JP2001144654A - Stationary reception monitor system for ground digital broadcast - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stationary reception monitor system for ground digital broadcast that can correctly transmit data even when digitally modulated data themselves at a transmitter side are in error. SOLUTION: An error rate measurement section 23 placed in a reception station 20a measures an error rate of received data and an electric field strength measurement section 24 measures the reception electric field strength of the received data. A data collection terminal 25 collects the measurement results and transmits the measured result to a transmission station 26 via a MODEM 26. The transmission station 10 receives the measured results via a MODEM 16, a data monitor terminal 17 compares the measured result with a predetermined numeral and uses changeover devices 12, 14 to switch the selection of outputs from data modulators 11A, 11B and transmission sections 13A, 13B under the control of a system control section 19 when the measurement result is the predetermined numeral or below.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a terrestrial digital broadcasting system, and more particularly to a terrestrial digital broadcasting stationary reception monitoring system for monitoring an abnormality on a transmitting side.

[0002]

2. Description of the Related Art In general, in analog TV broadcasting, when a power amplifier or the like on the transmitting side deteriorates and the transmission output drops, the receiving state may gradually deteriorate on the receiving side. Unless the output of the transmitting side completely stops (output stops), a situation in which a transmission signal from the transmitting side cannot be received suddenly at all is unlikely to occur.

[0003] On the other hand, in digital TV broadcasting, compression / expansion techniques are used to suppress the transmission rate, so that the reception side installed at the end (fringe) of the service area slightly changes the reception state. This also causes a phenomenon that the transmission signal from the transmission side cannot be received suddenly. This phenomenon is called the Cliff effect.

Therefore, a failure detection method in which the receiving side measures the electric field intensity level from the transmitting side, detects an abnormality on the transmitting side based on the measurement result, and notifies the transmitting side of the abnormality is disclosed in Japanese Patent Application Laid-Open No. HEI 5-1993. No. 103368 discloses this.

[0005]

In a digital broadcasting system using radio, even if the electric field intensity level on the receiving side is sufficient, if there is an abnormality in the digitally modulated data itself, the image on the receiving side will be displayed. And it may not be possible to properly demodulate the sound.

Therefore, as disclosed in Japanese Patent Application Laid-Open No. Hei 5-103368, digital modulation is performed only by measuring the electric field strength level on the receiving side and detecting an abnormality on the transmitting side based on the measurement result. If there is an abnormality in the data itself, the abnormality cannot be detected, and the receiving side cannot correctly demodulate video or audio.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and in a digital broadcasting system using radio, an abnormality is found in data itself digitally modulated on a transmission side. It is an object of the present invention to provide a fixed reception monitoring system for digital terrestrial broadcasting capable of transmitting correct data even in a case where the data is present.

[0008]

To achieve the above object, the present invention provides a transmitting station for transmitting digital data, and a transmitting station provided in a service area of the transmitting station for receiving data transmitted from the transmitting station. A plurality of receiving stations, and a terrestrial digital broadcast stationary reception monitoring system for monitoring an abnormality at the transmitting station, wherein each of the plurality of receiving stations receives data transmitted from the transmitting station. Receiving means, error rate measuring means for measuring the error rate of the data received by the receiving means at predetermined time intervals, collecting means for collecting the measurement results in the error rate measuring means, and collecting by the collecting means Modulating means for modulating and transmitting the measured result, wherein the transmitting station modulates data to be transmitted to the receiving station; and the plurality of data modulating means. Selecting means for selecting one of the data modulated by the first and second means; a plurality of transmitting means for transmitting the data selected by the first selecting means; and a plurality of transmitting means for transmitting the data selected by the first selecting means. Second selecting means for selecting one of the received data, demodulating means for demodulating a measurement result transmitted from the receiving station, and a measurement result demodulated by the demodulating means and a predetermined numerical value. And a monitoring unit that outputs alarm information when the measurement result demodulated by the demodulation unit is equal to or less than a predetermined numerical value, and a second unit that outputs the alarm information when the alarm information is output from the monitoring unit. System control means for switching the selection by the first and second selection means, wherein the data selected by the second selection means is transmitted to the receiving place.

In addition, the apparatus further comprises an electric field intensity measuring means for measuring a received electric field intensity of the data received by the receiving means at predetermined time intervals, wherein the collecting means comprises an error rate measuring means and an electric field intensity measuring means. It is characterized by collecting measurement results.

[0010] Further, the present invention is characterized in that it has an alarm output means for outputting an alarm when alarm information is output from the monitoring means.

The alarm output means is a display for displaying the alarm information.

Further, the alarm output means is a speaker which outputs the alarm information in a voice.

[0013] Further, the plurality of receiving stations are each provided at an end of a service area of the transmitting station.

(Operation) In the present invention configured as described above, one of the data modulated by the plurality of data modulating means is selected by the first selecting means in the transmitting station. One of the data transmitted by the plurality of transmitting means is selected by the second selecting means, and the selected data is transmitted to the receiving station. At the receiving station, when the data transmitted from the transmitting station is received by the receiving means, the error rate measuring means measures the error rate of the received data every predetermined time, and In, the reception electric field strength of the received data is measured every predetermined time. The measurement results of the error rate measurement unit and the electric field strength measurement unit are collected by the collection unit, and then modulated by the modulation unit and transmitted to the transmitting station. At the transmitting station, when the measurement result transmitted from the receiving station is demodulated by the demodulation means, the monitoring means compares the demodulated measurement result with a predetermined numerical value, and compares the demodulated measurement result with the predetermined value. If the value is less than the predetermined value, alarm information is output. When the alarm information is input to the system control means, the selection by the first and second selection means is switched by the system control means, and the currently selected data modulation means or transmission means is replaced with another data modulation means or transmission means. And the data is transmitted to the receiving station using the newly selected data modulating means and transmitting means.

As described above, the error rate and the received electric field strength of the data received at the receiving station are measured, and based on the measurement results, the data modulating means or the transmitting means which is considered to be abnormal at the transmitting station is used to perform other data modulation. Since the switching is made to the means or the transmitting means, even if there is an abnormality in the digitally modulated data itself at the transmitting station, the abnormality is detected, and the system down due to the abnormality is automatically avoided.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of a stationary monitoring system for digital terrestrial broadcasting according to the present invention.

As shown in FIG. 1, in the present embodiment, a transmitting station 10 serving as a digital broadcasting station and a fringe (end) of a service area of the transmitting station 10 are provided to receive data transmitted from the transmitting station 10. And receiving stations 20a and 20b for returning the state of the received data to the transmitting station 10.

In the terrestrial digital broadcasting stationary monitoring system configured as described above, when the data transmitted from the transmitting station 10 is received by the receiving stations 20a and 20b,
At the receiving stations 20a and 20b, the state of the received data is measured, and the measurement result is notified to the transmitting station 10.

FIG. 2 is a diagram showing the configuration of the transmitting station 10 and the receiving station 20a shown in FIG. The receiving station 20b shown in FIG. 1 has the same configuration as the receiving station 20a.

As shown in FIG. 2, the transmitting station 1 in the present embodiment
0, digital modulators 11A and 11B as data modulating means for modulating image data and audio data to be transmitted into digital signals, and digital modulators 11A and 11B.
A switching unit 12 as first selection means for selecting and outputting one of the data modulated by the transmission unit 13 and a transmission unit 13 for transmitting the data selected by the switching unit 12
A, 13B, a switch 14 as a second selecting means for selecting and outputting any one of the data output from the transmission units 13A, 13B, and the data selected by the switch 14 An antenna 15 for transmission, a modem 16 as demodulation means for demodulating data transmitted from the receiving stations 20a and 20b, and a data monitoring terminal 17 as monitoring means for processing data demodulated by the modem 16.
An alarm output unit 18 for outputting an alarm based on the data processed by the data monitoring terminal 17; and a switch 1 based on the data processed by the data monitoring terminal 17.
System control unit 1 for controlling the selection operation in units 2 and 14
9 and the receiving station 2 in the present embodiment.
0a, an antenna 2 for receiving a radio signal
1; a receiving unit 23 for receiving data transmitted from the transmitting station 10 from radio signals received by the antenna 21;
An error rate measurement unit 23 that measures the error rate of the data received by the reception unit 23 every predetermined time, and an electric field strength measurement unit that measures the reception electric field strength of the data received by the reception unit 23 every predetermined time 24, a data collection terminal 25 that is a collection unit that collects measurement results in the error rate measurement unit 23 and the electric field strength measurement unit 24, and a modem 26 that is a modulation unit that modulates data collected by the data collection terminal 25. Is provided, and the data modulated by the modem 26 is transmitted to the transmitting station 1
0 and demodulated by the modem 16 in the transmitting station 10. Note that examples of the alarm output unit 18 include a display for displaying alarm information and a speaker for outputting alarm information by voice.

The operation of monitoring the status of the transmitting station 10 in the terrestrial digital broadcasting stationary monitoring system configured as described above will be described below.

Image data and audio data to be transmitted are first modulated into digital signals by digital modulators 11A and 11B.

Next, in the switching unit 12, under the control of the system control unit 19, one of the data modulated into digital signals by the digital modulators 11A and 11B is selected, and only the selected data is output. Is the transmission unit 13
A, 13B. In the present embodiment, it is assumed that data converted into a digital signal by the digital modulator 11A is first selected in the switch 12, and the data is input to the transmission units 13A and 13B.

Next, the transmitting sections 13A and 13B transmit the digital signal modulated by the digital modulator 11A.

Next, in the switch 14, under the control of the system controller 19, one of the data transmitted by the transmitters 13A and 13B is selected, and only the selected data transmits the antenna 15 Sent through. In the present embodiment, it is assumed that the data transmitted by the transmission unit 13A is first selected by the switch 14 and the data is transmitted via the antenna 15.

The data transmitted from the transmitting station 10 is received via the antenna 21 and the receiving unit 23 in the receiving station 20a, and the error rate measuring unit 23 measures the error rate of the received data every predetermined time. At the same time, the received electric field intensity of the data received by the electric field intensity measuring unit 24 is measured every predetermined time.

Error rate measuring section 23 and electric field strength measuring section 24
Are collected by the data collection terminal 25,
Thereafter, the signal is modulated by the modem 26 and transmitted to the transmitting station 10.

The measurement result transmitted from the receiving station 20a is demodulated by the modem 16 in the transmitting station 10 and input to the data monitoring terminal 17.

Then, in the data monitoring terminal 17, the input error rate and the received electric field strength are compared with predetermined numerical values, respectively, and at least one of the input error rate and the received electric field strength is determined in advance. If the value is equal to or less than the numerical value, an alarm is output via the alarm output unit 18 and the alarm information is transmitted to the system control unit 1.
9 is output.

When alarm information is input to the system control unit 19, the system control unit 19 switches the switches 12, 1
4 is controlled, and data transmission is newly performed using the digital modulator 11B or the transmission unit 13B. By the operation of the switches 12 and 14,
The data modulated by the data modulator 11B is transmitted to the transmitting unit 13
A, the data modulated by the data modulator 11A is transmitted through the transmission unit 13B, and the data modulated by the data modulator 11B is transmitted by the transmission unit 13B.
, And the combination is selected such that the error rate and the received electric field strength inputted to the data monitoring terminal 17 are respectively larger than predetermined numerical values.

In the present embodiment, each of the digital modulators 11A and 11B and the transmission units 13A and 13B has 2
However, the present invention is not limited to this, and it is only necessary that a plurality of units are provided, one of which is selected.

