Signal simulation device, signal simulation method, and program

Abstract

To provide a signal simulation device capable of simulating a frequency shift of a signal even if a relative velocity between a satellite and a ground station is not obtained.SOLUTION: A signal simulation device according to one aspect of the present disclosure includes: motion information receiving means for receiving motion information including information on a transition of a motion of a transmitter and information on a transition of a motion of a receiver; shift amount calculating means for using the motion information to calculate a transition of a frequency shift amount that occurs in a target signal when the target signal transmitted by the transmitter is received by the receiver; control means for controlling a read timing at which signal data, which is time-series data of sampled values of a waveform of the target signal, is read in chronological order in accordance with the transition of the shift amount; shift signal generating means for acquiring the signal data in a chronological order in accordance with the read timing, and generating a shift signal, which is the target signal in which a frequency shift has occurred in which shift amount transitions in accordance with the calculated transition of the shift amount, from the acquired signal data; and signal output means for outputting the shift signal.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a signal simulation device, a signal simulation method, and a program. [Background technology]

[0002] When communicating between a satellite (such as a probe) and a ground station, if the satellite approaches or moves away from the ground station, the frequency of the carrier and subcarrier of the signal shifts due to the Doppler effect. The transmitter and receiver of the ground station are equipped with a function to compensate for this frequency shift due to the Doppler effect. In order to check the soundness of this function before operation, the ground station has a function to simulate the Doppler effect of communication. With this function, even if there is no target satellite, the soundness of the function can be checked by looping back within the station. However, for example, if a method is adopted in which the frequency shift due to the Doppler effect is added to the frequency of the carrier and subcarrier in advance, the generated waveform is strictly different from the waveform generated by the actual Doppler effect. In this case, it is not possible to check the operation of the equipment under exactly the same conditions as in actual operation.

[0003] Patent Document 1 describes a simulated target generating device. The simulated target generating device of Patent Document 1 writes input signal data generated by sampling an input wireless signal every first sampling period into a memory device at a timing corresponding to the first sampling period. The simulated target generating device of Patent Document 1 reads out the input signal data every second sampling period, which is sample-compressed and expanded with a relative speed parameter over time, and transmits the read signal data as an output wireless signal.

[0004] Patent Document 2 describes a propagation signal simulator. The propagation signal simulator of Patent Document 2 obtains a propagation delay time occurring in communication between a ground station and a satellite based on startup information. The propagation signal simulator of Patent Document 2 controls the delay time of a transmission signal in a delay circuit according to the propagation delay time. The propagation signal simulator of Patent Document 2 obtains a shift frequency occurring in a communication signal between a ground station and a satellite based on speed information over time, and controls the frequency shift of the delayed transmission signal by providing the obtained shift frequency to a Doppler shift circuit. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-084545 A [Patent Document 2] Japanese Patent Application Publication No. 10-154954 Summary of the Invention [Problem to be solved by the invention]

[0006] The techniques of Patent Documents 1 and 2 can simulate the frequency shift of a radio signal when the relative speed between a satellite and a ground station (i.e., a transmitter and a receiver) changes over time. However, the techniques of Patent Documents 1 and 2 cannot simulate the frequency shift of a radio signal unless the relative speed between a satellite and a ground station that changes over time is obtained.

[0007] An object of the present disclosure is to provide a signal simulation device, a signal simulation method, and a program that can simulate the frequency shift of a signal even if the relative velocity between a transmitter and a receiver is not obtained. [Means for solving the problem]

[0008] A signal simulation device according to one aspect of the present disclosure includes: motion information receiving means for receiving motion information including information on a transition of a motion of a transmitter and information on a transition of a motion of a receiver; shift amount calculating means for using the motion information to calculate a transition of a frequency shift that occurs in a target signal when the target signal transmitted by the transmitter is received by the receiver; control means for controlling a read timing at which signal data, which is time-series data of sampled values ​​of a waveform of the target signal, is read in chronological order in accordance with the transition of the shift amount; shift signal generating means for acquiring the signal data in chronological order in accordance with the read timing, and generating a shift signal, which is the target signal in which a frequency shift has occurred and whose shift amount transitions in accordance with the calculated transition of the shift amount, from the acquired signal data; and signal output means for outputting the shift signal. Effect of the Invention

[0009] The present disclosure has the advantage that it is possible to simulate the frequency shift of a signal even if the relative velocity between the transmitter and receiver is not available. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram illustrating an example of a configuration of a signal simulation device according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a flowchart illustrating an example of the operation of the signal simulation device according to an embodiment of the present disclosure. [Diagram 3] FIG. 3 is a block diagram illustrating an example of a configuration of a signal simulation device according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is a flowchart illustrating an example of the operation of the signal simulation device according to an embodiment of the present disclosure. [Diagram 5] FIG. 5 is a flowchart illustrating an example of the operation of the signal simulation device according to an embodiment of the present disclosure. [Figure 6] FIG. 6 is a block diagram showing an implementation example of a signal simulation device according to this embodiment. [Figure 7]FIG. 7 is a diagram illustrating an example of a hardware configuration of a computer 1000 capable of realizing a signal simulation device according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0012] <First embodiment> First, a signal simulation device according to a first embodiment of the present disclosure will be described in detail with reference to the drawings.

