JPS63273999A - Information transmitter - Google Patents

Abstract

PURPOSE:To facilitate data communication and to improve the transmission speed by performing the data communication which does not require any identification code for the kind of data by utilizing a high-accuracy time signal that a GPS receiver outputs. CONSTITUTION:A transmission-side ship 1 is equipped with a GPS receiver B and a reception-side ship 2 is also equipped with a GPS receiver H. A transmission-side ultrasonic wave transmitter E sends plural pieces of information as a constant time-series signal which accords with the time of the GPS. A reception-side ultrasonic wave receiver L, on the other hand, receives the sent time-series signal as plural pieces of information according to the corresponding time of the GPS. Then plural pieces of information are transmitted and received by the transmitter E and receiver L by the discrimination of the GPSs in time series. Consequently, the data communication which does not require any identification code for the kind of data is enabled, so the data communication is facilitated and the transmission speed is improved.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention utilizes a highly precise time signal output from a GPS receiver (hereinafter simply referred to as GPS) to perform data communication that does not require an identification code to indicate the type of data. More specifically, both the data (information) transmitter and receiver have GPS, and the type of information transmitted from the transmitter and the time at which the information is transmitted are predetermined. The receiving side also knows this, and either the receiving side knows in advance the maximum value of the transmission delay time, or it assumes that it is sufficiently small compared to one information transmission cycle, and the receiving side uses GPS. The present invention relates to an information transmission device capable of receiving information based on an output high-precision time signal, the type and time of received information, and delay time.

(Prior Art) When a conventional information transmission device transmits and receives multiple pieces of information at the same time, a means for mutually identifying the information is provided, which makes the structure of the device complicated and, in some cases, The disadvantage was that the transmission speed was slow.

GPS, a recently proposed satellite navigation system, is called the Global Positioning System.
m (global positioning system), satellite navigation that uses a high-precision clock to passively measure the distance between the satellite and the user (without the user transmitting radio waves) It is a system.

All NAVSTAR satellites, which are GPS satellites, have atomic clocks (2 cesium atomic clocks and 2 rubidium atomic clocks).
It is scheduled to be equipped with. The clocks on these satellites have been proven to have a stability of about IQ-13 per day, so the clocks on these satellites have a daily stability of Ions (nanoseconds, IO-8
), and that lead/lag can be compensated for by the thick molecule.

GPS consists of a space part, a control part, and a user part.The control part is an unmanned ground station facility that receives signals from satellites and monitors the status of the clock on the satellite and the orbit of the satellite. related data to the main control station.

The main control station predicts the future state of the satellite's clock and the satellite's position based on the data from the monitor stations at these various locations, and stores these predicted values in the memory on the satellite from one of the unmanned ground antennas. Send to. The ground antenna also receives telemetry signals from the satellite and transmits command signals for operation of the satellite.

The space part is a satellite, and the atomic clock on the satellite is 10.2
3MI (oscillates at the frequency of z, and the transmission frequency is 1572.42Ml-1z(L,), which is 154 times that frequency, and 120
It is 1227 times as high as 6 MHz (L y). The reason why two frequencies are transmitted is to correct the propagation delay of radio waves in the ionosphere.

The ranging signal is a binary code similar to noise, called a pseudo-noise (PN) code, in which the same number of 0's and 1's are randomly generated. Two types of PN codes are transmitted from the satellite. One of them is a signal called P code, which is a fast code of 10.23 megabits (Mb) per second.
It is a long code with a length of one week. The other signal has a speed of 1.023 Mb/s and a length of ms (millisecond, one-tenth of a second), and is called the C/A code.

A is said to be a signal that captures (Aquisi[1on) (the P signal). When using P code,
First, after receiving the C/A code, an operation is performed to move to the P code. It is said that this C/A code will be available for civilian use. However, since the O/A code beam is not transmitted at the same frequency, the ionospheric error is corrected by another method.

