Communication system, adjustment instruction device, antenna direction adjustment method, antenna direction adjustment instruction method and program

Abstract

To adjust a beam direction in a relatively short time.SOLUTION: A communication system comprises: a transmission antenna which comprises a plurality of pieces of transmission means for transmitting radio waves; transmission control means which inputs a signal having a phase for forming nulls through mutual cancellation of the radio waves from the plurality of pieces of transmission means to the plurality of transmission means to let the respective transmission means transmit the radio waves; a reception antenna which receives a composite wave of the radio waves from the plurality of transmission means; adjustment instruction means which determines a direction to which the beam direction of the transmission antenna should be changed based upon the phase of the reception signal; and direction adjustment means which changes the beam direction of the transmission antenna to the determined due direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a communication system, an adjustment instruction device, an antenna direction adjustment method, an antenna direction adjustment instruction method, and a program. [Background technology]

[0002] A technique has been proposed for adjusting the direction of a transmission wave depending on the state of a wireless communication path. For example, in the wireless communication system described in Patent Document 1, the transmitting wireless station changes the pilot signal and changes the beam direction according to the pilot signal. The receiving wireless station searches for a pilot signal with a high reception level. The transmitting wireless station then directs its antenna toward the receiving wireless station according to the pilot signal found by the receiving wireless station. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-347997 Summary of the Invention [Problem to be solved by the invention]

[0004] When adjusting the beam direction of a transmission wave in accordance with the state of a wireless communication path, it is preferable to be able to adjust the beam direction in as short a time as possible.

[0005] An example of an object of the present invention is to provide a communication system, an adjustment instruction device, an antenna direction adjustment method, an antenna direction adjustment instruction method, and a program that can solve the above-mentioned problems. [Means for solving the problem]

[0006] According to a first aspect of the present invention, a communication system comprises a transmitting antenna having a plurality of transmitting means for transmitting radio waves, a transmission control means for inputting signals to the plurality of transmitting means having phases that form nulls due to cancellation of radio waves from the plurality of transmitting means, thereby causing each transmitting means to transmit radio waves, a receiving antenna for receiving a composite wave of radio waves from the plurality of transmitting means, an adjustment instruction means for determining a direction in which the beam direction of the transmitting antenna should be changed based on the phase of the received signal, and a direction adjustment means for changing the beam direction of the transmitting antenna to the determined direction in which it should be changed.

[0007] According to a second aspect of the present invention, an adjustment instruction device includes an adjustment instruction means for determining a direction in which the beam direction of the transmitting antenna should be changed based on the phase of a received signal of a composite wave of radio waves having phases in which a null is formed due to cancellation of radio waves from multiple transmitting means included in the transmitting antenna.

[0008] According to a third aspect of the present invention, an antenna direction adjustment method includes inputting signals of phases that form nulls due to cancellation of radio waves from a plurality of transmitting means included in a transmitting antenna, causing each transmitting means to transmit radio waves, receiving a composite wave of the radio waves from the plurality of transmitting means at a receiving antenna, determining a direction in which the beam direction of the transmitting antenna should be changed based on the phase of the received signal, and changing the beam direction of the transmitting antenna to the determined direction in which the beam direction should be changed.

[0009] According to a fourth aspect of the present invention, an antenna direction adjustment instruction method includes determining a direction in which the beam direction of a transmitting antenna should be changed based on the phase of a received signal of a composite wave of radio waves from multiple transmitting means provided in the transmitting antenna, the composite wave having phases in which a null is formed due to cancellation of the radio waves.

[0010] According to a fifth aspect of the present invention, a program is provided for causing a computer to execute a process of determining a direction in which the beam direction of a transmitting antenna should be changed based on the phase of a received signal of a composite wave of radio waves having phases in which a null is formed due to cancellation of radio waves from a plurality of transmitting means provided in the transmitting antenna. [Effects of the Invention]

[0011] According to the present invention, the beam direction can be adjusted in a relatively short time. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a communication system according to a first embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of a first antenna according to the first embodiment. [Figure 3] 4 is a diagram showing an example of a composite wave when transmission waves from two transmission units according to the first embodiment are in phase. FIG. [Figure 4] 4A and 4B are diagrams illustrating an example of a composite wave when transmission waves from two transmission units according to the first embodiment are in opposite phases. [Figure 5] 10A and 10B are diagrams illustrating an example of the configuration of a transmission frame in a transmission signal generated by a first transmission control unit according to the first embodiment. [Figure 6] 10A and 10B are diagrams illustrating an example of the relationship between deviation of the beam direction of the first antenna and the received signal of the direction finding symbol at the second antenna according to the first embodiment. [Figure 7] FIG. 10 is a diagram illustrating an example of the configuration of a communication system according to a second embodiment. [Figure 8] 10 is a diagram illustrating an example of the configuration of a demodulation circuit and a symbol processing circuit according to a second embodiment. FIG. [Figure 9] FIG. 10 is a diagram illustrating an example of the configuration of a communication system according to a third embodiment. [Figure 10] FIG. 10 is a diagram illustrating an example of the configuration of a first antenna according to a third embodiment. [Figure 11]FIG. 11 is a diagram illustrating an example of the configuration of a transmission frame in a transmission signal generated by a first transmission control unit according to the third embodiment. [Figure 12] FIG. 10 is a diagram illustrating an example of the configuration of a communication system according to a fourth embodiment. [Figure 13] FIG. 13 is a diagram illustrating an example of the configuration of an adjustment instruction device according to a fifth embodiment. [Figure 14] FIG. 13 is a diagram illustrating an example of a processing procedure in an antenna direction adjustment method according to a sixth embodiment. [Figure 15] FIG. 13 is a diagram showing an example of a processing procedure in an antenna direction adjustment instruction method according to the seventh embodiment. [Figure 16] FIG. 1 is a schematic block diagram illustrating the configuration of a computer according to at least one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] The following describes embodiments of the present invention, but the following embodiments do not limit the scope of the invention as claimed. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0014] First Embodiment Fig. 1 is a diagram showing an example of the configuration of a communication system according to the first embodiment. In the configuration shown in Fig. 1, the communication system 1 includes a first communication system 100 and a second communication system 200. The first communication system 100 includes a first transmission control unit 110, a first antenna 120, a first reception processing unit 130, an adjustment instruction unit 140, and a direction adjustment unit 150. The first antenna 120 includes a plurality of transmitters 121. The second communication system 200 includes a second antenna 210, a second reception processing unit 220, a direction adjustment information generation unit 230, and a second transmission control unit 240.

[0015] 1 illustrates an example in which a communication system 1 transmits communication between a first upper layer 910 and a second upper layer 920. The first upper layer 910 may be any of various types that output data to the second upper layer 920. The second upper layer 920 may be any of various types that receive data from the first upper layer 910.

[0016] For example, the first upper layer 910 and the second upper layer 920 may each be configured to include an unspecified communication device such as a mobile phone or a landline phone. Alternatively, the first upper layer 910 and the second upper layer 920 may each be configured to include a data processing function by a specific device or a specific application program. The first upper layer 910 may be configured as a part of the first communication system 100. The second upper layer 920 may be configured as a part of the second communication system 200. Furthermore, each of the first upper layer 910 and the second upper layer 920 may include one or more units for inputting and outputting data, such as a device or an application program.

[0017] The first communication system 100 transmits the transmission data acquired from the first upper layer 910 to the second communication system 200. At that time, the first communication system 100 transmits the transmission signal including a signal for detecting a deviation in the beam direction (the direction of the peak in the directivity of the transmission wave). Furthermore, the first communication system 100 adjusts the beam direction based on the detection result of the deviation of the beam direction notified from the second communication system 200. The first communication system 100 adjusts the beam direction so that the beam direction of the transmission wave from the first communication system 100 faces the direction of the second communication system (particularly, the direction of the second antenna 210). The beam direction of an antenna or transmitter is also referred to as the direction of that antenna or transmitter.

[0018] Furthermore, the first communication system 100 restores the transmission data that the second communication system 200 acquires from the second upper layer 920 from the received signal from the second communication system 200. The first communication system outputs the received data restored from the transmission data from the second upper layer 920 to the first upper layer 910.

[0019] Here, in order for the first communication system 100 to perform good communication with the second communication system 200 with as little transmission power as possible, it is preferable that the beam direction of the transmission wave from the first communication system 100 is directed toward the second antenna 210 of the second communication system 200. On the other hand, even if the direction of the first antenna 120 is fixed, the beam direction may change due to changes in the state of the transmission path, such as atmospheric conditions. Changes in the beam direction during communication can cause fading.

[0020] Therefore, the first communication system 100 adjusts the beam direction as described above. In particular, the first communication system 100 periodically transmits a signal for detecting a deviation in the beam direction to the second communication system 200. Then, the first communication system 100 periodically acquires information indicating the detection result of the deviation in the beam direction from the second communication system 200, and periodically adjusts the beam direction.

[0021] In the first antenna 120, a plurality of transmitting units 121 are fixedly installed with respect to the main body of the first antenna 120. When the orientation of the main body of the first antenna 120 is changed, the beam direction of each transmitting unit 121 changes accordingly. When the beam direction of each transmitting unit 121 changes, the beam direction of the first antenna 120 changes accordingly. The beam direction of the first antenna 120 here refers to the beam direction of the transmission wave from the first antenna 120, which is a composite wave of the transmission waves from each transmitting unit 121.

[0022] The multiple transmitting units 121 are arranged with the beam direction slightly shifted so that the transmitted waves from the multiple transmitting units 121 form a composite wave and the reception level at the second antenna 210 differs depending on the amount of deviation of the direction of the second antenna 210 as seen from the first antenna 120 from the beam direction of the first antenna 120. The deviation of the direction of the second antenna as seen from the first antenna from the beam direction of the first antenna is also referred to as the deviation of the beam direction of the first antenna or the deviation of the direction of the first antenna.

[0023] In the following, an example will be described in which each of the transmitting units 121 is configured using a horn antenna (angle horn). However, the configuration of the first antenna 120 and the configuration of the transmitting unit 121 can be variously configured so as to be capable of forming peaks and nulls by the composite wave of the transmitted waves from each transmitting unit 121, and to be capable of adjusting the beam direction while maintaining the angle of deviation of the beam direction of each transmitting unit 121.

[0024] For example, when the distance between the first antenna 120 and the second antenna 210 is known, the multiple transmitters 121 may be arranged so that their beam directions are parallel, and may be arranged at intervals such that the reception level at the second antenna 210 varies depending on the magnitude of the deviation in the beam direction of the first antenna 120. In this case, the first communication system 100 or the second communication system 200 may calculate the magnitude of the deviation in the beam direction of the first antenna 120 based on the reception status of radio waves at the second antenna 210 and the distance between the first antenna 120 and the second antenna 210.

[0025] In the first and second embodiments, an example in which the first antenna has two transmitting units will be described, whereas in the third embodiment, an example in which the first antenna has three transmitting units will be described. Alternatively, the first antenna may include four or more first antennas. For example, the first antenna 120 may include a set of two transmitting units in each of the vertical and horizontal directions. The first communication system may then adjust the beam direction of the first antenna in each of the vertical and horizontal directions.

[0026] In the following, an example will be described in which the communication system 1 adjusts the beam direction of the first antenna 120. The first antenna 120 corresponds to an example of a transmitting antenna. The second antenna 210 corresponds to an example of a receiving antenna. The transmitter 121 corresponds to an example of a transmitting means. The communication system 1 may also adjust the beam direction of the second antenna 210 in the same manner as the first antenna 120. Alternatively, the communication system 1 may not have a mechanism for adjusting the beam direction of the second antenna 210, for example, when communication between the first upper layer 910 and the second upper layer 920 is only one-way communication from the first upper layer 910 to the second upper layer 920.

[0027] Fig. 2 is a diagram showing an example of the configuration of first antenna 120. In the configuration shown in Fig. 2, first antenna 120 includes two horn antennas, first horn 121a and second horn 121b. First horn 121a and second horn 121b each correspond to an example of transmitter 121. As described above for transmitter 121, first horn 121a and second horn 121b are arranged with their beam directions slightly offset from each other.

[0028] The direction in which first horn 121a and second horn 121b are arranged is not limited to a particular direction. For example, first horn 121a and second horn 121b may be arranged side by side in the vertical direction. Alternatively, first horn 121a and second horn 121b may be arranged side by side in the horizontal direction.

[0029] The first transmission control unit 110 acquires transmission data from the first upper layer 910 and generates a transmission signal for transmitting the transmission data for each of the two transmission units 121. The first transmission control unit 110 inputs the transmission signal to each of the two transmission units 121, causing them to transmit radio waves. When generating the transmission signals to be input to the two transmitters 121, the first transmission control unit 110 includes in the transmission signals a signal for detecting deviation in the beam direction of the first antenna. The first transmission control unit 110 is an example of a transmission control means.

[0030] Specifically, the first transmission control unit 110 includes in the transmission signal a signal of opposite phase so that a null is formed by the cancellation of radio waves from the two transmission units 121. Furthermore, for comparison with the case of a null, the first transmission control unit 110 includes in the transmission signal a signal of the same phase so that a peak is formed by the reinforcement of radio waves from the two transmission units 121.

[0031] Fig. 3 is a diagram showing an example of a composite wave when the transmitted waves from two transmitting units 121 are in phase. The vertical axis of the graph in Fig. 3 represents the angle of the radio wave transmission direction, and the horizontal axis represents the radio wave intensity. Line L111 represents the distribution of radio wave intensity of the transmission wave from first horn 121a. Line L112 represents the distribution of radio wave intensity of the transmission wave from second horn 121b. Line L121 represents the distribution of radio wave intensity of the composite wave of these two transmission waves.

[0032] When the transmission waves from the two transmitting units 121 (first horn 121a and second horn 121b) are in phase, the peak of the composite wave is formed midway between the beam directions of the two transmitting units 121 due to the in-phase synthesis of these two transmission waves. In particular, when two transmitters 121 transmit radio waves of the same intensity (same amplitude) in phase, a peak of the composite wave is formed in the direction of the center of the angle formed by the beam directions of the two transmitters 121. In the example of Fig. 3, a peak of the composite wave is formed in the direction of angle θ21, which is the direction of the center of angle 2Δθ formed by angle θ11 of the beam direction of first horn 121a and angle θ12 of the beam direction of second horn 121b.

[0033] Fig. 4 is a diagram showing an example of a composite wave when the transmitted waves from two transmitting units 121 are in opposite phases. The vertical axis of the graph in Fig. 4 represents the angle of the radio wave transmission direction, and the horizontal axis represents the radio wave intensity. Line L211 represents the distribution of radio wave intensity of the transmission wave from first horn 121a, line L212 represents the distribution of radio wave intensity of the transmission wave from second horn 121b, and line L221 represents the distribution of radio wave intensity of the composite wave of these two transmission waves.

[0034] When the transmission waves from the two transmitting units 121 (first horn 121a and second horn 121b) are out of phase, the out-of-phase synthesis of these two transmission waves forms a null of the synthesis wave midway between the beam directions of the two transmitting units 121. The null here means that the radio wave intensity is 0 or is very small compared to the radio wave intensity in other angular directions.

[0035] In particular, when two transmitters 121 transmit radio waves of the same intensity in opposite phases, a null of the composite wave is formed in the direction of the center of the angle formed by the beam directions of the two transmitters 121. In the example of Fig. 4, a null of the composite wave is formed in the direction of angle θ21, which is the direction of the center of angle 2Δθ formed by angle θ11 of the beam direction of first horn 121a and angle θ12 of the beam direction of second horn 121b.

[0036] Fig. 5 is a diagram showing an example of the configuration of a transmission frame in a transmission signal generated by first transmission control unit 110. In Fig. 5, each frame includes a frame symbol, a data symbol, and a direction detection symbol. A frame symbol is a symbol that indicates information about the frame, such as a frame header. The number of frame symbols included in one frame can be determined according to the frame standard. The position at which the frame symbol is inserted within the frame can also be determined according to the frame standard. First transmission control section 110 causes first horn 121a and second horn 121b to transmit radio waves of the same intensity with the frame symbol phases in the same phase, thereby forming a peak of the composite wave as in the example of FIG.

[0037] The data symbols are symbols that indicate actual data to be transmitted, that is, transmission data from the first higher layer 910. The number of data symbols included in one frame can be any number that can be selected according to the standard of that frame. First transmission control section 110 causes first horn 121a and second horn 121b to transmit radio waves of the same intensity with the same phase of the data symbols, thereby forming a peak of the composite wave as in the example of FIG.

[0038] Various modulation methods involving control of the phase of a transmission signal, such as Phase Shift Keying (PSK) or Quadrature Amplitude Modulation, can be used as a modulation method for transmitting transmission data from the communication system 1. Furthermore, as long as the communication system 1 has a function for controlling the phase of a transmission signal, a modulation method that does not involve control of the phase of a transmission signal can also be used as a modulation method for transmitting transmission data from the communication system 1.

