JPH11298392A - Transmission power controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmission power controller capable of calculating a more accurate rainfall attenuation amount and performing highly accurate transmission power control. SOLUTION: After transmission signals from a circulating satellite 3 are received by an antenna 4 and reception signals are high frequency amplified in a low noise amplifier 6, they are frequency converted in a down converter 7 and inputted to a beacon receiver and frequency information by the frequency and phase error of beacon signals and level information by an attenuation amount are outputted to this transmission power controller 9. The transmission power controller 9 calculates an appropriate rainfall attenuation compensation amount from the frequency information and the level information and outputs level control signals to a level controller 11. The level controller 11 controls the level of transmission frequency signals frequency converted in an up converter 12 by the level control signals and outputs them to a transmission power amplifier 10 and they are power amplified there and then, transmitted through a power feed part 5 to the circulating satellite 3 by the antenna 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to frequency information and level information obtained by receiving a beacon signal among transmission signals from orbiting satellites when controlling transmission power of a satellite communication base station using orbiting satellites. The present invention relates to a transmission power control device capable of discriminating a level change amount due to orbital movement of an orbiting satellite and a level change amount due to rain attenuation using information.

[0002]

2. Description of the Related Art A conventional transmission power control device operates without any problem in satellite communication using a geostationary satellite. But,
In the satellite communication using the orbiting satellite, as shown in FIG. 4, there is a problem in the level change caused by the change in the propagation distance of the transmission signal transmitted by the orbiting satellite 1 as the orbiting satellite 1 moves in orbit. is there. Therefore, the conventional transmission power control device cannot distinguish between this level change and the level change due to rain attenuation. For this reason, all the changes in the reception level of the transmission signal transmitted by the orbiting satellite 1 received by the transmission / reception antenna 2 on the ground are calculated as rain attenuation, and there is a problem that the transmission power cannot be accurately corrected. Was.

For example, Japanese Patent Application Laid-Open No. 08-2984 discloses
A method as disclosed in Japanese Patent Publication No. 84 has been proposed. In the case of this publication, the antenna control device performs tracking control so that the antenna always faces the orbiting satellite, and sends azimuth and elevation information of the antenna to the transmission power controller. The beacon receiver receives the beacon signal from the orbiting satellite, detects the reception level, and sends the reception level information to the transmission power controller.

[0004] The storage device stores a change in reception level with respect to a change in the azimuth and elevation angle in fine weather according to the orbital position of the satellite, and transmits the reception level in fine weather in response to a request from the transmission power controller. The transmission power controller calculates the orbital position of the orbiting satellite based on the azimuth and elevation information from the antenna controller, compares the orbital position of the orbiting satellite with the reception level in clear weather from the storage device, and compares it with the reception level from the beacon receiver. The rain attenuation amount of the link is obtained, and the rain attenuation compensation amount of the uplink to be compensated is calculated.

However, in this transmission power control apparatus, when an error occurs in the azimuth / elevation angle information from the antenna control apparatus, an error occurs in the control or when the antenna itself is a fixed phased array antenna. There is a problem that it cannot be used, etc., and it is not a completely effective solution, and many methods have been proposed at present. For example,
Japanese Patent Application Laid-Open No. 09-233012 discloses that in order to set the transmission power of an orbiting satellite to an appropriate value according to weather conditions, the transmission power of the orbiting satellite is predicted in a time zone in which communication with the orbiting satellite earth station is performed. Control by the value based on the meteorological condition to be performed, and the transmission power value of the orbiting satellite and the power consumption value of the orbiting satellite
It is disclosed that transmission power control of an orbiting satellite is performed in a short time to prevent disconnection of a communication line and guarantee communication quality.

[0006] Japanese Patent Application Laid-Open No. 09-8719 discloses that
One of the plurality of first frequency uplink signals is transmitted as an uplink reference signal from a ground station and received by a satellite, and a second frequency downlink that is lower than the first frequency and hardly attenuated. A signal is transmitted from a satellite, one of the downlink signals is received as a reference signal by a terrestrial receiver, and the attenuation of the uplink reference signal between the ground station and the satellite is measured from the received downlink reference signal. It discloses that the transmission power of a plurality of uplink signals from a ground station is adjusted in accordance with the measured attenuation to correct the attenuation.

[0007]

However, in each of the above-mentioned conventional examples, when the orbiting satellite moves in orbit,
In order to compensate for leveling due to changes from the propagation distance of radio waves, frequency information and level information are not output from the beacon signal transmitted from the orbiting satellite and the level of transmission power is not controlled. When errors occur in the azimuth and elevation information from a simple antenna controller, the accurate position of the orbiting satellite cannot be ascertained.Therefore, accurate transmission power control can be performed by following changes in the propagation distance of transmitted radio waves. There is a problem that cannot be performed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and can perform high-accuracy transmission power control, and can confirm the current position of the orbiting satellite from the frequency shift of the beacon signal. It is an object to provide a transmission power control device.

