JP6400323B2 - Array antenna apparatus and mobile station communication system - Google Patents

Description

  The present invention relates to an array antenna apparatus and a mobile station communication system.

  In a system in which a reference station device and a plurality of dependent station devices communicate with each other, the reference station device and each of the plurality of dependent station devices usually establish a communication network by transmitting and receiving beacon signals. The reference station device and each of the plurality of dependent station devices transmit and receive data while maintaining the communication network.

  In a communication system in which all of the reference station apparatus and the plurality of subordinate station apparatuses move at high speed, when each apparatus is equipped with an omnidirectional antenna, each apparatus communicates without knowing the position of each other in advance. Can do.

  On the other hand, in the case of a communication system in which all of the reference station apparatus and the plurality of subordinate station apparatuses move at high speed and are equipped with directional antennas, each apparatus acquires the position of each other in advance to establish a communication network. Need to be established. In such a communication system, a beam search may be employed in order for each device to acquire the position of each other. The beam search is to radiate by changing the beam directing direction so that the beam (radio wave) output from the antenna covers the entire predetermined communication area, that is, by scanning the communication area with the beam. is there.

  The time required for the beam search generally depends on the number of times the beam is emitted to scan the communication area (the number of required searches). For example, when the beam directing direction is changed to a one-dimensional direction, the required number of searches is inversely proportional to the beam width. Also, for example, when the beam directing direction is changed to two-dimensional in the azimuth and elevation directions, the required number of searches is inversely proportional to the square of the beam width. Therefore, in order to shorten the time required for beam search, it is desirable to employ a fan beam having a wide beam width instead of a pencil beam having a narrow beam width.

  The beam width is generally inversely proportional to the antenna aperture length. Therefore, in order to form a fan beam, it is preferable to make the antenna aperture surface physically or electrically small.

  For example, in the phased array antenna, a group of a plurality of antenna elements functions as one directional antenna. Some phased array antennas can control the phase of radio waves output from each antenna element and the power supplied to each antenna element. In such a phased array antenna, for example, it is output from the phased array antenna by cutting off power supply to some antenna elements or controlling the phase distribution of radio waves from a plurality of antenna elements. The beam width can be changed.

  For example, Patent Document 1 discloses an array antenna device including a plurality of antenna elements arranged to form a surface array. This surface array is divided into four regions concentrically from the central portion toward the outer peripheral portion. And only one antenna element in the central part is connected to the transmission / reception switch with the boundary between any one of the plural areas divided in the outward direction from the center part of the surface array, and the antenna element located in the outer peripheral part is connected to On / off control is performed so that the supply of the high-frequency signal is cut off. As a result, the antenna element in the selected outer peripheral region becomes non-operating, and the antenna opening surface can be substantially narrowed. As a result, the antenna beam width formed by the surface array is widened, and the spatial region can be scanned in a short time.

JP 2001-094330 A

  However, the fan beam generally has an antenna gain (C / N (Carrier to Noise Ratio)) lower than that of the original pencil beam, so that the reachability of the beam from the antenna is lowered. Further, when the antenna is a phased array antenna, the output from the antenna element in the non-operating state cannot be obtained, so that the combined power is lowered, and thereby the reachability of the beam from the antenna is lowered. As described above, the array antenna device described in Patent Document 1 has a problem that the reachability of the beam is lowered by using the fan beam as the beam output from the array antenna.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide an array antenna device and the like that can reduce the time required for establishing a communication network while suppressing a decrease in beam reachability. .

In order to achieve the above object, an array antenna apparatus according to the present invention is connected to a plurality of antenna elements arranged two-dimensionally and to each of the plurality of antenna elements, and via the antenna elements connected to each of the antenna elements. In the acquisition mode for establishing a communication network between a plurality of transmission / reception units that transmit / receive signals to / from other devices, a modulation / demodulation unit that modulates transmission signals and demodulates reception signals, Stop transmission / reception of signals via some of the multiple antenna elements, and communicate with other devices when the established communication network is disconnected and the transmission mode for transmitting / receiving information on the established communication network mode management unit to widen the beam width than recapture mode for establishing the network again, the same and the beam width of the beam width and the re-acquisition mode of transmission mode To control the pointing direction of the beam output by the plurality of antennas to operate, and a beam management unit for scanning the beam in the 360 degree is in the acquisition mode. The modem unit modulates or demodulates a smaller amount of information in the acquisition mode than in the transmission mode and the re-acquisition mode. Alternatively, the array antenna device according to the present invention is connected to each of the plurality of antenna elements arranged in a two-dimensional manner and the plurality of antenna elements, and to other devices via the antenna elements connected to each of the antenna elements. In the acquisition mode for establishing a communication network between a plurality of transmission / reception units for transmitting and receiving signals, a modulation / demodulation unit for modulating transmission signals and demodulating reception signals, and other devices, a plurality of antenna elements Stops transmission / reception of signals via a part, transmits / receives mutual position information to / from other devices, and transmits / receives information via a communication network established with other devices using the position information Re-acquisition mode in which the beam width of the transmission mode is narrower than the beam width of the acquisition mode, and the communication network is re-established with another device when the established communication network is disconnected And a mode management unit for narrower than the beam width of the acquisition mode the beam width. The modem unit modulates or demodulates a smaller amount of information in the acquisition mode than in the transmission mode and the re-acquisition mode.