The C/A code and P code are further superimposed with the broadcast ionosphere from the satellite in binary code at a speed of 50 b/s. This data circulates every 30 seconds (1,500 bits) and is called one frame. This frame is further divided into 5 subframes every 6 seconds, subframe 1 is mainly correction data for predicting the satellite clock, and subframes 2 and 3 are prediction data for calculating the satellite orbit. Contains. subframes 4 and 5
The contents change every frame and return to the previous data at the 25th frame. Therefore, both subframes alone require 12.5 minutes to acquire all of their data.

(Structure of the Invention) The present invention utilizes such a GPS, and the transmitting side and the receiving side each have a GPS, and the transmitting side transmits a plurality of pieces of information as a constant time series signal according to the GPS time. On the receiving side, a means for receiving the time-series signal as a plurality of pieces of information is provided according to the time corresponding to the GPS, and a plurality of pieces of information are transmitted by the above-mentioned means.
This is a newly created information transmission device characterized by transmitting and receiving based on PS time series identification. Further, as a preferred embodiment, in the above-mentioned information transmission device, the transmitting side is provided with means for sequentially encrypting a plurality of pieces of information, and the receiving side is provided with a means for sequentially encrypting a plurality of pieces of information in correspondence with the above-mentioned encryption. It is characterized in that it is provided with means for decoding it as information. Therefore, the information transmission device of the present invention uses the high-precision time signal outputted by the GPS to perform data communication that does not require an identification code for the data type, and also uses the high-precision signal outputted from the GPS. Data communication is performed by encrypting data, and the types of data transmitted include a) sensor output data b) general data (ship name, size of ship, amount of catch, date of return to port, etc.) Yes, and the means of communication that can be used are a) light (direct waves) b) nitrogen (radio waves) C) sound (including ultrasonic waves), and the data transmission formats are a) amplitude b) Frequency (analog) C) Frequency (digital) d) Period e) Pulse width can be used, therefore, the transmission method, communication means, and transmission form of various devices as shown in Table 1 on the next page. Data can be transmitted depending on the combination.

(Margins below) Table 1 (Effects of the Invention) The present invention, which has the above-described configuration, does not require a special means for identifying multiple pieces of information, making this type of data communication easier than before. It is something that can be done. In particular, the transmission speed is slow when communicating using a medium with a slow propagation speed such as sound or when communicating in a state with a poor S/N ratio, but the present invention eliminates the need for an identification code in such cases, improving the transmission speed. be done. Furthermore, in the present invention, when data is superimposed on the radar's original signal, it is easy to superimpose data because there is no identification code. In addition, this means that in addition to radar, sonar,
The same applies to laser radars and the like.

(Example) Hereinafter, the present invention will be explained in detail with reference to the drawings.

First, as an embodiment of the information transmission device according to the present invention,
The case where information is transmitted from ship 1 to ship 2 as shown in FIG. 1 will be explained.

In Figure 1, the ship on the transmitting side is GPS antenna A.
and GPS receiver B, while the laser.

It is equipped with a transmitter C and an antenna D for aerial communication such as radar and radio, as well as an ultrasonic transmitter E for underwater communication such as sonar, and further accommodates an information source F such as memory and sensors. Ship 2 on the receiving side has a GPS antenna G and a GPS receiver! 4, and an antenna J and a receiver K for aerial communication.
It is equipped with an ultrasonic receiver for underwater communication, and also houses an information display device M such as a cathode ray tube and printer.