[0039] The direction detection symbols are symbols for detecting deviations in the beam direction of the first antenna. First transmission control unit 110 includes anti-phase symbols and in-phase symbols in the transmission frame as direction detection symbols. The anti-phase symbols are symbols in anti-phase between first horn 121a and second horn 121b. The in-phase symbols are symbols in phase between first horn 121a and second horn 121b.

[0040] However, the method by which the first transmission control unit 110 includes the direction finding symbol in the transmission signal is not limited to a specific method. For example, the first transmission control unit 110 may include the direction finding symbol in every predetermined number of frames. Alternatively, when the frame length is long, the first transmission control unit 110 may include multiple direction finding symbols in one frame. By the first communication system 100 repeatedly transmitting the transmission wave of the direction finding symbol, it is possible to adjust the beam direction of the first antenna in response to changes in the state of the transmission path during communication between the first communication system 100 and the second communication system 200.

[0041] Furthermore, the position in the frame where the first transmission control unit 110 includes the direction detection symbol is not limited to a specific position, and can be any position that is allowed by the frame standard and that is commonly recognized by the first communication system 100 and the second communication system 200. From the viewpoint of comparing the received signal of the opposite phase symbol with the received signal of the same phase symbol to detect a deviation in the beam direction of the first antenna, it is preferable that the first transmission control unit 110 arranges the opposite phase symbol and the same phase symbol consecutively. The first transmission control unit 110 may arrange either the opposite phase symbol or the same phase symbol first. The timing when the first antenna 120 transmits the in-phase symbol corresponds to a first example of timing, and the timing when the first antenna 120 transmits the anti-phase symbol corresponds to a second example of timing.

[0042] Fig. 6 is a diagram showing an example of the relationship between the deviation of the beam direction of first antenna 120 and the received signal of the direction finding symbol at second antenna 210. Fig. 6 shows the distribution of the radio wave intensity of the composite wave of the transmitted wave from first horn 121a and the transmitted wave from second horn 121b, and the received level and phase of the received signal of the direction finding symbol.

[0043] The vertical axis of the graph showing the distribution of radio wave intensity of the composite wave of transmitted waves represents the angle of the radio wave transmission direction. The horizontal axis represents radio wave intensity. Line L121 represents the distribution of radio wave intensity of the composite wave of in-phase symbols. Line L122 represents the distribution of radio wave intensity of the composite wave of anti-phase symbols. In the example of Figure 6, when transmitting an opposite phase symbol, the first horn 121a transmits radio waves with the same phase as in the case of an in-phase symbol, and the second horn 121b transmits radio waves with the opposite phase to that in the case of an in-phase symbol.

[0044] The horizontal axis of the graph showing the reception level and phase of the received signal represents time, and the vertical axis represents the reception level, which is also referred to as the magnitude of the received signal. In Figure 6, the phase of the received signal is represented by the positive or negative sign of the received level. The sign of the received level when the phase is the same as the in-phase symbol is positive (+), and the sign of the received level when the phase is opposite to the in-phase symbol is negative (-).

[0045] Case 3 in Fig. 6 shows an example in which the direction of the second antenna 210 as seen from the first antenna 120 coincides with the beam direction of the first antenna 120. In this case, the composite wave of the opposite phase symbols forms a null at the position of the second antenna 210. As a result, the reception level of the received signal becomes 0 or almost 0, as shown in Fig. 6. In this way, when the received signal of the composite wave of the opposite phase symbol is null, it can be detected that the direction of the second antenna 210 as seen from the first antenna 120 matches the beam direction of the first antenna 120.

[0046] Case 2 shows an example in which the direction of second antenna 210 as seen from first antenna 120 is shifted toward first horn 121a with respect to the beam direction of first antenna 120. In this case, as shown in Fig. 6, the phase of the received signal of the composite wave of the opposite phase symbol is the same as the phase of the received signal of the composite wave of the in-phase symbol.

[0047] Case 4 shows an example in which the direction of second antenna 210 as seen from first antenna 120 is shifted toward second horn 121b with respect to the beam direction of first antenna 120. In this case, as shown in Fig. 6, the phase of the received signal of the composite wave of the opposite phase symbol is opposite to the phase of the received signal of the composite wave of the in-phase symbol.

[0048] In this way, by detecting the phase of the received signal of the composite wave of the opposite phase symbol, it is possible to detect whether the direction of the second antenna 210 as seen from the first antenna 120 is shifted toward the first horn 121a or the second horn 121b from the beam direction of the first antenna 120.

[0049] Case 1 shows an example in which the direction of second antenna 210 as seen from first antenna 120 is further shifted toward first horn 121a than the beam direction of first antenna 120 compared to Case 2. In this case, as shown in Fig. 6, the received signal of the composite wave of the opposite phase symbol has the same phase as the received signal of the composite wave of the in-phase symbol, and the received level is higher than in Case 2.

[0050] Case 5 shows an example in which the direction of second antenna 210 as seen from first antenna 120 is further deviated from the beam direction of first antenna 120 toward second horn 121b than in case 4. In this case, as shown in Fig. 6, the received signal of the composite wave of the antiphase symbol has the opposite phase to the received signal of the composite wave of the inphase symbol, and the absolute value of the received level is greater than in case 4.

[0051] In this way, by detecting the reception level of the composite wave of the opposite phase symbols, the magnitude of the deviation in the beam direction of the first antenna 120 can be detected. However, the reception level varies not only depending on the amount of deviation of the direction of the second antenna 210 as seen from the first antenna 120 from the beam direction of the first antenna 120, but also on the state of the transmission path.

[0052] On the other hand, the composite wave of the in-phase symbols is also affected by the transmission path in the same way as the composite wave of the opposite-phase symbols. As a result, the ratio of the reception level of the composite wave of the opposite-phase symbols to the reception level of the composite wave of the in-phase symbols is a constant value that corresponds to the magnitude of the deviation in the beam direction of the first antenna 120, regardless of the state of the transmission path.

[0053] Therefore, the second communication system 200 detects (e.g., calculates) the magnitude of the deviation in the beam direction of the first antenna 120 based on the relative magnitude of the reception level of the composite wave of the opposite phase symbols to the reception level of the composite wave of the in-phase symbols. This allows the second communication system 200 to detect the magnitude of the deviation in the beam direction of the first antenna 120 with higher accuracy than when detecting the magnitude of the deviation based only on the reception level of the composite wave of the opposite phase symbols.

[0054] Furthermore, the second communication system 200 compares the phase of the received signal of the composite wave of the opposite phase symbol with the phase of the received signal of the composite wave of the same phase symbol to detect the direction of deviation of the beam direction of the first antenna 120. This allows the second communication system 200 to detect the direction of deviation of the beam direction of the first antenna 120 with high accuracy even when the phase of the transmitted symbol is inverted on the transmission path.

[0055] As described above, the first antenna 120 transmits the transmission signal generated by the first transmission control unit 110 for each transmission unit 121 from each of the transmission units 121. The first antenna 120 also receives radio waves from the second communication system 200 and outputs the received signal to the first reception processing unit 130.

[0056] The first reception processing unit 130 processes the received signal from the second communication system 200. Specifically, the first reception processing unit 130 generates received data by restoring the transmission data from the second higher layer from the received signal from the second communication system 200, and outputs the received data to the first higher layer 910. The first reception processing unit 130 also extracts direction adjustment information from the received signal from the second communication system 200, which the second communication system 200 will include in the transmission signal and transmit, and outputs the information to the adjustment instruction unit 140. The direction adjustment information here is, for example, information indicating the direction and magnitude of deviation of the beam direction of the first antenna 120, which is detected by the second communication system 200 based on the received signal of the direction detection symbol as in the example of FIG.

[0057] The adjustment instruction unit 140 calculates a control amount for adjusting the beam direction of the first antenna 120, and outputs a control command to the direction adjustment unit 150. The direction adjustment unit 150 changes the beam direction of the first antenna 120 based on the control command from the adjustment instruction unit 140. For example, the adjustment instruction unit 140 calculates the direction and angle by which to change the orientation of the main body of the first antenna 120 in order to eliminate the deviation in the beam direction of the first antenna 120 indicated in the direction adjustment information. The direction adjustment unit 150 drives a motor for adjusting the orientation of the main body of the first antenna 120, and changes the orientation of the main body of the first antenna 120 by the direction and angle calculated by the adjustment instruction unit 140. The adjustment instruction unit 140 corresponds to an example of an adjustment instruction means. The direction adjustment unit 150 corresponds to an example of a direction adjustment means. The first communication system 100 corresponds to an example of an adjustment instruction device in that it includes the adjustment instruction unit 140.

[0058] The second communication system 200 generates received data by restoring the transmission data from the first upper layer 910 from the received signal from the first communication system 100 , and outputs the data to the second upper layer 920 . 6, the second communication system 200 detects a deviation in the beam direction of the first antenna 120 based on the direction detection symbol included in the received signal from the first communication system 100, and generates direction adjustment information. The second communication system 200 transmits the generated direction adjustment information to the first communication system 100. The second communication system 200 transmits the transmission data acquired from the second higher layer 920 to the first communication system 100. At this time, the second communication system 200 transmits the direction adjustment information included in the transmission signal.

[0059] The second antenna 210 receives radio waves from the first communication system 100 and outputs the received signal to the second reception processing unit 220. The second antenna 210 also transmits a transmission signal generated by the second transmission control unit 240.

[0060] The second reception processing unit 220 processes the received signal from the first communication system 100. Specifically, the second reception processing unit 220 generates received data by restoring the transmission data from the first higher layer from the received signal from the first communication system 100, and outputs the received data to the second higher layer 920. The second reception processing unit 220 also extracts, from the received signal from the first communication system 100, the direction detection symbol that the first communication system 100 includes in the transmission signal and transmits, and outputs the extracted symbol to the direction adjustment information generation unit 230.

[0061] 6, the direction adjustment information generator 230 detects a deviation in the beam direction of the first antenna 120 based on the direction detection symbol included in the received signal from the first communication system 100, and generates direction adjustment information. The direction adjustment information generator 230 outputs the generated direction adjustment information to the second transmission control unit 240.

[0062] The second transmission control unit 240 acquires transmission data from the second upper layer 920 and generates a transmission signal for transmitting the transmission data. When generating the transmission signal, the second transmission control unit 240 includes direction adjustment information in the transmission signal. The second transmission control unit 240 inputs the transmission signal to the second antenna 210 to cause it to transmit radio waves.

[0063] The configuration of the communication system 1 is not limited to that shown in Fig. 1. For example, either or both of the first communication system 100 and the second communication system 200 may include a receiving antenna in addition to a transmitting antenna. Furthermore, the communication system 1 may also adjust the beam direction of the transmitting antenna (for example, the second antenna 210) of the second communication system 200 in the same manner as in the case of the first antenna 120.

[0064] Furthermore, the communication between the first upper layer 910 and the second upper layer 920 may be unidirectional communication from the first upper layer 910 to the second upper layer 920. In this case, the second communication system 200 may transmit only direction adjustment information to the first communication system 100. Furthermore, the adjustment instruction unit 140 may be located outside the first communication system 100. For example, the direction adjustment information generation unit 230 may also perform the function of the adjustment instruction unit 140. In that case, the second communication system 200 may transmit, as direction adjustment information, information indicating the direction in which the beam direction of the first antenna 120 should be changed and the amount of change to the first communication system 100.

[0065] Alternatively, the first transmission control unit 110 may include only opposite phase symbols in the direction detection symbols, without including in-phase symbols. In this case, the direction adjustment information generation unit 230 may generate direction adjustment information indicating only the direction of deviation of the beam direction of the first antenna 120, based on the phase of the received signal of the composite wave of the opposite phase symbols. Then, the direction adjustment unit 150 may change the beam direction of the first antenna 120 by a predetermined angle in a direction that eliminates the deviation indicated in the direction adjustment information.

[0066] For example, if it is known in advance whether or not the phase of the transmitted symbol is inverted in the transmission path, it is expected that the direction adjustment information generating unit 230 can detect the direction of deviation of the beam direction of the first antenna 120 with high accuracy without having to compare the phase of the received signal of the composite wave of the opposite phase symbol with the phase of the received signal of the composite wave of the same phase symbol.

[0067] The direction adjustment information generating unit 230 may detect the magnitude of deviation in the beam direction of the first antenna 120 based on the reception level of the composite wave of the opposite phase symbol without comparing it with the reception level of the composite wave of the in-phase symbol, and include the magnitude in the direction adjustment information. When the reception level according to the deviation of the beam direction of the first antenna 120 is approximately constant, such as when the attenuation rate in the transmission path is approximately constant, it is expected that the direction adjustment information generation unit 230 can detect the magnitude of the deviation of the beam direction of the first antenna 120 with high accuracy without having to compare the reception level of the composite wave of the opposite phase symbol with the reception level of the composite wave of the opposite phase symbol.

[0068] As described above, the first antenna 120 includes a plurality of transmitters 121 that transmit radio waves. The first transmission control unit 110 inputs signals of phases that form nulls due to cancellation of radio waves from the plurality of transmitters 121 to the plurality of transmitters 121, and causes each transmitter 121 to transmit radio waves. The second antenna 210 receives a composite wave of radio waves from the plurality of transmitters 121. The adjustment instruction unit 140 determines a direction in which the beam direction of the first antenna 120 should be changed, based on the phase of the signal received by the second antenna 210. The direction adjustment unit 150 changes the beam direction of the first antenna 120 to the determined direction in which the beam direction should be changed.

[0069] This allows the communication system 1 to detect, without trial and error, the direction in which the beam direction of the first antenna 120 should be changed. In this respect, the communication system 1 can adjust the beam direction in a relatively short time. Furthermore, in the communication system 1, the beam direction of the first antenna 120 can be directed toward the second antenna 210 as seen from the first antenna 120, so there is no need to increase the size of the antenna or the transmission power output in anticipation of fluctuations in the reception input level due to changes in the beam direction caused by changes in the transmission path. In this respect, the communication system 1 can be made smaller.

[0070] Here, as a comparison with the beam direction adjustment by communication system 1, consider a case where a communication system changes the beam direction of a transmitting antenna by trial and error to determine the direction to which the beam direction of the transmitting antenna should be changed. Specifically, the communication system tentatively changes the beam direction of the transmitting antenna and measures the reception level. If the reception level increases, the communication system determines that the direction to which the beam direction of the transmitting antenna was tentatively changed is the direction to which the beam direction of the transmitting antenna should be changed. On the other hand, if the reception level decreases, the communication system determines that the direction opposite to the direction to which the beam direction of the transmitting antenna was tentatively changed is the direction opposite to the direction to which the beam direction of the transmitting antenna should be changed.

[0071] When the reception level decreases, the communication system first changes the beam direction of the transmitting antenna in the opposite direction to the direction it should be changed to, and then changes it back to the direction it should be changed to. Therefore, compared to changing the beam direction of the transmitting antenna in the desired direction from the beginning, it takes extra time to change the beam direction of the transmitting antenna in the opposite direction to the direction it should be changed to, and to return the changed beam direction to the original direction.

[0072] Furthermore, when a communication system uses the reception level as an index for determining the appropriate beam direction, it is difficult to distinguish between a change in reception level due to a change in beam direction and a change in reception level due to the effects of fading, which may result in a decrease in the accuracy of detecting the appropriate beam direction. Furthermore, if the communication system continues to transmit transmission data, which is the actual data to be communicated, until it adjusts the beam direction of the transmitting antenna to the appropriate direction, changing the beam direction of the transmitting antenna in the opposite direction to the direction it should be changed will result in a decrease in the reception level of the transmission data.

[0073] In contrast, in the communication system 1, the direction in which the beam direction of the first antenna 120 should be changed can be detected without the need for trial and error, and it is possible to avoid changing the beam direction of the first antenna 120 in the opposite direction to the direction in which it should be changed. In this respect, the communication system 1 can adjust the beam direction in a relatively short time.

[0074] Furthermore, the communication system 1 detects the direction in which the beam direction of the first antenna 120 should be changed based on the phase of the received signal of the composite wave of the opposite phase symbols. In this respect, the communication system 1 can detect the direction in which the beam direction of the first antenna 120 should be changed with high accuracy even when the reception level changes due to the influence of fading. Furthermore, in the communication system 1, it is possible to avoid changing the beam direction of the first antenna 120 in the opposite direction to the direction in which it should be changed, and thus it is possible to avoid a decrease in the reception level of the transmitted data even until the beam direction of the first antenna 120 is adjusted to the appropriate direction.

[0075] Furthermore, the adjustment instruction unit 140 determines the amount by which the beam direction of the first antenna 120 should be changed based on the reception level of the composite wave of the opposite phase symbols. According to the communication system 1, it is possible to detect not only the direction in which the beam direction of the first antenna 120 should be changed, but also the amount of change without the need for trial and error. In this respect, the communication system 1 also allows the beam direction to be adjusted in a short time.