  According to the present invention, in the acquisition mode, the modem unit modulates or demodulates a smaller amount of information than in the transmission mode. As a result, the throughput of communication with other devices can be reduced to compensate for the reduction in antenna gain and combined power.

  In the capture mode, signal transmission / reception via a part of the plurality of antenna elements is stopped. Thereby, the beam radiated | emitted from an array antenna apparatus can be made into a fan beam.

  It is possible to reduce the time required for establishing a communication network while suppressing a decrease in beam reachability.

It is a figure which shows the structure of the mobile station communication system which concerns on Embodiment 1 of this invention. 2 is a diagram showing a configuration of a reference station apparatus according to Embodiment 1. FIG. 3 is a diagram showing an arrangement of phased array antennas according to Embodiment 1. FIG. 3 is a diagram illustrating an example of a physical configuration of a transmission / reception unit according to Embodiment 1. FIG. It is a figure which shows the relationship of the transition of the operation mode of the phased array antenna comprised from the some antenna element which concerns on Embodiment 1. FIG. It is a figure which shows the example of the relationship between the scanning angle direction of a fan beam, and an amplitude. It is a figure which shows the example of the relationship between the scanning angle direction of a pencil beam, and an amplitude. 3 is a sequence diagram showing an operation of the mobile station communication system according to Embodiment 1. FIG. It is a figure which shows the example of the spatial order of each pointing direction of reference station apparatus AP and dependent station apparatus ST in the scanning of a communication area. It is a figure which shows the example of the temporal relationship of each directional direction of reference | standard station apparatus AP and dependent station apparatus ST in the scanning of a communication area. It is a figure which shows the state which the reference station apparatus AP and the subordinate station apparatus ST mutually detected by the scan of the beacon signal. It is a figure which shows the relationship of each band of the beacon signal and transmission signal which concern on Embodiment 1. FIG. 6 is a diagram illustrating a configuration of a reference station apparatus according to Embodiment 2. FIG. It is a figure which shows the relationship of each band of the beacon signal which concerns on Embodiment 2, and a transmission signal.

  Embodiments of the present invention will be described below with reference to the drawings. The same elements are denoted by the same reference symbols throughout the drawings.

Embodiment 1 FIG.
The mobile station communication system 100 according to Embodiment 1 of the present invention is a system that performs communication between mobile stations. As shown in FIG. 1, the mobile station communication system 100 includes one reference station device AP101 and four dependent station devices ST103 in the communication area 102 of the reference station device AP101. The number of dependent station devices ST103 may be one or more.

  Each of the reference station device AP101 and the plurality of dependent station devices ST103 is an array antenna device, and can be mounted and moved on, for example, an aircraft, a railcar, or an automobile. Note that a part of each of the reference station device AP101 and the dependent station device ST103 may be fixed on the ground and cannot move.

  Since the reference station device AP101 and each of the plurality of dependent station devices ST103 do not initially hold each other's position information, a communication network has not been established and communication with each other is not possible. Therefore, the reference station device AP101 and each of the plurality of dependent station devices ST103 cannot transmit / receive a signal including transmission information. Here, the transmission information is a main part of information transmitted / received via a communication network, that is, information that is an original purpose of transmission / reception. As an example of the transmission information, information that is commonly held in each of the apparatuses 101 and 103 can be cited.

  In order to establish a communication network, the reference station device AP101 transmits a beacon signal 104 including its own location information to each of the dependent station devices ST103. When each of the dependent station devices ST103 receives the beacon signal 104 transmitted from the reference station device AP101, the dependent station device ST103 holds the position information included in the received beacon signal 104 as information indicating the position of the reference station device AP101. Subsequently, each of the dependent station devices ST103 transmits a beacon signal 104 including its own position information toward the position of the reference station device AP101.

  When receiving the beacon signal 104 transmitted from each of the dependent station devices ST103, the reference station device AP101 holds the position information of each of the dependent station devices ST103 based on the received beacon signal 104. Thereby, each of the reference station device AP101 and the dependent station device ST103 establishes a communication network based on the position information held mutually.

  Each of the reference station device AP101 and the dependent station device ST103 appropriately transmits and receives a communication signal including transmission information via the established communication network. As a communication method at this time, a time division multiplexing method, a space division multiplexing method, or the like may be employed in order to avoid radio wave interference.

  As shown in FIG. 2, the reference station device AP101 functionally radiates radio waves to the subordinate station device ST103, which is another device, or receives a radio wave from the subordinate station device ST103, and a plurality of sets of antenna elements 105 and transmitting / receiving units 106 And a communication control unit 107 that controls communication by controlling each of the transmission / reception units 106, and a power supply 108 that supplies power for operating each of the plurality of transmission / reception units 106 and the communication control unit 107.

  The plurality of antenna elements 105 are two-dimensionally arranged in a rectangular arrangement area 109 as shown in FIG. As shown in FIG. 2, the plurality of transmission / reception units 106 are provided in association with the plurality of antenna elements 105 on a one-to-one basis. The plurality of transmission / reception units 106 radiate radio waves (signals and beams) including information to the air via the associated antenna elements 105 and receive radio waves from the air.

  Note that the region in which the plurality of antenna elements 105 are two-dimensionally arranged is not limited to a rectangle but may be an arbitrary shape such as a circle.

