KR0165941B1 - Manless ground based station and method for examining its state for satellite communication system - Google Patents

Abstract

The present invention relates to an unmanned terminal earth station system operating under unmanned management or installed in an unmanned area, and a method for checking a state of the earth station for the same. The present invention relates to an outdoor device (antenna and antenna) at a satellite communication terminal earth station system receiving unit using a frequency band of 10 GHz or more. Level classification of the received signal according to the change of the length of the Inter Facility Link cable due to the installation place of the low noise amplification unit and the indoor unit (the demodulation unit in the receiving unit) and the downstream due to the rainfall of the terminal earth station area. It automatically compensates for link rainfall attenuation to prevent transmission quality degradation and interruption of communication, and manages the status of the central earth station and the terminal earth station by managing the status of all terminal earth stations including the rainfall of the terminal earth area using the network management system. System performance by the statistical processing of all terminal earth stations. So as to identify discloses a status check method for unattended terminals and an earth station system for satellite earth station for this communication system.

Description

Unmanned terminal earth station system for satellite communication system and method for checking status of earth station for it

1 is a configuration diagram of a satellite communication earth station system employing an unmanned terminal earth station system according to the present invention.

2 is a configuration diagram of the terminal earth station system of FIG.

3 is a detailed block diagram of an unmanned terminal earth station system according to the present invention.

4 is a flowchart illustrating a state check of a terminal earth station system according to the present invention;

5 is a flowchart illustrating a state check of the terminal earth station statistical processing and the central earth station system according to the present invention.

* Explanation of symbols for main parts of the drawings

1: first data processing unit 2: 1F modulation unit

3: RF conversion unit 4: antenna for central earth station

5: antenna for terminal earth station 6: low noise amplifier block (LNB)

7: Received signal level compensator 8: 1F demodulator

9: second data processing unit 10: outdoor device (including antenna and LNB)

11 variable IFL cable 12 received signal level compensation device.

13 Demodulator 21 Beacon Signal Level Detector

22: adder 23: variable gain amplifier

24: demodulator (including decoder) 25: demodulator control unit

26: BER detector 27: Timer and controller

28: network management system interface 29: restore data processing unit

100: Central earth station

200: Network Management System (NMS)

300: satellite system 400: terminal earth station

The present invention relates to an unmanned terminal earth station system operating under unmanned management or installed in an unmanned area and a method for checking the state of the earth station therefor. The present invention relates to an outdoor device (antenna) in a satellite communication terminal earth station system receiving unit using a frequency band of 10 GHz or more. Level change of the received signal according to the length of the Inter Facility Link (hereinafter referred to as IFL) cable due to the installation location of the low noise amplifier block) By automatically compensating downlink rainfall attenuation due to rainfall in the earth station area, it prevents the decrease of transmission quality and the interruption of communication, and manages the status of all the earth earth stations including the rainfall of the earth earth area using the network management system. Understand the status of the central station and terminal earth station, and by statistical processing of all terminal stations The present invention relates to an unmanned terminal earth station system for a satellite communication system to grasp system performance instantaneously, and a method for checking a state of an earth station.

In the conventional satellite communication earth station receiving system using a frequency band of 10 GHz or more, the length of the IFL cable is limited due to the level deterioration of the lost signal according to the length of the IFL cable, and the 14/12 GHz ku band or In order to compensate for signal attenuation in rainfall, one of the biggest disadvantages of the 20 / 30GHz Ka band satellite communication system, an uplink power control (UPC) system was installed in the central earth station.

The conventional satellite communication receiver as described above does not compensate the loss value of the received signal according to the length of the IFL cable, so that the length of the IFL cable is limited and fixed, so that the outdoor device including the antenna and the low noise bend (LNB) Has been constrained by the installation location. In addition, although the uplink power control (UPC) system is installed and operated to compensate for the attenuation of the signal due to the rain, the UPC system only compensates for the rainfall attenuation of the uplink and the rainfall attenuation in the downlink cannot be compensated. There was a frequent problem that communication was interrupted during rainfall in the terminal earth area because there was no method.

Therefore, the present invention enables unmanned operation by adding a receiving number level compensation device between the IFL cable and the demodulator to automatically compensate for the level loss of the received signal according to the length of the IFL cable and the rain attenuation of the downlink. The purpose of the present invention is to provide an unmanned terminal earth station system and a method for checking the state of the earth station, which can alleviate the above-mentioned disadvantages by alleviating the system design constraints and the IFL cable length constraints.

