JP3869125B2 - Satellite communication system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a satellite communication system having an external structure of IDU (IN DOOR UNIT, hereinafter referred to as “IDU”) and ODU (OUT DOOR UNIT, hereinafter referred to as “ODU”). In the conventional method, the temperature compensation of the gain is performed individually for each IDU or ODU, but in this method, variations in frequency characteristics and temperature characteristics are large and adjustment is required. Therefore, the present invention has a structure in which the gain with respect to the frequency and temperature of the ODU is stored in a ROM (READ ONLY MEMORY, hereinafter referred to as “ROM”) installed in the ODU, and the gain of the IDU is varied by the signal. That is, the present invention relates to a structure for solving the problems of the conventional methods.
[0002]
[Prior art]
In a conventional satellite communication system, the IDU and the ODU each perform temperature compensation for gain alone. 4 to 6 are actual examples. FIG. 4 shows a case for transmission, FIG. 5 shows a case for transmission / reception, and FIG. 6 shows a case for transmission / reception with a booster amplifier.
[0003]
[Problems to be solved by the invention]
However, in the conventional satellite communication system as described above, there are variations in the elements of high-frequency amplifiers such as C-band and Ku-band used in the ODU, and variations due to the adjustment method between the cascaded stages. As a result, the frequency characteristics and temperature characteristics vary greatly. This necessitates a complex temperature compensation circuit and many readjustments and re-temperature tests.
[0004]
[Means for Solving the Problems]
Therefore, in the present invention, the above problems have been solved by the following first to third means. First of all, based on the channel information, the CPUs to be processed (CENTRAL PROCESSING UNIT, hereinafter referred to as “CPU” only) 1a and 1b, the ROM 2 for storing the information on the attenuation with respect to the temperature and the frequency, and the processed It includes a voltage variable attenuator 3 controlled by a signal, an amplifier used for signal amplification, a frequency converter for converting the frequency of the signal, and a filter for removing unnecessary components from the frequency. In the satellite communication system, the external structure is separated into IDU4 and ODU5, gain fluctuation information with respect to temperature and frequency of ODU5 is stored in ROM2 installed in ODU5, and installed in IDU4 by the stored information The voltage variable attenuator 3 is controlled so that the total gain is substantially constant or Is due to the means characterized by having a transmission structure that is controlled to an arbitrary value.
[0005]
Secondly, in the satellite communication system, the voltage variable attenuator 6, an amplifier used for signal amplification, and a frequency converter for converting the frequency of the signal are combined with the transmission structure. And a receiving structure 7 including a filter for removing unnecessary components from the frequency is installed, and information on gain fluctuations with respect to the temperature and frequency of the ODU 5 is stored in the ROM 2 installed in the ODU 5, and the stored information is stored. The voltage variable attenuator 3 and the voltage variable attenuator 6 installed in the IDU 4 are controlled by the above, and the transmission / reception structure is such that the total gain is controlled to be substantially constant or an arbitrary value. This is due to the means.
[0006]
Thirdly, in the satellite communication system, a booster amplifier 10 including an amplifier and the like is installed together with a transmission / reception structure, a CPU 8, a ROM 9, and information on gain variation with respect to the temperature and frequency of the ODU 5. The voltage variable attenuator 3 and voltage variable attenuator 6 installed in the IDU 4 are controlled by the information stored in the ROM 2 installed in the ODU 5, thereby making the total gain substantially constant or arbitrary. This is due to the means characterized by having a transmission / reception structure controlled by the value of.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
1 to 3 show an embodiment of the present invention by the above means. FIG. 1 is a schematic diagram of a satellite communication system for transmission according to an embodiment of the present invention. The temperature data of the ODU5 and the gain data for the channel are stored in the ROM 2, and the CPU 1a of the ODU 5 performs calculation such as data interpolation, and the temperature information at that time and the gain information for the channel are transmitted to the CPU 1b of the IDU 4, and this information is stored. Based on this, the voltage variable attenuator 3 is varied by the CPU 1b of the IDU 4 so that the total gain becomes a desired numerical value. Next, FIG. 2 is a schematic diagram of a satellite communication system in which a reception structure 7 is added to FIG. 1 to have a transmission / reception structure, and FIG. 3 is a booster amplifier 10 added to FIG. 1 is a schematic diagram of a satellite communication system having a transmission / reception structure.
[0008]
【The invention's effect】
As described above, by configuring as in the present invention, it is not necessary to perform temperature compensation by the ODU 5 alone, and compensation is performed in the IF frequency band of the IDU 4, so that an inexpensive system can be configured. Further, the temperature compensation by the booster amplifier 10 alone is very difficult because it is a temperature compensation at a high frequency and high output level, but according to the present invention, the temperature compensation and channel compensation by the booster amplifier 10 alone are unnecessary. .
[Brief description of the drawings]
FIG. 1 is a schematic diagram for transmission of a satellite communication-like system that is an embodiment of the present invention.
FIG. 2 is a schematic diagram for transmission / reception of a satellite communication-like system according to an embodiment of the present invention.
FIG. 3 is a schematic diagram for transmission / reception with a booster amplifier of a satellite communication-like system according to an embodiment of the present invention.
FIG. 4 is a schematic diagram for transmission of a conventional satellite communication-like system.
FIG. 5 is a schematic diagram for transmission / reception of a conventional satellite communication-like system.
FIG. 6 is a schematic diagram for transmission / reception with a booster amplifier in a conventional satellite communication-like system.
[Explanation of symbols]
1a ... CPU
1b ... CPU
2 ROM
3 …… Voltage variable attenuator 4 …… IDU
5 …… ODU
6 …… Voltage variable attenuator 7 …… Reception structure 8 …… CPU
9 …… ROM
10 …… Booster amplifier