[0009]

In order to achieve the above object, a transmission power control apparatus according to the present invention receives a beacon signal among transmission signals from an orbiting satellite and inputs the beacon signal to a beacon receiver. A receiving system that outputs frequency information and level information from a beacon receiver, and a transmission that receives the frequency information and level information output from the receiving system, calculates an appropriate amount of rain attenuation compensation, and transmits the amount to the orbiting satellite. A transmission power amplifier that controls transmission power of the frequency signal, amplifies the power of the transmission frequency signal, and transmits the amplified power to the orbiting satellite.

[0010] According to the present invention, a transmission signal transmitted from an orbiting satellite in a receiving system is received and input to a beacon receiver, whereby frequency information due to frequency and phase errors and level information as an attenuation amount are transmitted. Output. The frequency information and the level information are output to the transmission system, and an appropriate amount of rain attenuation compensation is calculated. Based on the calculation, the transmission power of the transmission frequency signal transmitted by the orbiting satellite is controlled, and the transmission power is controlled. The transmission frequency signal thus amplified is amplified and transmitted to the orbiting satellite, and retransmitted from the orbiting satellite based on the transmission frequency signal. Therefore, according to the present invention, it is possible to distinguish between the level change due to the orbital movement of the orbiting satellite and the level change due to the rain attenuation, to calculate the rain attenuation accurately, and to control the transmission power with high accuracy. And the current position of the orbiting satellite can be confirmed.

[0011]

Embodiments of a transmission power control apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the first embodiment according to the present invention. In FIG. 1, a transmission signal transmitted from an orbiting satellite 3 is received by a transmitting / receiving antenna 4 and
The signal is input to the low-noise amplifier 6 of the receiving system via the power supply unit 5. The low-noise amplifying unit 6 includes a band-pass filter (hereinafter, referred to as a BPF) not shown in FIG.
The signal is input to the down-converter 7, where it is frequency-converted and input to the beacon receiver 8.

As is clear from the above, this receiving system is composed of the low-noise amplifying unit 6, the down-converter 7, and the beacon receiver 8. The beacon receiver 8 is one of the characteristic elements in the first embodiment, and details of its internal configuration are shown in FIG. The detailed internal configuration of the beacon receiver 8 will be described later with reference to FIG. The beacon receiver 8 receives a beacon signal from the reception signal frequency-converted by the down converter 7 and outputs the frequency and phase difference, that is, frequency information and attenuation (level information) to the transmission power controller 9. It has become.

The transmission power controller 9 calculates the amount of rain attenuation compensation by inputting the frequency information and the amount of attenuation, and outputs it to the level controller 11. The level controller 11 receives a frequency-converted transmission signal from the up-converter 12. The level controller 11 determines the level of the transmission signal by the transmission power controller 9.
Is controlled by the Level controller 11
Is transmitted to the transmission power amplifier 10 where the power is amplified and transmitted as a radio wave from the antenna 4 to the orbiting satellite 3 via the feeder 5. Thus, the transmission power controller 9, the up-converter 12, the level controller 11, and the transmission power amplifier 10
These form a transmission system.

Next, the internal configuration of the beacon receiver 8 will be described with reference to the block diagram of FIG. This figure 2
1, the beacon signal received from the input terminal 13 serving as the output terminal of the down converter 7 in FIG. 1 is input to the frequency converter 14. The local oscillator signal output from the local oscillator 15 is also input to the frequency converter 14, so that the beacon signal input to the frequency converter 14 is mixed with the local oscillator signal to perform frequency conversion. And BPF1
6 is input. The BPF 16 extracts a signal in a predetermined frequency band from the output signal of the frequency converter 14 and sends the signal to the variable attenuator 17.

The output signal of the variable attenuator 17 is supplied to the detection circuit 1
8 and the phase comparator 19.
The detection circuit 18 detects the output signal of the variable attenuator 17 to detect level information (level attenuation), and outputs a level information output from the output terminal 23 to the transmission power controller 9.

The variable attenuator 17 is operated on the basis of the level information, and is always sent to the phase comparator 19 at a constant level. The phase comparator 19, LPF (low-pass filter) 20, and voltage-controlled oscillator 21
An L (Phase Locked Loop) circuit is configured to output the control voltage of the voltage controlled oscillator 21 to the transmission power controller 9 from the output terminal 22 as frequency information.