Another object of the present invention is to easily maintain the maintenance of the unmanned terminal earth station and to monitor the state of the terminal earth station to the network management system by monitoring the rainfall state of the unmanned operation area such as mountain or island wallpaper and the state of the terminal earth station system by the network management system. Statistical processing is used to detect the performance of the entire system including the central earth station.

Unmanned terminal earth station system according to the present invention for achieving the above object is an antenna for terminal earth station for receiving a signal transmitted from a satellite, and a low noise amplifier block for low-noise amplifying the received signal via the antenna and lowering the frequency And a beacon signal received from the satellite to detect a variable attenuation value of the received signal according to a change in length of the IFL cable and an IFL cable connected from the low noise amplifier block, and a downlink rainfall attenuation value due to the rainfall of the terminal earth station. The difference between the beacon signal level detecting means for detecting the level of the beacon signal, the initial request level value Vbri of the terminal earth station beacon signal initially set, and the current level value Vbci of the beacon signal detected from the beacon signal level detecting means. An adder means for calculating attenuation amount (Vbri-Vbci) of the beacon signal, and outputting of the adder means The process restores the received signals transmitted from the variable gain amplifier means, the variable gain amplifying means to compensate for attenuation of the received signal in accordance minutes and is characterized in that the demodulation means configured to be connected to the network management system.

According to the present invention, a method for checking a state of an earth station includes: (A) inputting a beacon signal initial request level value ABRi of a selected terminal earth station and an initial request level value ACRi of a received signal, and (B) a current state of the terminal earth station. Status value, current reception level of beacon signal (ABCi), signal loss value (AIFLi) according to IFL cable length, current level value of received signal (ACCi) and uncompensated value in uplink received from central earth station (AUL) ), Monitoring the loss value (α) due to a sun transit (Sun Transit) transmitted from the network management system, (C) attenuation value (ABAi) of the beacon signal due to downlink rainfall of the terminal earth station, the terminal earth station Calculating an attenuation value (ACAi) of the received signal and an uncompensated value (ACDAi) in the downlink of the terminal earth station, respectively, by the following equations,

ABAi = ABRi-AIFLi -ABCi-α

ACAi = ACRi-ACCi

ACDAi = ACAi-AUL

(D) detecting and displaying the rainfall attenuation value, rainfall value, BER value, received signal level value, received signal attenuation value, and uncompensated value in downlink according to the result obtained in step (C); (E) transmitting the value detected in step (D) to the statistical data processing unit and returning to step (B).

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

1 is a configuration diagram of a satellite communication earth station system according to the present invention. As shown in the figure, the central earth station system 100 includes a first data processor 1, an IF modulator 2, an RF converter 3, and an antenna for the central earth station 4. The first data processor 1 is provided as an interface between the user and the network management system 200 and multiplexes baseband data. The IF modulator 2 modulates the baseband signal with a carrier in the IF band of 70 MHz band. The modulated signal is converted to a satellite frequency by the RF converter 3, and then amplified to high power, and forms a communication link with the satellite 300 through the antenna 4 for the central earth station. The signal received from the antenna of the satellite 300 is frequency-converted by the repeater (not shown) of the satellite 300 and then amplified. The amplified satellite signal is communicated with the terminal earth station 400 and is received by the terminal earth station antenna 5 of the terminal earth station 400. The received satellite signal is low noise amplified by the low noise amplifier block 6, and is frequency down and transmitted to the received signal level compensator 7. The received signal level compensator 7 automatically compensates for the loss value of the signal due to the length of the IFL cable and the downlink rainfall attenuation caused by the rainfall in the terminal earth station area, and transmits the compensated satellite signal to the IF demodulator 8. do. The IF demodulator 8 demodulates and decodes the satellite signal to the baseband and then transmits the restored signal to the second data processor 9. The second data processing unit 9 interfaces with the user by demultiplexing the restored data. In addition, the IF demodulator 8 provides an interface to communicate with the network management system 200.

2 is a configuration diagram of the terminal earth station system of FIG. 1, and as shown in the drawing, the received signal is amplified and frequency-reduced in the outdoor device 10 including the antenna for the terminal earth station and the low noise amplifier block. The amplified received signal is transmitted to the received signal level compensator 12 through the variable IFL cable 11. In the present invention, the received signal is received even if the length of the IFL cable 11 changes depending on the installation location of the outdoor device 10. The signal level compensation device 12 automatically compensates for the loss of the signal level due to the length of the IFL cable and also automatically compensates for the downlink rainfall attenuation caused by the rainfall in the terminal earth station area. The compensated received signal is demodulated and decoded by the demodulator 13, and the state of the terminal earth station system and the level of the signal are monitored and processed according to the program and interfaced with the network management system 200 to remotely operate the unmanned terminal earth station system. Manage it.

