of the phase shifter one by one so that the level reaching the level detector 16 is maximized. The system is set to the optimal phase state.
The return from the phase control process to the broadcast wave retransmission process (returning the path switchers 13 and 19 to the retransmission state) can be preliminarily assumed to be a control time. Although it is possible to return automatically, it is also possible to return to the broadcast wave retransmission process according to the operation of the phase control instruction device 12 at the user's intention as in the case of the transition to the phase control state.

  As a result, the reception point is in an optimal phase state in the transmission direction during retransmission operation, and the reception level is maximized near the reception point, while the TV terminal output signal level is distributed and radiated in other places. Therefore, it can be expected that the calculated signal level becomes less than the value specified in the Radio Law, and it is possible to prevent interference with other systems.

  As a better mode, it is desirable that in conjunction with a remote controller attached to the receiver 11, optimal phase control is performed at the frequency of the designated channel each time a channel is operated from the remote controller. That is, once the phase control is performed on the predetermined channel by the above-described method, the control unit 17 of the transmission-side device 5 stores the control value of each variable phase shifter 15 in association with the channel, and the control value thereafter When the stored channel is designated, the stored control value is simply read out and applied to each variable phase shifter 15. Further, the control unit 22 of the receiving side apparatus 10 causes the oscillator 20 to oscillate the reference signal for a predetermined time at a frequency corresponding to the channel designated by the remote controller. Alternatively, phase control is performed once at a fixed reference frequency, and the control values of other frequencies are corrected by a predetermined calculation formula. The interlocking with the remote controller attached to the receiver 11 is not limited to directly receiving (receiving) a signal from the remote controller, but via the receiver 11, a wireless LAN, IEEE802.15.1 (Bluetooth) (registered trademark), You may receive by IEEE802.15.4 (ZigBee) (trademark) etc.

  On the other hand, if the phase control is fixed regardless of the channel selection, the phase control instruction device 12 does not need to be a remote controller, and the intention of the user to start and end phase control is transmitted to the transmission unit 4 and the reception unit 8 almost simultaneously. For example, a mechanism such as a wired device or a timer may be used, or operation buttons may be provided on both the transmission side device 5 and the reception side device 10. In this embodiment, a single reception antenna 9 is used. However, in principle, even if there are a plurality of reception antennas 9, control can be performed without any problem if the reception signals are simply combined, and the same effect can be obtained. Is possible.

  Further, even for a portable receiver having no broadcast signal input means other than the built-in antenna, the receiver unit 8 is simply placed near the receiver 11 to instruct phase control (that is, the output of the receiver unit 8). By connecting the terminals, the same effect can be obtained, and the receiving unit 8 may be cleared after the phase control. Further, in order to completely prevent interference with nearby frequencies such as a mobile phone, the transmission side device 5 may be provided with a cutoff filter for those bands. Further, one of the retransmission credential antennas 7 may be directly connected to the transmission side device 5 without using the retransmission credential antenna cable 6. Further, the re-transmission system of this example may be configured integrally with the surround speaker system. That is, a retransmission antenna is built in each of the four speakers usually placed at the four corners of the room, and an audio signal to the speaker is desirably transmitted by being superimposed on a retransmission trust antenna cable (coaxial). This makes it possible to achieve an ideal antenna arrangement that surrounds the reception point without deteriorating the aesthetic appearance.

  As described above, according to the embodiment of the retransmission system according to the present invention described above, the TV terminal 3 is managed below the maximum input level of the receiver except for a special case. Thus, the individual antenna radiation level can be suppressed below the regulation without using an attenuator. Further, the electric field is weak except for the reception point that is the focal point of the transmission wave of each retransmission trust antenna, and can be maintained substantially below the electric field allowable value of the weak radio station defined by the Radio Law.

(When controlling the phase using the signal level given from the receiving unit)
Next, as another embodiment of the retransmission system according to the present invention, a case where phase control is performed using a signal level given from a receiving unit will be described with reference to FIGS. FIG. 7 is a block diagram showing an example of the second embodiment of the retransmission system, FIG. 8 is a circuit diagram showing a configuration of a phase control unit of another embodiment of the retransmission system, and FIG. It is a circuit diagram which shows the structure of the level measurement part of other embodiment of a retransmission system.

  In the case of Japanese terrestrial digital broadcasting signals, even if signals with various delay times are combined, if the signals have the same information (symbols) and their respective delay times are within the guard interval (126 μs), A mechanism that does not cause signal degradation (symbol interference) is employed. If this 126 μs is converted into a distance (× speed of light), it corresponds to 37.8 km, and it may be considered as a sufficiently long distance for indoor transmission. Therefore, it is not necessary to synchronize the wave directly entering the room and the re-radiated wave, which is expected to have a slight delay, in absolute time. .