Now, regarding the case where two pieces of information are transmitted in the form of signal amplitudes between the two ships 1.2, the transmitting side in FIG. 2(a) and the receiving side in FIG. 2(b) will be described. In the circuit mounted on the ship l shown in Fig. 2(a), the information source F is the sensor l.
This is data such as sea temperature, water depth, salinity, and catch amount obtained in 1.12. 16 is an amplifier. Sensor 11. The two data obtained in +2 are passed through the switch 13 as a switching means as one time-series signal, that is, data d at 91 in the period and data d at 99 in the next period appear as a series of signals. In the top continuous state, the transmitting means 14
send to The switching operation of the switch 13 is performed according to the GPS time. That is, based on the momentary time signal as shown in FIG. 8(A) received by the GPS receiver 15, a pulse signal of a constant period as shown in FIG. 8(B) is obtained, and this pulse signal is used to control the switch. Transmission means 1 by operating 13
Only when the sensors 11 and 12 are connected to the transmitting means 14, the data of the respective sensors 11 and 12 is sent to the transmitting means 14 and transmitted to the receiving ship 2. to be sent to.

In the circuit installed on the ship 2 shown in FIG. 2(b), the time-series signals transmitted from the transmitting means 14 received by the receiving means 17 are separated via a switch 18, and two rows of latches are applied. (19) Bow 10M (20) Display (The corresponding data is sent to the two circuits. In other words, the switching operation of the above switch is performed according to the GPS time, and the data received by the GPS receiver 22 is Based on the instantaneous time signal as shown in FIG. 8(A), a pulse signal of a constant period as shown in FIG. switch 18
to switch. At this time, if there is a time difference between the transmitting side and the receiving side, a delay means (not shown) may be provided in the receiving side circuit to absorb the time difference. In any case, data d1 at 91 o'clock in the period, data d at 94 o'clock in the next period.
, as a series of signals, one time-series signal received by the receiving means I7 is switched by the receiving switch 18 by the GPS 22, and the signal is transmitted for a period p.

At the same time, data d is transferred to the first latch/ROM/display circuit (1
9a, 20a, 21a), while the initator d during period p7 is sent to the second latch/ROM/display circuit (19b).

20b, 21b). When the transmission form of the above-mentioned time-series signal is amplitude, as shown in Fig. 3(a), the start bit of the rising edge of the pulse signal is set to 1, and the stop bit of the falling edge of the pulse signal is set to 0, and various communication means are used. Through, ie, light, Ti Qi.

When transmission and reception are performed as sound signals, and when the transmission form is an analog frequency, as shown in Figure 3(b),
Transmission is performed as a specific frequency, and for frequencies where the transmission form is digital, for example, the high frequency is set to I and the low frequency is set to 0, as shown in FIG. 3(C). In addition, if the transmission form is an analog period,
As shown in FIG. 3(d), transmission is performed as a pulse signal with a specific period, and when the transmission form is an analog pulse width, as shown in FIG. 3(e), a specific period is transmitted. Transmission is performed as a pulse signal having a pulse width.

Furthermore, the present invention is a transmission nostem that transmits a signal from an underwater transmitter E to a ship 2 as shown in FIG. It can be applied in any case.

In this case, there is a GPS antenna G and a GP on the receiving ship 2 side.
S receiver■] and ultrasonic receiver for underwater communication! The underwater object 4, which is equipped with an ultrasonic transmitter E underwater, is equipped with a GPS receiver B and a sensor F, and is also equipped with a GPS receiver B and a sensor F.
A GPS antenna A connected to a receiver B is installed on a float 3 floating on the water, and as in Fig. 1, the GPS is used as a type of identification signal to connect an underwater ultrasonic transmitter E and an ultrasonic receiver on the ship. Enable multiple pieces of data to be sent and received between devices.

Therefore, the information transmission device shown in the above embodiment is equipped with GPS receivers B and I-1 on the transmitting side and the receiving side, respectively, and the transmitting side transmits a plurality of pieces of information in a fixed time series according to the GPS time. While transmitting as a signal, on the receiving side the above G
G
By identifying the PS in time series, it is possible to classify and confirm the information into a plurality of pieces of information.

