WO2018199454A1

WO2018199454A1 - Hybrid passive/decoding delivery relay terminal for underwater magnetic-field communications, and method for relay thereof

Info

Publication number: WO2018199454A1
Application number: PCT/KR2018/002212
Authority: WO
Inventors: 신요안; 오선애
Original assignee: 숭실대학교산학협력단
Priority date: 2017-04-25
Filing date: 2018-02-22
Publication date: 2018-11-01
Also published as: KR20180119270A; KR101945102B1

Abstract

The present invention relates to a hybrid passive/decoding delivery relay terminal for underwater magnetic-field communications and a method for relay thereof. The method for relay using the hybrid passive/decoding delivery relay terminal for underwater magnetic-field communications comprises: a step in which the hybrid passive/decoding delivery relay terminal receives a magnetically induced signal from a transmission terminal; a step for delivering the received signal to a reception terminal and simultaneously storing same in a buffer during a first time slot; and a step for decoding and modulating the signal stored in the buffer and transmitting the modulated signal to the reception terminal during a second time slot. The present invention can improve the performance of magnetic-field communications in an underwater environment by reducing path loss as well as expanding the transmission distance of the magnetic-field communications in the dynamically changing underwater environment.

Description

Hybrid Passive-Decryption Relay Terminal for Underwater Magnetic Field Communication and Its Relay Method

The present invention relates to a hybrid passive-decryption relay terminal for submerged magnetic field communication and a relay method thereof, and more particularly, to improve communication performance while extending transmission distance of underwater magnetic field communication using passive-decryption relay terminal. The present invention relates to a hybrid passive-decryption relay terminal for improving underwater magnetic field communication and a relay method thereof.

Underwater sensor network collects various kinds of underwater information through underwater sensor and transmits it to the ground through underwater base station. Underwater information includes marine climate observation and ecological environment analysis, shipping industry information such as ship's route and territorial sea defense. It can be used in various areas such as the defense field.

In other words, through the underwater detection function, not only the temperature and flow of the sea water but also the earthquake waves can be used to make accurate predictions of natural disasters starting from the seabed and observation of the ocean climate, as well as quick response to ship accidents. Therefore, the interest of the underwater sensor network is increasing.

In general, data transmission for the underwater sensor network uses optical, electromagnetic, and acoustic techniques.However, in order to improve communication performance due to poor channel conditions in the underwater environment, magnetic induction is required. Magnetic field communication technology using Induction is most suitable.

Magnetic field communication technology is a transmission technology that is very interested in all environments, such as ground, underground, and underwater. Technically, the antenna size can be efficiently reduced and long distance high speed transmission is possible, and the antenna price is cheaper than other communication technologies. Therefore, it is evaluated as an economical technology.

However, underwater magnetic field communication is highly affected by propagation path loss. In particular, since the path loss of the magnetic field communication is not actually lost but is not sufficiently transmitted from the transmitting end to the receiving end, the transmission and reception power decreases when the transmission distance becomes far. The path loss of magnetic field communication is affected by operating frequency, transmission distance, coil antenna size, number of wire windings, coaxial nature of the transmitting and receiving coil antenna, and underwater environmental conditions. When propagated, eddy currents are generated, which causes problems with insufficient energy.

Therefore, in order to increase the efficiency of underwater exploration, the mobility and scalability of the underwater network is required, and a technique for increasing the accuracy of the underwater long-distance high-speed transmission technology is required.

The background technology of the present invention is disclosed in Korean Patent Registration No. 10-1284151 (July 10, 2013).

SUMMARY OF THE INVENTION The present invention provides a hybrid passive-decryption relay terminal and a relay method for underwater magnetic field communication, which extends the transmission distance of underwater magnetic field communication and improves communication performance by using the passive-decryption relay terminal. To provide.

According to an embodiment of the present invention for achieving the above technical problem, in the relay method using a hybrid passive-decryption relay terminal for underwater magnetic field communication, the hybrid passive-decryption relay terminal is a signal induced magnetically from the transmitting terminal Receiving, transmitting the received signal to a receiving terminal during a first time slot and simultaneously storing the received signal in a buffer, and decoding and modulating a signal stored in the buffer during a second time slot to transmit a modulated signal to the receiving terminal. Transmitting.

In the receiving of the magnetically induced signal from the transmitting terminal, the current induced by the coil antenna of the transmitting terminal may be received through the coil antenna in a magnetic field induction manner.

Blocking the power supply line during the first time slot to control the transmission of the received signal to the receiving terminal, and connecting the power supply line during the second time slot to decode the received signal and modulate the decoded signal. In addition, by applying an AC voltage to the coil antenna can be controlled to transmit a modulated signal.

When receiving a pilot signal before receiving the received signal, the method may further include generating information on the strength and magnetic field distortion of the pilot signal and correcting an axis of the coil antenna in response to the generated information. .

Receiving a self-derived signal from the transmitting terminal, receiving a signal from the transmitting terminal during the nth time slot, receiving a signal from the transmitting terminal during the n + 1 time slot, the nth time And comparing the signal received during the slot with the signal received during the n + 1th time slot, and requesting retransmission of the signal to the transmitting terminal when it is determined that the signal is not the same signal.

According to another embodiment of the present invention, a hybrid passive-decryption relay terminal receives a signal received from a transmitting terminal, the self-induced signal, and stores the received signal in a buffer during a first time slot, the buffer during a second time slot And a transmitter for decoding and modulating a signal stored in the transmitter, and a transmitter for transmitting the received signal to the receiving terminal during the first time slot and transmitting the modulated signal to the receiving terminal during the second time slot.

According to the present invention, it is possible to improve the performance of the magnetic field communication in the underwater environment by extending the transmission distance of the magnetic field communication in the dynamically changing underwater environment and reducing the path loss.

1 is an exemplary view showing the operation of a hybrid passive-decryption relay terminal according to an embodiment of the present invention.

2 is a block diagram showing a hybrid passive-decryption relay terminal according to an embodiment of the present invention.

3 is a flowchart illustrating a relay method of a hybrid passive-decryption relay terminal according to an embodiment of the present invention.

4 is a view for explaining the step S310 of FIG. 3 in detail.

5 and 6 are diagrams for comparing the path loss between the transmission method and the direct transmission method according to an embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

Hereinafter, the operation of the hybrid passive-decryption relay terminal in underwater magnetic field communication according to an embodiment of the present invention will be described in detail with reference to FIG. 1.

1 is an exemplary view showing the operation of a hybrid passive-decryption relay terminal according to an embodiment of the present invention. FIG. 1A illustrates a case where one hybrid passive passive decoding relay terminal 200 is used, and FIG. 1B illustrates a plurality of hybrid passive passive decryption relay terminals 200-1 and 200-2. In the case of using.

As shown in (a) and (b) of Figure 1, the underwater magnetic field communication according to an embodiment of the present invention is a transmission terminal 100, hybrid passive-decryption relay terminal (200: 200-1,200-2) and It includes a receiving terminal 300.

As shown in (a) of FIG. 1, the transmitting terminal 100 represents a terminal that collects underwater information through an underwater sensor and transmits a signal including the collected underwater information, and a hybrid passive-decryption relay terminal ( 200 denotes a terminal positioned between the transmitting terminal 100 and the receiving terminal 300 and serving as a relay to extend a transmission distance of a signal transmitted by the transmitting terminal 100. In addition, the receiving terminal 300 finally indicates a destination terminal to which the transmitting terminal 100 intends to transmit a signal.

First, when the transmitting terminal 100 applies an alternating voltage to the coil antenna, a magnetic field is formed, and the formed magnetic field induces a current to the coil antenna of the adjacent hybrid passive-decryption relay terminal 200. As such, when a current is induced, the hybrid passive-decryption relay terminal 200 selects a signal having the greatest intensity through a search process from the induced current and transmits the signal to the transmitting terminal 100 during the first time slot # 1. The same method transmits the received signal to the receiving terminal 300 in a self-induction method.