  As shown in FIG. 4, each of the transmission / reception units 106 physically receives power supply from the power supply 108 and operates under the control of the communication control unit 107. Each of the transmission / reception units 106 includes a filter circuit 110, a power amplifier 111, a phase shifter 112, a high frequency circuit 113, and a low noise power amplifier 114. As the power amplifier 111 and the phase shifter 112 associated with each of the plurality of antenna elements 105 operate under the control of the communication control unit 107, the plurality of antenna elements 105 are, as shown in FIG. It functions as one phased array antenna (in this embodiment, active phased array antenna) 115 having directivity.

  Specifically, for example, power supply from the power supply 108 is controlled by the high-frequency circuit 113 that operates in accordance with the antenna control signal from the communication control unit 107. For example, when the power supply to the power amplifier 111 is cut off, the operation of the antenna element 105 associated with the transmission / reception unit 106 including the power amplifier 111 (that is, transmission / reception of a signal via the antenna element 105) is substantially performed. Stop. Thereby, the beam width and combined power of the beam output from the phased array antenna 115 are controlled.

  As control of the beam width, there is formation of a pencil beam and a fan beam. For example, a pencil beam can be formed by supplying power to the power amplifier 111 of the transmission / reception unit 106 corresponding to all the antenna elements 105 arranged in the arrangement region 109. Further, for example, as shown in FIG. 3, by supplying power only to the power amplifier 111 of the transmission / reception unit 106 corresponding to the antenna elements 105 arranged in the central rectangular partial region 116 in the arrangement region 109, any power can be obtained. A fan beam having a beam width of can be formed.

  For example, the phase shifter 112 operates based on a signal from the high frequency circuit 113 that operates according to an antenna control signal from the communication control unit 107. Thus, the phase of the radio wave radiated from the antenna element 105 associated with the transmitting / receiving unit 106 including the phase shifter 112 is controlled. By controlling the phase of the radio waves from the plurality of antenna elements 105, the directivity direction of the beam output from the phased array antenna 115 is controlled. By controlling the directivity direction of the beam, the reference station device AP101 can radiate the beam in all directions of 360 °, for example, and scan the entire communication area.

  In the passive phased array antenna, the above-described pencil beam and fan are also controlled by controlling the phase shifter 112 associated with each antenna element 105 and controlling the phase distribution of the beam radiated from each antenna element 105. A beam having an arbitrary beam width such as a beam can be formed.

  For example, the filter circuit 110, the power amplifier 111, and the phase shifter 112 exchange an IF (Intermediate Frequency) signal with the communication control unit 107 via the high frequency circuit 113. Thus, a beam including desired information is transmitted from the array antenna, and information included in the beam received by the array antenna is acquired by the reference station device AP101.

  The communication control unit 107 is physically composed of, for example, a processor that executes a program incorporated in advance while referring to a storage area, a RAM (Random Access Memory), a ROM (Read Only Memory), a storage medium, and the like. As the storage medium, a hard disk drive, a semiconductor memory, or the like may be appropriately employed.

  As shown in FIG. 2, the communication control unit 107 functionally includes a network control unit 117 that manages operation mode transitions, a modulation / demodulation unit 118 that performs digital modulation / demodulation and signal processing, and instructions from the network control unit 117. And an antenna control unit 119 for controlling each of the transmission / reception units 106.

  The network control unit 117 includes a mode management unit 120 that manages an operation mode, a beam management unit 121 that manages a beam emitted from the phased array antenna 115, and a slot management unit 122 that manages time.

  The mode management unit 120 manages the transition of the operation mode shown in FIG.

  The operation modes of the phased array antenna 115 according to the present embodiment include an initial acquisition mode 123, a network mode 124, a transmission mode 125, and a re-acquisition mode 126, as shown in FIG.

  The initial acquisition mode 123 is an operation mode for establishing a communication network with the dependent station device ST103 in the communication area 102 that has not yet established a communication network. By operating in the initial acquisition mode 123, the reference station device AP101 acquires and holds the position information of the dependent station device ST103 in the communication area 102 that has not established a communication network until now. As a result, a communication network is established, and the mode management unit 120 shifts the operation mode to the network mode 124.

  The network mode 124 is an operation mode for maintaining an established communication network. The transmission mode 125 is an operation mode in which a beam including transmission information is radiated to the dependent station apparatus ST103 in which a communication network is established and maintained. Therefore, once a communication network is established with the dependent station device ST103, the reference station device AP101 transmits the data to and from the dependent station device ST103 in the transmission mode 125 while maintaining the communication network in the network mode 124. Send and receive information. When the communication network is disconnected while operating in the network mode 124 or the transmission mode 125, the mode management unit 120 shifts the operation mode to the reacquisition mode 126.

  The re-acquisition mode 126 is an acquisition mode for re-acquiring the dependent station device ST103 in which the communication network once established is disconnected even though it is in the communication area 102 of the reference station device AP101. By operating in the reacquisition mode 126, the reference station device AP101 acquires and holds position information of the dependent station device ST103 in the communication area 102. When the communication network is reestablished as a result of the operation in the reacquisition mode 126, the mode management unit 120 shifts the operation mode to the network mode 124. When the communication network is not established again as a result of the operation in the reacquisition mode 126, the management unit 120 shifts the operation mode to the initial acquisition mode 123.

Reference is again made to FIG.
The beam management unit 121 manages the beam width of the beam radiated from the phased array antenna 115, the combined power, the beam pointing direction, the information included in the beam, the beam band, and the like according to the operation mode determined by the mode management unit 120.

  The beam width in each operation mode will be described.

  In the initial acquisition mode 123, the beam management unit 121 receives a fan beam having a wide beam width from the phased array antenna 115 (a plurality of antenna elements 105) as shown in the relationship between the scanning angle direction of the fan beam and the amplitude in FIG. Manage to be emitted. More specifically, as described above, the beam management unit 121 supplies power only to the power amplifier 111 of the transmission / reception unit 106 corresponding to the antenna elements 105 arranged in the central rectangular partial region 116 in the arrangement region 109. Control to be supplied. As a result, transmission / reception of signals through the antenna element 105 to which power supply has been stopped is stopped, so that the antenna aperture surface can be substantially reduced to ensure a wide radiation range of the beam.

  In the network mode 124, the transmission mode 125, and the re-acquisition mode 126, the beam management unit 121 receives a pencil beam having a narrow beam width as shown in the relationship between the scanning angle direction and the amplitude of the pencil beam in FIG. To be radiated from. More specifically, the beam management unit 121 performs control so that power is supplied to the power amplifier 111 of the transmission / reception unit 106 corresponding to all the antenna elements 105 arranged in the arrangement region 109 as described above. As a result, communication throughput can be improved.

  The combined power in each operation mode will be described.

  As described above, the fan beam is radiated from the phased array antenna 115 in the initial acquisition mode 123. In the network mode 124, the transmission mode 125, and the reacquisition mode 126, the pencil beam is emitted from the phased array antenna 115. The combined power is usually greater for the pencil beam than for the fan beam. As a result, when a beam is emitted with the same bandwidth, the fan beam generally has a lower C / N (Carrier to Noise Ratio) ratio than the pencil beam. As a result, beam reachability is generally lower for fan beams than for pencil beams.

  The beam pointing direction in each operation mode will be described.

  In the initial acquisition mode 123 or the re-acquisition mode 126, the beam management unit 121 sequentially changes the beam directing direction so as to cover the entire communication area 102. Typically, the directivity direction is sequentially changed to 360 degrees in all directions. Thereby, since the communication area 102 is scanned with a beam, it is possible to radiate the beam to the dependent station apparatus ST103 in which no communication network is established in the communication area 102. In the reacquisition mode 126, for example, a predetermined range or a predetermined time may be scanned around the last position information where the established communication network is disconnected.

  In the network mode 124 and the transmission mode 125, the beam management unit 121 controls the directivity direction toward the dependent station device ST103 in which the communication network is established. Thus, transmission information can be transmitted to and received from the dependent station apparatus ST while tracking the moving dependent station apparatus ST103 and maintaining the communication network.

  Information included in the beam and the band of the beam in each operation mode will be described.

  In the initial acquisition mode 123, the beam management unit 121 emits a beam having a smaller amount of information than transmission information. Preferably, the beam management unit 121 emits a beam including a minimum amount of information necessary for establishing a communication network. This information includes position information of the reference station device AP101 itself. In the initial acquisition mode 123, the beam management unit 121 narrows the band of the beam by narrowing down the information included in the beam to the minimum information necessary for establishing a communication network. Note that the position accuracy in the position information may be lower than that of the position information included in the beam in the network mode 124 or the reacquisition mode 126 in order to reduce the amount of information.

  In this way, by reducing the amount of information included in the beam in the initial supplement mode 123, information necessary for establishing a communication network can be transmitted even with a narrowband beam. Therefore, even with low power, a communication network can be established while suppressing a decrease in beam reachability.

  In the transmission mode 125, the beam management unit 121 emits a beam including transmission information. In the transmission mode 125, the beam management unit 121 widens the beam band. Thereby, in the transmission mode 125, a large amount of information can be transmitted with a broadband pencil beam, and the communication throughput can be improved.

  In the network mode 124 and the reacquisition mode 126, the beam management unit 121 emits a beam including position information. In the transmission mode 125, as described above, the pencil beam is radiated, so that the reference station device AP101 and the dependent station device ST103 with which the communication network is established can track the positions of each other with high accuracy.

  Thus, in the operation mode (initial acquisition mode 123) before the construction of the communication network, the beam management unit 121 uses a fan beam having a wide beam width to detect the dependent station device ST103 as a communication partner at an early stage. Scan. In addition, by reducing the amount of information included in the fan beam, reduction in beam reachability is suppressed.

  In the operation mode (network mode 124, transmission mode 125, and reacquisition mode 126) after the construction of the communication network, the beam management unit 121 holds position information with each of the dependent station devices ST103. Radiates a narrow pencil beam for high precision beam control.

  The slot management unit 122 manages transmission / reception timing in time division multiplexing. The antenna control unit 119 described later in detail outputs an antenna control signal at a timing determined by the slot management unit 122. This antenna control signal includes information for controlling the beam width, the combined power, and the beam pointing direction.

  When the modulation / demodulation unit 118 acquires timing information indicating the output timing from the slot management unit 122, the modulation / demodulation unit 118 modulates signals transmitted via the antenna elements 105 connected to the plurality of transmission / reception units 106, respectively. The modem unit 118 outputs the modulated signal to each of the plurality of transmission / reception units 106.