[0013] <Configuration> 1 is a block diagram illustrating an example of a configuration of a signal simulation device according to an embodiment of the present disclosure. In the following, a signal simulation device according to a first embodiment of the present disclosure will be described with reference to FIG.

[0014] In the example shown in FIG. 1, the signal simulation device 10 includes a motion information receiving section 110, a shift amount calculating section 120, a control section 130, a shift signal generating section 140, and a signal output section 150. The signal simulation device 10 includes a motion information receiving section 110, a shift amount calculating section 120, a shift amount calculating section 130, a shift signal generating section 140, and a signal output section 150.

[0015] The information receiving unit 110 receives motion information including information on the transition of the motion of the transmitter and information on the transition of the motion of the receiver. The deviation amount calculating unit 120 uses the motion information to calculate the transition of the amount of frequency deviation that occurs in the target signal when the target signal transmitted by the transmitter is received by the receiver. The control unit 130 controls the read timing for reading signal data, which is time-series data of sampled values ​​of the waveform of the target signal, in chronological order according to the transition of the amount of deviation. The deviation signal generating unit 140 acquires the signal data in chronological order according to the read timing, and generates a deviation signal, which is the target signal in which a frequency deviation occurs and whose amount of deviation transitions according to the calculated transition, from the acquired signal data. The signal output unit 150 outputs the deviation signal.

[0016] The target signal is a signal that is expected to be transmitted by the transmitter described above. The target signal is, for example, an electromagnetic signal such as a radio signal. The shifted signal is a signal that simulates a signal that is observed when the signal transmitted by the transmitter reaches the location of the receiver described above. In other words, the shifted signal is a signal that simulates a signal that is expected to be received by the receiver described above.

[0017] The shift amount calculation unit 120 calculates the shift amount of the signal frequency from the information on the transition of the motion of the transmitter and the information on the transition of the motion of the receiver, which are included in the motion information, using an existing formula for calculating the frequency shift amount due to the Doppler effect of electromagnetic waves. In general, the frequency of the signal on the receiving side when the Doppler effect is occurring can be calculated by multiplying the frequency of the signal on the transmitting side by a coefficient determined by the speed of the transmitting side and the speed of the receiving side. The above-mentioned frequency shift amount refers to the value of the coefficient by which the frequency of the signal on the transmitting side is multiplied to calculate the frequency of the signal on the receiving side.

[0018] The motion of the transmitter and the motion of the receiver may be represented, for example, by coordinates in a coordinate system defined in outer space. The coordinate system defined in outer space may be defined, for example, with the center of the Earth as its origin. The coordinate system defined in outer space may be defined, for example, with the center of the solar system (for example, the center of the sun) as its origin. The coordinate system defined in outer space may be defined, for example, with another point (for example, the position of the receiver) as its origin. The transition of the motion of the transmitter includes a time series of the speed of the transmitter for each predetermined time. The transition of the motion of the receiver includes a time series of the speed of the receiver for each predetermined time. The transition of the frequency shift represents time series information of the frequency shift for each predetermined time.

[0019] The signal data is time-series data representing a target signal, i.e., data including a plurality of values ​​sampled at timings indicated by a clock representing the write timing of the waveform of the target signal, in a form in which the order obtained by sampling (i.e., the chronological order) can be specified. The signal data is generated, for example, by analog-to-digital conversion (A / D (Analog / Digital) conversion) of the target signal at timings determined by a write clock signal (also simply referred to as a write clock in this disclosure) of a predetermined frequency. The signal data is stored in a storage device such as a memory.

[0020] As described above, the control unit 130 controls the read timing for reading signal data, which is time-series data of sampled values ​​of the waveform of the target signal, in a chronological order according to the transition of the deviation amount. The control unit 130 controls, for example, the frequency of a read clock signal (hereinafter also simply referred to as a read clock) indicating the timing for reading signal data from the above-mentioned memory or the like, according to the transition of the deviation amount. The oscillator that generates the read clock (hereinafter also referred to as a write oscillator) is an oscillator that can change the frequency of the generated clock signal by external control. The oscillator that generates the above-mentioned write clock signal (hereinafter also referred to as a write oscillator) does not have to be an oscillator that can change the frequency of the generated clock signal by external control. The control unit 130 calculates the transition of the frequency of the read clock by, for example, multiplying the frequency of the write clock by the deviation amount included in the transition of the above-mentioned deviation amount in a chronological order. The control unit 130 controls the frequency of the read clock, which is a clock (i.e., a clock signal) generated by the read oscillator, so that it transitions according to the calculated transition of the frequency.

[0021] As described above, the deviation signal generating unit 140 acquires signal data in chronological order according to the read timing, and generates a deviation signal, which is a target signal in which a frequency deviation occurs and the deviation amount changes according to the calculated change, from the acquired signal data. Specifically, the deviation signal generating unit 140 acquires signal data in chronological order from, for example, the memory in which the signal data is stored, according to the read clock indicating the read timing. The deviation signal generating unit 140 generates a deviation signal, which is a target signal in which a frequency deviation occurs and the deviation amount changes according to the calculated frequency change, from the acquired signal data by digital / analog conversion (D / A (Digital / Analog) conversion). The deviation signal generating unit 140 generates, as the deviation signal, an analog signal having a waveform whose value at the timing indicated by the read clock is the value of the signal data read at that timing.

[0022] <Operation> Next, the operation of the signal simulator 10 according to the first embodiment of the present disclosure will be described in detail with reference to the drawings.