FIG. 3 is a detailed configuration diagram of the reception signal level compensator 12 and the demodulator 13 of FIG. 2, wherein a beacon signal and a modulated signal are received through the variable IFL cable 11, and the beacon signal level is received. The detector 12 detects the reception level value Vbci of the beacon signal and inputs it to the-terminals of the demodulator control unit 25 and the adder 22. In addition, the initial request level value Vbri of the beacon signal is input to the + terminal of the adder 22 when the weather is clear and when there is no loss of the received signal having the length of the IFL cable within several meters. Here, the adder 22 is a differential amplifier composed of an operational amplifier and a resistor and having a gain of 1. Attenuation amount Vbri-Vbci of the beacon signal, which is the input difference between the + terminal and the-terminal of the adder 22, is input to the voltage control unit (not shown) of the variable gain amplifier 23 composed of the variable gain amplifier and the resistor. By compensating for the attenuation of the signal, the loss value 12 due to the length of the IFL cable and the rainfall attenuation value 5 of the downlink are automatically compensated. The modulated received signal whose loss value is compensated by the variable gain amplifier 23 is demodulated and decoded into a baseband signal by the control of the demodulator 24 and the demodulator controller 25. In the same manner as above, after the data and the clock are restored, the decompression data processing unit 29 demultiplexes the user data to interface with the user. In addition, the symbol error value output by the Viterbi decoder in the demodulator 24 is input to the transmission performance (hereinafter referred to as BER) detector 26 to detect the BER. The BER detector 26 includes a counter (counter) and a comparator. And a counter and a comparator in the BER detector 26 by controlling the timer and the controller 27 (selecting reset and comparator values). The demodulator control unit 25 controls the demodulator 24 to operate normally, such as a reception channel or a reception data rate selection control, controls a timer and a controller 27 for BER detection, and receives the state and reception of the demodulator from the demodulator 24. The carrier level Acci is monitored from the beacon signal level detector 21 to the reception level value of the beacon signal (the Vbci value is converted into Abci in dBm), and the BER is monitored from the BER detector 26. In addition, the contents of FIG. 4 are processed to check the status of the terminal earth station, and communication with the network management system 200 through the network management system interface 28 for changing the setting value of the terminal earth station or detecting the state is performed. Hundreds of terminal earth stations will be installed under unmanned management.

4 is a flowchart for checking the status of an i terminal earth station system according to the present invention, which is processed by the demodulator control unit 25 of FIG. 3 and the processed result is displayed on the front side of the terminal earth station system and is displayed on the network management system 200. Reported and statistically processed. First, it starts at the beginning 30 of the state check flowchart of the i-terminal system, and the initial request value of the terminal earth station (initial required level value of i-beacon signal of i-terminal station ABRi and initial request level values of i-terminal received signal). ACRi) and (31) the current status value of i terminal earth station (current reception level value of i terminal beacon signal ABCi and i loss of signal due to the length of i station cable IFL cable AIFLi and i terminal earth station reception) The current level value ACCi of the signal, the uncompensated value (AUL) in the uplink received from the central earth station, and the loss value (α) due to the solar disturbance received from the network management system are monitored (32). Attenuation value of beacon signal by downlink rainfall of i terminal earth station ABAi and attenuation value of i terminal earth station received signal ACAi and i terminal using the monitored status of i terminal earth station and uncompensated value in uplink The uncompensated value ACDAi in the downlink of the earth station is calculated 33 as follows.