The hybrid passive-decryption relay terminal 200 decodes, modulates, and modulates a signal received during the second time slot # 2 to the receiving terminal 300.

That is, the receiving terminal 300 receives a signal from the hybrid passive type-decoding relay terminal 200 in the first time slot # 1 and the second time slot # 2.

On the other hand, Figure 1 (b) uses a plurality of hybrid passive-decryption relay terminal (200-1, 200-2) to extend the transmission distance of the magnetic field communication than (a).

Although two hybrid passive-decryption relay terminals 200 are shown in FIG. 1B, the number of hybrid passive-decryption relay terminals 200 may be adjusted according to the underwater communication environment.

According to FIG. 1B, the passive-decryption relay terminal 200-2 may receive a second time slot (# 1) and a second time slot from the hybrid passive-decryption relay terminal 200-1. If a signal is received during 2), it is determined whether the signal is the same by comparing the signals received in the first time slot # 1 and the second time slot # 2. If the hybrid passive-decryption relay terminal 200-2 determines that the two signals are the same, the hybrid passive-decryption relay terminal 200-2 sends a signal to the third time slot # 3 through the same process as the hybrid passive-decryption relay terminal 200-1. The signal is transmitted to the receiving terminal 300, the signal is decoded and modulated in the fourth time slot # 4, and the modulated signal is transmitted to the receiving terminal 300.

As such, the magnetic field communication according to the embodiment of the present invention may transmit and transmit a signal using at least one hybrid passive-decryption relay terminal 200 according to a distance to be transmitted.

Hereinafter, a hybrid passive-decryption relay terminal 200 for selectively transmitting a signal to an adjacent terminal or decoding and modulating the signal by using a power source will be described in detail with reference to FIG. 2.

As shown in FIG. 2, the hybrid passive-decryption relay terminal 200 may include a receiver 210, a controller 220, and a transmitter 230, and may further include an axis corrector 240.

First, the receiver 210 receives a magnetically induced signal from the transmitting terminal 100 through a coil antenna. That is, when a signal having the greatest intensity is selected through a search process in the current derived from the transmitting terminal 100, the selected signal is estimated as a received signal.

In addition, the reception unit 210 may compare the signal received during the nth time slot and the signal received during the n + 1th time slot and request a retransmission to the transmitting terminal 100 when the signal is not the same signal.

Next, the controller 220 stores the received signal in a buffer (not shown) during the first time slot, and decodes and modulates the signal stored in the buffer during the second time slot.

In addition, the controller 220 controls the connection with the power supply line to block the power supply line during the first time slot so that the received signal is transmitted as it is using magnetic field communication (Passive relay), and the power supply during the second time slot. The supply line may be connected to decode and modulate the received signal to transmit a modulated signal (DF: Decode and Forward relay).

The transmitter 230 transmits the received signal to the receiving terminal 300 during the first time slot and transmits the modulated signal to the receiving terminal 300 during the second time slot through a coil antenna.

If the axis correction unit 240 receives the pilot signal before receiving the received signal, the axis correction unit 240 may generate information on the strength and magnetic field distortion of the pilot signal, and correct the axis of the coil antenna in response to the generated information.

At this time, the axis correction unit 240 may correct the axis of the coil antenna by using a correction value corresponding to the information on the strength and magnetic field distortion of the pilot signal stored in a separate database.

Hereinafter, a method of performing magnetic field communication using a hybrid passive-decryption relay terminal in an underwater environment will be described in detail with reference to FIGS. 3 and 4.

3 is a flowchart illustrating a relay method of a hybrid passive-decryption relay terminal according to an exemplary embodiment of the present invention, and FIG. 4 is a view for explaining step S310 of FIG. 3 in detail.

As shown in FIG. 3, the hybrid passive type-decryption relay terminal 200 receives a magnetically induced signal from the transmitting terminal 100 (S310).

The hybrid passive-decryption relay terminal 200 may receive the current induced by the coil antenna of the transmitting terminal 100 through the coil antenna in a magnetic field induction manner.

The hybrid passive-decryption relay terminal 200 selects the largest signal from the induced current and estimates the received signal.

Meanwhile, as shown in FIG. 1B, in the communication between the hybrid passive type-decoding relay terminals 200-1 and 200-2, a magnetic field induction method is applied to the first time slot # 1 and the second time slot # 2. Receive the signal. That is, the hybrid passive-decryption relay terminal 200-2 receives a signal from the hybrid passive-decryption relay terminal 200-1 to the first time slot # 1 and the second time slot # 2. Receive a signal to

Hereinafter, the step S310 will be described in more detail with reference to FIG. 4 below. For convenience of description, the hybrid passive-decryption relay terminal 200-1 will be referred to as a transmission terminal 100, and the hybrid passive-decryption transmission will be described. The relay terminal 200-2 is referred to as a hybrid passive-decryption relay terminal 200.

As shown in FIG. 4, the hybrid passive-decryption relay terminal 200 receives a signal from the transmitting terminal 100 during an nth time slot (S311). The hybrid passive-decryption relay terminal 200 receives a signal from the transmitting terminal 100 during the n + 1th time slot (S312).

That is, the signal received in step S311 and the signal received in step S312 are the same signal, but the signal received during the nth time slot is simply a received signal, and the signal received during the n + 1th time slot is the transmitting terminal 100. Denotes the decoded and modulated signal.

Next, the hybrid passive-decryption relay terminal 200 compares whether the signal received during the nth time slot and the signal received during the n + 1th time slot are the same (S313).

That is, the hybrid passive-decryption relay terminal 200 may determine whether the received signal and the received signal are the same during each time slot.

As a result of the comparison, if it is determined that the hybrid passive-decryption relay terminal 200 is not the same signal, it requests a retransmission of the signal to the transmitting terminal 100 (S314).

When the hybrid passive-decryption relay terminal 200 is determined to be the same signal, the hybrid passive-decryption relay terminal 200 proceeds from step S310 to step S320.

Next, the hybrid passive-decryption relay terminal 200 transmits the received signal to the receiving terminal 300 during the first time slot and simultaneously stores the received signal in the buffer (S320).

During the first time slot, the hybrid passive-decryption relay terminal 200 cuts off the power supply line and transfers the received signal directly to the receiving terminal 300 through the magnetic field induction method. The hybrid passive-decryption relay terminal 200 temporarily stores the received signal in a buffer to compensate for the time difference between the first time slot and the second time slot.

Next, the hybrid passive-decryption relay terminal 200 decodes and modulates the signal stored in the buffer during the second time slot and transmits the modulated signal to the receiving terminal 300 (S330).

Here, the hybrid passive-decryption relay terminal 200 connects the power supply line during the second time slot to decode the received signal and modulates the decoded signal.

At this time, since the hybrid passive-decoding relay terminal 200 modulates in the same manner as the first received signal, the signal transmitted during the first time slot and the signal transmitted during the second time slot are substantially the same.

The hybrid passive-decryption relay terminal 200 transmits a modulated signal by applying an AC voltage to the coil antenna by connecting a power supply line during the second time slot.

On the other hand, if the hybrid passive-decryption relay terminal 200 receives the pilot signal before receiving the received signal from the transmitting terminal 100, it may generate information on the strength and magnetic field distortion of the pilot signal. The hybrid passive-decryption relay terminal 200 may correct the axis of the coil antenna to move and rotate in response to the information on the strength of the pilot signal and the magnetic field distortion.

Hereinafter, the path loss shown in the waveguide transmission method through the hybrid passive-decryption relay terminal and the direct transmission method of the transmitting terminal and the receiving terminal according to an embodiment of the present invention will be compared with reference to FIGS. 5 and 6.

FIG. 5A illustrates a case where the axes of the coils between a transmitter terminal and a receiver coil that perform direct communication are aligned in a line with each other. FIG. Under the same conditions as in FIG. 5A, the coaxial property of the coil antenna is broken and thus not disposed in a straight line (displaced).

