JPH01232835A - Transmission power compensation control system for satellite communication earth station - Google Patents

Abstract

PURPOSE:To attain the automatic control of a transmission level, precipitation attenuation compensation and output object level matching in the case of fine weather by adding an output object value correction circuit in the case of fine weather, a precipitation attenuation compensating circuit and an automatic output level control circuit. CONSTITUTION:An intermediate frequency transmission input signal is inputted to an up-converter 15, amplified up to a transmission level by a high output amplifier 16 and outputted as a transmission output. The circuit is provided with the fine weather output object correction circuit 11, the precipitation attenuation compensating circuit 12 and the automatic output level control circuit 14. The output object correction circuit in the case of fine weather 11 is provided with an offset correction circuit 11a and an attenuator 11b. The compensating circuit 12 consists of an adder. Moreover, the automatic output level control circuit 14 consists of a detector 14b and a subtractor 14a.

Description

[Detailed Description of the Invention] [Summary] Regarding a satellite communication earth station, the purpose of this invention is to control the output of transmission power, compensate for rain attenuation, and compensate for the output target value in clear weather. A satellite communication earth station that outputs a transmission power signal of a predetermined frequency and a predetermined output level via an amplifier includes a detector for detecting the output level of the high-power amplifier, and a detector for detecting the output level of the high-power amplifier and a reference value for the output of the detector. an automatic level control circuit that compares and outputs the difference to an uplink converter to control the output level of the transmission power signal to correspond to the reference value; Correcting an offset value within the control range of the automatic level control circuit with respect to the output target value for clear skies, further compensating the corrected fine weather output target value with a rain attenuation compensation value, and The configuration includes a compensation circuit that outputs as a reference value.

[Industrial application field]

The present invention relates to a satellite communication earth station, and more specifically, to a radio device for a small earth station that controls the output of transmission power, compensates for a target output value in clear weather, and compensates for rain attenuation.

[Conventional technology]

Figure 10 shows a configuration diagram of a conventional satellite communication earth station (for example, NEC Edane, VOl, 37.N (17,198
4゜page 64). The satellite communication earth station shown in the figure has a redundant transmitting and receiving system to improve reliability. That is, the antenna 101, the transmitter/receiver duplexer (guiplexer)
For 102, high output amplifier for transmission (IIP^) 1
06.107, low noise amplifier (LNA) for reception 11
4.115 and intermediate frequency transmitting/receiving sections 130 and 140 are provided in duplicate. To switch these dual systems, selector switches 103, 111, 116 and 3-way branch 1
24 are provided. Active intermediate frequency transmitter/receiver 130
consists of a 23 GHz synthesizer 132, an up converter 131 that steps up the transmission IF multiplied signal XIF-1 to a predetermined transmission frequency, and a down converter 133 that steps down the received signal to the IF multiplied signal XIF-1. The standby intermediate frequency transmitter/receiver 140 also has the same circuit configuration as above. In the figure, 104, 105, 112, 113,
118 each indicates a dummy load. Further, an antenna controller 121 is connected to the antenna 101, and a beacon receiving section 122 is connected to the antenna controller.

By adopting the above configuration, if a failure occurs in either the active transmission system neartub converter 131 or HPA 106, the switching device 103 is activated to switch to the backup transmission system neartub converter 141/HPA 107. It is possible to continue transmission. Working system receiving system = LN^114, down converter 133 and backup system receiving system: LNA 115, down converter 1
The same applies to the switching of 43.

In the same figure, a 30/20 GHz converter 10
) IPA 106 or 107 and L
It is configured such that a return test of the internal circuits of the transmitting system and the receiving system can be performed via the NA 114 or 115.

[Problem to be solved by the invention]

The above-described satellite communication earth station can be said to represent the minimum circuit configuration necessary for a satellite communication earth station.

However, the high output amplifier 106°10 in the same figure
7, due to its high output, characteristic deterioration occurs due to its own heat generation.

As a result, there is a problem in that the transmission power level from antenna 101 decreases, and the quality of the received signal at the other party's satellite communication earth station, which is received via the communication satellite, deteriorates. Similar problems also occur when high-power amplifiers deteriorate over time.

A small satellite communication earth station having the circuit configuration shown in FIG. 10 is placed outdoors in the shade of an antenna.

Therefore, it is difficult to operate under sufficient temperature conditions, and the high-output amplifier is strongly influenced by the outside temperature, such as the difference in outside temperature between summer and winter, and daily temperature changes. This changes the characteristics of other circuits, fluctuates the transmission level, and causes a reduction in reception quality as described above.

Then, rainfall in uplink in satellite communication,
It is necessary to compensate for rain attenuation of the transmission level due to snowfall, etc.

Further, for convenience, the target value of the transmission level is set as an absolute value within the output range of the high-output amplifier, which is easy to handle, but in terms of internal circuitry, it is handled as a relative value within the control range. Therefore, when performing rain attenuation compensation or output control of a high-output amplifier, these levels must be matched.

In Figure 10, a 30/20 G7 converter 108 is installed, making it possible to check the operation of a series of systems as a standby system or a working system, but which circuit in the system is causing the failure? I can't determine whether or not. Therefore, even if a fault is detected, individual testing must be performed to identify the faulty circuit. Therefore, there are problems of lack of maintainability and long downtime.

In order to solve the above-mentioned problems, the present invention has a configuration that is excellent in maintainability and system separation, and in particular, stabilizes the transmission power level, and improves rain (including snowfall, etc., hereinafter the same).
The purpose is to perform attenuation compensation and level matching of set values.

[Means to solve the problem]

FIG. 1 shows a block diagram of the principle of the transmission power compensation control system of the present invention.

The intermediate frequency transmitted human signal IhM is converted into an up converter (U/
Powered by CH5 and further high power amplifier (HPA) 16
The circuit configuration in which the signal is amplified to the transmission level and output as the transmission output OUT is the same as the conventional one. The present invention provides a clear weather output target value correction circuit 11, a rain attenuation compensation circuit 12, and an automatic output level control circuit (AL) for this circuit configuration.
C) Add 14.

The clear weather output target value correction circuit 11 is the offset correction circuit 1.
1a and a subtracter 11b. Rain attenuation compensation circuit 12
consists of an adder. The ALC 14 includes a detector 14b and a subtracter 14a.

[For production]

In ALC14, detector 14 b l! )IPA
16 is detected and output to the subtracter 14a.

The output of the HPA 16 reflects all factors such as outside temperature, aging, and characteristic deterioration due to its own heat generation. Therefore, by detecting the output of HPA 16 with detector 14b,
You can see how to correct the output level. Subtractor 14a
subtracts the output of the detector 14 from the target value R[liF,
A correction amount corresponding to the difference ΔC is output to the up converter 15. The up-converter 15 is provided with a variable gain adjustment circuit, which changes the gain of the human input signal according to the amount of correction. By inputting the gain-changed signal to the HPA 16, the HPA 16 outputs a transmission output OUT having a transmission level corresponding to the target value RBF. Incidentally, the reason why the gain adjustment is performed by the up converter 15 is that it is not common to provide a variable gain adjustment means in the HPA 16 that amplifies the high frequency signal with a high gain up to the transmission level.

The above is the action of C14.

Clear weather output target value RE set by the user! F is generally an absolute level value relative to the output range of the HPA 16, for example 0 to 60 dB. On the other hand, the control range of AlCl2 is a relative range in which the transmission level from the HPA 16 can be varied (controlled), for example, from 0 to 20 dB. Therefore, the clear sky output target value RBF is directly -ALC
The target value RBF of 14 cannot be used if it is closed.

For this reason, the clear weather output target value RE! In order to adjust the level of Fp to the target value R8F of the ALC 14, the offset value CO1 is set to 40, for example, in the clear weather output target value correction circuit 11.
dB from the clear sky output target value RIEFF.

This offset value is set for each satellite communication earth station, but is a constant value for that earth station.

For the clear-weather output target value corrected in this way,
The rain attenuation compensation value C1 is added by the rain attenuation compensation circuit 12 and output as the target value RBF of the ALC 14. The rain attenuation compensation value C1 is calculated by calculating the amount of uplink rain attenuation using a separately provided transmission power control device, etc.
The amount of compensation (relative value level) is given periodically.

〔Example〕

FIG. 2 shows a configuration diagram of a satellite communication earth station according to an embodiment of the present invention.

In the same figure, the current upconverter (hereinafter referred to as IJ
/C1') 21 and high output amplifier (hereinafter referred to as HPA 1
) 22, a standby up converter (hereinafter referred to as U/C2) 31 and a high output amplifier (hereinafter referred to as 11
PA 2 ) 32 series circuits are provided. These active transmission system 20 and standby transmission system 30 include an input side switch (hereinafter referred to as 5111) 62 and an output side switch (5111).
Hereinafter, switching is performed by 5112) 63. 511
A vibration lift circuit (hereinafter referred to as HYB 1 ) 61 that manually inputs the intermediate frequency transmission input signal IFI 11 is connected to the front stage of the HYB 162 . 5W263 has a coupler (hereinafter referred to as CPL)
) 64 to which a dummy load 65 is connected.

In addition, the output of 31N263 is a bandpass filter (BP
F) 204, a dry air light port (AIL) 203, and a branching filter 202 for orthogonal polarization separation. On the other hand, 5W1
An oscillator (O3C) 26 is connected to 62.

An automatic output level control circuit 14, a clear-weather output target value correction circuit 11, and a rain attenuation compensation circuit 12 are provided between the active transmission system 20 and the backup transmission system 30. These will be described later.

As for the receiving system, a working receiving system 40 and a backup receiving system 50 are installed in parallel. Switching between the active receiving system 40 and the backup receiving system 50 is performed by switching an input side switch (hereinafter referred to as SW 3 ) 71 and an output side switch (hereinafter referred to as 5W5) 73 . A switch (hereinafter referred to as SW 6 ) 74 is further connected after the 5W573.

A detector (DBT) 46 is also connected to the 5W573.

The current receiving system 40 basically includes a low noise amplifier (hereinafter referred to as LNA 1 ) 41 and a down converter (hereinafter referred to as LNA 1 ).
D/CI) 43, but LNA141 and D
Hybrid circuit (hereinafter referred to as HYB3) between /C143
42 are provided. Similarly, the preliminary reception system 50 is basically composed of a low-noise amplifier (hereinafter referred to as LNA 2) 51 and a down converter (hereinafter referred to as D/C 2) 53, but there is a hybrid circuit between the LNA 251 and the D/C 253. (hereinafter referred to as HYB4) 52 is provided. These HYB342 and HYB452 are switches (hereinafter referred to as
5W4)? Connected to 2.

In the receiving system 40.50, HYB342,
By providing a switch circuit consisting of HYB452 and 5W472, the following circuits can be formed.

(a) 5W3-LNA1-HYB3- D/C1-
3W5(b) 5W3-LNA1-HYB3-311
4-HYB4- D/C2-5W5(c) SW 3
-LNA2-HYB4- D/C2-3W 5(d)
5W3-LNA2-HYB4-3W4-)IYB3-
D/C1-3W5 That is, the working receiving system is usually the above (
a) The preliminary reception system is composed of the above (C), HYB342, SV472 and HYB452.
Furthermore, the above (b) and (d) can be achieved by a switch circuit consisting of
system can be constructed. Therefore, the reliability of the receiving system is significantly improved. In addition, by testing the circuits (a) to (d) above, LNA141, D/C
143, LNA 251, and D/C 253 can be identified.

The switch circuit consisting of HYB342, SV472 and HYB452 in this reception system is connected to the current transmission system 20.
By inserting it between the auxiliary transmission system 30 and the backup transmission system 30, the reliability of the transmission system can be similarly improved, and failures in individual circuits can be identified. In the drawing, the ALC 14 is shown and is omitted.

Note that the received signal from the antenna 201 is applied to the SV 371 via the orthogonal polarization separation splitter 202, the dry air filling port (^IL) 211, and the bandpass filter 212.
The intermediate frequency received output signal IFoua is taken out via the receiving system 40.50 and the SV 674.