[0023] 2 is a flowchart illustrating an example of the operation of the signal simulator 10 according to the embodiment of the present disclosure. The operation of the signal simulator 10 according to the first embodiment of the present disclosure will be described below with reference to FIG.

[0024] In the example of the operation shown in FIG. 2, the motion information receiving unit 110 receives motion information including information on the transition of the motion of the transmitter and information on the transition of the motion of the receiver (step S11). The deviation amount calculating unit 120 uses the motion information to calculate the transition of the amount of frequency deviation that occurs in the target signal when the target signal transmitted by the transmitter is received by the receiver (step S12). The control unit 130 controls the read timing at which signal data, which is time-series data of sampled values ​​of the waveform of the target signal, is read in chronological order according to the transition of the amount of deviation (step S13). The deviation signal generating unit 140 acquires the signal data in chronological order according to the read timing, and generates a deviation signal from the acquired signal data (step S14). The signal output unit 150 outputs the deviation signal (step S15).

[0025] <Effects> The embodiment described above has an advantage that the frequency shift of a signal can be simulated even if the relative speed between the transmitter and the receiver is not obtained. This is because the shift amount calculation unit 120 uses the motion information to calculate the transition of the frequency shift amount that occurs in the target signal when the target signal transmitted by the transmitter is received by the receiver. Then, the control unit 130 controls the read timing at which the signal data, which is time-series data of sampled values ​​of the waveform of the target signal, is read in chronological order according to the transition of the shift amount. Furthermore, the shift signal generation unit 140 acquires the signal data in chronological order according to the read timing, and generates a shift signal from the acquired signal data.

[0026] <Second embodiment> Next, a signal simulation device according to a second embodiment of the present disclosure will be described in detail with reference to the drawings.

[0027] <Configuration> FIG. 3 is a block diagram illustrating an example of a configuration of a signal simulation device according to an embodiment of the present disclosure.

[0028] The configuration of the signal simulation device according to the second embodiment of the present disclosure will be described in detail below with reference to FIG.

[0029] 3, the signal simulation device 100 includes a motion information receiving unit 110, a shift amount calculating unit 120, a control unit 130, a shift signal generating unit 140, and a signal output unit 150. The signal simulation device 100 further includes a signal receiving unit 160, a signal data generating unit 170, a write oscillator 171, a signal data storage unit 180, and a read oscillator 141. The motion information receiving unit 110, the shift amount calculating unit 120, the control unit 130, the shift signal generating unit 140, and the signal output unit 150 of this embodiment are the same as the information receiving unit 110, the shift amount calculating unit 120, the control unit 130, the shift signal generating unit 140, and the signal output unit 150 of the first embodiment, except for the differences described below.

[0030] <Signal Receiving Unit 160> The signal receiving unit 160 receives a target signal. The signal receiving unit 160 may convert the target signal of electromagnetic waves into an electrical signal, for example, by an antenna. The signal receiving unit 160 may receive, for example, an electrical signal representing the target signal.

[0031] <Write Oscillator 171> The write oscillator 171 generates a write clock. The write oscillator 171 is an oscillator that generates a write clock. It corresponds to the write clock oscillator of the first embodiment.

[0032] <Signal Data Generator 170> The signal data generating unit 170 is driven by a write clock generated by the write oscillator 171. In other words, the signal data generating unit 170 samples the target signal at the timing indicated by the write clock generated by the write oscillator 171, and generates signal data representing the waveform of the target signal. As described above, the signal data is a time series of values ​​at the timings at which the waveform of the target signal is sampled (i.e., a time series of information indicating values). The signal data generating unit 170 stores the generated signal data in the signal data storage unit 180. The signal data generating unit 170 stores the value of the generated signal data in the signal data storage unit 180, for example, at the timing indicated by the write clock generated by the write oscillator 171.

[0033] <Signal Data Storage Unit 180> The signal data storage unit 180 stores the signal data stored by the signal data generation unit 170. The signal data storage unit 180 receives the value of the signal data from the signal data generation unit 170, for example, at the timing indicated by the write clock generated by the write oscillation unit 171. The signal data storage unit 180 stores the value of the received signal data. The signal data storage unit 180 corresponds to a storage device such as a memory in the description of the first embodiment.

[0034] <Readout oscillator 141> The read oscillator 141 generates a read clock. The read oscillator 141 is an oscillator that generates the read clock. The read oscillator 141 can change the frequency of the read clock under the control of the control unit 130. The read oscillator 141 corresponds to the read clock oscillator of the first embodiment.

[0035] <Shift signal generation unit 140> The shift signal generating unit 140 reads out the signal data values ​​in chronological order from the signal data storage unit 180 at the timing indicated by the read clock generated by the read oscillator 141. The shift signal generating unit 140 generates a shift signal using the signal data values ​​read out from the signal data storage unit 180 at the timing indicated by the read clock generated by the read oscillator 141.

[0036] <Operation> Next, the operation of the signal simulation device 100 according to the second embodiment of the present disclosure will be described in detail with reference to the drawings.

[0037] 4 and 5 are flowcharts illustrating an example of the operation of the signal simulation device according to the embodiment of the present disclosure. In the following, the operation of the signal simulation device 100 according to the second embodiment of the present disclosure will be described in detail with reference to FIGS. 4 and 5.

[0038] 4, first, the motion information receiving unit 110 receives motion information including information on the transition of the motion of the transmitter and information on the transition of the motion of the receiver (step S101). The deviation amount calculating unit 120 uses the motion information to calculate the transition of the amount of frequency deviation that occurs in the target signal when the target signal transmitted by the transmitter is received by the receiver (step S102).

[0039] The signal receiving unit 160 receives a target signal (step S103). Then, the signal data generating unit 170 generates signal data from the target signal (step S104). The signal data generating unit 170 stores the generated signal data in the signal data storage unit 180. The signal data storage unit 180 stores the signal data (step S105).

[0040] 5, the control unit 130 controls the read timing at which signal data, which is time-series data of sampled values ​​of the waveform of the target signal, is read in chronological order according to the transition of the deviation amount (step S106). The deviation signal generating unit 140 acquires the signal data in chronological order according to the read timing, and generates a deviation signal from the acquired signal data (step S107). Specifically, the deviation signal generating unit 140 acquires the signal data values ​​in chronological order according to the read timing, and generates a deviation signal from the acquired signal data values.

[0041] Then, the signal output unit 150 outputs the deviation signal (step S108).

[0042] <Implementation example> An implementation example of the signal simulation device 100 of the present disclosure will be described.

[0043] FIG. 6 is a block diagram showing an implementation example of the signal simulation device according to the present embodiment. In the example shown in FIG. 6, "A / D conversion" is a circuit that performs A / D conversion. "A / D conversion" operates as a signal data generating unit 170. The line to the left of "A / D conversion" in FIG. 6 operates as a signal receiving unit 160. "MEMORY" operates as a signal data storage unit 180. "D / A conversion" is a circuit that performs D / A conversion. "D / A conversion" operates as a shift signal generating unit 140. The line to the right of "D / A conversion" operates as a signal output unit 150. "Oscillator" on the lower left side operates as a write oscillator 171. "Oscillator" on the lower right side operates as a read oscillator 141. "CPU" (Central Processing Unit) operates as a motion information receiving unit 110, a shift amount calculating unit 120, and a control unit 130.

[0044] <Effects> The present embodiment described above has the same effects as the first embodiment, for the same reasons as those for which the effects of the first embodiment are obtained.

[0045] <First Modification of the Second Embodiment> The first modified example of the second embodiment and other modified examples of the second embodiment described below are the same as the second embodiment, except where there is a description different from the description of the second embodiment. The following description will focus on the differences from the second embodiment. In addition, one or more of the modified examples of the second embodiment can be combined.

[0046] One of the transmitter and receiver may be mounted on a satellite, and the other may be installed on the ground. Information on the movement of one of the transmitter and receiver mounted on the satellite represents the movement of the satellite. Information on the movement of the other of the transmitter and receiver installed on the ground represents the movement of the location where the other of the transmitter and receiver installed on the ground is installed.

[0047] A facility that houses a communication device (i.e., a collective term for a transmitter and a receiver) installed on the ground is referred to as a ground station. The position of the ground station may be used as the position of the communication device installed on the ground. The movement of the ground station (e.g., the movement of the ground station due to the rotation of the earth) may be used as the movement of the communication device installed on the ground. The movement of the ground station may be a change in the speed of the ground station, or a change in the speed of the ground station and a change in the position of the ground station, etc. Furthermore, the position of the artificial satellite may be used as the position of the communication device mounted on the artificial satellite, except when information on the rotation of the artificial satellite described below is used. The movement of the artificial satellite may be used as the movement of the communication device mounted on the artificial satellite, except when information on the rotation of the artificial satellite described below is used. The movement of the artificial satellite may be a change in the speed of the artificial satellite, or a change in the speed of the artificial satellite and a change in the position of the artificial satellite, etc.

[0048] The artificial satellite may be, for example, an artificial satellite such as an observation satellite that orbits the Earth and observes the Earth's surface. The artificial satellite may be, for example, a meteorological satellite that observes the weather and the like in an orbit called a geostationary orbit. The artificial satellite may be, for example, a communication satellite that mediates communication from the Earth to another location on the Earth. The artificial satellite may be, for example, an artificial satellite that observes at least one of the Sun, the Moon, a planet, and a planetary satellite. The artificial satellite may be another type of artificial satellite.

[0049] <Second Modification of the Second Embodiment> The information on the movement of the communication device, either the transmitter or the receiver, mounted on the satellite may be information on the movement of the satellite, including information on the movement of the satellite's acceleration in addition to information on the movement of the satellite. In this case, the information on the movement of the satellite's speed is information on the movement of the satellite when the acceleration indicated by the information on the acceleration of the satellite does not occur in the movement of the satellite. The information on the movement of the acceleration of the satellite represents the movement of the acceleration of the satellite when the speed of the satellite is changed by a propulsion device such as an engine mounted on the satellite, for example. Note that the above-mentioned communication device is a collective term for the transmitter and the receiver. Note that in the present disclosure, the transmitter and the receiver may be communication devices having the same configuration.