  In addition, the modem unit 118 demodulates signals received via the antenna elements 105 connected to the plurality of transmission / reception units 106 in accordance with instructions from the network control unit 117.

  Specifically, the modem unit 118 operates under the control of the beam management unit 121 as described above, in the initial acquisition mode 123, an operation mode (network mode 124, Modulate or demodulate a smaller amount of information than at least one of transmission mode 125 and reacquisition mode 126. Note that the modem unit 118 may appropriately perform error correction processing and the like.

  The antenna control unit 119 calculates a parameter for controlling each of the transmission / reception units 106 so that the beam managed by the beam management unit 121 is emitted, and controls each of the transmission / reception units 106 based on the calculation result. The antenna control unit 119 includes an arithmetic processing unit 127 that performs arithmetic operations, a storage unit 128 that holds the results of the arithmetic operations performed by the arithmetic processing unit 127 as information indicating the current state of the transmitting / receiving unit 106, and the arithmetic processing unit 127. And a signal output unit 129 that outputs an antenna control signal based on the calculation result.

  Specifically, the arithmetic processing unit 127 acquires the beam width, combined power, and beam directing direction of the emitted beam from the beam management unit 121. The arithmetic processing unit 127 refers to the information acquired from the beam management unit 121 and the information in the storage unit 128. Then, the arithmetic processing unit 127 calculates parameters for controlling each of the transmission / reception units 106 so as to emit a beam corresponding to the operation mode managed by the beam management unit 121. The signal output unit 129 generates an antenna control signal according to the calculation result by the calculation processing unit 127 and outputs the antenna control signal to each of the plurality of transmission / reception units 106 at the timing determined by the slot management unit 122.

  So far, the configuration of the reference station device AP101 has been described. The reference station device AP101 uses the dependent station device ST103 as another device (a communication partner that transmits and receives radio waves), but each of the dependent station devices ST103 uses the reference station device AP101 as another device. Except for this point, each of the dependent station devices ST103 has the same configuration as the reference station device AP101 described so far.

  So far, the configuration of the mobile station communication system 100 has been described. From here, the operation of the mobile station communication system 100 will be described.

  FIG. 8 is a sequence diagram showing the operation of mobile station communication system 100 according to Embodiment 1, and shows the flow of processing executed by each of reference station apparatus AP101 and dependent station apparatus ST103.

  When the communication network is not established, the reference station device AP101 and the dependent station device ST103, as shown in FIG. 8, beacon signal 104 (see FIG. 1) in the acquisition mode (initial acquisition mode 123, re-acquisition mode 126). Send and receive. Here, the beacon signal 104 is a signal (beam) output from the phased array antenna 115 in order to establish a communication network.

  That is, the beacon signal 104 is a signal (beam) output in the initial acquisition mode 123 or the re-acquisition mode 126. In the initial acquisition mode 123, as described above, the beacon signal 104 includes position information with lower accuracy than the re-acquisition mode 126. The position information included in the beacon signal 104 indicates the position of the output reference station device AP101 or dependent station device ST103 itself in any of the operation modes of the initial acquisition mode 123 and the reacquisition mode 126. The beacon signal 104 in the initial acquisition mode 123 is output as a fan beam having a wider beam width than the beam (pencil beam) output in the re-acquisition mode 126. Therefore, the combined power of the beacon signal 104 in the initial acquisition mode 123 is smaller than that of the beacon signal 104 output in the re-acquisition mode 126. The beacon signal 104 in the initial acquisition mode 123 is sequentially changed to 360 degrees in all directions so that the directing direction extends over the entire communication area 102, and is thereby controlled and output so as to scan the communication area 102. Even in the re-acquisition mode 126, the acquisition mode that is an operation mode for establishing a communication network is the same as in the initial acquisition mode 123 (that is, for example, position information with low accuracy is directed to 360 degrees in all directions with a fan beam). Output) and may operate.

  In the example shown in FIG. 8, the reference station device AP101 transmits the beacon signal 104 while changing the directivity direction, and the subordinate station device ST103 receives the beacon signal 104 while changing the directivity direction. Then, when the directivity directions face each other, the dependent station device ST103 holds the position information included in the beacon signal 104 output from the reference station device AP101 (step S100).

  Here, the relationship between the directivity directions changed by the reference station device AP101 and the dependent station device ST103 in scanning of the communication area 102 will be described in more detail with reference to FIGS.

  FIG. 9 shows an example of the order in which the reference station device AP101 and the subordinate station device ST103 change the directing direction in order to scan the communication area 102. FIG. 10 shows an example of the temporal relationship of the directivity direction that each of the reference station device AP101 and the dependent station device ST103 changes to scan the communication area 102.

  As shown in FIG. 9, the reference station device AP101 and the subordinate station device ST103 scan each communication area 102 with a beacon signal 104 by spatially changing the directivity direction from region 1 to region n sequentially. .

  In terms of time, as shown in FIG. 10, reference station apparatus AP101 transmits a beacon signal while sequentially changing the directivity direction from region 1 to region n. Meanwhile, dependent station apparatus ST103 waits for reception of beacon signal 104 with the pointing direction directed to region 1. Thereafter, the same is repeated. That is, dependent station apparatus ST103 sequentially changes the directivity direction for receiving beacon signal 104 from region 2 to region n. The reference station device AP101 transmits the beacon signal 104 while sequentially changing the directing direction to the regions 1 to n while the pointing direction of the dependent station device ST103 is one region i (i is an integer of 2 to n). To do.