In the figure, a frequency conversion circuit (hereinafter referred to as XLTR) 81 provided between 511263 and SV371 is a transmission frequency fl from transmission system 20.30 for internal circuit testing.
For example, the receiving frequency f of the receiving system from 30 GHz to 40.50
2. Convert to 23G7, for example.

SWI 62, SN263, SV37 mentioned above
1, SV472.

The S stomach 573 and the SV674 are connected to the switch control circuit (SwCONT) 82, respectively, and the switch control signal C3w1~
C3v46 works fine. The switching signals [:SW1 to C3116 of the switch control circuit 82 are output based on signals from the antenna controller 223 via the monitoring/control interface (SV I/h) 83.

In the test mode described later, the switch control circuit 82 outputs the switching signal C3WI based on the operator's settings.
~C5W6 is output.

On the right side of FIG. 2, 221 is a display, 222 is a drive unit, 224 is a step track controller, 225 is a beacon detector, 227 is a beacon hybrid circuit,
226 indicates a beacon down converter.

Figure 3 shows the automatic output level control circuit (AL) shown in Figure 2.
C) 14 shows the rain attenuation compensation circuit 12 and the clear weather output target value compensation circuit 11.

The ALC 14 consists of a comparator 14a, a detector 14b, and switches 14C and 14d. Switch 14d connects detector 14b to IIPA 22 or 32, either in service or under test. Switch 14C is the U/U in operation or to be tested.
A comparator 14a is connected to C21 or C32. Detector 14
(b) is manually operated via the output coupler 23 or 33 of the selected IP^, and its maximum amplitude value AIIIX is detected. This maximum amplitude value AIIX represents the characteristic change of the selected HPA. This maximum amplitude value A. X is compared with the actual target output REF by the comparator 14a, and the difference ΔC is output to the selected II/C. As a result, output control is performed according to ΔC, and the actual target output RE is changed from the selected HPA.
Output according to F. s out is output.

The actual target output R8F is basically determined by the clear weather target value RBF set by the user. This clear-weather output target value R[EFF is an absolute value level of 0 to 60 dB in the effective output range of the HPA so that it can be easily set by the user.

It is expressed as On the other hand, the control system is handled within a relative control range of 0 to 20 dB centered on the reference value. For this reason, users
In advance, the degree of coupling of the turntable 23 or 33 is considered, and the output target value Rt in clear weather is determined! In order to level the FF, for example 50 dB, to a value corresponding to 5 dB of the control range of the ALC 14, the offset value C7 is set to Cp=45 dB in the coefficient multiplier 11a. As a result, the fine weather output target value correction circuit 11
, a corrected clear-sky output target value (equivalent level) of REh CF = 5 dB is output.

Rain attenuation compensation circuit 12
Rain attenuation compensation is performed at , and the actual target output REF is output. The rain attenuation compensation amount is calculated for the uplink by a separately provided transmission power control device (TPC, not shown). This compensation amount is a relative level, for example, 5 dB, and is manually entered into the register 12b and added to the corrected clear sky output target value in the adder 12H, resulting in the actual target value RBF, = 1
It is output to the ALC 14 as 0 dB (relative value level). However, the amount of rainfall attenuation compensation applies not only to rainfall, but also to snowfall,
It represents the amount of compensation for all attenuation in the uplink due to fog, clouds, etc., and is a variable value.

In this way, ALC14 controls the HPA within a range of ±10 dB relative to the corrected clear-sky target value and the actual target value RBF for the rain attenuation compensation value: 0 to 20 dB, and the above actual target value RBF = 10 dB. Control output.

As described above, the clear-weather output target value at the absolute value level is corrected to the relative value level for control, so the user can adjust the absolute value level corresponding to the output of the HPA without considering the relative value level for control. The clear weather output target value can be set arbitrarily. Rain attenuation compensation is then performed. Furthermore, ALC is performed based on the actual target value corrected for the fine weather output target value and compensated for rain attenuation.