ABAI = ABRi-AIFLi-ABCi-α

ACAi = ACRi-ACCi

ACDAi = ACAi-AUL

The attenuation value ABAi of the i-terminal earth station beacon signal, which is the value calculated from step 33, is detected as a downlink rainfall attenuation value that appears during downlink rainfall, and the rainfall value corresponding to the rainfall attenuation value ABAidB is stored in the database. The BER value of the i terminal earth station and the level value of the received signal, the attenuation value of the received signal and the uncompensated value in the downlink are detected (41). The status value of the i terminal earth station detected from step 41 is displayed on the front panel of the terminal earth station system for use in the maintenance of the terminal earth station system, and the statistical data processing unit 42 for processing in the network management system 200. It returns to the terminal earth station status value monitoring step 32, which is the first step for continuous monitoring of the terminal earth station. In addition, after calculating in step 33, it is determined whether or not to check the i-terminal earth station (34). The selection of whether to check is to be selected from the terminal earth station 400 system or the network management system 200. The process is terminated (43) and if it is desired to check whether it is clear weather and whether there is no uncompensated value (AUL) in the uplink (35). At this time, if there is an uncompensated value in the uplink or uplink (AUL> 0), the checking process is terminated (43). If the weather is clear and AUL≤0, the attenuation value (ABAi) of the i-terminal earth station beacon signal is If it is positive (36), if it is positive, antenna pointing is requested (40). If it is negative, the level of the received signal is normal. Therefore, it is determined whether the current bit error rate (BER) is greater than the required bit error rate (BER) (37) and the performance of the demodulator. Check the condition. If the current bit error rate (BER) is greater than the required bit error rate (BER) in step 37, it is determined that the demodulator performance is poor (aging detection) and that the check of the demodulator is requested 38, and the current bit error rate BER is If it is less than or equal to the required bit error rate (BER), it is determined that the demodulator performance is good (39).

5 is a flow chart of the terminal station statistical processing and the central earth station system according to the present invention. The network management system 200 monitors and statistically monitors the state value of the central earth station and the state value of the terminal earth station to monitor the performance of the entire system. Evaluate, manage network status, and operate terminal earth station under unmanned management. First, the statistical data processing unit 42 starts and instantaneously calculates the current state values 41 of all the terminal earth stations of FIG. 4 and the central state station 100 from the central earth station 100 (attenuation amount of rainfall of the central earth station and uncompensated values in the uplink). (44) the local average rainfall and statistical value of the system in in-service by the statistical processing (45) from the current state values of all monitored terminal earth stations and the average BER performance detection of the whole system. Etc. The statistical process 45 is a statistical process target for a system without hardware failure. The rainfall value corresponding to the current state value from the step 44, the rainfall reduction value and the rainfall reduction value of the central earth station, which are the statistical processing values processed from the step 45, are found from the database and are not compensated for in the uplink, The average rainfall of the terminal earth station region, the average BER performance, and the current state values of all terminal earth stations are detected (52). The status value and system performance of the central earth station and the terminal earth station detected from the step 52 are sent to the screen of the network management system and the printer for maintenance and status monitoring, and also to check the status of the central earth station and the terminal earth station in an instant. In order to return to the first step, the central earth station and the terminal earth station status value monitoring step 44 is returned. In addition, it is determined whether or not to check the central earth station after the statistical process in step 45 (46). The selection of the inspection is to be selected from the central earth station system 100 or the network management system 200. If the inspection process ends (43) and the inspection is desired, it is determined whether the central earth area is sunny (47). At this time, if it is raining, the inspection process is terminated (43). If it is sunny, the determination of the uncompensated value (AUL) is positive in the uplink of the central earth station (48). If it is determined that the performance of the central earth station is poor (50), the central earth station check is requested, and if it is negative, step 49 is performed. If the determination of step 48 is negative, the signal level on the uplink is normal, and it is determined 49 whether all current bit error rates BER are greater than the required bit error rates BER, thereby checking the performance status of the central earth station. Since the performance of the central earth station affects the performance of all the terminal earth stations, if the current bit error rate (BER) is greater than the required bit error rate (BER) in the step 49, the performance of the central earth station is poor (aging detection) and the central earth station It is determined that the check is required (50), and if any one of the current bit error rates (BER) is less than or equal to the required bit error rate (BER), it is determined that the performance of the central station modulator is good (51).

As described above, according to the present invention, the following unique effects can be obtained.

First, it is easy to install the system by automatically compensating the level change of the received signal according to the length of the IFL cable connecting the outdoor device (including antenna and low noise amplifier block) and the demodulator which is the indoor device in the satellite communication earth station system receiver. It is easy to choose the installation location according to the length flexibility of the IFL cable.

Second, by automatically compensating for downlink rainfall attenuation caused by rainfall in the terminal earth station area, it is possible to prevent a decrease in transmission quality and interruption of communication.

Third, it is possible to know the rainfall of unmanned operation area where terminal earth station is installed such as mountains or island walls, and it is easy to maintain and maintain the status and performance check of all terminal earth stations by using network management system.

Fourth, statistical processing of all terminal earth stations enables instant grasping of the overall system performance and the performance check of the central station.