Next, the internal configuration of the transmission power controller 9 will be described with reference to FIG. FIG. 3 is a block diagram showing a detailed configuration inside the transmission power controller. In FIG. 3, frequency information from the beacon receiver 8 is input from an input terminal 24, and level information is input from an input terminal 26.
After being input by the A / D (analog / digital) converters 25 and 27, respectively,
An O (input / output) device 28 (hereinafter, referred to as I / O) is input to the device. The I / O 28 is a C
The PU 29 is connected to a ROM (read only memory) 30 and a RAM (random access memory) 31 storing frequency information necessary for confirming the position of the satellite, and performs rain attenuation compensation based on the input information. Calculate the quantity and convert the level control signal to D / A (digital / analog)
After the D / A conversion in the converter 32, a level control output is output from the output terminal 33 to the level controller 11.

Next, the operation of the first embodiment configured as described above will be described. First, referring to FIG.
First, the overall operation will be described. In the receiving system, a transmission signal from the orbiting satellite 3 received by the antenna 4 is used as a reception signal, and the low-noise amplifier 6 performs high-frequency amplification through the BPF,
After the frequency conversion in the down converter 7, the beam
The data is sent to the console receiver 8. The beacon receiver 8 inputs a beacon signal from the frequency-converted received signal and transmits a frequency / phase error (frequency information) and an attenuation (level information) obtained from the beacon signal to a transmission power controller 9. Output to

The transmission power controller 9 controls the transmission power of the transmission frequency signal by calculating the appropriate rain attenuation compensation amount and outputting it as a level control output to the level controller 11 of the transmission system. In the transmission system, the upconverter 12
In, the transmission signal is frequency-converted into a transmission frequency signal and output to the level controller 11. In the level controller 11, the transmission signal is attenuated by a predetermined amount by the level control output output from the transmission power controller 9. Level controller 11
The transmission frequency signal, the level of which is controlled to a predetermined amount, is power-amplified by the transmission power amplifier 10 and the power supply unit 5
Is output to the orbiting satellite 3 through the common antenna 4 for transmission and reception. The satellite relays or frequency converts the transmitted frequency and retransmits it to Earth.

Next, the operation of the beacon receiver will be described with reference to FIG. 2, a beacon signal input from an input terminal 13 serving as an output terminal of the down converter 7 in FIG. 1 is input to a frequency converter 14. In the frequency converter 14, the frequency is converted by mixing the local oscillation signal from the local oscillator 15 and the beacon signal, and the BPF 16 extracts a frequency in a predetermined frequency band. The beacon signal that has passed through the BPF 16 is then sent to a variable attenuator 17 where the level is attenuated and output to a detection circuit 18.

The detection circuit 18 detects the beacon signal whose level has been attenuated by the variable attenuator 17, detects level information, and outputs the level information from the output terminal 23 to the transmission power controller 9. Further, the variable attenuator 17 is operated based on the level information, and the output signal of the BPF 16, that is, the beacon signal, is attenuated so that the variable attenuator 17 can always be sent to the phase comparator 19 at a constant level.

In the PLL circuit constituted by the phase comparator 19, the LPF 20, and the voltage controlled oscillator 21,
The output signal of the phase comparator 19 is input to the LPF 20, the low frequency component is extracted, and the frequency information is converted to the voltage controlled oscillator 2
The frequency information is output to the voltage control oscillator 21 as one control voltage, and the frequency information is output to the transmission power controller 9 from the output terminal 22. Since the frequency shift can be detected by this control voltage, the position of the satellite can be confirmed from the shift.

Next, the operation of the transmission power controller 9 will be described with reference to FIG. The frequency information input from the beacon receiver 8 of FIG. 1 is input from an input terminal 24 to an A / D converter 25, and the level information is input to an input terminal 26A / D converter 27.
, And after being A / D converted, I / O2
8 is input. In this I / O 28, the control voltage of the voltage controlled oscillator 21 which is frequency information
Compared with the information stored in M30, the position of the orbiting satellite is confirmed, and the level change amount due to the difference in the propagation distance from the orbiting satellite is calculated. Furthermore, the level change amount due to rainfall attenuation can be obtained by comparing the simultaneously input level information and the level change amount due to the difference in the propagation distance.

A rain attenuation compensation amount for level control is calculated from the two level change amounts, and the D / A converter 32
After the D / A conversion, a level control signal is output from the output terminal 33 to the level controller 11 in FIG. In this way, it is possible to distinguish between the level change caused by the movement of the satellite and the level change caused by the rain attenuation, and more accurate and accurate control can be performed.

[0025]

As described above, according to the present invention, the beacon signal is actually received, and the frequency and phase error (frequency information) and the attenuation (level information) are used to make the level by the movement of the satellite in orbit. It is possible to distinguish between the amount of change and the amount of level change due to rain attenuation. As a result, it is possible to calculate the rain attenuation more accurately, and it is possible to perform high-precision transmission signal power control. According to the present invention, by monitoring the control voltage of the voltage-controlled oscillator,
The current position of the satellite can be confirmed from the frequency shift of the beacon signal, and can be used even when the antenna is a fixed phased array antenna.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of a first embodiment of a transmission power control device according to the present invention.

FIG. 2 is a block diagram showing a detailed internal configuration of a beacon receiver in the transmission power control device of FIG.

FIG. 3 is a block diagram showing an internal configuration of a transmission power controller in the transmission power control device of FIG.

FIG. 4 is an explanatory diagram of a satellite communication system using a conventional orbiting satellite.

[Explanation of symbols]

3 orbiting satellite, 4 antenna, 5 feeding unit, 6
... low noise amplifier, 7 ... down converter, 8 ... beacon receiver, 9 ... transmission power controller, 10 ... transmission power amplifier, 11 ... level controller, 12 ... up converter, 13, 24, 26 input terminal, 14 frequency converter, 15 local oscillator, 16 BPF, 17
... variable attenuator, 18 ... detection circuit, 19 ... phase comparator, 20 ... LPF, 21 ... voltage-controlled oscillator, 22,
23, 33 ... output terminal, 25, 26 ... A / D converter, 28 ... I / O, 29 ... CPU, 30 ... RO
M, 31 RAM, 32 D / A converter.

Claims (6)

[Claims] 1. A receiving system for receiving a beacon signal among transmission signals from an orbiting satellite and inputting the signal to a beacon receiver to output frequency information and level information from the beacon receiver, and an output from the receiving system. Input the frequency information and the level information, calculate an appropriate rain attenuation compensation amount, control the transmission power of the transmission frequency signal to be transmitted to the orbiting satellite, and perform power amplification of the transmission frequency signal to perform the circulation. A transmission power control device, comprising: a transmission system for transmitting to a satellite. 2. The low-noise amplifier for high-frequency amplification of a reception signal received by the antenna from a transmission signal from the orbiting satellite, a down-converter for converting a frequency of an output signal of the low-noise amplifier, The transmission power control device according to claim 1, further comprising: a beacon receiver that receives an output signal of the down converter and outputs frequency information based on a frequency and phase error and level information based on an attenuation amount. 3. A transmission power controller that inputs the frequency information and the level information output from the beacon receiver, calculates an appropriate rain attenuation compensation amount, and outputs a level control signal. An upconverter that converts a transmission signal into a transmission frequency signal, a level controller that performs level control on a level of the transmission frequency signal output from the upconverter by a level control signal output from the transmission power controller, and The transmission power control device according to claim 1, further comprising a transmission power amplifier that power-amplifies a transmission frequency signal output from the level controller. 4. A frequency converter for receiving a beacon signal, mixing the beacon signal with a local oscillation signal from a local oscillator, and converting the frequency, and a predetermined frequency band of an output signal of the frequency converter. And a variable attenuator for attenuating the level of the output signal of the band-pass filter, and detecting the output signal of the variable attenuator to output level information, and based on the level information, A detection circuit that causes the variable attenuator to perform an attenuating operation and outputs a signal of a constant level from the variable attenuator; and a PLL circuit that receives an output signal of the variable attenuator and outputs the frequency information. The transmission power control device according to claim 1, wherein: 5. The PLL circuit according to claim 1, wherein the PLL circuit receives a signal of a constant level and an oscillation signal of a voltage controlled oscillator from the variable attenuator, and outputs a signal corresponding to a phase difference between the two. A low-pass filter that extracts a predetermined low-frequency component from an output signal of the comparator, outputs a control voltage to the voltage-controlled oscillator, and outputs the control voltage as the frequency information. 5. The transmission power control device according to 4. 6. The transmission power controller includes: a first A / D converter that converts the frequency information input from the beacon receiver into a digital signal; and a digital signal that converts the level information input from the beacon receiver. A second A / D converter for converting the signal into a signal, and a digital signal output from the first A / D converter are input and compared with information stored in a ROM in advance to confirm the position of the orbiting satellite. Calculating the level change amount due to the difference in the radio wave propagation distance from the orbiting satellite, and inputting the digital signal output from the second A / D converter, and changing the digital signal and the level change due to the difference in the radio wave propagation distance The amount of level change due to rain attenuation is calculated by comparing the amounts, and the rain attenuation compensation amount for level control is calculated based on the two level changes. Input / output device and CPU for calculation
And D which outputs the level control signal by converting the rain attenuation compensation amount calculated by the input / output device into an analog signal.
The transmission power control device according to claim 1, further comprising a / A converter.