JPS6378621A - Repeater for communication satellite - Google Patents

Abstract

PURPOSE:To attain communication quality even when a mobile objection comes off the communication area of a communication satellite, by providing a function to decide the lowering of the received electric field of an electromagnetic wave received by a repeater from the mobile objection, and a function to insert and transfer a result to a line in communicating with a terrestial station as a blank burst signal. CONSTITUTION:Receivers RX1-RXn corresponding to the mobile objection are connected to an electric field strength detector LVDET, and the LVDET detects received electric field strength. A level comparator COM, when detecting the fact that the above stated detected level is lowered below a reference level value set in the COM, transfers the bit of information of the fact to a coding device COD. The COD encodes the above stated information, and also, pulls in a communication path momentarily to the coding device COD, by operating an IFSW being connected to the receiver RX whose received electric field strength is lowered, out of IF switch matrices IFSW corresponding to the receivers RX1-RXn. The COD inserts the fact of the lowering of the received electric field strength into the communication path as the blank burst signal, and synthesizes it with an output from another IFSW at a signal synthesizer, and transmits it from an antenna ANTE to the terrestial station through a transmitter TXE, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to mobile communications, and particularly to a repeater for communication satellites in mobile communications using communication satellites.

[Conventional technology]

Mobile communication using conventional communication satellites was developed in Japanese Patent Application Laid-Open No. 57-20
As described in Publication No. 2142, to configure a communication line connecting a communication satellite and a mobile object, the communication range is divided by using multiple spot beams from the communication satellite as shown in Figure 2. Examples are known.

However, in the conventional method, this problem occurs when a mobile subscriber's power outlet near the border of the area covered by the communication satellite or when the mobile unit during communication moves out of the area covered by the communication satellite due to the mobile unit moving over a wide range. No consideration was given to the deterioration in communication quality caused by In other words, no consideration was given to the fact that communications would not be able to continue if the area was outside the coverage area.

[Problems to be Solved by the Invention] ゛The above-mentioned conventional technology has a problem in that the scope of use for mobile communication is increasingly expanded, such as by using communication satellites, and as the speed at which mobile objects move and move becomes faster, There was no consideration given to ensuring continuous communication quality when a mobile object leaves the communication area covered by a communication satellite. As a result, there have been problems such as the quality of communication during communication rapidly deteriorating or communication being interrupted.

An object of the present invention is to provide a 1G satellite repeater for constructing a system to solve this phenomenon.

[Means for solving problems]

In order to continuously ensure the communication quality of a moving mobile object, the passing satellite repeater must be able to constantly monitor the received field strength of the TA waves received from the communicating mobile object.

When the reception level drops below a certain value, the information is inserted into the active line as a blank burst signal and transferred to the ground station, which enables the ground station to strongly receive the t-magnetic waves emitted from the mobile object. By switching to communication lines using other available communication satellites, it is possible to ensure that mobile units can purchase 100 items.

[Effect]

The present invention provides a communication satellite repeater with an electric signal received from a mobile body.
By providing a function to monitor his received electric field strength, a function to determine whether the received electric field has decreased, and a function to insert and transmit the results as a blank burst signal into the line communicating with the ground station.

〔Example〕

An embodiment of the present invention will be explained below with reference to FIG. 1. In FIG. 1, ANTE is an antenna that has a fixed line with the ground station, DUp is a deplexer, RXE is a receiver that receives signals from the ground station, and TXE is a receiver that receives signals from the ground station. Transmitters TX1 to TXn transmit signals to the ground station, transmitters 9MDUP1 to MDUPn transmit signals to mobile stations, and ANT multi-decoplexers.

~, 4 A' T n is an antenna provided for each communication range with a mobile body, RX, ~RX le is a receiver that receives signals from a mobile body, and LVDET is an electric field of electromagnetic waves that the receiver receives from a mobile body. A detector detects the intensity, CON is a level comparator, and COD is a device that encodes the result of the level comparison into a blank burst ('1).