Claims (7)

An antenna for a terminal earth station for receiving a signal transmitted from a satellite, a low noise amplifier block for low noise amplifying a received signal through the antenna, an IFL cable connected from the low noise amplifier block, and a change in length of the IFL cable Beacon signal level detection means for detecting the level of the beacon signal received from the satellite to detect the variable attenuation value of the received signal and the downlink rainfall attenuation value due to the rainfall of the terminal earth station, and the terminal earth station beacon signal initially set An adder means for calculating attenuation amount Vbri-Vbci of a beacon signal, which is a difference between an initial required level value of Vbri and a current level Vbci detected from the beacon signal level detecting means, and received according to an output of the adder means; Variable gain amplifying means for compensating attenuation of the signal, and the variable gain amplifying means Treatment to restore the received signal and an unattended terminal earth stations in the system, characterized in that the demodulation means is configured to be connected to the network management system. The method of claim 1, wherein the demodulation means comprises: a demodulator control unit for inputting the output of the beacon signal level detecting unit and a signal output from the variable gain amplifying unit according to a control signal of the demodulator control unit to a baseband signal; A demodulator, a reconstruction data processor for demultiplexing the baseband signal reconstructed by the demodulator, a timer and a controller controlled according to an output of the demodulator controller, a demodulator controller and an output of the timer and controller And a transmission performance detector for detecting a bit error rate (BER) of received data by a symbol error value output by a beater decoder in a demodulator, and a network management interface provided as an interface between the demodulator control unit and a network management system. Unmanned terminal earth station system. 2. The unmanned terminal earth station system according to claim 1, wherein the adder means comprises a differential amplifier having a gain of 1. (A) inputting the beacon signal initial request level value ABRi of the selected terminal earth station and the initial request level value ACRi of the received signal, (B) the current state value of the terminal earth station and the current reception level of the beacon signal ( ABCi), the loss value of the signal (AIFLi) according to the length of the IFL cable, the current level value (ACCi) of the received signal, the uncompensated value (AUL) in the uplink transmitted from the central earth station and the solar disturbance transmitted from the network management system. Monitoring the loss value (α), (C) the attenuation value ABAi of the beacon signal due to the downlink rainfall of the terminal earth station, the attenuation value AACi of the received signal of the terminal earth station, and the downward of the terminal earth station. Calculating each uncompensated value (ACDAi) at the link by the following equation, ABAi = ABRi-AIFLi-ABCi-α ACAi = ACRi-ACCi ACDAi = ACAi-AUl (D) Detecting the rainfall attenuation value, rainfall value, received signal level value, received signal attenuation value and uncompensated value in downlink according to the result obtained in step (C) and detecting BER value from BER detector Displaying by; (E) A method for checking the state of an earth station for an unmanned terminal earth station system, comprising transmitting the value detected in step (D) to a statistical data processing unit and returning to step (B). 5. The method of claim 4, further comprising: (F) determining whether the terminal earth station is checked from the step (C), and (G) ending the checking process of the terminal earth station according to the determination of the step (F) or clear weather. Determining whether there is an uncompensated value in recognition and uplink; and (H) checking the terminal earth station if it is rainy or there is an uncompensated value in uplink according to the determination of the step (G). (I) determining whether the attenuation value of the UE earth station beacon signal is positive if the weather is clear according to the determination of step G and there is no compensation value in the uplink, and (J) the step (I) requesting antenna pointing when the attenuation value of the beacon signal is positive according to the determination of (I); and (K) present bit error rate when the attenuation value of the beacon signal is negative according to the determination of step (I). Than required bit error rate And determining the performance of the demodulator according to the determination. 5. The method of claim 4, further comprising: (L) instantaneously monitoring a current state value obtained through step (D) and a current state value of the central earth station in each of the plurality of terminal earth stations; Statistical processing of regional average rainfall, normal service system statistics, and average BER performance detection of the entire system; (N) Rainfall attenuation due to rainfall in the central earth area from the above step (L) and compensation in uplink Detects an unfavorable value, finds a rainfall value corresponding to the rainfall reduction amount from a database, and detects a rainfall value, and the average rainfall and average BER performance of the terminal earth station region, which is a value calculated from the step M, And detecting a state value of the earth station for the unmanned terminal earth station system. 5. The method of claim 4, further comprising: (O) determining whether the central earth station is checked from the step (M); and (P) ending the checking process of the central earth station according to the determination of the step (O), Determining whether the weather is clear, and (Q) determining whether the central earth station is in a cloudy state when the central earth station is cloudy, and determining whether there is an uncompensated value in the uplink if it is sunny; R) requesting a check of the central earth station if there is an uncompensated value in the uplink according to the determination of step (Q); and (S) an uncompensated value in the uplink according to the determination of the step (Q). Otherwise, determining whether all current bit error rates are greater than the required bit error rates and requesting a check of the central earth station or determining that the central earth station is good. How to check the status of the earth station.