And (c) of Figure 5 is a waveguide transmission method through the hybrid passive-decryption relay terminal according to an embodiment of the present invention, the coaxial property of the coil antenna is destroyed so that the axis of the coil of each terminal is not arranged in a straight line Indicated if replaced.

5A and 5B show that the distance between the transmitting terminal and the receiving terminal is r, the distance between the transmitting terminal and the hybrid passive-decryption relay terminal is r / 2 in FIG. Set the position of the hybrid passive-decryption relay terminal and perform simulation.

In this condition, a graph showing the path loss for each frequency band of the simulation result is shown in FIG. 6, and the result in the condition of FIG. 5 (a) is represented by a straight line (directly-MI; horizontally deployed). The result in the condition of (b) of (b) is shown as a red square (direct-MI; displaced), the result in the condition (c) of Figure 5 is shown as a black circle (MI-waveguide; displaced).

As shown in FIG. 6, when the magnetic field communication is performed using the hybrid passive-decryption relay terminal according to (c) of FIG. 5, it can be seen that path loss occurs on average.

Thus, according to the embodiment of the present invention, by extending the transmission distance of the magnetic field communication in the dynamically changing underwater environment and reducing the path loss, it is possible to improve the performance of the magnetic field communication in the underwater environment.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims

In the relay method using a hybrid passive-decryption relay terminal for underwater magnetic field communication,

Receiving, by the hybrid passive type-decoding relay terminal, a magnetically induced signal from a transmitting terminal,

Transmitting the received signal to a receiving terminal and simultaneously storing the received signal during a first time slot; and

And decoding and modulating a signal stored in the buffer during a second time slot to transmit a modulated signal to the receiving terminal.
The method of claim 1,

In the step of receiving a magnetically induced signal from the transmitting terminal,

The relay method for receiving the current induced by the coil antenna of the transmitting terminal through the coil antenna in a magnetic field induction method.
The method of claim 1,

Cut off a power supply line during the first time slot to control the reception signal to be transmitted to the reception terminal;

And connecting a power supply line during the second time slot to decode the received signal, modulate the decoded signal, and apply an alternating voltage to a coil antenna to transmit the modulated signal.
The method of claim 3,

If the pilot signal is received before receiving the received signal, generating information on the strength and magnetic field distortion of the pilot signal, and further comprising correcting the axis of the coil antenna in response to the generated information .
The method of claim 4, wherein

Receiving a self-derived signal from the transmitting terminal,

Receiving a signal from the transmitting terminal during an nth time slot,

Receiving a signal from the transmitting terminal during an n + 1 time slot;

Comparing the signal received during the nth time slot with a signal received during the n + 1th time slot, and

Requesting retransmission of the signal to the transmitting terminal if it is determined that the comparison is not the same signal.
Receiving unit for receiving the self-induced signal from the transmitting terminal,

A controller which stores the received signal in a buffer during a first time slot and decodes and modulates a signal stored in the buffer during a second time slot;

And a transmitter for transmitting the received signal to a receiving terminal during the first time slot and transmitting a modulated signal to the receiving terminal during the second time slot.
The method of claim 6,

The receiving unit,

Hybrid passive-decryption relay terminal for receiving the current induced by the coil antenna of the transmitting terminal through the coil antenna in a magnetic field induction method.
The method of claim 6,

Cut off a power supply line during the first time slot to control the reception signal to be transmitted to the reception terminal;

And connecting a power supply line during the second time slot to decode the received signal, modulate the decoded signal, and apply an alternating voltage to a coil antenna to transmit the modulated signal.
The method of claim 8,

If the pilot signal is received before receiving the received signal, the hybrid passive type further comprises a correction unit for generating information on the strength and magnetic field distortion of the pilot signal, and correcting the axis of the coil antenna in response to the generated information Decryption relay terminal.
The method of claim 9,

The control unit,

When a signal is received from the transmitting terminal during the nth time slot and a signal is received from the transmitting terminal during the n + 1th time slot, the signal received during the nth time slot and the received signal during the n + 1th time slot are received. And comparing the signals and controlling to request retransmission of the signals to the transmitting terminal when it is determined that the comparison is not the same signal.