IP51F' is an IF switch that switches the intermediate frequency signal that separates the communication line and inserts a COD-coded signal as a 1-rank burst signal.

Radio waves from the ground station are input to the receiver RXE via the antenna ANTE and deplexer DUP, and are converted into intermediate frequency signals. The converted intermediate frequency signal is separated into five frequencies fl, f, ... by a signal distribution filter, and each is inputted to a transmitter rxl-rxrL and frequency-converted to Fl t "! ... h. The beams are then connected to antennas ANT and ANT via multi-deplexers MDUP and MDUPn, respectively, and beams are irradiated onto different communication areas.

On the other hand, the signal from the mobile body is transmitted by the antenna ANT, ~ANTn
received by the multi-deplexer M DUp.

~, MDUPn to the receivers RX, ~RX1. Each receiver RX, .about.RXY receives an input signal.

The doubled frequency signal is converted to an intermediate frequency, passes through the IP switch matrix IFSIF', is combined by a signal synthesizer, is up-converted and amplified by the transmitter TXE, and is sent to the deplexer D U P s antenna AN T E Y
transmitted to the ground station via

Here, a receiver RX receives a signal from a mobile object.

~RX, L are connected to a detector DVDET that detects the electric field strength of a signal received from a mobile object.

The field strength level detector LVDET is connected to the receivers RX1 to R.
While the XU is receiving signals from the mobile object, it detects the electric field strength at regular intervals and transfers the output to the level comparator COM.

The level comparator CON is the electric field strength level detector LVDE.
The received signal level transferred from T is compared with a base level value set in advance in the level comparator CON. When the level comparator COM determines that the received signal level has decreased below the standard level value, the received level decrease information is transferred to the signal conversion device C0DK. signal converter rt
cOD encodes information indicating that the reception level has decreased, and also indicates that the reception field strength has decreased at the receiver RX that is communicating with the mobile object among the IF switch matrices IFSF provided corresponding to the reception aRX, ~RxrL. The IF switch matrix IFSW'l connected to the received receiver RX operates to instantaneously draw the communication path to the signal HftCOD. Then, the signal generator COD inserts into the lead-in communication channel a 1-rank burst signal indicating that the electric field strength of the signal being received by the receiver has decreased, and a signal synthesizer outputs the signal from another IF switch matrix IFSW. Combine with the output of Then, it is up-converted and amplified by the transmitter 1fi T It becomes possible to transmit information that the electric field strength of the received signal has decreased to the ground station using the communication line.

〔Effect of the invention〕

As explained above, by providing a communication satellite repeater using the technology of the present invention, if the communication quality deteriorates while communicating with a mobile object using a communication satellite, it is possible to maintain the communication quality by using another vacant repeater. This has the effect of building a system that allows communication to continue by selecting and switching lines.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a communication satellite repeater according to an embodiment of the present invention, and Fig. 2 shows a conventional system in which a single communication satellite uses spot beams to subdivide the area covered by mobile communications. It is a perspective explanatory view. ANTE...Antenna DUP...Duplexer RXE...Receiver TXE...Transmitter TX1
~Txn...Transmitter MDUP that communicates with the mobile object, ~M
DU fan...Multi-duplexer ANT, ~ANTn
... Antenna RX1 to RX corresponding to each communication range ... Receiver LVDET that receives signals from a moving object ... Detector COM that determines the electric field strength from a moving object ... Level comparator fee I Patent Attorney Koyo Katsuo Business (Cursed)

Claims (1)

[Claims] 1. In communication satellites used for mobile communication, in which a communication satellite is used for communication between a ground station and a mobile object, and a radio frequency communication line is used to connect the mobile object and the communication satellite, the communication satellite is transferred to a communication satellite repeater. Equipped with a function to monitor and judge the electric field strength of the radio frequency during communication received from the body, and a function to insert the judged result as a blank burst signal into the communication line with the ground station during communication and transmit it to the ground station. A communications satellite repeater characterized by: