JPH0433425A - Site diversity switching controller - Google Patents

Abstract

PURPOSE:To detect the attenuation of an up-link wave by detecting reinfall attenuation of a feeder link wave from a satellite input level telemetory data and using an IS signal superimposed on an television signal so as to identify whether or not its own station is making transmission. CONSTITUTION:An IS signal superimposing section 15 superimposes an IS signal onto a television signal at a station A11 for a vertical blanking period and the resulting signal is sent from a transmitter 16. The transmission signal is recovered by a receiver 17 via a broadcast satellite 13 and an IS signal detecting section 18 detects an IS signal in a received television signal 15. Then a transmitter OFF control signal 25 is sent to the transmitter 16. On the other hand, the IS signal detector 26 of a B station 12 detects the interruption of an IS signal and a transmitter ON control signal 28 is sent to a transmitter 27 to select the B station 12 as the transmission station. Thus, the attenuation of an up-link wave is detected with high reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a site diversity switching control device for satellite broadcasting.

[Conventional technology]

The site diversity method is one of the rain attenuation measures for satellite communication feeder links. Conventionally, this type of control method performs attenuation detection that detects changes in the reception level or cross-polarization components of downlink waves to turn on the transmitter of the backup transmitting station through the control line, and also controls the transmission of the own station. The transmitting station is switched by turning off the transmitter.

[Problem to be solved by the invention]

Such conventional control methods require a dedicated downlink wave attenuation detection device, and because the downlink waves are monitored, attenuation due to failure of the satellite repeater is also included. In addition, in satellite broadcasting, there are multiple stations that divide time zones and transmit different programs, so it is necessary for a human to determine whether the own station is transmitting when attenuation is detected. Furthermore, since the transmitter is controlled through a control line for switching to a backup transmitting station, there are problems such as instantaneous interruptions or overlapping of broadcast waves when switching between transmitting stations.

An object of the present invention is to provide a switching control device that detects attenuation of uplink waves with high reliability without using a dedicated downlink wave detection device, and switches transmitting stations without momentary interruption. be.

[Means to solve the problem]

The switching control device of the present invention provides a means for detecting rainfall attenuation of a feeder link wave from satellite input level telemetry data, and a transmitting station identification signal superimposed on a television signal, for a ground station that forms a site diversity system with a broadcasting satellite. (hereinafter referred to as the Is multiplied signal) is provided with means for identifying the transmitting station and timing for switching the transmitting station.

For example, the ground station superimposes Is times the signal on the television signal.
an S signal superimposing section, a transmitter that transmits the superimposed television signal, a receiver that receives the television signal from a broadcasting satellite, an Is signal detection section that detects the IS signal in the received television signal, and a satellite input. It includes a telemetry receiver that outputs level telemetry data, and a switching judgment unit that controls on/off the Is signal superimposition unit and the transmitter based on the satellite input level telemetry data and the output from the Is signal detection unit. There is.

[Effect]

According to the present invention, the rain attenuation of the feeder link wave is detected from satellite input level telemetry data, and the attenuation of the uplink wave is detected by identifying whether the own station is transmitting from the Is multiplied signal superimposed on the television signal. be able to.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing a configuration between broadcasting satellite transmitting stations equipped with a site diversity switching control device of the present invention. In the figure, station A 11 is a normal transmitting station, and 8 stations 12
as its backup station, and broadcasting satellite 13 between these stations.
Transmitting station switching for site diversity is performed via the .

A station 11 broadcasts A during the blanking period of the television signal 14.
The transmitting station identification signal that the station 11 is transmitting (hereinafter referred to as the Is-fold signal superimposition 15 that superimposes the Is-fold signal on the television signal, and the transmitter 16 that transmits the television signal on which the Is-fold signal is superimposed)
has. It also has a receiver 17 that receives a television signal from the broadcasting satellite 13, and an IS signal detection section 18 that detects an Is-fold signal from this received signal. Further, there is a telemetry receiver 22 that outputs satellite input level telemetry data, and a switching judgment that controls on/off the superposition of the IS signal in the Is multiplied signal superposition 15 according to this data value and the output of the IS signal detection section 18. 19.

Further, although the eight stations 12 have substantially the same configuration, only the Is signal detection section 26 and the transmitter 27 are shown here. And A
The stations 11 and 8 stations 12 are connected by a land line 29.

In this configuration, the A station 11 superimposes the IS signal on the television signal during the blanking period using the Is times signal superimposition 15, and transmits it from the transmitter 16. This transmission signal is received by the receiver 17 via the broadcasting satellite 13, and is received by the Is signal detection unit 1.
At step 8, the Is multiplied signal in the received television signal 15 is detected, and the local station transmitting information 20 is sent to the switching determination section 19.

At this time, the television signal 21 on which the IS signal is superimposed is sent to the eight stations 12 via the terrestrial line 29.

When rain occurs at the A station 11, the attenuation of the feeder link wave increases, and when the content of the satellite input level telemetry data 23 from the telemetry receiver 22 falls below a certain level, the switching judgment unit 19 determines that the local station is transmitting. IS signal off command 2 to Is multiplied signal superimposition 15 when information 20 is on
Send 4.

As a result, the Is signal detection section 18 detects the interruption of the transmission Is signal, and sends a transmitter off control 25 to the transmitter 16 after a certain delay time thereafter.

On the other hand, the Is signal detection unit 26 of the 8th station 12 also detects the Is signal disconnection, and asks the transmitter 27 whether the transmitter is turned on or not. ll12B
By sending this, the transmitting station is switched to the 8th station 12.

Therefore, the attenuation of uplink waves can be detected and site diversity switching can be performed without using a dedicated downlink wave attenuation detection device.

Note that the Is signal interruption is detected at the current transmitting station and the backup transmitting station, and the transmitter is turned on and off after a certain delay time.
If the time is set in consideration of the radio wave propagation time between the transmitting station and the broadcasting satellite as described in the program switching control method for broadcasting satellites described in No. 2411, the switching of the transmitting station can be done automatically without momentary interruption. It is also possible to do so.

〔Effect of the invention〕

As explained above, the present invention detects rainfall attenuation of feeder link waves from satellite input level telemetry data,
Since the IS signal superimposed on the blanking period of the TV signal identifies when the local station is transmitting, it is possible to detect uplink wave attenuation at high signal rates without using a dedicated downlink wave attenuation detection device. , there is an effect that suitable switching of transmitting stations can be realized.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a configuration between broadcasting satellite transmitting stations equipped with a site diversity switching control device of the present invention.

Claims (1)

[Claims] 1. In a site diversity system consisting of a plurality of ground stations each set as a normal transmitting station or a backup transmitting station, and a broadcasting satellite interposed between these, the ground station has a , comprising means for detecting rainfall attenuation of feeder link waves from satellite input level telemetry data, and means for identifying the transmitting station itself and determining transmitting station switching timing based on a transmitting station identification signal superimposed on the television signal. A site diversity switching control device featuring: 2. The ground station includes a transmitting station identification signal superimposing section that superimposes a transmitting station identification signal on the television signal, a transmitter that transmits the superimposed television signal, and a receiver that receives the television signal from the broadcasting satellite. , a transmitting station identification signal detection unit that detects a transmitting station identification signal in a received television signal, a telemetry receiver that outputs satellite input level telemetry data, and the satellite input level telemetry data and the transmitting station identification signal detection unit. 1. A site diversity switching control device comprising a transmitting station identification signal superimposing section and a switching determining section that controls on/off a transmitter based on an output from the transmitting station identification signal superimposing section.