JP2879836B2 - Transmission power control method for satellite communication and broadcasting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for communicating or broadcasting via a communication / broadcasting satellite, which is used for satellite communication and broadcasting for compensating and correcting signal strength attenuation due to information on the amount of radio interference such as rainfall. Of the control method.

[0002]

2. Description of the Related Art In conventional satellite communication or satellite broadcasting, the amount of rain attenuation, which is one type of radio interference information associated with the attenuation of radio waves in a communication or broadcasting service area, is estimated in advance by a statistical method. In addition, a radio wave of a certain intensity is radiated from a satellite to an earth station or from an earth station to a satellite in anticipation of an estimated value of rain attenuation (rain margin) that satisfies a target line operation rate. In the case of satellite communication, there is a method of compensating for rain attenuation on the uplink from the earth station to the satellite based on the state of rain attenuation on the downlink from the satellite to the earth station at the earth station.

[0003] In the case of satellite communication in which the signal of the child earth station is once collected at the central earth station, the amount of rain attenuation of the downlink to the child earth station is determined by the state of the attenuation of the signal of the child earth station at the central earth station. There is also a method to compensate for
-110, 1988, IEICE, Kimura et al., 1
Report of VSAT satellite experiment using 4/11 GHz band, p
p. 93-98). Further, in the multi-beam satellite communication in which a satellite has a plurality of spot beams, there is a method of compensating rain attenuation by providing a satellite with a dedicated frequency and a high-power transmitting device in a rain area (Japanese Patent Publication No. 63-21369).

[0004]

The communication / broadcasting satellites expect a rainfall margin of a fixed amount of radio interference in order to ensure the quality of the communication or broadcasting, so that the communication / broadcasting satellites are located within the same communication or broadcasting service area. However, rainfall areas that require more transmission power than the rainfall margin for quality assurance, and even the rainfall margin are necessary despite maintaining good line quality without signal strength attenuating There is now a clear sky area that is receiving a large amount of transmitted power, which results in an irrational distribution of limited power to the satellite.

In the transmission power control of the earth station, when a communication partner is specified, the received signal strength from the partner station is compared with a standard value of the received signal strength in fine weather, and the transmission power is controlled by the difference. However, in satellite broadcasting, which is a broadcasting-type service for satellite communication and a service dedicated to reception,
Since an unspecified number of earth stations are distributed over a wide area as reception-only stations, it is impossible to control the transmission power of the satellite in each earth station. If the satellite is equipped with high-power transmitters dedicated to rainy areas, the number of such equipments depends on the number of service areas for communication or broadcasting and the simultaneous occurrence rate of rainfall between the areas.

[0006] Therefore, judging from the average rainfall situation in Japan, it is expected that a plurality of high-output transmitters will be required (see JP-B-63-21369), and the power consumption of the satellite may increase. . Furthermore, the provision of a dedicated frequency for rainfall areas complicates the configuration of the satellite communication broadcast-type service receiving station and satellite broadcasting receiving station, which should have a simple device scale, and the receiving-only station itself has It is impossible to directly transmit information on the occurrence of rain attenuation of radio waves to satellites.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and uses a plurality of spot beams by using weather information provided immediately or intermittently in an area to be subjected to satellite communication or satellite broadcasting. A satellite that compensates for signal strength attenuation due to radio interference such as rainfall by controlling the transmission power of the onboard transmitter of a multi-beam satellite with a variable transmission characteristic or the radiation directivity of the onboard transmitter of a satellite with a variable radiation characteristic It is intended to provide a communication and broadcast control system.

[0008]

Means for Solving the Problems The above objects can be attained by employing the following novel characteristic constitution means of the present invention. That is, the first feature of the present invention is a means for collecting regional weather information for each service area relating to the amount of radio wave attenuation of communication or broadcasting via satellite and outputting the information as radio wave interference amount information, Means for calculating an average radio interference amount per unit time for each service area and a total of all the service areas of the average radio interference amount, calculating a distribution ratio for each service area, and outputting as transmission power control information. Means for transmitting the transmission power control information to the satellite, controlling the transmission power of the satellite for each service area based on the transmission power control information, and compensating in advance when transmitting from the satellite. Satellite communication
This is a broadcast transmission power control method.