Claims (3)

Based on the channel information, a CPU (CENTRAL PROCESSING UNIT) to process, a ROM (READ ONLY MEMORY) for storing attenuation information with respect to temperature and frequency, a voltage variable attenuator controlled by the processed signal, It includes an amplifier used for signal amplification, a frequency converter for converting the frequency of the signal, and a filter for removing unnecessary components from the frequency. The external structure includes IDU (IN DOOR UNIT) and ODU (OUT In a satellite communication system separated into a DOOR UNIT, information on gain fluctuations with respect to the temperature and frequency of the ODU (OUT DOOR UNIT) is stored in a ROM (READ ONLY MEMORY) installed in the ODU (OUT DOOR UNIT). Let The voltage variable attenuator installed in the IDU (IN DOOR UNIT) is controlled based on the stored information, thereby having a transmission structure in which the total gain is controlled to be substantially constant or an arbitrary value. Satellite communication system. In the satellite communication system, together with the transmission structure, a voltage variable attenuator, an amplifier used for signal amplification, a frequency converter for converting the frequency of the signal, and unnecessary components are removed from the frequency. A receiving structure including a filter for performing the operation is stored, and information on gain fluctuation with respect to the temperature and frequency of the ODU (OUT DOOR UNIT) is stored in a ROM (READ ONLY MEMORY) installed in the ODU (OUT DOOR UNIT). The voltage variable attenuator installed in the IDU (IN DOOR UNIT) is controlled by the stored information, thereby having a transmission / reception structure in which the total gain is controlled to be substantially constant or an arbitrary value. The satellite communication system according to claim 1. In the satellite communication system, a booster amplifier including a CPU (CENTRAL PROCESSING UNIT), a ROM (READ ONLY MEMORY), an amplifier, and the like is installed together with a transmission / reception structure, and an ODU (OUT DOOR UNIT) temperature and frequency Is stored in a ROM (READ only memory) installed in the ODU (OUT DOOR UNIT), and the voltage variable attenuator installed in the IDU (IN DOOR UNIT) is controlled by the stored information. 3. A satellite communication system according to claim 2, wherein the system has a transmission / reception structure in which the total gain is controlled to be substantially constant or an arbitrary value.

Images