Next, when transmitting encrypted data, as shown in FIGS. 5(a) and (b), the sending side provides means for encrypting the signal, and the receiving side provides means for decoding the encrypted signal. establish. On the transmitting side of FIG. 5(a), the analog signal from the sensor is digitized by the A/D 24, and then the digital signal is encoded based on the instantaneous time signal of the GPS I 5. The corresponding ROM (2
5) manually and the ROM 25a. 25b performs certain conversions and encrypts the digital signal, then the GPS t
The encrypted digital signal is sequentially sent from the ROMs 25a and 25b to the D/A 26 via the switch 13 controlled by the pulse signal of 5. The D/A 26 converts the signal into an analog signal once again, and the transmitting means 14 converts the signal into a series of signals. Ship I as a time series signal
Have it sent to the side. On the receiving side in FIG. 5(b), the series of time-series signals received by the receiving means 17 are sent to the A/D 2.
9 and the corresponding R whose decoding changes based on the instantaneous time signal of the GPS 22 through the latches 27a and 27b.
Manually input to OM28a, 28b, and write the ROM28a, 28b
After decrypting the input signal in accordance with the encryption on the transmitting side, the switch 1 controlled by the pulse signal of the GPS 22
8, the decoded signals are sequentially displayed on the display means 21. The ROMs 28a and 28b on the receiving side are connected to the corresponding ROMs 25a and 25b on the sending side in a so-called reverse r.
It forms a ZOM, and the display means 21 includes
Multiple pieces of decrypted data will be displayed one after another for a certain period of time. In this case as well, it goes without saying that delay means, various transmission objects, and transmission systems can be applied, as in FIG. Therefore, in addition to the information transmission device shown in FIG. 2, the above embodiment is further provided with a means for sequentially encrypting a plurality of pieces of information on the transmitting side, and a means for sequentially encrypting a plurality of pieces of information on the receiving side. By providing means for sequentially decoding several pieces of information, a plurality of pieces of data can be encrypted and sent and received by identification based on GPS time series.

Next, FIG. 6 shows an embodiment in which an analog frequency is used for the transmission form, in which a V/F converter 30 and a modulator 32 are connected in series as the transmitting means I4 in FIG. 2(a). On the other hand, the demodulator 33 and the period measuring device 34 are connected in series and used as the receiving means 17 in FIG. 2(b).

31 is a monostable multivibrator. FIG. 7 shows a specific circuit of the period measuring device, and FIG. 8 shows a signal waveform diagram in the circuit of FIG. 7.

In Fig. 7, the 1 marks are A, E, and F shown in Fig. 8.

Indicates that the operation is performed at the rising edge of the G isovolume signal pulse, and the O mark of the 0LEArt input indicates F'/ when the pulse is "L".
F and counter are cleared (counter count output Cout=
0. F/F Q output = “L”). On the receiving side, the pulse period is measured, and the pulse period measured when the 10° digit of the second of the time is an odd number is stored in the latch and ROM.
The value of sensor 1 is displayed on the sensor 1 display through the sensor 1 display, and the value of sensor 2 is displayed on the sensor 2 display through the latch and ROM, and the pulse period measured at an even number is displayed on the sensor 2 display. Further, the ROM converts the pulse width into sensor information and outputs it.

In FIG. 8, signals A and B are output from the GPS 22 and are the same on both the transmitting and receiving sides. Switches 13 and 18 in FIGS. 5 and 6 are switched by the B signal, and the
” when the 1 side is “L”, it is connected to the 2 side. The pulse width te of the E signal is larger than the transmission delay tdmax between transmitting and receiving, and the pulse width t of the F signal is the longest among the information. longer than the pulse period.

Furthermore, the pulse width of the G signal becomes the measurement pulse period, and in order to measure this pulse period, a clock with a pulse period of lll1 sec is used. Note that a block diagram similar to that in FIG. 6 is also used when a period is used as the transmission form.

