KR20190060144A - Buoy apparatus for relaying communication - Google Patents

Abstract

According to an embodiment of the present invention, provided is a communication relay buoy apparatus, which comprises: a floating body which can float on the water surface; a sensor array unit installed at a lower portion of the floating body and receiving signals transmitted from different directions in the water, when the floating body is floating on the water surface; a matching filter unit processing to match the signals received from different directions through the sensor array unit; a delay compensation unit performing delay compensation on the signals processed to match from the matching filter unit and outputting delay compensation signals; and a signal combination unit combining the delay compensation signals.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a communication relay apparatus,

The present invention relates to a communication relaying apparatus.

Spatio - temporal variability of multipath in underwater acoustical communication channels is a major environmental factor that affects communication performance. Sea surface variation, tide, salinity and water temperature, and reflection media characteristics of the seabed have temporal and spatial variation characteristics and change the characteristics of each channel of the transmission signal transmitted by underwater multipath.

It is also influenced by extraneous factors such as the depth and distance of the transmitter and receiver, the frequency of the transmitted carrier, and the location of the underwater system with mobility. Other environmental factors that affect the performance of underwater acoustic communication include absorption loss, background noise, and Doppler.

As shown in FIG. 6, the underwater multipath channel has temporal and spatial variation characteristics due to sea surface variation, depth variation due to tide, movement of the transmitter / receiver, irregularity at the reflection boundary, It affects the time delay. As a result, in a time-varying multipath channel, the transmit frequency has a Doppler spread and a phase shift.

Therefore, each symbol signal of digital underwater acoustic communication is subjected to a phase change, and each symbol signal is delay spread by a multipath, so that a coherence bandwidth of a communication channel is limited and inter symbol interference do.

The performance of a communication system in an underwater multipath channel with spatio - temporal variation characteristics is affected by frequency selective and fading of the channel.

In this underwater acoustic communication environment, a phase modulation method, such as phase shift keying (PSK), which is robust against underwater multipath environments and has good band efficiency and is suitable for high-speed digital transmission, is applied to an underwater acoustic communication system have.

However, phase and frequency fluctuations occur due to environmental fluctuations in the water and movement of the transceiver. For example, information transmission between a bus and an AUV (Autonomous underwater vehicle) is affected by changes in the underwater environment and the movement of the robot in the space-time marine acoustic communication channel environment.

Patent Publication 10-2012-0033810 (public date: April 09, 2012)

The communication relaying apparatus according to the embodiment of the present invention relays communication accurately and stably even when the phase and the frequency vary due to environmental fluctuations in the water and movement of the transceiver.

The task of the present application is not limited to the above-mentioned problems, and another task which is not mentioned can be clearly understood by a person skilled in the art from the following description.

According to an aspect of the present invention, A sensor array unit installed at a lower portion of the float to receive signals transmitted in different directions in the water when the floater is floating on the water surface; A matched filter unit for matching signals received from different directions through the sensor array unit; A delay compensation unit for performing delay compensation on the signals subjected to the matching processing from the matched filter unit and outputting delay compensation signals; And a signal combining section for combining the delay compensation signals.

The sensor array unit includes a housing in which a plurality of sensors are provided, the plurality of sensors each receiving signals in different directions, and the plurality of sensors includes first group sensors and second group sensors The first group sensors are arranged to intersect a virtual horizontal plane passing through the center of the housing and the second group sensors are arranged to cross a virtual vertical plane passing through the center of the housing and perpendicular to the virtual horizontal plane.

The matched filter unit may extract the phase synchronization point by correlating the signals received from the different directions with the matching signal.

The delay compensation unit may shift the phases of the matched signals based on the fastest phase synchronization point among the phase synchronization points of the matched signals.

The communication relay unit according to an aspect of the present invention may further include a position sensing unit for sensing a position of the underwater transmission device through the phase and intensity of the matched signals.

The communication relay unit according to the embodiment of the present invention can accurately and reliably relay the communication through the sensor array unit and the matched filter unit even if the phase and the frequency vary due to environmental fluctuations in the water and movement of the transceiver.

The effects of the present application are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the following description.

1 shows a communication repeater unit according to an embodiment of the present invention.
Figure 2 shows a housing with a sensor array.
3 shows a block diagram of a communication relay subsystem according to an embodiment of the present invention.
4 is a diagram for explaining application of space-time diversity.
5 is a diagram for explaining a method of locating a transmitting apparatus.
Figure 6 shows an underwater multipath channel.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It is to be understood, however, that the appended drawings illustrate the present invention in order to more easily explain the present invention, and the scope of the present invention is not limited thereto. You will know.