In addition, the above correction, compensation, and ALC are performed using switch 14C914.
By selectively driving d, it is not only possible to perform this for either the entire working transmission system or the entire protection transmission system, but also to create a configuration that can be applied to any combination of upconverters and HPAs available within these systems. It becomes. In other words, the present invention is not only applied to a simple switching system but also to a highly reliable configuration shown in FIG. 2 and further described with reference to FIGS. 4 to 9.

4 to 9 are diagrams mainly for explaining circuit inspection inside the satellite communication earth station, but the compensation control circuit 11 in FIG.
, 12.14 can also be applied during testing. During operation, in FIG. 2, Sn263 is connected to the bandpass filter 204 and Sn371 is connected to the bandpass filter 212, while the frequency exchanger (XLTR) described with reference to FIGS. )81 is Sn263 and 5
It becomes disconnected from the route of 11371. Possible configurations of the routes of the other transmission systems 20.30 are the same during testing and during operation.

Referring to FIGS. 4 to 9, the operation of inspecting the circuit of FIG. 2 will be described. The circuit configuration of FIGS. 4 to 9 is the same as that of FIG. 2. However, the tester operates the switch control circuit 82 so that an arbitrary path is formed as shown by the broken line.

Test 1: Figure 4 The tester uses the intermediate frequency input signal IP! HY where x is input
The signal from BI 61 is 11 intermediate frequency output signal IFOU
Sn2 to be output from Sn274 which outputs T
Operate 74. That is, Sn274 is 51157
Signals are input from 3 and HYBI61, but HYBI
It is driven to output the signal from 61. In this state, the tester sends the test IF signal to HYB16.
1 manually, and confirm that the same signal as the IF multiplied signal that was manually input is output from Sn274. This leads to the path shown by the dashed line in FIG.
The normality of 4 can be confirmed.

Test: Figure 5 5till 62 HYB1610) Output IJ/C1
211:: Driven to output. Sn263 is H
The output of the PAI 22 is driven to be output to a frequency converter (XLTR) 81 via a coupler 64. Sn
271 is driven to output the output of XLTR 81 to LNAI 41. 5W472 is HYB342,
Both of the HYBs 452 are driven to be cut off. Sn573 is the output from D/C143.
274.

Sn274 is driven to output the input from Sn573. As a result, a path from the working transmitting system 20 to the XLTR 81 to the working receiving system 40 is formed as shown by the broken line in the figure. At this time, since HP^122 and the bandpass filter 204 are cut off by Sn263,
It is not transmitted from output antenna 201 of IPAI 22. Similarly, the band pass filter 212 is
Since the connection between LNAI 41 and LNAI 41 is cut off, the received signal from antenna 201 is not applied to LNAI 41.

The test IF signal is 1 (1 when applied to YBI 61)
, applied to U/CI 21 via SWl 62 and f
, =30GHz frequency signal, and IIPAI
22, it is amplified to the transmission level. This transmitted signal is S
n263 and is applied to the XLTR 81 via the coupler 64, and converted into a signal with a receiving frequency f 2 = 23 GHz. This frequency converted signal is sent to the LNA via Sn271.
It is applied to I 41 to be attenuated and applied to [1/C 143 via HYB 342. I in D/C143
Converted to F. This IF multiplied signal Sn573 and 5l
1674.

The tester: ) (Human signal to YBI 61 and Sn274
The normality of the path indicated by the broken line in the figure is checked by comparing the output signals of the two. Furthermore, HYBI 61 and St! i6
The operation of 74 has already been confirmed in the test 1 mentioned above.

Therefore, if an abnormality is discovered, these HYBI 61
゜There is an abnormality in the circuit other than Sn274.

Test 3: If an abnormality is detected in Test 2 of FIG. 6, the receiving system is switched from the active receiving system 40 to the backup receiving system 50 as shown. In other words, the output of XLTR81 outputs Sn271 to LNA251, and the human power from D/C253 outputs Sn573 to Sn.
274 to output the signal. In this circuit state, as in test 2, the IF human input signal is
and read the IF output signal from Sn274.