FIG. 9 shows an embodiment in which a digital frequency is used for the transmission form, and FIG. 9(a) shows a soft register 40, switch 36, and two
The shift register 40 connects either of the two oscillators 41, 42 to the modulator 32 via the switch 36, while the ) includes a demodulator 33, a bandpass filter 43, and a detector 4 as the receiving means in FIG. 5(b).
4, an A/D converter 46, and a shift register 45 are connected in series.

Note that, as a method of outputting the GPS time signal, it is processed by the CPU control circuit shown in FIG. 10, for example. That is, in FIG. 10, the GPS receiver can know the distance to each satellite and the rate of change in distance by measuring the reception timing of the PN code from the four GPS satellites and the Doppler frequency of the transmission frequency. However, since this measured value is obtained based on the clock signal within the receiver, it includes errors such as offset. Therefore, these obtained distances are called pseudo distances, and the rate of change in distance is called a pseudo distance change rate.

If the pseudo distance to the satellite is Rn, then Rn=nN+CX△t +C△t・・・・・・・・・・・・(1) xi, yi, zi: Position of satellite i Xo * Yo + Zo: Receiver antenna position C
: Speed of light △t: Clock errors xi, yi, and zi in the receiver become known by knowing the transmission time from the satellite, and ``OJO, Z(1, △t are the four unknown quantities.

Therefore, equation (1) can be solved by knowing xi, yl, and zi for the four satellites.

The pseudo distance change rate can also be determined as a three-dimensional velocity using a similar method.

In this way, X. The three-dimensional position of +yo+Zo, the offset value of Δt, and its own speed can be found.

By knowing the offset value of Δt, the deviation from the GPS time is known, so it is possible to adjust the clock in the receiver to match the GPS time (which is maintained within a difference of 160 μs in Coordinated Universal Time).

In this way, a GPS receiver can obtain accurate latitude, longitude, and altitude, as well as its own moving speed and accurate time.

After the GPS signal received by the antenna is amplified, it is
The frequency is converted by the l mixer.

Since the GPS signal is subjected to spectrum spreading using a PN code, this demodulation is performed first.

Since the PN code is unique to each satellite, the CP
Use U to select the code. Next, since the PN code is a pulse train of 1 chip (976 ns) and 1023 chips (1 ms), it is necessary to align the start point of this code with the start point of the code from the satellite.

The CPU checks the code match signal while changing the PN code start point and determines whether the code matches.

Next, the phase of the PN code clock (the phase with a period of 976 ns per chip) is adjusted to determine the phase amount that maximizes the A/D conversion output of the code matching signal. Human power for A/D conversion is PN
After the code and the signal multiplied by m of the PSC output are mixed at M3, they are mixed with the GPS signal at M2, and the spread spectrum signal is despread (de-R) so that the existence of the received signal is known.

By detecting the maximum value of A/D conversion at the start point and phase adjustment of the PN code, the delay time of the code from the satellite (I
(within ms). Next, the received signal squared by the M4 mixer is sent to the PLL consisting of the VCO and M5.
The carrier is demodulated in the circuit.

By demodulating the carrier, it is possible to measure the Doppler frequency from the difference in the position of each satellite, which becomes the basis for measuring its own three-dimensional velocity. On the other hand, the output of the VCO is 172
By mixing the multiplied and 90° phase-shifted carrier with M6, information from each satellite (time, satellite position, satellite orbit information, parameters, etc.) that is phase modulated with 501-1z can be obtained. .

The time is the time information from the satellite (in 1.5 s units every 6S) and the timing of this time information.
By knowing the time within the code pulse train), the time to know the position of each satellite can be found.

This series of operations is performed for the four satellites, and the measurement is completed by knowing each satellite's information, Doppler frequency, and time information. It is not necessary to know satellite information all the time, and it is sufficient to know it every 30 minutes. The latter two need to be measured each time.