Also, the terms used in the present application are used only to describe certain embodiments and are not intended to limit the present invention. The singular expressions include plural expressions unless the context clearly dictates otherwise.

In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

1 shows a communication repeater unit according to an embodiment of the present invention. Figure 2 shows a housing with a sensor array. 3 is a block diagram of a communication relay subsystem according to an embodiment of the present invention.

1 to 3, the communication relay unit according to the embodiment of the present invention includes a float 100, a sensor array unit 200, a matched filter unit 300, a delay compensation unit 400 and a signal synthesizer 500. [

The float 100 may float on the surface of the water. Such float 100 may be made of materials and structures that generate buoyancy, and is a general matter to a person skilled in the art, and a detailed description thereof will be omitted.

The sensor array unit 200 is installed under the float 100 and receives signals transmitted in different directions in the water when the float 100 floats on the surface of the water. The sensor array unit 200 may be installed according to a spatial arrangement for receiving signals transmitted in different directions. This will be described in detail later.

The matched filter unit 300 performs matching processing on signals received from different directions through the sensor array unit 200. To do this, the matched filter unit 300 performs an impulse response in which the input signal s (t) is inverted (-t) on the time axis and a time delay T is applied thereto, that is, h (t) = s .

The delay compensation unit 400 performs delay compensation on the matched signals from the matched filter unit 300 and outputs delay compensation signals.

The signal combiner 500 combines the delay compensation signals.

Also, as shown in FIG. 1, the communication relay subunit according to the embodiment of the present invention may further include a solar generator 10 and a transmission antenna 20. The communication relay unit according to the embodiment of the present invention can operate in water and is difficult to be connected to the on-ground power grid, so that the power required for operation can be supplied from the solar generator 10. The transmission antenna 20 can transmit the synthesized signal to the outside through the signal combining unit 500. [

As described above, the influence of the phase, frequency variation, fading, etc. of the communication signal on the spatial and temporal environment variation due to environmental factors of the underwater multipath channel can make the phase of the phase modulation scheme unstable.

In order to prevent this, a plurality of sensors 210 may be provided in the housing 230 to receive signals in different directions. 1 and 2, the sensor array unit 200 includes a housing 230 having a plurality of sensors 210 therein, and the plurality of sensors 210 includes a plurality of sensors 210, (211) and second group sensors (213). At this time, the directions in which the plurality of sensors 210 receive signals may be different from each other.

The first group sensors 211 are arranged to intersect a virtual horizontal plane passing through the center of the housing 230 and the second group sensors 213 are arranged to cross the virtual vertical plane passing through the center of the housing 230 and perpendicular to the virtual horizontal plane. Respectively.

As shown in FIG. 2, a sensor disposed at a position where a virtual horizontal plane intersects with a virtual vertical plane among the plurality of sensors 210 is included in the first group sensors 211, and is included in the second group sensor 213 .

In order to arrange the sensors 210 arranged in this manner, the housing 230 may have the shape of a quasi-regular polyhedron. The sensors 210 may be installed adjacent to or attached to the housing 230 of the quadrangular pyramid, which is a double-cut quasi-regular polyhedron. The shape of the housing 230 is only one example, but is not limited thereto.

Through the plurality of sensors 210 arranged in this way, the communication relay subunit according to the embodiment of the present invention solves inter-symbol interference and phase locking by the multi-path reflected wave, It is possible to apply time diversity and spatial diversity for ensuring performance in demodulation.

Unlike the embodiments of the present invention, if the sensor is disposed in only one direction or if the number of directions in which the sensor is disposed is not sufficient, the signal may not be detectable or accurate. This is because the signals transmitted in the water are received in different paths, so that if the number of directions received or received in one direction is not sufficient, the sense of direction may be lost.

Meanwhile, the matched filter unit 300 may extract the phase synchronization point by correlating signals received from different directions with the matching signal. That is, the matched filter unit 300 can apply time diversity. As shown in FIG. 4, the signals transmitted in the water can be received by the respective sensors 210 arranged in the horizontal and vertical directions with a time difference.

