JP2007214980A - Satellite communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a satellite communication system with which C/N and a reception level are detected and transmission power control with higher precision is performed based on detection of them. <P>SOLUTION: In a transmission power control part 3, the C/N is detected from a reception signal by a C/N detection circuit 7, a comparison operation is performed to the detected C/N and a C/N reference value by a C/N comparison operation circuit 8 to calculate a change amount. An automatic deterioration amount judgment circuit 10 automatically judges a deterioration amount of a line, based on the reception level input from a receiver 2 and a comparison operation result by the C/N comparison operation circuit 8. When the change amount of the reception level is smaller than a threshold when the change amount of the C/N is larger than the threshold, a line status is estimated to be in a disturbance state such as erosion, and a reception level detection result is selected to compensate transmission power. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a satellite communication apparatus that controls transmission power based on a quality deterioration amount of a satellite communication line and compensates the quality deterioration amount to perform satellite communication.

  Since the quality of satellite communication lines is significantly affected by the weather conditions in the atmosphere, it is necessary to control the transmission power based on the amount of quality deterioration caused by changes in weather conditions in order to maintain the satellite communication lines without interruption. is there. For example, Japanese Patent Application Laid-Open No. 9-46286 describes a transmission power control technique. The transmission power control described in this publication includes a circuit that monitors the C / N (carrier-to-noise ratio) of a received signal and a circuit that monitors the reception level of the received signal. In addition, an abnormal state based on a failure of one of the circuits is monitored to perform higher quality transmission power control.

JP-A-9-46286

  According to the conventional technique described in Japanese Patent Application Laid-Open No. 9-46286, although transmission control is performed by monitoring failures of the C / N detection circuit and the reception level detection circuit, transmission power control for disturbance input such as corrosion is considered. However, there is a problem of malfunctioning with respect to such disturbance input. Furthermore, it has been a technical problem to obtain a satellite communication device capable of automatically selecting transmission power control in consideration of disturbance input such as corrosion and the influence of rainfall and the like.

  The present invention has been made to solve the above problems, and can detect the C / N and the reception level, and perform transmission power control with higher accuracy based on these detections. The object is to obtain a satellite communication device.

  A satellite communication apparatus according to a first aspect of the present invention includes a receiver that receives radio waves in a satellite line, a transmission power control unit that controls transmission power based on a reception signal received by the receiver, and the transmission power control unit. A transmitter for changing transmission power by power control by the transmitter and transmitting to a satellite line, wherein the transmission power control unit detects a change amount of C / N detected from the received signal or a change amount of the level of the received signal Is selected, and the transmission power transmitted by the transmitter is controlled based on the selected change amount.

  According to a second aspect of the present invention, there is provided a satellite communication apparatus including a receiver that receives radio waves on a satellite line, a transmission power control unit that controls transmission power based on a reception signal received by the receiver, and the transmission power control unit. And a transmitter for changing the transmission power by the power control according to the above and transmitting to the satellite line, and the transmission power control unit has a level of the received signal when the amount of change in C / N detected from the received signal is large. When the change amount is small, the transmission power is controlled based on the change amount of the received signal level.

  According to a third aspect of the present invention, there is provided a satellite communication apparatus comprising: a receiver that receives radio waves on a satellite line; a transmission power control unit that controls transmission power based on a received signal received by the receiver; and the transmission power control unit And a transmitter for changing the transmission power by the power control according to the above and transmitting to the satellite line, and the transmission power control unit has a level of the received signal when the amount of change in C / N detected from the received signal is large. The transmission power is controlled based on the C / N change detected from the received signal.

  According to the present invention, the transmission power control unit in the satellite communication device selects either the C / N change amount detected from the received signal or the change amount of the level of the received signal, and based on the selected change amount. Thus, transmission power control can be performed by automatic selection in consideration of disturbance input such as erosion, influence of rainfall, and the like.

Embodiment 1

  A radio communication system according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 is a functional block diagram of a satellite communication apparatus according to Embodiment 1 of the present invention. 1 is an antenna, 2 is a receiver that receives radio waves on a satellite line, and converts a different reception frequency (for example, beacon signal) for each satellite into a reception signal of the same frequency, 3 detects the C / N of the reception signal, A transmission power control unit for controlling transmission power based on the C / N and the reception level output from the receiver 2, 4 is a transmitter for generating a transmission signal to be transmitted to the satellite, and the transmitter 4 is for transmission power control. The transmission power can be changed by the control from the unit 3. FIG. 2 is a functional block diagram of the receiver 2 and the transmission power control unit 3. In the receiver 2 of FIG. 2, 5 is a frequency conversion circuit that converts the frequency of the received signal, 6 is an AFC / AGC circuit that performs AFC (automatic frequency control) and AGC (automatic gain control), and is controlled in the AGC portion. The AGC voltage (reception level) is detected and output to the transmission power control unit 3. In the transmission power control unit 3, 7 is a C / N detection circuit that detects C / N from the received signal, and 8 is a C / N that compares the detected C / N with the C / N reference value to obtain a change amount. The comparison operation circuit 9 is an input point for the C / N reference value. 10 is an automatic deterioration amount determination circuit that automatically determines the deterioration amount based on the reception level input from the receiver 2 and the comparison calculation result in the C / N comparison calculation circuit 8, and 11 is the input point of the C + N reference value , 12 is a transmission loss estimation circuit for estimating a transmission loss based on the output value of the deterioration amount determined by the automatic deterioration amount determination circuit 10. The AGC voltage output from the receiver 2 corresponds to the carrier signal level, and strictly speaking, is a level obtained by adding the carrier signal level and the noise level, and this is expressed as a C + N value. The automatic deterioration amount determination circuit 10 of the transmission power control unit 3 automatically determines the deterioration amount based on the C + N value input from the AFC / AGC circuit 6 and the comparison calculation result in the C / N comparison calculation circuit 8. To do.

  FIG. 3 is a process flow diagram of automatic deterioration amount determination of the satellite communication apparatus according to Embodiment 1 of the present invention. The C / N detection in step S1 and the C level detection in step S2 in FIG. 3 are performed in real time. That is, the C / N measurement in step S3 is performed in real time in the transmission power control unit 3, and the C + N measurement in step S4 is performed in real time in the receiver 2, respectively. In step S5, the C / N comparison operation circuit 8 compares the C / N measurement value with the C / N reference value to obtain a change amount of the C / N measurement value. If the C / N value in fine weather is taken as the C / N reference value, the amount of change in the C / N measurement value in step S5 is small in fine weather. Since the C value deteriorates during rainfall, the C / N measurement value changes greatly with respect to the C / N reference value (C / N value in fine weather), so the change amount of the C / N measurement value in step S5 is large. Become. In step S6, the automatic deterioration amount determination circuit 10 determines the magnitude of the change amount of the C / N measurement value in step S5 and a predetermined threshold value. On the other hand, in step S7, the automatic deterioration amount determination circuit 10 compares the C + N measurement value and the C + N reference value (the C + N value in fine weather is used as a reference value) to obtain a change amount of the C + N measurement value. In step S8, the magnitude of the change amount of the C + N measurement value obtained in step S7 and a predetermined threshold value are determined.

  Based on the magnitude judgment result between the predetermined threshold values in step S6 and step S8, the treatment content and the line status are estimated in the automatic deterioration amount judgment circuit 10 in step S9. First, when the change amount of the C / N measurement value is smaller than the threshold value by the determination in step S6, when the change amount of the C + N measurement value is smaller than the threshold value by the determination in step S8 (case 1), the line status is It is estimated that the weather is in a fine weather state, a C / N detection result is selected, and transmission power correction is not performed. Further, when the change amount of the C / N measurement value is smaller than the threshold value by the determination in step S6, when the change amount of the C + N measurement value is larger than the threshold value in the determination in step S8 (case 2), the line status Is assumed to be a change state of the environmental temperature, and since the change amount of the C / N measurement value is small and the reception is good, the C / N detection result is selected and the transmission power correction is not performed.

  Next, when the change amount of the C / N measurement value is larger than the threshold value by the determination in step S6, when the change amount of the C + N measurement value is smaller than the threshold value in the determination in step S8 (case 3), the line status Is estimated to be a disturbance state such as erosion, the C + N detection result is selected, and the transmission power correction is made to exceed the predetermined threshold value of the change amount of the C + N measurement value in the C + N detection. Further, when the change amount of the C / N measurement value is larger than the threshold value by the determination in step S6, when the change amount of the C + N measurement value is larger than the threshold value by the determination in step S8 (case 4), the line status is It is estimated that it is in a rainy state, a C / N detection result is selected, and transmission power correction is set to an amount exceeding the predetermined threshold value of the change amount of the C / N measurement value in C / N detection.

It is a functional block diagram of the satellite communication apparatus which concerns on Embodiment 1 of this invention. It is a functional block diagram of a receiver and a transmission power control unit It is a processing flowchart of the automatic degradation amount determination of the satellite communication apparatus which concerns on Embodiment 1 of this invention.

Explanation of symbols

2 Receiver 3 Transmission power control unit 4 Transmitter 10 Automatic degradation amount determination circuit

Claims (3)

A receiver that receives radio waves in a satellite line, a transmission power control unit that controls transmission power based on a reception signal received by the receiver, and a satellite line that changes transmission power by power control by the transmission power control unit The transmission power control unit selects either the C / N change amount detected from the received signal or the change amount of the received signal level, and sets the selected change amount to the selected change amount. A satellite communication apparatus that controls transmission power transmitted by the transmitter based on the transmission power. A receiver that receives radio waves in a satellite line, a transmission power control unit that controls transmission power based on a reception signal received by the receiver, and a satellite line that changes transmission power by power control by the transmission power control unit The transmission power control unit is configured such that when the amount of change in the C / N detected from the received signal is large and the amount of change in the level of the received signal is small, the level of the received signal A satellite communication device that controls transmission power based on a change amount of the satellite. A receiver that receives radio waves on a satellite line, a transmission power control unit that controls transmission power based on a received signal received by the receiver, and a satellite line that changes transmission power by power control by the transmission power control unit The transmission power control unit detects from the received signal when the amount of change in the level of the received signal is large when the amount of change in C / N detected from the received signal is large. A satellite communication apparatus that controls transmission power based on the amount of change in C / N.

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