That is, in the retransmission system of the second embodiment, the receiving unit is installed in the vicinity of the desired reception location, the channel whose level is to be measured is set as the desired viewing channel, and the re-radiation is first turned off on the transmitting unit side. Measure the reception level at the receiving unit (only broadcast waves radiated directly from the broadcasting station to the room). Next, turn on re-radiation and check the reception level change report to change the radiating phase in sequence, then detect the phase that maximizes the reception level, and the best phase that the transmission unit should set and maintain. Can be found. In the second embodiment, not only the retransmitted broadcast wave but also the direct broadcast wave is sufficiently utilized, so that the necessary reception level can be obtained with only one retransmit antenna of the transmission unit. .
Also, when the re-transmission system is configured with a plurality of antennas, the same phase control may be performed in order for each transmission unit corresponding to each antenna.

  Next, the configuration of the second embodiment of this retransmission system will be described below. In addition, the same code | symbol is attached | subjected to the structure same as previous embodiment, and description is abbreviate | omitted. FIG. 7 shows a state in which a broadcast wave incident from the glass window 31 is incident.

  The transmission unit 4 includes a transmission side device 5-2 and a retransmission credit antenna 7. The transmission side device 5-2 receives the output of the TV terminal 3 through a coaxial cable. The signal processed by the transmission side apparatus 5-2 is radiated from the retransmission trust antenna 7 through the retransmission trust antenna cable 6. The receiving unit 8 includes a receiving antenna 9 and a receiving side device 10-2 connected to the receiving antenna 9 for detecting a signal level. The receiving unit 8 is placed in the vicinity of the receiver 11 and connected thereto. The antenna signal received by is supplied to the receiver 11.

  Further, as shown in FIG. 8, the transmission side device 5-2 provided in the transmission unit 4 includes a variable phase shifter 32 that controls the phase of the retransmitted broadcast wave, and the on / off state of the retransmitted broadcast wave. An on / off circuit 33 for controlling the off, a control unit 34 for controlling the variable phase shifter 32 and the on / off circuit 33, a wireless communication unit 35 for communicating with the receiving unit 8 or the like using infrared rays or radio signals, A power source (not shown) such as a battery is provided. The control unit 34 is, for example, a low power consumption microcomputer, and is desirably usable for several years with a lithium battery.

  Further, as shown in FIG. 9, a receiving side device 10-2 provided in the receiving unit 8 includes a branching device 36 that divides the signal from the receiving antenna 9 into two and outputs one to the receiver 11, and a branching device. The signal level of the broadcast wave (direct broadcast wave transmitted from the broadcast station and retransmitted wave from the retransmission credit antenna 7 of the transmission unit 4) connected to the other output of 36 and received by the receiving antenna 9 is detected. Level measuring device 37, a control unit 38 for controlling the operation of the level measuring device 37, a wireless communication unit 39 for communicating with the transmission unit 4 or the like using a wireless signal such as infrared rays or IEEE802.15.4, and a power source (Not shown).

The branching device 36 has a small amount of branching (coupling amount) to the level measuring device 37, and most of the input power is output to the receiver 11. Therefore, the antenna to the receiver 11 is not provided with an amplifier. The output quality will not be degraded.
The level measuring device 37 detects a reception level of a channel designated by the control unit 38, and includes a frequency synthesizer, a mixer, a channel filter (bandpass filter), a detector, and the like. Since it is only necessary to detect the relative change in level, the amplification of the input signal may be a rough amplification that is not conscious of the CN deterioration amount (an increase amount of noise with respect to the carrier). As will be described later, the level measuring device 37 is not necessary when information about the reception level, quality, and the like is obtained from the receiver 11.

  In the retransmission system according to the embodiment of the present invention having such a configuration, the phase control process and the retransmission process from the transmission unit 4 to the reception unit 8 are performed as follows. That is, first, the channel of the broadcast station (viewing desired channel) received by the receiver 11 is set in the receiving side device 10-2 of the receiving unit 8 placed near the receiver 11 (when the level measuring device 37 is provided). ). Since the setting method is not the essence of the present invention, the details are omitted, but it is desirable that the receiver 11 be linked to the remote controller.

  Alternatively, if the receiver 11 includes a wireless communication unit, the reception-side apparatus 10-2 may inquire about the frequency and reception level of the channel that the receiver 11 is receiving, and acquire them. A tuner having an AGC (Auto Gain Control) function generally used in a receiver can easily obtain information corresponding to the reception level from the AGC control voltage. When the reception channel is set, the reception side apparatus 10-2 adjusts the band to be measured of the signal input from the branching device 36 to the level measuring device 37 to the set reception channel. Unless a special channel preset is performed, the frequency can be specified from the channel number.