[0050] In this case, the deviation amount calculation unit 120 updates the information on the change in the speed of the communication device included in the information on the movement of the communication device mounted on the artificial satellite using the information on the change in the acceleration of the communication device included in the information on the movement of the communication device. Specifically, the deviation amount calculation unit 120 identifies the first timing at which the acceleration is not zero in the change in the acceleration of the communication device. The deviation amount calculation unit 120 calculates the change in the speed of the communication device from the next timing after the identified timing, using the speed at the identified timing and the change in the acceleration after the first timing at which the speed is not zero. The deviation amount calculation unit 120 updates the change in the speed of the communication device so that the change in the speed of the communication device up to the identified timing is the change in the speed of the communication device included in the received movement information, and the change in the speed of the communication device from the next timing after the identified timing is the calculated change in the speed.

[0051] The information on the movement of the communication device mounted on the artificial satellite may include information on the initial value of the speed of the artificial satellite on which the communication device is mounted, and information on the change in acceleration of the artificial satellite on which the communication device is mounted. The deviation amount calculation unit 120 considers that the speed of the artificial satellite is the speed of the communication device mounted on that artificial satellite, and the change in the acceleration of the artificial satellite is the change in the acceleration of the communication device mounted on that artificial satellite. The information on the movement of the communication device mounted on the artificial satellite may include information on the initial value of the speed of the communication device, and information on the change in the acceleration of the communication device.

[0052] In these cases, deviation amount calculation unit 120 generates information on the transition of the velocity of the communication device using information on the initial value of the velocity of the communication device and information on the transition of the acceleration of the communication device. In other words, deviation amount calculation unit 120 calculates the transition of the velocity of the communication device when the velocity of the communication device at the first timing is the initial value of the velocity of the communication device included in the information on the movement of the communication device, and the acceleration of the communication device transitions according to the transition of the acceleration of the communication device.

[0053] <Third Modification of the Second Embodiment> The information on the movement of the communication device mounted on the artificial satellite may include information on the rotation of the artificial satellite on which the communication device is mounted. In this case, the information on the movement of the communication device may include information on the change in the speed of the artificial satellite as information on the change in the speed of the communication device. The information on the rotation of the artificial satellite may be information on the change in the position of the communication device mounted on the artificial satellite, which changes with the rotation of the artificial satellite, for example, based on a point determined on the artificial satellite. The deviation amount calculation unit 120 may use the information on the change in the position of the communication device to calculate, for example, the change in the relative speed of the communication device with respect to the artificial satellite. The deviation amount calculation unit 120 calculates the change in the speed of the communication device from the information on the change in the speed of the artificial satellite and the change in the relative speed of the communication device with respect to the artificial satellite.

[0054] The information on the movement of the communication device mounted on the artificial satellite may further include information on the transition of the position of the artificial satellite. The information on the movement of the communication device installed on the ground may further include information on the transition of the position of the communication device installed on the ground. For example, the deviation amount calculation unit 120 may calculate the movement of the ground station due to the rotation of the earth (specifically, the transition of the position of the ground station due to the rotation) using information on the latitude, longitude, and altitude of the point where the ground station is installed. The ground station refers to a facility that houses the communication device installed on the ground surface. The deviation amount calculation unit 120 may take the calculated transition of the position of the ground station as the transition of the position of the communication device installed on the ground. The deviation amount calculation unit 120 may calculate the movement of the communication device installed on the ground surface due to the rotation of the earth (specifically, the transition of the position of the communication device due to the rotation) using information on the latitude, longitude, and altitude of the point where the communication device installed on the ground surface is installed.

[0055] The control unit 130 may estimate the transition of the strength of the shifted signal from the information of the transition of the position of the communication device installed on the ground, the transition of the position of the satellite, and the transition of the position of the communication device mounted on the satellite with respect to a point determined on the satellite. The transition of the strength of the shifted signal may be represented, for example, by the transition of the reach indicating whether the shifted signal reaches or not. In the description of the present disclosure, this reach indicates 1 when the target signal transmitted from the communication device, which is a transmitter, reaches the communication device, which is a receiver, as a shifted signal. Furthermore, this reach indicates 0 when the target signal transmitted from the communication device, which is a transmitter, does not reach the communication device, which is a receiver, as a shifted signal.

[0056] Specifically, the control unit 130 specifies the timing when the transmitted target signal is blocked by the satellite between the communication device installed on the ground and the communication device installed on the satellite from the information on the transition of these positions. The control unit 130 may specify the timing when the transmitted target signal is blocked by the earth between the communication device installed on the ground and the communication device installed on the satellite from the information on the transition of these positions. The control unit 130 may set the reachability at the timing when the target signal that is not blocked between the communication device installed on the ground and the communication device installed on the satellite reaches the communication device on the receiving side (i.e., the receiver) to 0. The control unit 130 may set the reachability at the timing when the target signal that is blocked between the communication device installed on the ground and the communication device installed on the satellite would have reached the communication device on the receiving side (i.e., the receiver) if it had not been blocked to 1.

[0057] The control unit 130 sends information representing the transition of the intensity of the shift signal (for example, information on the transition of the degree of reach described above) to the shift signal generating unit 140. Specifically, as described above, the control unit 130 controls the read timing at which signal data, which is time-series data of sampled values ​​of the waveform of the target signal, is read in chronological order in accordance with the transition of the amount of shift as described above. In addition, the control unit 130 sends information representing the intensity of the shift signal at the read timing (i.e., information indicating the value of the degree of reach described above) to the shift signal generating unit 140 in accordance with the read timing.

[0058] The shift signal generating section 140 generates a shift signal such that the intensity of the shift signal changes according to the intensity of the shift signal.

[0059] Specifically, the shift signal generating unit 140 changes the value of the signal data read at the read timing according to the strength indicated by the information indicating the strength of the shift signal at the read timing. For example, if the value of the degree of arrival is 1, the shift signal generating unit 140 does not change the value of the signal data at the read timing from the value of the signal data read at the read timing. If the value of the degree of arrival is 0, the shift signal generating unit 140 changes the value of the signal data at the read timing from the value of the signal data read at the read timing to 0. The shift signal generating unit 140 may multiply the value of the signal data read at the read timing by the value of the degree of arrival at the read timing. Then, the shift signal generating unit 140 generates a shift signal using the value of the signal data at the read timing changed according to the strength indicated by the information indicating the strength of the shift signal at the read timing.

[0060] <Fourth Modification of the Second Embodiment> In this modification, the information on the movement of the communication device mounted on the artificial satellite further includes information on the position of the communication device mounted on the artificial satellite. The information on the movement of the communication device mounted on the artificial satellite may include information on the transition of the position of the communication device mounted on the artificial satellite. Furthermore, the information on the movement of the communication device installed on the ground further includes information on the position of the communication device installed on the ground. The information on the movement of the communication device installed on the ground may include information on the transition of the position of the communication device installed on the ground.

[0061] As described above, the information on the movement of the communication device mounted on the artificial satellite may be information on the movement of the artificial satellite. The information on the movement of the artificial satellite may include information on the position of the artificial satellite. The position of the artificial satellite may be used as the position of the communication device mounted on the artificial satellite. Furthermore, the information on the movement of the communication device installed on the ground may be information on the movement of a ground station. The information on the movement of the ground station may include information on the position of the ground station. The position of the ground station may be used as the position of the communication device installed on the ground.

[0062] The control unit 130 calculates the distance between the communication device mounted on the artificial satellite and the communication device installed on the ground from the position of the communication device mounted on the artificial satellite and the position of the communication device installed on the ground. The control unit 130 may calculate the transmission distance of the target signal when the target signal transmitted by one communication device at the timing of starting transmission of the target signal reaches the other communication device as a shifted signal from the change in the position of the communication device mounted on the artificial satellite and the change in the position of the communication device installed on the ground. In this case, the control unit 130 sets the calculated distance as the distance between the communication device mounted on the artificial satellite and the communication device installed on the ground.

[0063] The control unit 130 estimates the delay of the shifted signal relative to the target signal from the distance between the communication device mounted on the artificial satellite and the communication device installed on the ground, using the previously obtained signal transmission speed. For example, the control unit 130 uses the previously obtained signal transmission speed to calculate the distance between the communication device mounted on the artificial satellite and the communication device installed on the ground, and the time it takes for the signal to transmit, as the delay of the shifted signal relative to the target signal.

[0064] The control unit 130 controls the read timing so that the timing at which the time indicated by the delay of the shift signal with respect to the target signal has elapsed from the first timing of the above-mentioned write timing becomes the first timing of the above-mentioned read timing. Specifically, the control unit 130 starts control of the read timing (i.e., control of the frequency of the read clock by the read oscillator 141) at the timing at which the time indicated by the delay of the shift signal with respect to the target signal has elapsed from the first timing of the above-mentioned write timing. The control unit 130 instructs the shift signal generating unit 140 to start reading the value of the signal data at the timing at which the time indicated by the delay of the shift signal with respect to the target signal has elapsed from the first timing of the above-mentioned write timing.

[0065] The shift signal generating unit 140 generates a shift signal having an estimated delay with respect to the target signal. Specifically, when the shift signal generating unit 140 is instructed by the control unit 130 to start reading the signal data value at a timing when a time indicated by the delay of the shift signal with respect to the target signal has elapsed from the first timing of the above-mentioned write timing, the shift signal generating unit 140 starts reading the signal data value at that timing.

[0066] <Other embodiments> The signal simulation device according to the embodiment of the present disclosure can be realized by a computer including a memory into which a program read from a storage medium is loaded and a processor that executes the program. The signal simulation device according to the embodiment of the present disclosure can also be realized by dedicated hardware. The signal simulation device according to the embodiment of the present disclosure can also be realized by a combination of the above-mentioned computer and dedicated hardware.

[0067] FIG. 6 is a diagram illustrating an example of a hardware configuration of a computer 1000 that can realize a signal simulation device according to an embodiment of the present disclosure. In the example illustrated in FIG. 6, the computer 1000 includes a processor 1001, a memory 1002, a storage device 1003, and an I / O (Input / Output) interface 1004. The computer 1000 can also access a storage medium 1005. The memory 1002 and the storage device 1003 are, for example, storage devices such as a RAM (Random Access Memory) or a hard disk. The storage medium 1005 is, for example, a storage device such as a RAM or a hard disk, a ROM (Read Only Memory), or a portable storage medium. The storage device 1003 may be the storage medium 1005. The processor 1001 can read and write data and programs from and to the memory 1002 and the storage device 1003. The processor 1001 can access, for example, other devices via the I / O interface 1004. The processor 1001 can also access the storage medium 1005. The storage medium 1005 stores a program that causes the computer 1000 to operate as a signal simulation device according to an embodiment of the present disclosure.

[0068] The processor 1001 loads a program stored in the storage medium 1005, which causes the computer 1000 to operate as a signal simulation device according to an embodiment of the present disclosure, into the memory 1002. The processor 1001 then executes the program loaded into the memory 1002, causing the computer 1000 to operate as the signal simulation device according to an embodiment of the present disclosure.

[0069] The motion information receiving unit 110, the deviation amount calculating unit 120, the control unit 130, the deviation signal generating unit 140, the read oscillator 141, the signal output unit 150, the signal receiving unit 160, the signal data generating unit 170, and the write oscillator 171 can be realized, for example, by a processor 1001 that executes a program loaded in a memory 1002. The signal data storage unit 180 can be realized by a memory 1002 included in the computer 1000 or a storage device 1003 such as a hard disk device. Some or all of the motion information receiving unit 110, the deviation amount calculating unit 120, the control unit 130, the deviation signal generating unit 140, the read oscillator 141, the signal output unit 150, the signal receiving unit 160, the signal data generating unit 170, the write oscillator 171, and the signal data storage unit 180 can be realized by a dedicated circuit that realizes the function of each unit.

[0070] Furthermore, some or all of the above-described embodiments can be described as, but are not limited to, the following supplementary notes.

[0071] (Appendix 1) a motion information receiving means for receiving motion information including information on a transition of a motion of the transmitter and information on a transition of a motion of the receiver; a shift amount calculation means for calculating a change in a frequency shift amount that occurs in a target signal when the target signal is received by the receiver, the target signal being transmitted by the transmitter, using the motion information; a control means for controlling a timing at which signal data, which is time-series data of sampled values ​​of the waveform of the target signal, is read out in a chronological order in accordance with a transition of the deviation amount; a shift signal generating means for acquiring the signal data in chronological order in accordance with the read timing, and generating, from the acquired signal data, a shift signal, which is the target signal and in which a frequency shift occurs and in which the shift amount changes in accordance with the calculated shift amount; a signal output means for outputting the deviation signal; A signal simulator comprising:

[0072] (Appendix 2) The deviation amount calculation means calculates a transition in the relative velocity between the transmitter and the receiver using information on the movement of a point on the earth's surface where the ground station is located and information on the movement of the artificial satellite when the transmitter is located in one of the ground station and the artificial satellite and the receiver is located in the other of the ground station and the artificial satellite, and calculates a transition in the deviation amount using the information on the transition in the relative velocity. 2. A signal simulator as defined in claim 1.

[0073] (Appendix 3) A signal receiving means for receiving the target signal; a data generating means for generating the signal data, which is time series data of values ​​obtained by sampling a waveform of the received target signal, from the target signal, and writing the generated signal data into a signal storage means; Equipped with The deviation signal generating means reads the signal data from the signal storage means at the read timing, and generates the deviation signal using the read signal data. 3. A signal simulator according to claim 1 or 2.

[0074] (Appendix 4) The control means uses the transition of the deviation amount to determine a transition of a frequency of a read clock that determines the read timing for reading the signal data from the signal storage means, and controls the read clock so that the frequency of the read clock transitions in accordance with the determined transition of the frequency. 4. A signal simulator as described in claim 3.

[0075] (Appendix 5) the signal receiving means generates the signal data by analog / digital conversion of the target signal at a write timing indicated by a write clock; the control means determines a transition of the frequency of the read clock from the frequency of the write clock and the transition of the deviation amount; The deviation signal generating means generates the deviation signal by performing digital / analog conversion on the signal data read out at the read timing. 5. A signal simulator as described in claim 4.

[0076] (Appendix 6) The deviation amount calculation means further uses information on the transition of the acceleration of the artificial satellite to calculate the transition of the deviation amount. 3. A signal simulator as described in claim 2.

[0077] (Appendix 7) the deviation amount calculation means further uses information on the rotation of the artificial satellite to calculate a transition of the deviation amount; The control means estimates a transition in the strength of the shift signal from information on the rotation of the artificial satellite, The shift signal generating means generates the shift signal such that the intensity of the shift signal transitions in accordance with the transition of the estimated intensity. 3. A signal simulator as described in claim 2.

[0078] (Appendix 8) The control means estimates a delay of the shifted signal relative to the target signal from a distance between the ground station and the artificial satellite; The shift signal generating means generates the shift signal having the estimated delay with respect to the target signal. 3. A signal simulator as described in claim 2.

[0079] (Appendix 9) The deviation calculation means calculates the movement of the ground station due to the rotation of the earth using information on the latitude, longitude and altitude of the point where the ground station is located. 3. A signal simulator as described in claim 2.

[0080] (Appendix 10) receiving motion information including transmitter motion history information and receiver motion history information; Using the motion information, a change in the frequency shift of the target signal when the target signal is received by the receiver after being transmitted by the transmitter is calculated; a read timing for reading signal data, which is time-series data of values ​​obtained by sampling the waveform of the target signal, in a chronological order is controlled in accordance with a transition of the deviation amount; acquiring the signal data in chronological order in accordance with the read timing, and generating, from the acquired signal data, a shifted signal that is the target signal and in which a frequency shift occurs and in which a shift amount transitions in accordance with the transition of the calculated shift amount; outputting the shifted signal; Signal simulation method.