If this test is normal, it means that there is a fault in the active receiving system 40. Note that if there is an abnormality, the failure cannot be identified, so it is necessary to switch the transmission system.

Test 4: FIGS. 7 and 8 In test 3, identification of the fault location in the working receiving system 40 will be described.

In this case, the 5W3-LNA
I-HYB3-3W4-HYB4- D/C2-3W5
Test the following route. The path from HYBI to XLTR81 is the same as in test 3.

Next, as shown by the broken line in FIG. 8, 5W3-LNA2
-HYB4-8114-HYB3- D/Cl-3W5
Test the following route.

In test 3, the working transmitting system 20 and the standby receiving system 50 were found to be normal, so by conducting the test along the routes shown in FIG.
It can be determined whether there is a failure in AI 40 or 0/C143. After identifying the fault, replace the faulty circuit or
Alternatively, the failed circuit can be bypassed and the remaining circuit can be operated.

Test 5: If the fault cannot be identified in Test 3 of FIG.
Switch to , and perform the same test as above. In the figure, only SWI 62 and 5W 263 were switched after Test 3 was completed. If the result of testing this route is normal, this means that there is a fault in the active transmission system 20. Identification of the faulty section within the active transmission system 20 is performed in the same manner as in Test 4.

If there is an abnormality, the receiving system is switched to a route that passes through the working receiving system and a test is performed.

As described above, by combining the operations of the switches, it is possible to identify the location of the failure, and maintainability is improved. This test is also effective because it is performed with real signals and under real operating conditions.

Also, HYB3, 3W4, )IYB4 in the receiving system
The switch circuit consisting of
Individually bypass the faulty circuit, e.g. LNAI and
C143 is LNA251 when a failure occurs in D/C253.
Since it can be used in combination with , reliability is significantly improved.

Although the test operations described with reference to FIGS. 4 to 9 mainly focus on troubleshooting, circuit operation can be checked during periodic inspection by setting various routes as shown in the figures.

In this case, ^LC14, clear weather output target value correction circuit 11
, the rain attenuation compensation circuit 12 is also operated to check these themselves as well as the HPAI.

It is also possible to check the followability of HP^2.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to automatically control the transmission level, compensate for rain attenuation, and adjust the level of the clear-weather output target value in a small satellite communication earth station. In particular, in the present invention, these automatic transmission level control, rain attenuation compensation, and clear-weather output target value level adjustment are applied to selected circuits in a transmission system configured as a highly reliable circuit. It looks like this. The control and compensation of the present invention can be applied not only during operation but also during testing.

[Brief explanation of the drawing]

FIG. 1 is a principle block diagram of the transmission power compensation control method for a satellite communication earth station according to the present invention, FIG. A transmission power compensation control circuit diagram, FIGS. 4 to 9 are test explanatory diagrams of a satellite communication earth station according to an embodiment of the present invention, and FIG. 10 is a configuration diagram of a conventional satellite communication earth station. (Explanation of symbols) 11... Clear weather output target value correction circuit, 12... Rain attenuation compensation circuit, 14... Automatic output level control circuit, 15... Up converter, 16... High output amplifier , 20... Working transmission system, 3
0...Preliminary transmission system, 40...Working reception system, 50
...Preliminary reception system.

Claims (1)

[Claims] 1. The transmission signal (IF_I_N) is transmitted through the uplink converter (15) and the high-power amplifier (16) to the transmission power signal (OUT
), a detector (14b) detects the output level of the high output amplifier (16).
), the output of the detector is compared with a reference value (REF_a), the difference (ΔC) is outputted to the uplink converter (15), and the output level of the transmission power signal (OUT) is made to correspond to the reference value. Automatic level control circuit (
14), and correcting an offset value in the control range of the automatic level control circuit (14) with respect to a clear weather output target value (REF_F) set corresponding to the absolute value output level of the high output amplifier (16). and a compensation circuit (11, 12) which further corrects the corrected clear-sky output target value with a rain attenuation compensation value (C_R) and outputs it as a reference value (REF_a) of the automatic level control circuit (14). A transmission power compensation control method for a satellite communication earth station, characterized by: