JP6505583B2 - Distributed array antenna system, distributed array controller and distributed array control method - Google Patents

Description

  The present invention relates to a distributed array antenna system, a distributed array control apparatus, and a distributed array control method using a distributed array antenna that causes a plurality of antenna devices to operate in cooperation with an earth station apparatus of a satellite communication system.

  The satellite communication system is widely used to create a communication environment at the time of an ocean, a digital divide area where it is difficult to use a landline, and a digital divide, because the satellite communication system has a strong service area and a strong feature against disasters. However, since propagation loss is very large when communicating by relaying a geostationary satellite over 36,000 km, it is necessary to improve the performance of the earth station apparatus in order to improve the transmission speed and transmission capacity. In Non-Patent Document 1, as a technology for realizing performance improvement of the earth station apparatus at low cost, a configuration using a distributed array antenna in which a plurality of antenna apparatuses are combined and operated cooperatively is studied.

  As shown in FIG. 9 (a), a general earth station apparatus is constituted by one antenna apparatus 11 and a modem 13. An earth station apparatus using a distributed array antenna cooperates with a plurality of antenna apparatuses 11-1 to 11-N (N is an integer of 2 or more) and these antenna apparatuses as shown in FIG. 9 (b). It comprises a distributed array control unit 12 to be operated and a modulation / demodulation unit 13 connected to each antenna unit via the distributed array control unit 12. At the time of transmission, the function of the distributed array control unit 12 distributes the transmission signal from the modulation / demodulation unit 13 to the antenna units 11-1 to 11-N so that each antenna unit is in phase with the communication satellite antenna. By performing phase control, the equivalent isotropically radiated power (EIRP) can be improved. On the other hand, at the time of reception, G / T (Gain to Noise Temperature Ratio: reception performance) is performed by performing gain and phase control such that received signals of the respective antenna devices 11-1 to 11-N are combined in phase or in maximum ratio. Improve).

Susaki, Suzuki, Ayase, Kobayashi, Sugiyama, "Experimental Verification of Distributed Array Antenna Technology for Shipboard Earth Stations in Satellite Communication Systems," Transactions of the Institute of Electronics, Information and Communication Engineers, Vol. J97-B, No. 11, pp. 1022-1031 , November 2014

  When installing an antenna on a moving object, take into consideration the position information of the moving object and the inclination of the moving object under shaking, and place it in a place that secures a view in all directions (360 ° azimuth angle, 0 to 90 ° elevation angle) It is desirable to install. However, due to the limitations of the structure of the mobile and the available location of the antenna, it is conceivable that the location can not be installed at such a location or there is no such location. In that case, an obstacle exists between the direction of the satellite and the antenna device, and the radio wave is blocked, resulting in a state in which communication can not be performed. In the case of mobile satellite communication, as shown in FIG. 10, line-of-sight lines between the antenna device 11 and the communication satellite 1 are used to avoid interference with other satellites due to diffraction or the like of transmission waves due to obstacles. Is calculated from the control information of the antenna device 11 and the structure coordinate information etc., and when the separation angle .theta. Becomes equal to or less than a predetermined value, the transmission from the antenna device 11 is interrupted. . Also, the communication satellite 1 is captured / tracked again, and when the deviation becomes equal to or greater than a predetermined value, the antenna device 11 is reactivated. The operation stop and restart of the antenna device 11 according to such an angle of separation θ with the obstacle are repeated according to the movement of the moving body on which the distributed array antenna is mounted.

  By providing an earth station apparatus including a plurality of antenna apparatuses as in the case of a distributed array antenna, not only the performance of the antenna is improved but also a plurality of propagation paths are provided. Communication can be maintained (even if the antenna is not working).

However, in the distributed array antenna, when the separation angle θ between a part of the antenna apparatus and the obstacle falls below a predetermined threshold and the transmission from the antenna apparatus is stopped, the EIRP drops sharply. Assuming that the number of antenna devices having the same performance is N, the EIRP of the distributed array antenna increases by N ² times, so if one of the distributed array antennas consisting of two antenna devices is interrupted, EIRP is 1 / It will be reduced to 4 (-6 dB). On the contrary, when the antenna which was in the shielding state is reactivated, it will increase 4 times (+6 dB). Such a rapid increase or decrease in EIRP results in an increase or decrease in the input level to the earth station apparatus at the other end of the communication, and if the AGC of the modulation / demodulation apparatus can not follow, a modulation method using amplitude information at the time of demodulation such as QAM or APSK. Is the first problem in that it causes a bit error to occur.

  The second problem is that the transmittable power possessed by each antenna device constituting the distributed array antenna can not be effectively used. This is caused by simply controlling each antenna device constituting the distributed array antenna to ON or OFF according to the separation angle θ. The EIRP of the distributed array antenna defines the value when transmitting predetermined power from each of all antenna devices as the operation level as the satellite communication operator, but usually the operation level is a fixed amount of output for the maximum transmission power It is in the attenuated state. In the case of simple ON / OFF control according to the conventional separation angle θ, the total amount of transmission power falls below the operation level due to the stop of the antenna, so the attenuation amount in the operating state can be reduced to increase individual antenna outputs. Even if possible, this can not be implemented. That is, it can be said that the problem is that the maximum performance can not be exhibited in the environment where the distributed array antenna is placed.

  Further, the above two problems are not only in the mobile environment, but also in failure and restoration of some antenna devices in the fixed station, causing rapid increase and decrease in EIPR, and configuring the distributed array antenna It has been a hindrance to the effective use of transmittable power possessed by each antenna device.

  In the present invention, the maximum EIRP fluctuation due to the operation stop / re-operation of some antenna devices is avoided and the capacity of the remaining antenna devices is effectively utilized for the operation stop of some antenna devices. It is an object of the present invention to provide a distributed array antenna system, a distributed array control apparatus and a distributed array control method which realize a limited EIRP.

According to a first aspect of the present invention, distribution / combination and phase control of transmission signals and reception signals transmitted / received by a plurality of antenna devices for capturing and tracking antennas mounted on communication satellites and distributed antennas are performed. In a distributed array antenna system provided with a distributed array control device, the distributed array control device comprises: an offset calculation means for sequentially calculating an offset between the propagation path between the antenna device and the communication satellite and an obstacle; With the transmission output of the antenna device with zero being less than or equal to the first threshold and the divergence being greater than the first threshold but being less than or equal to the second threshold, the declination is sum of transmission power of all of the antenna device exceeding the first threshold is a function value that varies between the nearest consisting value and zero to a predetermined becomes operational level or a predetermined operating level, elongation is the The transmission output of more than the threshold antenna device, elongation is controlled to vary so that the sum of transmission power of all of the antenna device exceeding the first threshold value is closest to made or predetermined operational level to a predetermined operational level And amplitude adjustment amount calculation means for

In the distributed array antenna system according to the first aspect of the present invention, the amplitude adjustment amount calculation means is a function value that monotonously changes the transmission output of the antenna device whose divergence is greater than the first threshold and smaller than or equal to the second threshold according to the divergence. It is good also as composition controlled.

In the distributed array antenna system according to the first aspect of the present invention, the amplitude adjustment amount calculating means discretely changes the transmission output of the antenna device whose divergence is greater than the first threshold and smaller than or equal to the second threshold according to the divergence. It may be configured to control as a value. Furthermore, the amplitude adjustment amount calculation means may be configured to set the hysteresis in the change of the transmission output when the deviation increases and decreases.

In a distributed array antenna system of the first invention, upon detection of a failure of the antenna device, instead of the elongation calculating means, as a release angle of the antenna device, the amplitude adjustment amount calculating a first threshold value following values You may provide the failure detection means output to a means.

According to a second aspect of the present invention, distribution / combination and phase control of transmission signals and reception signals transmitted / received by a plurality of antenna devices in which each of the distributed antennas is captured / tracked on a mounted antenna of a communication satellite are performed. In a distributed array control apparatus of a distributed array antenna system including a distributed array control apparatus, an offset calculation means for sequentially calculating an offset between the propagation path between the antenna apparatus and the communication satellite and the obstacle, and an offset When the transmission output of the antenna device which is less than or equal to the first threshold is zero and the deviation is greater than the first threshold but less than or equal to the second threshold, the deviation is the first using the deviation as a parameter. summing the transmission output of all exceeding the threshold value of the antenna device is a function value that varies between the nearest consisting value and zero to a predetermined becomes operational level or a predetermined operating level, elongation second The transmission output of the antenna device exceeding the threshold, the control elongation alters so that the sum of transmission power of all of the antenna device exceeding the first threshold value is closest to made or predetermined operational level to a predetermined operational level And amplitude adjustment amount calculation means to be performed.

In a distributed array control apparatus of the second aspect of the invention, upon detection of a failure of the antenna device, instead of the elongation calculating means, as a release angle of the antenna device, the amplitude adjustment amount calculating a first threshold value following values You may provide the failure detection means output to a means.

According to a third aspect of the present invention, distribution / combination and phase control of transmission signals and reception signals transmitted / received by a plurality of antenna devices in which each of the distributed antennas is captured / tracked on a mounted antenna of a communication satellite are performed. In a distributed array control method of a distributed array antenna system including a distributed array control device, an offset calculation step of sequentially calculating an offset between a propagation path between an antenna device and a communication satellite and an obstacle, and an offset When the transmission output of the antenna device which is less than or equal to the first threshold is zero and the deviation is greater than the first threshold but less than or equal to the second threshold, the deviation is the first using the deviation as a parameter. summing the transmission output of all the antenna device exceeding the threshold as a function value that varies between the nearest comprising values and zero made or predetermined operational level to a predetermined operating level, elongation is The transmission output of the antenna device exceeding the second threshold value, elongation alters to the nearest predetermined becomes operational level or a predetermined operational level is the sum of the transmission output of all the antenna device exceeding the first threshold value And an amplitude adjustment amount calculating step of performing control.

  The present invention is expected that the antenna apparatus of the distributed array antenna system suppresses abrupt changes in EIRP accompanying stop waves and restart due to shielding in a mobile environment or failure in a fixed environment, and prevents bit errors in a modem. it can. Also, regardless of the simple ON / OFF control of the antenna device, the transmission power is determined to be, for example, the satellite communication provider in the entire operating antenna device instead of the antenna device that stops wave according to the separation angle of each antenna device. Since control can be performed so as to compensate the output without exceeding a predetermined operation level, it is possible to make the most of the transmission performance of the distributed array antenna system.

It is a figure which shows the structural example of Example 1 of the distributed array antenna system of this invention. It is a figure which shows the example of amplitude weight A ((theta)) provided with respect to detachment angle (theta). It is a figure which shows the example of amplitude weight A ((theta)) provided with respect to detachment angle (theta). It is a figure which shows the time-lapse model of separation angle theta of an antenna device. It is a figure which shows the example of amplitude weighting coefficient _Apro of an antenna apparatus. It is a figure which shows the example of the attenuation amount (A ((theta)) _xApro ) given to an antenna apparatus. It is a figure which shows the example of improvement of EIRP by this invention. It is a figure which shows the structural example of Example 2 of the distributed array antenna system of this invention. It is a figure which shows the structure of the earth station apparatus using a general earth station apparatus and a dispersion | distribution array antenna. It is a figure which shows the structure in a propagation path, and the relationship of separation angle (theta).

Example 1
FIG. 1 shows a configuration example of Embodiment 1 of the distributed array antenna system of the present invention. The first embodiment is applied to a distributed array antenna system for mobiles.

  In FIG. 1, the distributed array antenna system according to the first embodiment includes an antenna angle calculation unit 14 and a structure information table in addition to N antenna devices 11-1 to 11-N, a distributed array control device 12, and a modulation / demodulation device 13. 15 comprises an amplitude adjustment amount calculation unit 16.

The deviation calculating unit 14 inputs control information (elevation angle, azimuth angle, polarization angle) of each of the antenna devices 11-1 to 11 -N and structure information of the periphery of each antenna device from the structure information table 15. , the antenna device 11-i (i is an integer of 1 to N) to elongation theta _i calculation of the propagation path and the obstacle between the communication satellite 1. Amplitude adjustment amount calculation unit 16, in response to the release angle theta _i calculated attenuation of the antenna device 11-i (amplitude weights), by giving the attenuation (amplitude weighting) to the distributed array controller 12, the appropriate The stop wave of the antenna device 11-i and the adjustment of the transmission power are implemented.

The first problem is, if below elongation theta _i is the threshold value (e.g., 3 degrees), (0 amplitude weight) because it was wave-stopping immediately is that have led to rapid change in EIRP. As a method of avoiding this, let the amplitude weight to be given be the amplitude weight function A (θ _i ) of the separation angle θ _i . Although it is essential that the amplitude weight to be given increase / decrease monotonically with the increase / decrease of the separation angle, as shown in FIG. 2, for example, in consideration of the linearly changing scheme and the continuity of the derivative We show the method of changing with trigonometric function. In this example, if the separation angle theta _i becomes 3 degrees or less, the suspension state to the amplitude weighting to zero. Moreover, if the elongation theta _i exceeds 10 degrees, the state of not giving the attenuation of the amplitude weights as 1. However, a prescribed amount of attenuation is given to each antenna device so that, for example, a predetermined operation level determined as a satellite communication carrier when all of the antenna devices 11-1 to 11-N operate, transmission is performed. There is a predetermined margin in power. This margin will be used as a measure to the second problem described below.

と表すことができ、三角関数の場合の振幅重み関数Ａ(θ_i) は、

と表すことができる。 If only the above transition state (3 ° <θ _i <10 °) is expressed by an equation, the amplitude weighting function A (θ _i ) in the linear case is

The amplitude weighting function A (θ _i ) for trigonometric functions can be expressed as

It can be expressed as.

となる。一方、本発明におけるアンテナ装置１１−ｉの離角θ_i から得られる振幅重み関数Ａ(θ)は、停波の判定閾値となる離角θ_th、過渡状態の開始／完了となる離角θ_tra を用いて

と表すことができる。図２に示す例では、θ_th＝３度、θ_tra ＝10度となる。 Here, the conventional amplitude weighting function A (θ) is compared to the separation angle θ _th, which is the determination threshold of the _wave break.

It becomes. On the other hand, it is obtained from separation angle theta _i of the antenna device 11-i in the present invention the amplitude weighting function A (theta) is elongation theta _th as a determination threshold of wave-stopping, elongation which is the start / completion of the transient theta _{with tra}

It can be expressed as. In the example shown in FIG. 2, θ _th = 3 degrees, θ _tra = 10 degrees.

In addition, as shown in FIG. 3, the amplitude weight may be defined discretely, and when the variation of the separation state is small, the change of the amplitude weight (attenuation amount) frequently avoided without following this. May be Furthermore, hysteresis may be provided to the amplitude weight at the time of increase and decrease of the angle of departure. Also, in the case of stopping wave by gradually reducing the amplitude so that the AGC can follow, the relationship of the separation angle θ _ir for shifting to the re-operation state with respect to the separation angle θ _i-th determined to be the stop _wave . _{May be set} as θ _{i -th} <θ _ir .

The second problem is caused by control of simply turning on or off each antenna device constituting the distributed array antenna according to the value of the divergence. As a method to avoid this, adaptively so as to control in accordance with transmission power of all of the antenna device of the distributed array antenna separation angle theta _i. That is, when the separation angle of a part of the antenna devices becomes less than the threshold θ _tra and the attenuation amount is gradually reduced and the _wave is stopped at the threshold θ _th , the separation angle exceeds the threshold θ _tra and the antenna is in operation Even if there is an antenna device that has stopped waves, the attenuation amount given to the device is not gradually given, and the remaining antenna devices as a whole do not exceed, for example, a predetermined operation level defined as a satellite carrier. Control to compensate the output to achieve maximum EIRP.

と表すことができる。 Assuming that the EIRP of the distributed array antenna is the antenna gain Gi of the antenna device 11-i, the maximum transmission power P _max i (amplitude value), and the amplitude weighting coefficient A _ope (0 A A _ope 1 1) used as the operation output. TX _ope , which is EIRP at level,

It can be expressed as.

となる。 Amplitude weight coefficient A _ope is a value determined by the operation level adjustment with the satellite carrier,

It becomes.

と表すことができる。 In addition, TX _conv which is EIRP in consideration of the amplitude weighting function A (θ _i ) of the antenna device 11-i obtained from the separation angle θ _{i of the} antenna device 11-i is

It can be expressed as.

In the present invention, the amplitude weighting coefficient A _{ope is set} to the following A _pro in order to make sure that the antenna device in operation always falls below the operation level in the situation where the separation angle of each antenna device ceases or attenuates the output. But the maximum value of A _pro is 1.

The operation of the first embodiment will be described by way of an example in which the distributed array antenna is configured of three antenna devices.
The gain of each antenna is 0 dBi and the rated power is 1 W. The maximum value of EIRP in this state is 9 W (9.54 dBW). Assuming that 6.3 W (8 dBW) is used as an example of the operation level, the amplitude weight coefficient A _ope of each antenna device is −1.54 dB.

FIG. 4 shows a temporal model of the separation angle θ of the antenna device.
In FIG. 4, the separation angles θ of the three antenna devices change independently, and here, with the antenna device 1 alone, the separation angles θ in the same time zone between the antenna device 2 and the antenna device 3 are less than the threshold θ _tra , θ _th It becomes. Note that θ _th = 3 degrees, θ _tra = 10 degrees.

FIG. 5 shows an example of the amplitude weighting coefficient A _pro of the antenna device. Here, corresponding to the temporal model of the separation angle θ in FIG. 4, the change in the amount of attenuation with respect to the separation angles θ _{th to} θ _tra uses the linear model shown in FIG. 2.
It is confirmed that A _pro = A _ope in a situation where three antenna devices are operating (A (θ) = 1), and the attenuation amount of the operating antenna decreases and the maximum value becomes 0 when there is a non-operating antenna. it can. Note that A _pro linearly changes between the separation angles θ _{th and} θ _tra .

FIG. 6 shows an example of the amount of attenuation (A (θ) × A _pro ) given to the antenna device. Here, an example corresponding to the temporal model of the separation angle θ of FIG. 4 is shown.
In FIG. 6, while the separation angle θ of the antenna device becomes equal to or less than the threshold θ _tra and the attenuation gradually increases and becomes smaller than the threshold θ _th and causes a _wave break, in the antenna device where the separation angle θ exceeds the threshold θ _tra It can be confirmed that the attenuation gradually decreases and reaches the maximum value 0. The EIRP at this time is shown in FIG. 7, but shows an operating level of 8 dBW when three antennas are in operation, and it can be confirmed that the decrease in output is smaller than in the conventional case when non-operating antennas are generated. Can be confirmed.

In the above description, the amplitude weighting function A (θ _i ) common to all the antenna devices is used, but different amplitude weighting functions A (θ _i ) may be used for each antenna device.

(Example 2)
The adaptive adjustment of the transmission power to solve the second problem is to utilize the transmission power margin of the remaining antenna devices not only in the mobile environment but also when the level drops due to the failure of some antenna devices in the fixed station. Is also possible.

FIG. 8 shows a configuration example of Embodiment 2 of the distributed array antenna system of the present invention. The second embodiment is applied to a distributed array antenna system for fixed stations.
In FIG. 8, the distributed array antenna system of the second embodiment is the same as the failure detection unit 17 in the first embodiment in addition to the N antenna devices 11-1 to 11 -N, the distributed array control device 12, and the modem device 13. The amplitude adjustment amount calculator 16 of FIG.

The fault detection unit 17 performs fault detection from the operation information of each antenna device, and adjusts the attenuation amount of each antenna device so as to regard the faulty system as a stop wave state, that is, θ _i = θ _th. Good. As a result, it is possible to appropriately set the transmission power margin as the distributed array antenna system, minimize the decrease in EIRP, and improve the reliability. For example, when each gain of four antenna devices is 0 dBi and rated power is 1 W, the maximum value of EIRP when all four antennas operate normally is 16 W (12 dBW), and one antenna fails Since the maximum value of EIRP is 9 W (9.54 dBW), there is no decrease in EIRP if there is a transmission power margin of 2.46 dB or more as the operation level.

Reference Signs List 1 communication satellite 11 antenna device 12 distributed array control device 13 modulation / demodulation device 14 divergence angle calculation unit 15 structure information table 16 amplitude adjustment amount calculation unit 17 failure detection unit

Claims (8)

A plurality of antenna devices in which each of the distributed antennas captures and tracks the onboard antenna of the communication satellite;
A distributed array antenna system comprising: a distributed array controller for distributing / combining and phase controlling transmission / reception signals transmitted / received by the plurality of antenna devices;
The distributed array controller
A deviation calculation means for sequentially calculating a separation between the propagation path between the antenna device and the communication satellite and an obstacle;
Setting the transmission output of the antenna device at which the deviation angle is equal to or less than a first threshold to zero,
The transmission output of the antenna device in which the deviation exceeds the first threshold and not more than the second threshold is the transmission output of all the antenna devices in which the separation exceeds the first threshold, using the separation as a parameter Function value that changes between zero and a value that brings the sum of the values to the predetermined operation level or is closest to the predetermined operation level,
The transmission output of the antenna device in which the deviation exceeds the second threshold, and the sum of the transmission outputs of all the antenna devices in which the deviation exceeds the first threshold becomes a predetermined operation level or a predetermined operation level And an amplitude adjustment amount calculating unit that performs control to change the position to be the closest to the distributed array antenna system. In the distributed array antenna system according to claim 1,
The amplitude adjustment amount calculation means is configured to control the transmission output of the antenna device in which the deviation exceeds the first threshold and is less than the second threshold as a function value that changes monotonously according to the deviation. Distributed array antenna system characterized by In the distributed array antenna system according to claim 1,
The amplitude adjustment amount calculation means is configured to control the transmission output of the antenna device in which the deviation exceeds the first threshold and is less than or equal to the second threshold as a value discretely changing according to the separation. Distributed array antenna system characterized in that. In the distributed array antenna system according to claim 3,
3. The distributed array antenna system according to claim 1, wherein said amplitude adjustment amount calculation means is configured to set a hysteresis in a change of said transmission output when said deviation increases and decreases. In the distributed array antenna system according to claim 1,
When detecting the failure of the previous SL antenna device, wherein instead of the elongation calculating means, as the elongation of the antenna device, failure detection for outputting said first threshold value or less of the value in the amplitude adjustment amount calculation means A distributed array antenna system comprising: A plurality of antenna devices for acquiring and tracking antennas mounted on communication satellites, each of the distributed antennas, and a distributed array control device for distributing and combining transmit signals and reception signals transmitted and received by the plurality of antenna devices and controlling the phase In a distributed array controller of a distributed array antenna system comprising
A deviation calculation means for sequentially calculating a separation between the propagation path between the antenna device and the communication satellite and an obstacle;
Setting the transmission output of the antenna device at which the deviation angle is equal to or less than a first threshold to zero,
The transmission output of the antenna device in which the deviation exceeds the first threshold and not more than the second threshold is the transmission output of all the antenna devices in which the separation exceeds the first threshold, using the separation as a parameter Function value that changes between zero and a value that brings the sum of the values to the predetermined operation level or is closest to the predetermined operation level,
The transmission output of the antenna device in which the deviation exceeds the second threshold, and the sum of the transmission outputs of all the antenna devices in which the deviation exceeds the first threshold becomes a predetermined operation level or a predetermined operation level And an amplitude adjustment amount calculating unit configured to perform control to change so as to be closest to the distribution array control device. In the distributed array controller according to claim 6,
When detecting the failure of the previous SL antenna device, wherein instead of the elongation calculating means, as the elongation of the antenna device, failure detection for outputting said first threshold value or less of the value in the amplitude adjustment amount calculation means A distributed array controller characterized by comprising: A plurality of antenna devices for acquiring and tracking antennas mounted on communication satellites, each of the distributed antennas, and a distributed array control device for distributing and combining transmit signals and reception signals transmitted and received by the plurality of antenna devices and controlling the phase In a distributed array control method of a distributed array antenna system comprising
An offset calculation step of sequentially calculating an offset between the propagation path between the antenna device and the communication satellite and an obstacle;
Setting the transmission output of the antenna device at which the deviation angle is equal to or less than a first threshold to zero,
The transmission output of the antenna device in which the deviation exceeds the first threshold and not more than the second threshold is the transmission output of all the antenna devices in which the separation exceeds the first threshold, using the separation as a parameter Function value that changes between zero and a value that brings the sum of the values to the predetermined operation level or is closest to the predetermined operation level,
The transmission output of the antenna device in which the deviation exceeds the second threshold, and the sum of the transmission outputs of all the antenna devices in which the deviation exceeds the first threshold becomes a predetermined operation level or a predetermined operation level And an amplitude adjustment amount calculating step of performing control to change so as to be closest to .

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