  Then, as shown in FIG. 11, when the pointing directions of the reference station device AP101 and the dependent station device ST103 face each other, the dependent station device ST103 refers to the beacon signal 104 from the reference station device ST101 to thereby determine the reference station device AP101. It is possible to hold position information indicating the position of the. FIGS. 9 and 11 show an example in which when the directivity directions of the reference station device AP101 and the subordinate station device ST103 are directed to the area m, the directivity directions face each other and a communication network is established.

  Dependent station apparatus ST103 transmits beacon signal 104 to the position of reference station apparatus AP101 based on the held position information. This beacon signal 104 includes position information of dependent station device ST103. Reference station apparatus AP101 receives beacon signal 104 from dependent station apparatus ST103. Here, since the beacon signal 104 in a specific directivity direction toward the position of the reference station device AP101 is transmitted from the dependent station device ST103, the reference station device AP101 may receive the signal by changing the directivity direction in order from the region 1. Thereby, the reference station device AP101 holds position information indicating the position of the reference station device AP101 by referring to the beacon signal 104 from the dependent station device ST103 (step S101). As a result, the reference station device AP101 and the dependent station device ST103 can mutually hold the position information of the counterpart device, and a communication network is established between the reference station device AP101 and the dependent station device ST103.

  When the communication network is established, for example, in the next period in time division multiplexing, the reference station device AP101 and the dependent station device ST103 transition to a network mode 124 and a transmission mode 125 as shown in FIG. Specifically, the reference station device AP101 and the subordinate station device ST103 repeat the operation mode transition between the network mode 124 and the transmission mode 125, thereby maintaining the communication network and transmitting the transmission signal 130 (see FIG. 1). Send and receive.

  The transmission signal 130 is a signal (beam) output from the phased array antenna 115 to transmit / receive transmission information.

  That is, the transmission signal 130 is a signal (beam) output in the transmission mode 125. Therefore, as described above, the transmission signal 130 is output as a pencil beam having a narrow beam width. The transmission signal 130 has a large combined power. The reference station device AP101 transmits the transmission signal 130 by controlling the directivity direction so as to go to the dependent station device ST103 with which the communication network is established, and controls the transmission signal 130 from the dependent station device ST103 in the same directivity direction. Receive. The dependent station device ST103 transmits the transmission signal 130 by controlling the directivity direction so as to go to the reference station device AP101 with which the communication network is established, and receives the control signal 130 from the reference station device ST101 in the same directivity direction. To do. The transmission signal 130 is a signal that includes a large amount of information and includes transmission information.

  In the network mode 124, the reference station device AP101 and the dependent station device ST103 may transmit a tracking signal including their highly accurate position information. The tracking signal may be a pencil beam having a directivity direction toward the other devices 103 and 101, similarly to the transmission signal 130.

  In FIG. 9, each of the reference station device AP101 and the dependent station device ST103 transmits a transmission signal (transmission signal m) 130 in which the directing direction is directed to the area m, and the transmission signal 130 is received by the other devices 103 and 101. An example is shown.

  Thereafter, the reference station device AP101 and the subordinate station device ST103 can maintain the established communication network by holding each other's position by transmitting and receiving a tracking signal. The reference station device AP101 and the dependent station device ST103 can transmit and receive the transmission signal 130 by appropriately changing the directing direction according to the established communication network.

  When the established communication network is disconnected, the reference station device AP101 and the dependent station device ST103 may return to the acquisition mode (re-acquisition mode 126).

  For example, when either the reference station device AP101 or the dependent station device ST103 moves, another dependent station device ST103 newly enters the communication area of the reference station device AP101, or another communication station of the dependent station device ST103 has another communication area. The reference station device AP101 may newly enter. In order to acquire such another dependent station device ST103 or reference station device AP101, each of the reference station device AP101 and the dependent station device ST103 executes the initial acquisition mode at a predetermined time (for example, periodically). May be.

  The first embodiment of the present invention has been described above.

  According to the present embodiment, the reference station device AP101 and the dependent station device ST103 that do not know the positions of each other operate in the initial acquisition mode 123. In this case, the reference station device AP101 scans the communication area 102 by transmitting the beacon signal 104 including its own position information while changing the directivity direction. At the same time, the dependent station device ST103 scans the communication area 102 by changing the directing direction and receiving the beacon signal 104 from the reference station device AP101. Then, the reference station device AP101 and the subordinate station device ST103 exchange position information with each other in the directivity directions in which the beams face each other. In the initial acquisition mode 123, the dependent station device ST103 may first scan with the beacon signal 104, and the reference station device AP101 may receive the signal with the pointing direction changed.

  When the beacon signal 104 is transmitted or received in the initial acquisition mode 123, the power supply to the power amplifier 111 associated with a part of the plurality of antenna elements 105 is cut off. As a result, the apparent aperture of the phased array antenna 115 can be reduced, so that the beam width of the beam radiated from the phased array antenna 115 can be widened and the range received by the phased array antenna 115 can be widened. it can. As a result, the number of times the beacon signal 104 is transmitted to scan the communication area 102 with the beacon signal 104 can be reduced, and the time required for establishing the communication network can be shortened.