A second feature of the present invention is a transmission power control system for satellite communication / broadcasting in which one of the radio interference information in the first feature is regional weather rainfall information.

[0010] A third feature of the present invention is a means for collecting regional weather information for each service area relating to the amount of radio wave attenuation of communication or broadcasting via satellite and outputting the information as radio wave interference amount information; Calculates the average amount of radio interference per unit time for each service area and the total of all the service areas of the average radio interference amount, calculates the distribution ratio for each service area, and outputs it as variable radiation characteristic antenna control information. Means for transmitting the variable radiation characteristic antenna control information to the satellite, and controlling the directivity of the variable radiation characteristic antenna mounted on the satellite based on the variable radiation characteristic antenna control information when transmitting and receiving the antenna. And a means for compensating in advance.

A fourth feature of the present invention is a transmission power control system for satellite communication / broadcasting in which one of the radio interference information in the third feature is local weather rainfall information.

[0012]

According to the present invention, since the above-mentioned means are taken, the transmission power of the multi-beam satellite onboard transmitter or the satellite using the weather information provided immediately or intermittently in the target area of the satellite communication or the satellite broadcasting. Control the radiation directivity characteristics of the onboard antenna. That is, the rain condition is grasped using the local weather information, and the transmission power of the on-board transmitter of the multi-beam satellite is controlled based on this information, and the transmission power corresponding to the rain margin which is unnecessary in the clear weather region is given to the rain region. Thus, the effective radiation power of the satellite is made larger in rainy areas than in clear weather areas. In addition, instead of controlling the transmission power of the multi-beam satellite transmitter, the radiation directivity of the satellite antenna is controlled using local weather information, and the effective radiation power and reception gain of the satellite are shifted from the clear weather area to the rainy area. Make it bigger.

[0013]

【Example】

First Embodiment A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a system configuration diagram showing the present embodiment of satellite communication or satellite broadcasting using multi-beams, and FIG. 2 is a graph showing the rain attenuation compensation effect of satellite communication or satellite broadcasting using multi-beams in this embodiment. .

In the figure, A, B, and C are a plurality of service areas for communication or broadcasting, Sa, Sb, and Sc are regional weather information such as rainfall in the service areas A, B, and C, respectively, and Sd is each service area A. , B, C local weather information Sa,
Sb and Sc are aggregated weather information, S1 is transmission power control information, 1 is a local weather information collection and distribution organization, 2 is an arithmetic unit, 3 is a satellite control station, 4 is a satellite, 5 is a multi-beam antenna, and T1 is transmission. Radio waves for transmitting the power control information S1 to the satellite 4, Ta is a communication wave or broadcast wave for the service area A, T
b is a communication or broadcast wave for the service area B, and Tc is a communication or broadcast wave for the service area C. In the present embodiment, the total number of communication or broadcasting service areas is three.

Since the specification of this embodiment is such a specific embodiment, the local weather information Sa, Sb, Sc of each service area A, B, C passes through the local weather information collection and distribution organization 1. Then, it is immediately or intermittently input to the arithmetic unit 2 as the aggregated weather information Sd of each service area A, B, C. The arithmetic unit 2 is a weather information Sd in which the local weather information Sa, Sb, Sc of each service area A, B, C is collected.
Based on the transmission power for rain attenuation compensation (in the transmission power corresponding to the rain margin of each service area A, B, C, other service areas A, B,
C, the total of the total number of transmission power areas that can be allocated to C, that is, the total of three areas in this embodiment) is preferentially allocated to service areas A, B, and C, where the degradation of line quality due to rainfall is expected to be greater. , Ie, transmission power control information S1.

The transmission power control information S1 is transmitted to the satellite control station 3
Is transmitted to the satellite 4 as a radio wave T1 for transmitting transmission power control information. The satellite 4 receives the service areas A,
The transmission power for B and C is controlled, and the communication wave or broadcast wave Ta, Tb, and Tc for each service area is radiated from the multi-beam antenna 5.

The radio interference amount information of the local weather information Sa, Sb, Sc and the weather information Sd is an AM provided by the Japan Meteorological Agency.
For example, hourly hourly rainfall of eDAS (hereinafter referred to as AMeDAS), synthetic rainfall of radar AMEDAS, short-time forecast of rainfall, and the like are considered. The local meteorological information collection and distribution organization 1 may be the Meteorological Agency, the Japan Meteorological Association, a private weather information company, or the like. In addition, for companies that operate satellite communications or satellite broadcasting throughout Japan, a method of collecting rainfall information from rain gauges and meteorological observation devices at sales offices and branches scattered throughout Japan through an in-company communication network Is also conceivable. In addition, as the radio disturbance amount information related to the weather information Sd, snowfall, wind power, temperature, humidity, dense fog, lightning, and the like can be considered.

As the transmission power control information S1, for example, the average rainfall of each area every hour obtained from the hourly rainfall of AMeDAS every hour is the total number of areas of average rainfall (3 in the case of the first embodiment). ), That is, the distribution ratio αi
A new rain margin Mri (i = A, B, or C) (dB) obtained from (i = A, B, or C) can be considered. New rainfall margin Mri for each service area
(I = A, B, or C) represents each service area A, B,
The transmission power for rain attenuation compensation is obtained by redistributing the transmission power for rain attenuation compensation to the service areas A, B, and C according to the distribution ratio αi (i = A, B, or C) of C, and is represented by the following equation. Mri = 10log {(10 ^{M / 10} -10 ^{Mk / 10} ) Nαi + 10 ^{Mk / 10} }

Here, M is a fixed rainfall margin (dB) estimated in advance for each service area A, B, and C that has been conventionally operated, and Mk is each service area A, B, and C.
In the transmission power corresponding to the rain margin M (dB) of each of the service areas A, B,
The power margin (dB) left for C, N is the total number of service areas, and 3 in the first embodiment. The satellite 4 has a new rainfall margin of Mri (i =
The transmission power is controlled so as to satisfy A, B, or C).

As described above, this embodiment dynamically and spatially and temporally uses the local weather information Sd provided instantaneously or intermittently to transmit the transmission power of the multibeam satellite transmitting apparatus. By controlling with the control information S1, the finite transmission power of the satellite 4 is preferentially allocated to the service area where the deterioration of the line quality due to the rainfall is predicted, and the downlink from the satellite 4 to the earth station is distributed. Implement rain attenuation compensation for the line.

In the present embodiment, the total number of service areas is set to 3, but is not limited to this. By the way, FIG.
It is a graph which shows the rain attenuation compensation effect when the total number N of communication service areas is set to six. In the figure, L1 is a cumulative time distribution curve of rain attenuation when there is no rain attenuation compensation, L
2 is a cumulative time distribution curve of rain attenuation with rain attenuation compensation, and L3 is a cumulative time distribution curve of rain attenuation indicating the limit of rain attenuation compensation.

In Japan (excluding the Nansei Islands), six regions (i
= 1: Hokkaido area, i = 2: Tohoku area, i = 3: Kanto Koshinetsu area, i = 4: Chubu Kinki area, i = 5: Chugoku-Shikoku area, i = 6: Kyushu area When the spot beam in each region has a rain margin M of 10 dB, the power margin M remaining in each region without being used for rain attenuation compensation in the power corresponding to the 10 dB.
When k is set to 5 dB, the transmission power for rain attenuation compensation is allocated to the distribution ratio αi (i = 1 to 6) (average rainfall in each region every hour obtained from hourly hourly rainfall for each AMeDAS is calculated as average rainfall). Divided by the total number of regions).