The matched filter unit 300, the delay compensation unit 400 and the signal combining unit 500 time-delay the received signals of the respective sensors 210 after matching processing of the received signals, It is possible to improve the reliability of the demodulation of the signal.

The matched filter unit 300 finds a phase synchronization point of each reception signal input to the sensor 210 with a time difference and the delay compensation unit 400 time delays the reception signal of each sensor 210 And phase matching can be performed based on the derived phase synchronization point. That is, the delay compensation unit 400 can shift the phases of the matched signals based on the fastest phase synchronization point among the phase synchronization points of the matched signals.

Also, the communication relay subsystem according to the embodiment of the present invention can apply spatial diversity. That is, the intensity of a signal received through the sensor 210 arranged at regular intervals in the horizontal and vertical directions differs for each sensor 210.

The performance can be secured by matching the reception signals having different signal intensities through the matched filter and adding the delay compensation signals through the signal combining unit 500. [ This can alleviate the fading effect of the received signal due to the temporal and spatial variation of the underwater multipath.

That is, in the case of underwater, a transmission signal by a multipath includes various changes in frequency, amplitude, and phase depending on the characteristics of the reflector, and thus fluctuation of the received signal occurs. Time and space diversity is applied to minimize the effect of such variations and to improve performance.

  Since the energy of signals received by the sensors 210 is different for each space-time diversity, energy can be extended through addition of the received signals, so that signals can be smoothly extracted during demodulation.

Meanwhile, as shown in FIG. 5, the position detecting unit 600 may further include a position sensing unit 600 sensing the position of the underwater transmitting apparatus through the phase and intensity of the matched signals. The transmitting device may be an AUV or an underwater communication modem, but is not limited thereto. The signal transmitted from the transmitting apparatus can be received through the sensor array unit 200.

The position detecting unit 600 checks the phase and amplitude of the matched signal in real time and detects the direction of the underwater transmitting device through the phase difference of the vertically and horizontally arranged sensors 210, The depth and direction can be detected.

5, the position sensing unit 600 measures the depth and direction of the underwater transmission device through Equation 1 for estimating the distance of the underwater transmission device and Equation 2 for estimating the direction of the underwater transmission device Can be detected.

[Equation 1]

&Quot; (2) "

As described above, the communication relay unit according to the embodiment of the present invention is capable of controlling the position and movement of the underwater communication device through the underwater communication and underwater position tracking transmission sub-system using the space- Minimize impact and improve performance. It also has small mobility and can be easily installed as needed.

Also, the communication relay unit according to the embodiment of the present invention can increase the SNR through the matching arrangement processing of the underwater acoustic communication system in which background noise in the water is relatively higher than that in the ground, and is affected by noise.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or scope of the invention as defined in the appended claims. . Therefore, the above-described embodiments are to be considered as illustrative rather than restrictive, and the present invention is not limited to the above description, but may be modified within the scope of the appended claims and equivalents thereof.

The float (100)
The sensor array unit 200 includes:
The plurality of sensors 210,
The first group sensors 211,
The second group sensors 213,
The housing (230)
The matched filter unit 300 includes:
The delay compensation unit (400)
The signal synthesizer 500,
The position sensing unit 600,

Claims (5)

Float that can float on the water;
A sensor array unit installed at a lower portion of the float to receive signals transmitted in different directions in the water when the floater is floating on the water surface;
A matched filter unit for matching signals received from different directions through the sensor array unit;
A delay compensation unit for performing delay compensation on the signals subjected to the matching processing from the matched filter unit and outputting delay compensation signals; And
And a signal combining unit
And a communication relay unit.
The method according to claim 1,
Wherein the sensor array unit includes a housing in which a plurality of sensors are provided,
Wherein each of the plurality of sensors receives signals in different directions,
Wherein the plurality of sensors includes first group sensors and second group sensors,
Wherein the first group sensors are arranged to intersect a virtual horizontal plane passing through the center of the housing and the second group sensors are arranged to cross a virtual vertical plane passing through the center of the housing and perpendicular to the virtual horizontal plane. Relay buoy device.
The method according to claim 1,
Wherein the matched filter unit extracts a phase synchronization point by correlating signals received from the different directions with a matching signal.
The method of claim 3,
The delay compensation unit
And shifts the phases of the matched signals based on the fastest phase synchronization point among the phase synchronization points of the matched signals.
The method according to claim 1,
And a position sensing unit for sensing the position of the underwater transmission device through the phase and intensity of the amplitude of the matched signals.

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