[0081] (Appendix 11) a motion information receiving process for receiving motion information including information on a transition of a motion of a transmitter and information on a transition of a motion of a receiver; a shift amount calculation process for calculating a change in a frequency shift amount that occurs in a target signal when the target signal transmitted by the transmitter is received by the receiver using the motion information; a control process for controlling a timing at which signal data, which is time-series data of values ​​obtained by sampling the waveform of the target signal, is read out in a chronological order in accordance with a transition of the deviation amount; a shift signal generation process for acquiring the signal data in chronological order according to the read timing, and generating, from the acquired signal data, a shift signal, which is the target signal and has a frequency shift whose shift amount changes according to the calculated shift amount; a signal output process for outputting the deviation signal; A program that causes a computer to execute the following.

[0082] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above embodiments. Various modifications that can be understood by a person skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. [Explanation of symbols]

[0083] 10 Signal simulator 100 Signal simulator 110 Information Receiving Department 120 Deviation amount calculation section 130 Control section 140 Shift signal generation section 141 Oscillator 150 Signal output section 160 Signal receiving unit 170 Signal Data Generation Unit 171 Oscillator 180 Signal data storage unit 1000 Computers 1001 Processor 1002 Memory 1003 Storage device 1004 I / O Interface 1005 Storage medium

Claims

1. a motion information receiving means for receiving motion information including information on a transition of a motion of the transmitter and information on a transition of a motion of the receiver; a shift amount calculation means for calculating a change in a frequency shift amount that occurs in a target signal when the target signal is received by the receiver, the target signal being transmitted by the transmitter, using the motion information; a control means for controlling a timing at which signal data, which is time-series data of sampled values ​​of the waveform of the target signal, is read out in a chronological order in accordance with a transition of the deviation amount; a shift signal generating means for acquiring the signal data in chronological order in accordance with the read timing, and generating, from the acquired signal data, a shift signal, which is the target signal and in which a frequency shift occurs and in which the shift amount changes in accordance with the calculated shift amount; a signal output means for outputting the deviation signal; A signal simulator comprising:

2. The deviation amount calculation means calculates a transition in the relative velocity between the transmitter and the receiver using information on the movement of a point on the earth's surface where the ground station is located and information on the movement of the artificial satellite when the transmitter is located in one of the ground station and the artificial satellite and the receiver is located in the other of the ground station and the artificial satellite, and calculates a transition in the deviation amount using the information on the transition in the relative velocity.

2. The signal simulation device according to claim 1.

3. A signal receiving means for receiving the target signal; a data generating means for generating the signal data, which is time series data of values ​​obtained by sampling a waveform of the received target signal, from the target signal, and writing the generated signal data into a signal storage means; Equipped with The deviation signal generating means reads the signal data from the signal storage means at the read timing, and generates the deviation signal using the read signal data.

3. A signal simulation device according to claim 1 or 2.

4. The control means uses the transition of the deviation amount to determine a transition of a frequency of a read clock that determines the read timing for reading the signal data from the signal storage means, and controls the read clock so that the frequency of the read clock transitions in accordance with the determined transition of the frequency.

4. The signal simulation device according to claim 3.

5. the signal receiving means generates the signal data by analog-to-digital conversion of the target signal at a write timing indicated by a write clock; the control means determines a transition of the frequency of the read clock from the frequency of the write clock and the transition of the deviation amount; The deviation signal generating means generates the deviation signal by performing digital / analog conversion on the signal data read out at the read timing.

5. The signal simulation device according to claim 4.

6. The deviation amount calculation means further uses information on the transition of the acceleration of the artificial satellite to calculate the transition of the deviation amount.

3. The signal simulation device according to claim 2.

7. the deviation amount calculation means further uses information on the rotation of the artificial satellite to calculate a transition of the deviation amount; The control means estimates a transition in the strength of the shift signal from information on the rotation of the artificial satellite, The shift signal generating means generates the shift signal such that the intensity of the shift signal transitions in accordance with the transition of the estimated intensity.

3. The signal simulation device according to claim 2.

8. The control means estimates a delay of the shifted signal relative to the target signal from a distance between the ground station and the artificial satellite; The shift signal generating means generates the shift signal having the estimated delay with respect to the target signal.

3. The signal simulation device according to claim 2.

9. receiving motion information including transmitter motion history information and receiver motion history information; Using the motion information, a change in the frequency shift of the target signal when the target signal is received by the receiver after being transmitted by the transmitter is calculated; a read timing for reading signal data, which is time-series data of values ​​obtained by sampling the waveform of the target signal, in a chronological order is controlled in accordance with a transition of the deviation amount; acquiring the signal data in chronological order in accordance with the read timing, and generating, from the acquired signal data, a shifted signal that is the target signal and in which a frequency shift occurs and in which a shift amount transitions in accordance with the transition of the calculated shift amount; outputting the shifted signal; Signal simulation method.

10. a motion information receiving process for receiving motion information including information on a transition of a motion of a transmitter and information on a transition of a motion of a receiver; a shift amount calculation process for calculating a change in a frequency shift amount that occurs in a target signal when the target signal transmitted by the transmitter is received by the receiver using the motion information; a control process for controlling a timing at which signal data, which is time-series data of values ​​obtained by sampling the waveform of the target signal, is read out in a chronological order in accordance with a transition of the deviation amount; a shift signal generation process for acquiring the signal data in chronological order according to the read timing, and generating, from the acquired signal data, a shift signal, which is the target signal and has a frequency shift whose shift amount changes according to the calculated shift amount; a signal output process for outputting the deviation signal; A program that causes a computer to execute the following.

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