  Here, when the beam width of the beacon signal is widened, the received power is usually lower than the received signal power of data communication due to a decrease in antenna gain and combined power. In contrast, according to the present embodiment, in the initial acquisition mode 123, the modem unit 118 modulates or demodulates a smaller amount of information than in the operation mode after the communication network such as the transmission mode 125 is established. Thereby, even if the band of the beacon signal is narrowed, the information can be transmitted and received.

For this reason, as shown in FIG. 12, the bandwidth of the beacon signal can be limited so as to ensure a C / N (Carrier to Noise Ratio ) or more of the transmission signal to compensate for the power reduction. As a result, it is possible to avoid the reduction of the communication area 102 and to secure the communication area 102 of the same level as in the case of a narrow beam.

  Specifically, for example, the antenna gain in the pencil beam of each of the reference station device AP101 and the subordinate station device ST103 is GA [dBm], the number of effective elements is N, the combined power is P [dBm], and the antenna gain in the fan beam is GA ′. When [dBi], the number of effective elements is N ′, and the combined power is P ′ [dBm], the reception power reduction due to switching from the pencil beam to the fan beam is {2 × (GA−GA ′) + (P−P ′)}. It becomes. Further, if the reception signal bandwidth of the transmission signal transmitted / received by the pencil beam is Bn and the reception signal bandwidth of the beacon signal transmitted / received by the fan beam is Bn ′, the condition of Bn ′ is expressed by the following equation (1). .

10 log (Bn / Bn ′) ≧ {2 × (GA−GA ′) + (P−P ′)} (1)

  Here, the combined power P depends on the number of elements. Further, P = Pa + 10 log (N / N ′). However, Pa is the power per element. Therefore, the formula (1) can be transformed as the following formula (2).

10 log (Bn / Bn ′) ≧ {2 × (GA−GA ′) + 10 log (N / N ′)} (2)

  By suppressing the information amount of the beacon signal 104, that is, Bn ′ so as to satisfy the expression (2), the C / N necessary for receiving information in the communication area 102 is secured, and the other devices 101, A reliable capture of 103 can be realized.

  Therefore, for example, according to the beam width of the fan beam applied to the beacon signal 104, the mode management unit 120 may reduce the position accuracy of the position information included in the beacon signal 104.

  In this way, by reducing the throughput of communication with the other apparatuses 101 and 103, it is possible to compensate for a decrease in antenna gain and a decrease in combined power due to a wide beam width. As a result, it is possible to suppress a decrease in reachability of the beacon signal.

  Further, according to the present embodiment, in the initial acquisition mode 123, the beacon signal is scanned in all directions of 360 degrees. This makes it possible to reliably capture other devices (reference station device AP101, dependent station device ST103) existing in the communication area.

Embodiment 2. FIG.
In the first embodiment, when operating in the initial acquisition mode 123, by transmitting a small amount of information with the narrowband beacon signal 104, the antenna gain and the combined power associated with the widening of the beam width of the beacon signal 104 are obtained. Compensated for decline.

  In the present embodiment, when operating in the initial acquisition mode 123, the beacon signal 104 modulated by the spread spectrum method is employed. According to this, even when the same band as the signal (transmission signal 130 etc.) output after the communication network is established is applied to the beacon signal 104 in the initial acquisition mode 123, the beam width of the beacon signal 104 is widened. It is possible to compensate for the decrease in the antenna gain and the combined power.

  Each of reference station apparatus AP 201 and dependent station apparatus ST 203 according to the present embodiment includes a modulation / demodulation unit 218 instead of modulation / demodulation unit 118 according to Embodiment 1. Except for this, the reference station device AP201 and the dependent station device ST203 have substantially the same configurations as the reference station device AP101 and the dependent station device ST103 according to Embodiment 1, respectively.

  Modulator / demodulator 218 modulates the transmission signal and demodulates the received signal, similarly to modulator / demodulator 118 according to Embodiment 1. Modulator / demodulator 218 differs from modulator / demodulator 118 according to Embodiment 1 in adopting a spread spectrum method as a modulation method.

  The operations of the reference station device AP201 and the dependent station device ST203 according to the present embodiment are the same as those of the reference station device AP101 and the dependent station device ST103 according to the first embodiment, respectively, except that the modulation / demodulation unit 218 performs modulation using the spread spectrum method. It is almost the same.

  As in the first embodiment, the beacon signal 104 according to the present embodiment has a reduced amount of information included therein and includes position information similar to that in the first embodiment. According to the present embodiment, spread spectrum modulation is employed for generating such a beacon signal 104.

  Therefore, as shown in FIG. 14, even if the band of the beacon signal 104 is set to the same band as the transmission signal 130, the C / N necessary for receiving information in the communication area 102 due to the spreading gain when the beacon signal 104 is received. Can be secured.

  Therefore, it is possible to compensate for a decrease in antenna gain and a decrease in combined power due to a wide beam width. As a result, it is possible to suppress a decrease in reachability of the beacon signal.

  Further, according to the present embodiment, the same filter circuit can be applied at the same operating frequency on the receiving side. As a result, the circuit configuration of the transmission / reception unit 106 can be simplified.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to each embodiment, The form which combined each embodiment and the modification suitably, and the form which added the various change to it including.