[0033]

As described above, in the present invention,
The error rate and received electric field strength of the data received at the receiving station are measured, and when an abnormality is found in the measurement result, the data modulation means or the transmission means is switched to another data modulation means or the transmission means, and the transmission is performed. Since the data is transmitted from the station to the receiving station, even if there is an abnormality in the digitally modulated data itself at the transmitting station, the abnormality can be detected and automatically recovered.

[0034] This is, of course, the failure of the transmitting station,
It is also possible to detect a change in the service area due to deterioration of the transmission equipment or other factors.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a stationary monitoring system for digital terrestrial broadcasting according to the present invention.

FIG. 2 is a diagram showing a configuration of a transmitting station and a receiving station shown in FIG.

[Description of Signs] 10 Transmitting Station 11A, 11B Digital Modulator 12, 14 Switch 13A, 13B Transmitting Unit 15, 21 Antenna 16, 26 Modem 17 Data Monitoring Terminal 18 Alarm Output Unit 19 System Control Unit 20a, 20b Receiving Station 22 Receiving unit 23 Error rate measuring unit 24 Electric field strength measuring unit 25 Data collection terminal

Continued on the front page F term (reference) 5C061 BB03 CC03 CC05 5K021 AA06 BB04 CC01 CC02 DD02 EE01 EE04 FF04 FF11 5K042 BA08 BA11 CA02 CA05 CA11 CA12 CA16 CA17 CA18 DA19 DA27 EA02 FA08 FA11 FA15 FA21 GA02 HA13

Claims (6)

[Claims] 1. A transmitting station for transmitting digital data, and a plurality of receiving stations provided in a service area of the transmitting station and receiving data transmitted from the transmitting station,
A terrestrial digital broadcast stationary reception monitoring system that monitors an abnormality at the transmitting station, wherein each of the plurality of receiving stations receives data transmitted from the transmitting station, and receives at the receiving means. Error rate measuring means for measuring the error rate of the obtained data at predetermined time intervals, collecting means for collecting the measurement results of the error rate measuring means, and modulating and transmitting the measurement results collected by the collecting means And a plurality of data modulating means for modulating data to be transmitted to the receiving station, and selecting one of the data modulated by the plurality of data modulating means. A first selecting unit, a plurality of transmitting units transmitting the data selected by the first selecting unit, and selecting one of the data transmitted by the plurality of transmitting units. A second selecting means for selecting, a demodulating means for demodulating the measurement result transmitted from the receiving station, and comparing the measurement result demodulated by the demodulating means with a predetermined numerical value. A monitoring unit that outputs alarm information when the measurement result demodulated in is equal to or less than a predetermined numerical value; and a monitoring unit that outputs the alarm information when the monitoring unit outputs the alarm information. And a system control unit for switching the selection. The data selected by the second selection unit is transmitted to the receiving station. 2. The stationary reception monitoring system for digital terrestrial broadcasting according to claim 1, further comprising: an electric field intensity measurement unit that measures a reception electric field intensity of data received by the reception unit at predetermined time intervals, The collecting means collects the measurement results of the error rate measuring means and the electric field strength measuring means, and is a stationary reception monitoring system for digital terrestrial broadcasting. 3. The stationary reception monitoring system for digital terrestrial broadcasting according to claim 1, further comprising an alarm output unit that outputs an alarm when alarm information is output from the monitoring unit. Terrestrial digital broadcasting stationary reception monitoring system. 4. The fixed reception monitoring system for digital terrestrial broadcasting according to claim 3, wherein the alarm output means is a display for displaying the alarm information. . 5. The fixed reception monitoring system for digital terrestrial broadcasting according to claim 3, wherein the alarm output means is a speaker that outputs the alarm information by voice. Monitoring system. 6. The stationary reception monitoring system for digital terrestrial broadcasting according to claim 1, wherein the plurality of receiving stations are respectively provided at ends of a service area of the transmitting station. A fixed reception monitoring system for digital terrestrial broadcasting characterized by the following.