As a result, assuming that communication or broadcasting by a satellite having a frequency of 22.75 GHz is operated for 1 month in September 1990 at an elevation angle of 30 degrees in the Kanto Koshinetsu region, the rain attenuation value is 10 dB or more. The time rate of L2 is increased from 1.8% (about 13 hours) of L1 to 1.
It is reduced to 0% (about 7 hours), and the effect of rain attenuation compensation can be confirmed. When the rain attenuation value further increases, the limit of rain attenuation compensation of L3 is approached, and it can be confirmed that the compensation effect continues to exist.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a diagram showing satellite communication or satellite broadcasting using the variable radiation characteristic antenna in the present embodiment, and FIG. 4 is a configuration diagram of a phased array antenna as an example of the variable radiation characteristic antenna in FIG.

In the figure, reference numeral 6 denotes a variable radiation characteristic antenna;
8,... N are array antenna elements of a phased array antenna as an example of the variable radiation characteristic antenna 6 (n is an arbitrary number), 9, 10,... N ′ are phase shifters of the phased array antenna (n ′ is an arbitrary number), 11 is a phased array antenna phase controller, 12, 13,..., N ”are feed points for antenna elements of the phased array antenna (n ″ is an arbitrary number), S2 is variable radiation characteristic antenna control information, and γ is a variable radiation characteristic antenna. It is a schematic diagram of the radiation directivity characteristic of No. 6. The same elements as those in the first embodiment are denoted by the same reference numerals.

Also in this embodiment, the total number of communication or broadcasting service areas is three. In the present embodiment, the satellite 4 includes a variable radiation characteristic antenna 6 instead of the multi-beam antenna 5 of FIG. The variable radiation characteristic antenna 6 is an antenna capable of controlling and changing the radiation directivity characteristic γ of the antenna, and a phased array antenna can be considered as an example. The phased array antenna has array antenna elements 7, 8,.
n, phase shifters 9, 10,... n ′, and a phase control device 11, which electronically changes the phase of power supply to each of the array antenna elements 7, 8,. It is.

Since the specification of the present embodiment is such a specific embodiment, the radiation directivity characteristic γ of the antenna 6 is a characteristic for both transmission and reception, so that the effective radiation power in any direction is large. When the radiation directivity characteristic γ is as follows, the reception gain in that direction also increases. The arithmetic unit 2 uses the effective radiation of the satellite 4 to the service areas A, B, and C where the deterioration of the line quality due to rainfall or the like is predicted to be larger based on the collected weather information Sd of the respective service areas A, B, and C. Information for forming the radiation directivity characteristic γ of the antenna 6, that is, variable radiation characteristic antenna control information S2 is derived such that the power is preferentially increased.

This variable radiation characteristic antenna control information S2
Is transmitted to the satellite 4 via the satellite control station 3 as a radio wave T2 for transmitting the variable radiation characteristic antenna control information S2.
The satellite 4 controls the radiation directional characteristic γ of the variable radiation characteristic antenna 6 based on the variable radiation characteristic antenna control information S2 transmitted by the radio wave T2, and communicates or broadcasts Ta for each service area A, B, C. , Tb, and Tc are radiated from the variable radiation characteristic antenna 6.

When the variable radiation characteristic antenna 6 is a phased array antenna as shown in FIG. 4, the satellite 4 controls the phase controller 11 based on the variable radiation characteristic antenna control information S2 to change the radiation directivity characteristic γ. When the effective radiation power of the satellite 4 is increased in the rain area using the variable radiation characteristic antenna 6, the reception gain of the satellite 4 in the rain area is also increased.

As described above, according to the present embodiment, the radiation directivity γ of the satellite-mounted antenna 6 is dynamically and spatially and temporally controlled using the weather information Sd provided immediately or intermittently. Then, the effective radiated power and the reception gain of the satellite 4 are preferentially increased to the service areas A, B, and C where the deterioration of the line quality due to the rainfall is expected to be increased.
The rain attenuation compensation for both the downlink from the satellite 4 to the earth station and the uplink from the earth station to the satellite 4 are performed simultaneously.

[0031]

As described above, the present invention grasps the rainfall condition as the radio interference information based on the local weather information provided immediately or intermittently. It is possible to individually implement a satellite communication broadcasting service in which an earth station becomes a reception-only station and rainfall attenuation compensation for a downlink from a satellite to a reception-only station in satellite broadcasting, which was impossible in the past. In each embodiment of the present invention, the case where the total number of communication or broadcasting service areas is 3 has been described, but the total number of areas can be set to any number.

Further, the present invention does not newly provide a high-output transmission device dedicated to a rainy area, but provides a part or all of transmission power corresponding to a rainfall margin which is unnecessary in a fine weather area to a rainy area. Therefore, it is not necessary to increase the total power consumption of the satellite as compared with the conventional multi-beam satellite. Since it can be operated with the minimum necessary transmission power in fine weather, it is useful for reducing the failure rate of the transmission power device mounted on the satellite and narrowing the interference adjustment area around the area where radio waves are radiated.

Further, when controlling the radiation directivity of the onboard satellite antenna, the effective radiation power and the reception gain of the satellite can be simultaneously increased, so that the downlink from the satellite to the earth station and the uplink from the earth station to the satellite. It can be used to perform both rain attenuation compensation at the same time.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention, showing satellite communication or satellite broadcasting using multiple beams.

FIG. 2 is a graph showing a rain attenuation compensation effect of satellite communication or satellite broadcasting using multiple beams to which the first embodiment of the present invention is applied.

FIG. 3 is a diagram illustrating a second embodiment of the present invention, and is a diagram illustrating satellite communication or satellite broadcasting using a variable radiation characteristic antenna.

4 is a diagram showing a configuration of a phased array antenna as an example of the variable radiation characteristic antenna in FIG.

[Explanation of symbols]

A, B, C: Service area L1: Cumulative time distribution curve of rain attenuation without rain attenuation compensation L2: Cumulative time distribution curve of rain attenuation with rain attenuation compensation L3: Rain indicating the limit of rain attenuation compensation Cumulative time distribution curve of attenuation S1 ... Transmission power control information S2 ... Variable radiation characteristic antenna control information Sa ... Local weather information of service area A Sb ... Local weather information of service area B Sc ... Local weather information of service area C Sd ... set Weather information Ta: communication wave or broadcast wave for service area A Tb: communication wave or broadcast wave for service area B Tc: communication wave or broadcast wave for service area C T1: transmission power control information S1 to satellite Radio waves to be transmitted T2: Radio waves for transmitting variable radiation characteristics antenna control information S2 to satellites 1 ... Regional meteorological information collection and distribution organization 2 ... Arithmetic unit 3 ... Satellite tube Station 4 satellite 5 multi-beam antenna 6 variable radiation characteristic antenna 7,8-n array antenna element 9,10-n 'phaser 11 phase controller 12,13-n "antenna element feed point γ ... Variable radiation characteristics Radiation directivity characteristics of antenna 6

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04B 7/14-7/22 H04H 1/00

Claims (4)

(57) [Claims] A means for collecting regional weather information for each service area relating to an amount of radio wave attenuation of communication or broadcasting via a satellite and outputting the information as radio interference information; Means for calculating the average amount of radio interference per unit time and the total of all the service areas of the average amount of radio interference, calculating the distribution ratio for each service area, and outputting as transmission power control information; To the satellite, controlling transmission power of the satellite for each service area based on the transmission power control information to compensate in advance when transmitting from the satellite. Transmission power control method for communication and broadcasting. 2. The satellite communication system according to claim 1, wherein one of the radio interference information is regional meteorological rainfall information.
A transmission power control method for broadcasting. 3. A means for collecting regional weather information for each service area relating to the amount of radio wave attenuation of communication or broadcasting via a satellite and outputting the information as radio interference information, and for each service area based on the radio interference information. Means for calculating an average amount of radio interference per unit time and a total of all the service areas of the average amount of radio interference to calculate a distribution ratio for each service area, and outputting as variable radiation characteristic antenna control information; Transmitting characteristic antenna control information to the satellite,
Means for controlling the directivity of the variable radiation characteristic antenna mounted on the satellite based on the variable radiation characteristic antenna control information to compensate in advance when transmitting and receiving the antenna, satellite communication / broadcasting Transmission power control method. 4. The satellite communication system according to claim 3, wherein one of the radio interference information is regional meteorological rainfall information.
A transmission power control method for broadcasting.