  100 Mobile station communication system 101, 201 Reference station apparatus AP, 102 Communication area, 103, 203 Dependent station apparatus ST, 104 Beacon signal, 105 Antenna element, 106 Transmission / reception unit, 107, 207 Communication control unit, 108 Power supply, 109 Array area , 110 filter circuit, 111 power amplifier, 112 phase shifter, 113 high frequency circuit, 114 low noise power amplifier, 115 phased array antenna, 116 partial region, 117 network control unit, 118, 218 modulation / demodulation unit, 119 antenna control unit, 120 Mode management unit, 121 Beam management unit, 122 Slot management unit, 123 Initial acquisition mode, 124 Network mode, 125 transmission mode, 126 Re-acquisition mode, 127 Arithmetic processing unit, 128 Storage unit, 129 Signal output unit, 30 transmission signal.

Claims (6)

A plurality of antenna elements arranged two-dimensionally;
A plurality of transmitting and receiving units connected to each of the plurality of antenna elements, and transmitting and receiving signals to and from other devices via the antenna elements connected to each of the plurality of antenna elements;
A modem unit that modulates the transmission signal and demodulates the reception signal;
In a capture mode for establishing a communication network with the other device, for stopping transmission / reception of signals through a part of the plurality of antenna elements, and for transmitting / receiving information on the established communication network When the transmission mode and the established communication network are disconnected, the beam width is made wider than the re-acquisition mode for re-establishing the communication network with the other device, and the beam width of the transmission mode and the A mode manager that makes the beam width of the re-acquisition mode the same ,
A beam management unit that controls a directivity direction of a beam output by operating the plurality of antennas, and scans the beam in all directions at 360 degrees in the capture mode ;
The modulation / demodulation unit is an array antenna apparatus that modulates or demodulates a smaller amount of information in the acquisition mode than in the transmission mode and the re-acquisition mode. A plurality of antenna elements arranged two-dimensionally;
A plurality of transmitting and receiving units connected to each of the plurality of antenna elements, and transmitting and receiving signals to and from other devices via the antenna elements connected to each of the plurality of antenna elements;
A modem unit that modulates the transmission signal and demodulates the reception signal;
In the acquisition mode for establishing a communication network with the other device, transmission / reception of signals through a part of the plurality of antenna elements is stopped, and mutual positional information is obtained with the other device. The transmission mode beam width is made narrower than the acquisition mode beam width, and the transmission mode for transmitting and receiving information on the communication network established with the other device using the position information is established. A mode management unit that narrows the beam width of the re-acquisition mode for re-establishing the communication network with the other device when the communication network is disconnected;
The modulation / demodulation unit is an array antenna apparatus that modulates or demodulates a smaller amount of information in the acquisition mode than in the transmission mode and the re-acquisition mode . The modulation / demodulation unit modulates or demodulates the acquisition mode with a bandwidth limited as compared with the transmission mode.
The array antenna apparatus according to claim 1 or 2 . The modulation / demodulation unit modulates or demodulates in the acquisition mode using a spread spectrum modulation method so as to have the same bandwidth as the transmission mode.
The array antenna apparatus according to claim 1 or 2 . A system for communicating between a reference station device and a dependent station device while moving,
Each of the reference station apparatus and the dependent station apparatus,
A plurality of antenna elements arranged two-dimensionally;
A plurality of transmitting and receiving units connected to each of the plurality of antenna elements, and transmitting and receiving signals to and from other devices via the antenna elements connected to each of the plurality of antenna elements;
A modem unit that modulates the transmission signal and demodulates the reception signal;
In a capture mode for establishing a communication network with the other device, for stopping transmission / reception of signals through a part of the plurality of antenna elements, and for transmitting / receiving information on the established communication network When the transmission mode and the established communication network are disconnected, the beam width is made wider than the re-acquisition mode for re-establishing the communication network with the other device, and the beam width of the transmission mode and the A mode manager that makes the beam width of the re-acquisition mode the same ,
A beam management unit that controls a directivity direction of a beam output by operating the plurality of antennas, and scans the beam in all directions at 360 degrees in the capture mode ;
In the acquisition mode, the modulation / demodulation unit modulates or demodulates a smaller amount of information than in the transmission mode and the re-acquisition mode.   A system for communicating between a reference station device and a dependent station device while moving,
  Each of the reference station apparatus and the dependent station apparatus,
  A plurality of antenna elements arranged two-dimensionally;
  A plurality of transmitting and receiving units connected to each of the plurality of antenna elements, and transmitting and receiving signals to and from other devices via the antenna elements connected to each of the plurality of antenna elements;
  A modem unit that modulates the transmission signal and demodulates the reception signal;
  In the acquisition mode for establishing a communication network with the other device, transmission / reception of signals through a part of the plurality of antenna elements is stopped, and mutual positional information is obtained with the other device. The transmission mode beam width is narrower than the acquisition mode beam width, and the established communication network is disconnected. A mode management unit that narrows the beam width of the re-acquisition mode for re-establishing the communication network with the other device, than the beam width of the acquisition mode;
  The modulation / demodulation unit modulates or demodulates a smaller amount of information in the acquisition mode than in the transmission mode and the re-acquisition mode.
  Mobile station communication system.

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