[0076] Furthermore, at a first timing, the first transmission control unit 110 inputs signals of the same phase so that a peak is formed by the reinforcement of radio waves from the multiple transmitters 121, and causes each transmitter 121 to transmit radio waves. At a second timing, the first transmission control unit 110 inputs signals of a phase so that a null is formed by the cancellation of radio waves from the multiple transmitters 121, and causes each transmitter 121 to transmit radio waves. The adjustment instruction unit 140 determines the direction in which the beam direction of the first antenna 120 should be changed, based on a comparison between the phase of the received signal of the composite wave at the first timing and the phase of the received signal of the composite wave at the second timing. The phase of the received signal of the composite wave of the in-phase symbol corresponds to an example of the phase of the received signal of the composite wave at the first timing, and the phase of the received signal of the composite wave of the anti-phase symbol corresponds to an example of the phase of the received signal of the composite wave at the second timing.

[0077] In the communication system 1, the phase of the received signal of the composite wave at the second timing is compared with the phase of the received signal of the composite wave at the first timing, thereby detecting the direction of deviation of the beam direction of the first antenna 120. As a result, in the communication system 1, even when the phase of the transmission symbol is inverted on the transmission path, the direction of deviation of the beam direction of the first antenna 120 can be detected with high accuracy.

[0078] Furthermore, the adjustment instruction unit 140 determines the amount by which the beam direction of the first antenna 120 should be changed based on a comparison between the reception level of the composite wave at the first timing and the reception level of the composite wave at the second timing. As a result, it is expected that the communication system 1 will be able to determine the amount by which the beam direction of the first antenna 120 should be changed with higher accuracy than if the amount by which the beam direction of the first antenna 120 should be changed were determined based only on the reception level of the composite wave at the second timing.

[0079] Second Embodiment In the second embodiment, a more specific example of the configuration of the communication system according to the first embodiment will be described. FIG. 7 is a diagram illustrating an example of the configuration of a communication system according to the second embodiment. In the configuration illustrated in FIG. 7, the communication system 3 includes a first communication system 300 and a second communication system 400. The first communication system 300 includes symbol information insertion circuits 311a and 311b, modulation circuits 312a and 312b, a first antenna 320, a demodulation circuit 331, a direction adjustment information extraction circuit 332, a direction adjustment instruction circuit 340, and a direction adjustment mechanism 350. The first antenna 320 includes two horn antennas, a first horn 321a and a second horn 321b. The second communication system 400 includes a second antenna 410, a demodulation circuit 421, a symbol processing circuit 422, a direction deviation determination circuit 430, a direction adjustment information insertion circuit 441, and a modulation circuit 442.

[0080] First antenna 320 is an example of first antenna 120. First antenna 320 includes two transmitting units, first horn 321a and second horn 321b. First horn 321a is similar to first horn 121a. Second horn 321b is similar to second horn 121b. First horn 321a and second horn 321b are collectively referred to as horn 321. Horn 321 is an example of transmission unit 121.

[0081] The combination of the symbol information insertion circuits 311a and 311b and the modulation circuits 312a and 312b corresponds to an example of the first transmission control unit 110. The combination of symbol information insertion circuit 311a and modulation circuit 312a enables first transmission control unit 110 to generate a transmission signal for first horn 121a and cause first horn 121a to transmit radio waves. Symbol information insertion circuit 311a generates a transmission frame similar to the transmission frame for first horn 121a illustrated in FIG. 5. Modulation circuit 312a generates a transmission signal by modulating a carrier wave in accordance with the transmission frame generated by symbol information insertion circuit 311a. Modulation circuit 312a outputs the generated transmission signal to first horn 121a, causing first horn 121a to transmit radio waves.

[0082] The combination of symbol information insertion circuit 311b and modulation circuit 312b performs the function of first transmission control unit 110 generating a transmission signal for second horn 121b and causing second horn 121b to transmit radio waves. Symbol information insertion circuit 311b generates a transmission frame similar to the transmission frame for second horn 121b illustrated in FIG. 5. Modulation circuit 312b generates a transmission signal by modulating a carrier wave in accordance with the transmission frame generated by symbol information insertion circuit 311b. Modulation circuit 312b outputs the generated transmission signal to second horn 121b, causing second horn 121b to transmit radio waves. The symbol information insertion circuits 311a and 311b are also collectively referred to as symbol information insertion circuits 311. The modulation circuits 312a and 312b are also collectively referred to as modulation circuits 312.

[0083] The combination of the demodulation circuit 331 and the direction adjustment information extraction circuit 332 corresponds to an example of the first reception processing unit 130. The demodulation circuit 331 demodulates the received signal of the first antenna 320 and generates received symbols by restoring the transmitted symbols from the second communication system 400. The demodulation circuit 331 outputs the generated received symbols to the direction adjustment information extraction circuit 332.

[0084] The direction adjustment information extraction circuit 332 extracts and demaps data symbols representing actual data to be transmitted from the received symbols generated by the demodulation circuit 331, and generates received data in the form of a bit string by restoring the transmission data from the second higher layer 920. The direction adjustment information extraction circuit 332 outputs the generated received data to the first higher layer 910. Furthermore, the direction adjustment information extraction circuit 332 extracts and demaps symbols representing direction adjustment information from the received symbols generated by the demodulation circuit 331, and restores the direction adjustment information in the form of a bit string. The direction adjustment information extraction circuit 332 outputs the restored direction adjustment information to the direction adjustment instruction circuit 340. The direction adjustment instruction circuit 340 is similar to the adjustment instruction unit 140. The direction adjustment mechanism 350 is similar to the direction adjustment unit 150.

[0085] The second antenna 410 is similar to the second antenna 210 . The combination of the demodulation circuit 421 and the symbol processing circuit 422 corresponds to an example of the second reception processing unit 220. The demodulation circuit 421 demodulates the received signal from the second antenna 410 and generates received symbols by restoring the transmitted symbols from the first communication system 300. The demodulation circuit 421 outputs the generated received symbols to the symbol processing circuit 422.

[0086] The symbol processing circuit 422 extracts and demaps data symbols representing actual data to be transmitted from the received symbols generated by the demodulation circuit 421, and generates received data in the form of a bit string by restoring the transmission data from the first higher layer 910. The symbol processing circuit 422 outputs the generated received data to the second higher layer 920. Furthermore, the symbol processing circuit 422 extracts direction detection symbols from the received symbols generated by the demodulation circuit 421 , and outputs the extracted direction detection symbols to the direction deviation determination circuit 430 .

[0087] The direction deviation determination circuit 430 is similar to the direction adjustment information generation unit 230 when generating information indicating the deviation of the beam direction of the first antenna 120 as the direction adjustment information. The combination of the direction adjustment information insertion circuit 441 and the modulation circuit 442 corresponds to an example of the second transmission control unit 240. The combination of the direction adjustment information insertion circuit 441 and the modulation circuit 442 executes the function of the second transmission control unit 240.

[0088] 8 is a diagram showing an example of the configuration of the demodulation circuit 421 and the symbol processing circuit 422. In the configuration shown in FIG. 8, a combination of an analog-to-digital converter (ADC) 421-1, an adaptive matched filter (AMF) 421-2, an auto gain control (AGC) 421-3, an equalizer 421-4, and a deframer 421-5 corresponds to an example of the demodulation circuit 421. A combination of a symbol information extraction circuit 422-1 and a demapper (Modulation Symbol Demapper) 422-2 corresponds to an example of the symbol processing circuit 422.

[0089] The analog-to-digital converter 421-1 converts the waveform data of the signal received by the second antenna 410 from analog data to digital data. Adaptive matched filter 421-2 performs processing such as clock recovery, carrier recovery, and multipath delay correction on the waveform data of the received signal to achieve symbol synchronization of the received symbols.

[0090] The automatic gain control 421-3 adjusts the gain of the received signal. The equalizer 421-4 equalizes the frequency of the received signal. The amplitude of the direction finding symbols included in the received symbols changes as a result of the correction of the received signals by auto gain control 421-3 and equalizer 421-4. Here, auto gain control 421-3 and equalizer 421-4 correct the received signals with a time constant larger than the symbol unit, so that the amplitude of the antiphase symbol and the amplitude of the in-phase symbol change by the same ratio. As a result, the direction finding symbols can retain information about the ratio between the reception level of the composite wave of the antiphase symbol and the reception level of the composite wave of the in-phase symbol, even after correction by auto gain control 421-3 and equalizer 421-4. Deframer 421-5 unwinds the received frame, allowing the received symbols to be extracted.

[0091] The symbol information extraction circuit 422-1 extracts direction detection symbols from the received symbols and outputs them to the direction deviation determination circuit 430. As described above, the direction deviation determination circuit 430 determines the direction and magnitude of deviation in the beam direction of the first antenna 320 based on the ratio of the reception levels of the opposite-phase symbols and the same-phase symbols included in the direction detection symbols, and based on a comparison of the phases indicated by the positive and negative of these reception levels. The direction deviation determination circuit 430 outputs direction adjustment information indicating the determination result to the direction adjustment information insertion circuit 441.

[0092] The demapper 422-2 demaps the data symbols from the remaining received symbols from which the symbol information extraction circuit 422-1 extracted the direction detection symbols. As a result, the demapper 422-2 generates received data in the form of a bit string, which is the restored transmission data from the first upper layer 910, which is the actual data to be transmitted. The demapper 422-2 outputs the generated received data to the second upper layer 920.

[0093] Third Embodiment In the third embodiment, an example will be described in which the first antenna includes three transmitting units. Fig. 9 is a diagram showing an example of the configuration of a communication system according to the third embodiment. In the configuration shown in Fig. 9, the communication system 3 includes a first communication system 500 and a second communication system 600. The first communication system 500 includes a first transmission control unit 510, a first antenna 520, a first reception processing unit 530, an adjustment instruction unit 540, and a direction adjustment unit 550. The first antenna 520 includes three transmitters 521. The second communication system 600 includes a second antenna 610, a second reception processing unit 620, a direction adjustment information generation unit 230, and a second transmission control unit 240.

[0094] The communication system 3 transmits direction finding symbols using three transmitters 521 included in the first antenna 520. The communication system 3 detects a deviation in the beam direction of the first antenna 520 in two dimensions based on a received signal of a composite wave of transmitted waves from each transmitter 521 of the direction finding symbols, and determines a direction in two-dimensional coordinates as a direction in which the beam direction of the first antenna 520 should be changed. In other respects, the communication system 3 is similar to the communication system 1.

[0095] Fig. 10 is a diagram showing an example of the configuration of the first antenna 520. Fig. 10 shows an example of the first antenna 520 when viewed from the front. 10, first antenna 520 includes three horn antennas, namely, first horn 521a, second horn 521b, and third horn 521c, which correspond to three examples of transmitting units 521. These three horn antennas are arranged so that the centers of the horn antennas are located at the vertices of an equilateral triangle whose center is point P101, which is the center of first antenna 520.

[0096] The beam direction of each horn antenna is offset by the same angle outward from the center of first antenna 520. These horn antennas are arranged with their beam directions slightly offset so that the transmitted waves from these horn antennas form a composite wave and the reception level at second antenna 610 varies depending on the amount of deviation of the direction of second antenna 610 as seen from first antenna 520 from the beam direction of first antenna 520.

[0097] FIG. 11 is a diagram showing an example of the configuration of a transmission frame in a transmission signal generated by first transmission control unit 510. As shown in FIG. 11, first transmission control unit 510 generates transmission frames for first horn 521a, second horn 521b, and third horn 521c, respectively. Depending on the arrangement of first horn 521a, second horn 521b, and third horn 521c shown in FIG. 10, the phases of the null-forming symbols corresponding to the antiphase symbols are shifted by 120 degrees. In other respects, the transmission frame generated by the first transmission control unit 510 is similar to the transmission frame generated by the first transmission control unit 110 illustrated in FIG.

[0098] 11, in the received signal received by the second antenna 610 from the composite wave of the null forming symbols, the phase of the null forming symbols indicates a phase angle corresponding to the direction of deviation of the direction of the second antenna 610 as seen from the first antenna 520 from the beam direction of the first antenna 520. From this phase angle, the direction adjustment information generator 630 can detect the deviation of the beam direction of the first antenna 520 in two dimensions.

[0099] The direction adjustment information generating unit 630 may generate direction adjustment information indicating the amount of deviation in the vertical and horizontal directions of the beam direction of the first antenna 520. Alternatively, the direction adjustment information generating unit 630 may generate direction adjustment information indicating the direction and amount of deviation of the beam direction of the first antenna 520 in polar coordinates.

[0100] The direction adjustment information generating unit 630 generates direction adjustment information that indicates the deviation of the beam direction of the first antenna 520 in two dimensions, and the adjustment instruction unit 540 can indicate the amount of change in the beam direction of the first antenna 520 in each of the vertical and horizontal directions, and instruct the direction adjustment unit 550 to change the beam direction of the first antenna 520. The direction adjustment unit 550 adjusts the beam direction of the first antenna 520 in both the vertical and horizontal directions in accordance with an instruction from the adjustment instruction unit 540 .

[0101] As described above, first antenna 520 includes three or more transmitters that are arranged so that the transmission direction (beam direction) of radio waves from at least one transmitter 521 is not included in a plane that includes the transmission directions of radio waves from the other two transmitters 521. Based on the phase of the signal received at second antenna 610, adjustment instruction unit 540 determines a direction in two-dimensional coordinates as a direction in which the beam direction of first antenna 520 should be changed. According to the communication system 3, the beam direction of the first antenna 520 can be adjusted in both the vertical and horizontal directions.

[0102] <Fourth embodiment> Fig. 12 is a diagram showing an example of the configuration of a communication system according to the fourth embodiment. In the configuration shown in Fig. 12, a communication system 710 includes a transmission control unit 711, a transmitting antenna 712, a receiving antenna 714, an adjustment instruction unit 715, and a direction adjustment unit 716. The transmitting antenna 712 includes a plurality of transmitters 713.

[0103] With this configuration, the transmission control unit 711 inputs signals of phases that form nulls due to the cancellation of radio waves from the multiple transmission units 713 to the multiple transmission units 713, and causes each transmission unit 713 to transmit radio waves. The receiving antenna 714 receives a composite wave of the radio waves from the multiple transmission units 713. The adjustment instruction unit 715 determines the direction in which the beam direction of the transmitting antenna 712 should be changed, based on the phase of the signal received by the receiving antenna 714. The direction adjustment unit 716 changes the beam direction of the transmitting antenna 712 in the determined direction in which it should be changed. The transmission control unit 711 corresponds to an example of a transmission control means. The transmission unit 713 corresponds to an example of a transmission means. The adjustment instruction unit 715 corresponds to an example of an adjustment instruction means. The direction adjustment unit 716 corresponds to an example of a direction adjustment means.

[0104] This allows the communication system 710 to detect the direction in which the beam direction of the transmitting antenna 712 should be changed without the need for trial and error. In this respect, the communication system 710 can adjust the beam direction of the transmitting antenna 712 in a relatively short time. In particular, the communication system 710 can avoid changing the beam direction of the transmitting antenna 712 in the opposite direction to the direction in which it should be changed by trial and error, thereby allowing the beam direction to be adjusted in a relatively short time.

[0105] Furthermore, in the communication system 710, the beam direction of the transmitting antenna 712 can be directed in the direction of the receiving antenna 714 as seen from the transmitting antenna 712, so there is no need to increase the size of the antenna or the transmission power output in anticipation of fluctuations in the reception input level due to changes in the beam direction caused by changes in the transmission path. In this respect, the communication system 710 can be made smaller.

[0106] Furthermore, in the communication system 710, the direction in which the beam direction of the transmitting antenna 712 should be changed is determined based on the phase of the received signal of the receiving antenna 714, so that even when the reception level changes due to the effects of fading, the direction in which the beam direction of the transmitting antenna 712 should be changed can be determined with high accuracy. Furthermore, in the communication system 710, it is possible to avoid changing the beam direction of the transmitting antenna 712 in the opposite direction to the direction in which it should be changed, and thus it is possible to avoid a decrease in the reception level of the transmitted data even until the beam direction of the transmitting antenna 712 is adjusted to the appropriate direction.

[0107] Fifth Embodiment 13 is a diagram showing an example of the configuration of an adjustment instruction device according to the fifth embodiment. In the configuration shown in FIG. In this configuration, the adjustment instruction unit 721 determines the direction in which the beam direction of the transmitting antenna should be changed based on the phase of the received signal of the composite wave of radio waves having phases in which a null is formed due to the cancellation of radio waves from the multiple transmitting means equipped in the transmitting antenna. The adjustment instruction unit 721 corresponds to an example of an adjustment instruction means.

[0108] The adjustment instruction device 720 can detect the direction in which the beam direction of the transmitting antenna should be changed without the need for trial and error. In this respect, the adjustment instruction device 720 can adjust the beam direction of the transmitting antenna in a relatively short time. In particular, the adjustment instruction device 720 can avoid changing the beam direction of the transmitting antenna in the opposite direction to the direction in which it should be changed by trial and error, so the beam direction can be adjusted in a relatively short time.

[0109] Furthermore, since the adjustment instruction device 720 can orient the beam direction of the transmitting antenna to the direction of the receiving antenna as seen from the transmitting antenna, it is not necessary to increase the size of the antenna or the transmission power output in anticipation of fluctuations in the receiving input level due to changes in the beam direction caused by changes in the transmission path, and therefore the adjustment instruction device 720 makes it possible to reduce the size of the communication system.

[0110] Furthermore, the adjustment instruction device 720 determines the direction in which the beam direction of the transmitting antenna should be changed based on the phase of the signal received by the receiving antenna, and therefore can determine the direction in which the beam direction of the transmitting antenna should be changed with high accuracy even when the reception level changes due to the effects of fading. Furthermore, the adjustment instruction device 720 can avoid changing the beam direction of the transmitting antenna in the opposite direction to the direction in which it should be changed, thereby preventing a decrease in the reception level of the transmitted data until the beam direction of the transmitting antenna is adjusted to the appropriate direction.

[0111] Sixth Embodiment Fig. 14 is a diagram showing an example of a processing procedure in the antenna direction adjustment method according to the sixth embodiment. The antenna direction adjustment method shown in Fig. 14 includes performing a transmission process (step S711), performing a reception process (step S712), determining a direction (step S713), and adjusting the antenna direction (step S714).

[0112] In performing the transmission process (step S711), signals of a phase that forms a null due to cancellation of radio waves from the multiple transmission means provided in the transmission antenna are input to the multiple transmission means, and radio waves are transmitted from each transmission means. In performing the receiving process (step S712), a composite wave of radio waves from a plurality of transmitting means is received by a receiving antenna. In determining the direction (step S713), the direction in which the beam direction of the transmitting antenna should be changed is determined based on the phase of the received signal. In adjusting the antenna direction (step S714), the beam direction of the transmitting antenna is changed in the determined direction to be changed.

[0113] According to the antenna direction adjustment method shown in Fig. 14, the direction in which the beam direction of the transmitting antenna should be changed can be detected without the need for trial and error. In this respect, according to the antenna direction adjustment method shown in Fig. 14, the beam direction of the transmitting antenna can be adjusted in a relatively short time. In particular, according to the antenna direction adjustment method shown in Fig. 14, the beam direction can be adjusted in a relatively short time by avoiding changing the beam direction of the transmitting antenna in the opposite direction to the direction in which it should be changed by trial and error.

[0114] Furthermore, with the antenna direction adjustment method shown in Fig. 14, the beam direction of the transmitting antenna can be directed in the direction of the receiving antenna as seen from the transmitting antenna, eliminating the need to increase the antenna size and transmission power output in anticipation of fluctuations in the received input level due to changes in the beam direction caused by changes in the transmission path. In this respect, the antenna direction adjustment method shown in Fig. 14 makes it possible to reduce the size of the communication system.

[0115] Furthermore, according to the antenna direction adjustment method shown in FIG. 14, the direction in which the beam direction of the transmitting antenna should be changed is determined based on the phase of the signal received by the receiving antenna, so that even when the reception level changes due to the effects of fading, the direction in which the beam direction of the transmitting antenna should be changed can be determined with high accuracy. Furthermore, according to the antenna direction adjustment method shown in FIG. 14, it is possible to avoid changing the beam direction of the transmitting antenna in the direction opposite to the direction in which it should be changed, and therefore it is possible to avoid a decrease in the reception level of the transmitted data even until the beam direction of the transmitting antenna is adjusted to an appropriate direction.

[0116] Seventh Embodiment Fig. 15 is a diagram showing an example of a processing procedure in an antenna direction adjustment instruction method according to the seventh embodiment. The antenna direction adjustment instruction method shown in Fig. 15 includes determining a direction (step S721). In determining the direction (step S721), the direction in which the beam direction of the transmitting antenna should be changed is determined based on the phase of the received signal of the composite wave of radio waves from the multiple transmitting means equipped in the transmitting antenna, the phase of which forms a null due to the cancellation of radio waves.

[0117] According to the antenna direction adjustment instruction method shown in Fig. 15, the direction in which the beam direction of the transmitting antenna should be changed can be detected without the need for trial and error. In this respect, according to the antenna direction adjustment instruction method shown in Fig. 15, the beam direction of the transmitting antenna can be adjusted in a relatively short time. In particular, according to the antenna direction adjustment instruction method shown in Fig. 15, the beam direction can be adjusted in a relatively short time by avoiding changing the beam direction of the transmitting antenna in the opposite direction to the direction in which it should be changed by trial and error.

[0118] Furthermore, with the antenna direction adjustment instruction method shown in Fig. 15, the beam direction of the transmitting antenna can be directed to the direction of the receiving antenna as seen from the transmitting antenna, eliminating the need to increase the antenna size and transmission power output in anticipation of fluctuations in the receiving input level due to changes in the beam direction caused by changes in the transmission path. In this respect, the antenna direction adjustment instruction method shown in Fig. 15 makes it possible to reduce the size of the communication system.

[0119] Furthermore, according to the antenna direction adjustment instruction method shown in FIG. 15, the direction in which the beam direction of the transmitting antenna should be changed is determined based on the phase of the signal received by the receiving antenna, so that even when the reception level changes due to the influence of fading, the direction in which the beam direction of the transmitting antenna should be changed can be determined with high accuracy. Furthermore, according to the antenna direction adjustment instruction method shown in FIG. 15, it is possible to avoid changing the beam direction of the transmitting antenna in the direction opposite to the direction in which it should be changed, and therefore it is possible to avoid a decrease in the reception level of the transmitted data even until the beam direction of the transmitting antenna is adjusted to an appropriate direction.

[0120] FIG. 16 is a schematic block diagram illustrating the configuration of a computer according to at least one embodiment. In the configuration shown in FIG. 16, a computer 800 includes a CPU 810, a main memory device 820, an auxiliary memory device 830, an interface 840, and a non-volatile recording medium 850.

[0121] One or more or some of the functions of the first communication system 100, the second communication system 200, the first communication system 300, the second communication system 400, the first communication system 500, the second communication system 600, the communication system 710, and the adjustment instruction device 720 may be implemented in the computer 800. In this case, the operation of each of the above-described processing units is stored in the auxiliary storage device 830 in the form of a program. The CPU 810 reads the program from the auxiliary storage device 830, loads it into the main storage device 820, and executes the above-described processing in accordance with the program. The CPU 810 also allocates a storage area in the main storage device 820 corresponding to the storage unit for processing in accordance with the program. Communication between each device and other devices is executed by an interface 840 having a communication function and performing communication under the control of the CPU 810.

[0122] When the first communication system 100 is implemented in a computer 800, the operation of each unit thereof is stored in the form of a program in an auxiliary storage device 830. The CPU 810 reads the program from the auxiliary storage device 830, loads it into the main storage device 820, and executes the above-described processing in accordance with the program.

[0123] Furthermore, the CPU 810 allocates a storage area in the main storage device 820 for processing of the first communication system 100 in accordance with the program. Communication between the first communication system 100 and other devices is performed by the interface 840, which has a communication function and operates under the control of the CPU 810. Interaction between the first communication system 100 and a user is performed by the interface 840, which has a display device and an input device, displaying various images under the control of the CPU 810 and accepting user operations.

[0124] When the second communication system 200 is implemented in a computer 800, the operation of each unit thereof is stored in the form of a program in an auxiliary storage device 830. The CPU 810 reads the program from the auxiliary storage device 830, loads it into the main storage device 820, and executes the above-described processing in accordance with the program.

[0125] Furthermore, the CPU 810 allocates a storage area in the main storage device 820 for processing of the second communication system 200 in accordance with the program. Communication between the second communication system 200 and other devices is performed by the interface 840, which has a communication function and operates under the control of the CPU 810. Interaction between the second communication system 200 and a user is performed by the interface 840, which has a display device and an input device, displaying various images under the control of the CPU 810 and accepting user operations.

[0126] When the first communication system 300 is implemented in a computer 800, the operation of each unit thereof is stored in the form of a program in an auxiliary storage device 830. The CPU 810 reads the program from the auxiliary storage device 830, loads it into the main storage device 820, and executes the above-described processing in accordance with the program.

[0127] Furthermore, the CPU 810 allocates a storage area for processing of the first communication system 300 in the main storage device 820 in accordance with the program. Communication between the first communication system 300 and other devices is performed by the interface 840, which has a communication function and operates under the control of the CPU 810. Interaction between the first communication system 300 and a user is performed by the interface 840, which has a display device and an input device, displaying various images under the control of the CPU 810 and accepting user operations.

[0128] When the second communication system 400 is implemented in a computer 800, the operation of each unit thereof is stored in the form of a program in an auxiliary storage device 830. The CPU 810 reads the program from the auxiliary storage device 830, loads it into the main storage device 820, and executes the above-described processing in accordance with the program.