  Then, the level measuring device 37 of the reception side apparatus 10-2 receives the broadcast wave (from the broadcast wave directly entering the room from the broadcast station and the transmission unit 4) supplied from the reception antenna 9 at regular intervals. Level measurement of a retransmitted wave (if any) to be transmitted is started, and an instruction to start control is transmitted to the corresponding transmission unit 4 via the wireless communication unit 39 including the channel number. To notify.

  When receiving the control start instruction, the control unit 34 of the transmission-side apparatus 5-2 determines whether the result obtained in the previous phase control is stored for the specified channel number, and if it is stored. Then, the stored control value is given to the variable phase shifter 32 and the on / off circuit 33, and the control is finished (the standby state is entered, and nothing is done for the subsequent level measurement result report). If it is not stored, an arbitrary initial control value is given, and the on / off circuit 33 is turned on.

The reception-side apparatus 10-2 notifies the transmission-side apparatus 5-2 of a level measurement result report (first) after a predetermined time.
Upon reception of the first level measurement result report, the transmission side device 5-2 immediately sends another control value to the variable phase shifter 32 (for example, a control value that gives a phase that differs by +180 degrees from the previous control value). And temporarily store it as needed for later comparison.

The reception-side apparatus 10-2 notifies the transmission-side apparatus 5-2 of a level measurement result report (second time) after a predetermined time.
Upon receiving the second level measurement result report, the transmitting side device 5-2 immediately determines whether the level has increased or decreased from the previous time (refer to the previous result report as necessary). If it has increased, another control value (control value giving a phase that is +60 degrees different from the phase according to the current control value), and if it has decreased, another control value (the above ( A control value that gives a phase that is +60 degrees different from the phase of the initial control value) is supplied to the variable phase shifter 32, and a result report is temporarily stored as necessary for later comparison.

Thereafter, similarly, the control value whose level is increased by the trial is searched for while reducing the amount of phase correction by the control value. Since the level takes only one maximum point and minimum point with respect to the phase variable range, even with such control, it is possible to converge to the optimum phase after a predetermined number of times.
The control unit 34 of the transmission-side device 5-2 holds the control value at that time after a predetermined number of times, or when it is determined that the convergence or control abnormality has occurred, and turns the on / off circuit 33 off. After that, when the level measurement result report is received from the receiving side apparatus 10-2, it is determined whether the level has increased or decreased immediately before the on / off circuit 33 is turned off. The control value at the time of convergence is supplied to the variable phase shifter 32, and the on / off circuit 33 is turned on again. If it is increased, the on / off circuit 33 is kept off and the control is terminated. At the end of control, the control result is stored. The receiving side device 10-2 also ends level measurement at a constant interval after a predetermined number of times, and enters an optimum standby state in which power consumption and unnecessary noise emission are suppressed.

  Note that the propagation path changes even if a person moves in the room 1, and the previous phase control is not always optimal even now. Therefore, when the previous control value is stored, the previous control value may be set as an initial value, and the control value may be finely adjusted and updated according to the level change while perturbing the control value.

  In the retransmission system according to this embodiment, the one-way communication from the reception-side device 10-2 to the transmission-side device 5-2 has been described. However, if bidirectional communication is used, more reliable and advanced control can be performed. In addition, by acquiring information such as the number of antennas from the transmission-side device 5-2, the reception-side device 10-2 can perform convergence control. Further, the reception-side device 10-2 may be built in the receiver 11. A receiver having a home network interface such as IEEE802.15.4 can be easily adapted to the system of this embodiment only by modifying the firmware.

As shown in FIG. 10, in the “retransmission system using the signal level given from the receiving unit”, which is the second embodiment, as shown in FIG. It is possible to perform retransmission by providing a plurality. When a sufficient reception level cannot be obtained with a single retransmission antenna, a necessary reception level can be obtained by using a plurality of antennas.
When there are a plurality of transmission units 4, identification numbers are provided to the transmission side device 5-2 and the reception side device 10-2, and the same control as described above is performed for each transmission unit that is not occupied by the reception side device. As a result, the best radiation phase state can be constructed in the vicinity of the receiving unit. Hereinafter, an example using IEEE 802.15.4 for forming a network in a simple manner will be described. In the process of searching for an end device (that is, a transmitting device) having the same application object as that of the receiving device using an IEEE address that can be easily obtained by broadcasting or the like as an identification number, a node descriptor or simple When receiving the descriptor, RSSI (RX Signal Strength Indicator) is acquired. Then, communication is performed at the application level with a transmission side apparatus whose RSSI is equal to or greater than a predetermined value (that is, at a short distance). First, if there is already a receiving-side device whose transmission-side device is currently subject to phase control and the identification number is different from the receiving-side device of the current communication partner, the transmitting-side device is set to BUSY. Notifies READY to the receiving apparatus of the communication partner in response to an inquiry from the receiving apparatus or voluntarily. The receiving-side apparatus excludes the transmitting-side apparatus that has notified BUSY from the phase control target for a certain period, and continues communication for phase control as described above at the application level to the transmitting-side apparatus that has seen READY. . In addition to such exclusive control, a method of simply pairing the receiving device and the transmitting device may be used.