The IS correction value can be determined by knowing ΔL for outputting the time pulse and by knowing the offset error of the clock in the receiver. Next, as shown in FIG. 11, a major correction of the rise of IS is made by first knowing the time after the next 6S in units of 1.5s with an error within 1IIls from the time information from each satellite. In Figure 1θ, at the rising edge of Is at the satellite time, CP
If you input the side bar to U, it is possible to determine the difference from the GPS time with an error of less than 1 ms, so set the correct time after the next 6S (adjust the advance using a shift register, counter, etc.). Generally, ±10On for GPS receivers
It is possible to synchronize the rise of the tS pulse with the GPS time within an error of +s.

In addition, as shown in Fig. 12, the pulse position of Is obtained on the receiver side as the timing on the receiver side corresponding to the output timing on the satellite side, the values of B and D are fixed, and the value of A is The value of B is (preamble + α), which is approximately 180m5°D, which is the delay time due to the length of the cable from the antenna to the receiver.

Synchronization with the true tS pulse can be achieved by setting the delay amount of toout=15-A-B-D.

Since a GPS receiver requires a stability of approximately to-1' as O20, synchronization of approximately ±100 ns is possible by measuring and correcting the amount of delay every 10 seconds.

As for the time information itself, it is necessary to output the time before Is in consideration of the delay.

If you only want to output a time pulse, if you know the satellite's position that can be determined from the received signal from any one satellite and your own exact position, you can find out the amount of delay in the time pulse from the satellite. , the time pulse can be corrected. By demodulating the received PN code, the timing pulse and its time can be determined. This situation is shown by comparing the time timing on the satellite side and the received timing.

As described above, the information transmission device according to the present invention has a simple configuration and can achieve the intended purpose.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram for transmitting information from ship to ship as an embodiment of the information transmission device of the present invention, and FIG. 2(a)
, (b) are circuit diagrams of the transmitting side and receiving side of Fig. 1, respectively;
3(a) to 3(e) are waveform diagrams illustrating data transmission formats, FIG. 4 is an explanatory diagram for transmitting information from underwater to a ship as a modification of FIG. 1, and FIG. 5 (a) , (
b) is a circuit diagram of the transmitting side and the receiving side when the signal is encrypted as a modification of Fig. 2, and Figs. 6(a) and (b) are transmission diagrams as a partial modification of Fig. 2. A circuit diagram of the transmitting means and receiving means when an analog frequency is used for the shape, FIG. 7 is a circuit diagram of the period measuring instrument of FIG. 6, and FIGS. 8 A to G are,
Signal waveform diagram in the circuit of Fig. 7, Fig. 9(a)
, (b) is a circuit diagram of a transmitting means and a receiving means when a digital frequency is used for the transmission form as a partial modification of FIG. 2, and FIG. 10 is a circuit diagram of a CP that outputs a GPS time signal.
U's control circuit diagram, Figures 1f (a) and (b) are waveform diagrams of the time pulse satellite and receiver internal clock, and Figure 12 is the
FIG. 3 is a waveform diagram of timing on the receiver side corresponding to output timing on the satellite side. ■...Ship, 2...Ship, 3...Float, 4...
Underwater object, A...GPS antenna, B...
GPS receiver, F...information source, E...ultrasonic transmitter, L...ultrasonic receiver, M...information display device,
It, 12...Sensor, 15.22...GPS
, 14... Transmitting means, 17... Receiving means,
2I...display.

Claims (2)

[Claims] (1) The transmitting side and the receiving side are each equipped with a GPS receiver, and the transmitting side is provided with means for transmitting a plurality of pieces of information as a fixed time series signal according to the GPS time, while the receiving side Information transmission characterized in that means is provided for receiving the time-series signal as a plurality of pieces of information according to the time corresponding to the time, and the plurality of pieces of information are transmitted and received by both of the above-mentioned means by identification based on the GPS time series. Device. (2) In the information transmission device according to claim (1), the transmitting side is provided with means for sequentially encrypting a plurality of pieces of information, while the receiving side is configured to handle the above-mentioned encryption for the time-series signal. and is provided with means for sequentially decoding it as multiple pieces of information.