[0129] Furthermore, the CPU 810 allocates a storage area in the main storage device 820 for processing of the second communication system 400 in accordance with the program. Communication between the second communication system 400 and other devices is performed by the interface 840, which has a communication function and operates under the control of the CPU 810. Interaction between the second communication system 400 and a user is performed by the interface 840, which has a display device and an input device, displaying various images under the control of the CPU 810 and accepting user operations.

[0130] When the first communication system 500 is implemented in a computer 800, the operation of each unit thereof is stored in the form of a program in an auxiliary storage device 830. The CPU 810 reads the program from the auxiliary storage device 830, loads it into the main storage device 820, and executes the above-described processing in accordance with the program.

[0131] Furthermore, the CPU 810 allocates a storage area for processing of the first communication system 500 in the main storage device 820 in accordance with the program. Communication between the first communication system 500 and other devices is performed by the interface 840, which has a communication function and operates under the control of the CPU 810. Interaction between the first communication system 500 and a user is performed by the interface 840, which has a display device and an input device, displaying various images under the control of the CPU 810 and accepting user operations.

[0132] When the second communication system 600 is implemented in a computer 800, the operation of each unit thereof is stored in the form of a program in an auxiliary storage device 830. The CPU 810 reads the program from the auxiliary storage device 830, loads it into the main storage device 820, and executes the above-described processing in accordance with the program.

[0133] Furthermore, the CPU 810 allocates a storage area in the main storage device 820 for processing of the second communication system 600 in accordance with the program. Communication between the second communication system 600 and other devices is performed by the interface 840, which has a communication function and operates under the control of the CPU 810. Interaction between the second communication system 600 and a user is performed by the interface 840, which has a display device and an input device, displaying various images under the control of the CPU 810 and accepting user operations.

[0134] When the communication system 710 is implemented in a computer 800, the operation of each unit thereof is stored in the form of a program in an auxiliary storage device 830. The CPU 810 reads the program from the auxiliary storage device 830, loads it into the main storage device 820, and executes the above-described processing in accordance with the program.

[0135] Furthermore, the CPU 810 allocates a storage area in the main storage device 820 for processing of the communication system 710 in accordance with the program. Communication between the communication system 710 and other devices is performed by an interface 840 having a communication function and operating under the control of the CPU 810. Interaction between the communication system 710 and a user is performed by the interface 840 having a display device and an input device, displaying various images under the control of the CPU 810, and accepting user operations.

[0136] When the adjustment instruction device 720 is implemented in the computer 800, the operation of each unit thereof is stored in the form of a program in the auxiliary storage device 830. The CPU 810 reads the program from the auxiliary storage device 830, loads it into the main storage device 820, and executes the above-described processing in accordance with the program.

[0137] Furthermore, the CPU 810 allocates a storage area in the main storage device 820 for processing by the adjustment instruction device 720 in accordance with the program. Communication between the adjustment instruction device 720 and other devices is performed by the interface 840, which has a communication function and operates under the control of the CPU 810. Interaction between the adjustment instruction device 720 and a user is performed by the interface 840, which has a display device and an input device, displaying various images under the control of the CPU 810 and accepting user operations.

[0138] One or more of the above-described programs may be recorded on nonvolatile recording medium 850. In this case, interface 840 may read the program from nonvolatile recording medium 850. Then, CPU 810 may directly execute the program read by interface 840, or may temporarily store the program in main storage device 820 or auxiliary storage device 830 and then execute it.

[0139] Note that a program for executing all or part of the processing performed by the first communication system 100, the second communication system 200, the first communication system 300, the second communication system 400, the first communication system 500, the second communication system 600, the communication system 710, and the adjustment instruction device 720 may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be read into a computer system and executed to perform the processing of each part. Note that the term "computer system" here includes hardware such as an OS and peripheral devices. Furthermore, "computer-readable recording media" refers to portable media such as flexible disks, optical magnetic disks, ROMs (Read Only Memory), and CD-ROMs (Compact Disc Read Only Memory), as well as storage devices such as hard disks built into computer systems. The program may be one that realizes part of the aforementioned functions, or may be one that can realize the aforementioned functions in combination with a program already stored in the computer system.

[0140] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs within the scope of the gist of the present invention. [Explanation of symbols]

[0141] 1, 2, 3, 710 Communication Systems 100, 300, 500 First Communication System 110, 510 First transmission control unit 120, 320, 520 First Antenna 121, 521, 713 Transmitter 121a, 321a, 521a First Horn 121b, 321b, 521b Second Horn 130, 530 First receiving processing unit 140, 540, 715, 721 Adjustment instruction section 150, 550, 716 direction adjustment section 200, 400, 600 Second Communication System 210, 610 Second antenna 220, 620 Second receiving processing unit 230, 630 Direction adjustment information generation unit 240, 640 Second transmission control section 311, 311a, 311b Symbol information insertion circuit 312, 312a, 312b, 442 Modulation circuit 331, 421 demodulation circuit 332 Direction adjustment information extraction circuit 340 Direction adjustment instruction circuit 350 direction adjustment mechanism 422 Symbol Processing Circuit 430 Directional deviation detection circuit 441 Direction Adjustment Information Insertion Circuit 521c Third Horn 711 Transmission control section 712 Transmitting Antenna 714 receiving antenna 720 Adjustment instruction device

Claims

1. a transmitting antenna having a plurality of transmitting means for transmitting radio waves; a transmission control means for inputting, to the plurality of transmitting means, signals of phases that form nulls due to cancellation of radio waves from the plurality of transmitting means, and causing each transmitting means to transmit radio waves; a receiving antenna for receiving a composite wave of radio waves from the plurality of transmitting means; an adjustment instruction means for determining a direction in which the beam direction of the transmitting antenna should be changed based on the phase of the received signal; a direction adjusting means for changing the beam direction of the transmitting antenna in the determined direction to be changed; A communication system comprising:

2. the adjustment instruction means determines an amount by which the beam direction of the transmitting antenna should be changed based on the magnitude of the received signal. The communication system of claim 1 .

3. the transmission control means, at a first timing, inputs signals of the same phase so that a peak is formed by the mutual reinforcement of radio waves from the plurality of transmission means, and causes each transmission means to transmit radio waves; and, at a second timing, inputs signals of a phase so that a null is formed by the mutual cancellation of radio waves from the plurality of transmission means, and causes each transmission means to transmit radio waves; the adjustment instruction means determines a direction in which the beam direction of the transmitting antenna should be changed based on a comparison between a phase of the received signal of the composite wave at the first timing and a phase of the received signal of the composite wave at the second timing.

3. The communication system according to claim 1 or 2.

4. 4. The communication system according to claim 3, wherein the adjustment instruction means determines an amount by which the beam direction of the transmitting antenna should be changed based on a comparison between a magnitude of the received signal of the composite wave at the first timing and a magnitude of the received signal of the composite wave at the second timing.

5. the transmitting antenna includes three or more transmitting means arranged such that the transmission direction of radio waves from at least one transmitting means is not included in a plane that includes the transmission directions of radio waves from the other two transmitting means; the adjustment instruction means determines a direction in a two-dimensional coordinate system as a direction in which the beam direction of the transmitting antenna should be changed, based on the phase of the received signal. A communication system according to any one of claims 1 to 4.

6. An adjustment instruction means for determining a direction in which the beam direction of the transmitting antenna should be changed based on the phase of a received signal of a composite wave of radio waves having phases in which nulls are formed due to cancellation of radio waves from a plurality of transmitting means provided in the transmitting antenna. An adjustment instruction device comprising:

7. A signal having a phase in which a null is formed by canceling out radio waves from a plurality of transmitting means provided in a transmitting antenna is input to the plurality of transmitting means, and radio waves are transmitted from each transmitting means; receiving a composite wave of radio waves from the plurality of transmitting means with a receiving antenna; determining a direction in which the beam direction of the transmitting antenna should be changed based on the phase of the received signal; changing the beam direction of the transmitting antenna in the determined direction to be changed; The antenna direction adjustment method includes:

8. The direction in which the beam direction of the transmitting antenna should be changed is determined based on the phase of the received signal of a composite wave of radio waves having phases in which a null is formed due to the cancellation of radio waves from a plurality of transmitting means provided in the transmitting antenna. The antenna direction adjustment instruction method includes:

9. On the computer, A direction in which the beam direction of the transmitting antenna should be changed is determined based on the phase of a received signal of a composite wave of radio waves having phases in which a null is formed due to the cancellation of radio waves from a plurality of transmitting means provided in the transmitting antenna. A program to execute.

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