  As described above, according to the re-transmission system of the present invention, even in an indoor environment in which direct broadcast waves are difficult to reach, a desired indoor space is desired when viewing digital terrestrial broadcasting using an antenna built in or directly connected to the device. By performing phase control so as to obtain the best radio wave condition at the receiving point, it is possible to realize the best environment in which the indoor incident broadcast wave and the indoor re-radiated broadcast wave cooperate.

  A plurality of the various embodiments described above can be implemented at the same time. With these descriptions, those skilled in the art can realize the present invention, but various modifications of these embodiments can be conceived. It is easy for a person skilled in the art and can be applied to various embodiments without inventive ability. Therefore, the present invention covers a wide range consistent with the disclosed principle and novel features, and is not limited to the above-described embodiments.

  DESCRIPTION OF SYMBOLS 1 ... Indoors, 2 ... Antenna indoor wiring, 3 ... Antenna terminal, 4 ... Transmission unit, 5-5-2-2-5-3 Transmission side apparatus, 6 ... Wiring, 7-1 to 7-N ... Retransmission credit antenna, DESCRIPTION OF SYMBOLS 8 ... Reception unit, 9 ... Reception antenna, 10 * 10-2 ... Reception side device, 11 ... Receiver, 12 ... Variable phase shifter, 13 ... Variable phase shifter, 14 ... Distributor, 15 ... Variable phase shifter, 16 DESCRIPTION OF SYMBOLS ... Level detector, 17 ... Control part, 18 ... Light receiving part, 19 ... Path switch, 20 ... Oscillator, 21 ... Light receiving part, 22 ... Control part, 25 ... Phase adjustment point, 31 ... Glass window, 32 ... Variable phase 33 ... ON / OFF circuit, 34 ... control unit, 35 ... wireless communication unit, 36 ... branching device, 37 ... level measuring device, 38 ... control unit, 39 ... wireless communication unit.

Claims (3)

In a retransmission system having a transmission unit that receives a broadcast wave signal and retransmits it as a broadcast wave, and a reception unit that receives the retransmitted broadcast wave,
The transmitting unit is
Multiple retransmission trust antennas;
A plurality of broadcast wave signals distributed to the plurality of broadcast wave signals, each having a different phase amount, and each of the plurality of retransmission wave antennas having the different phase amount Each has a distribution unit to supply
The receiving unit is
A receiving antenna for receiving a plurality of broadcast waves retransmitted from a plurality of retransmission trust antennas of the transmission unit;
A re-transmission system comprising: an oscillating unit that oscillates a reference signal transmitted from the receiving antenna toward the transmitting unit. The transmitting unit is
A first path for supplying the given broadcast wave signal to the distributing unit, and a second path for supplying the reference signal supplied from the receiving antenna of the receiving unit to the distributing unit. Having a first path switch to switch,
The receiving unit is
A third path for outputting a plurality of retransmitted broadcast wave signals supplied from the receiving antenna to the outside, and a fourth path for supplying the reference signal from the oscillating unit to the receiving antenna The re-transmission system according to claim 1, further comprising a second path switching unit that switches between the two. In a retransmission system having a transmission unit that receives a broadcast wave signal and retransmits it as a broadcast wave, and a reception unit that receives the retransmitted broadcast wave,
The transmitting unit is
Based on the reception level information reported from the receiving unit, a variable phase unit that varies the phase of the broadcast wave to be retransmitted and transmits it from the retransmission trust antenna
A controller for controlling on / off of a broadcast wave retransmitted by the variable phase unit;
The receiving unit is
A level detector that receives at least the broadcast wave transmitted from the retransmission trusted antenna and detects a reception level of the received broadcast wave;
A re-transmission system comprising: a communication unit that transmits information based on a reception level of the broadcast wave detected by the level detection unit to the transmission unit.

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