KR102711394B1 - Method and apparatus for improving performance for underwater acoustic communication using multi-channel combination of multi-channel receiver - Google Patents

Abstract

The present technology relates to a method and device for improving underwater acoustic communication performance for underwater acoustic communication using multi-channel combining of a multi-channel receiver. The method for improving underwater acoustic communication performance for underwater acoustic communication using multi-channel combining of a multi-channel receiver implemented by a processor of the present technology includes the steps of: obtaining a communication signal through a multi-channel receiver; predicting a baseband underwater channel impulse response of a training symbol section in the multi-channel receiver; calculating a SINR-based weight and an RMS delay spread-based weight for each channel using the predicted channel impulse response; and applying the weights to the communication signal to reduce energy of a channel that deteriorates communication performance, and then applying the communication signal to which the weights have been applied to communication demodulation through multi-channel combining. The present technology can provide a method for improving communication performance by preemptively analyzing channel characteristics of a communication signal received from a multi-channel receiver and applying channel characteristic-based weights to the communication signal using the same.

Description

Method and apparatus for improving performance for underwater acoustic communication using multi-channel combination of multi-channel receiver

The present invention relates to a method and device for improving underwater acoustic communication performance for underwater acoustic communication using multi-channel combining of a multi-channel receiver, and more specifically, to a method and device for improving underwater acoustic communication performance for underwater acoustic communication using multi-channel combining of a multi-channel receiver considering relative weights based on underwater acoustic communication channel characteristics.

Underwater acoustic channels have multipath characteristics due to the ocean boundary, and these multipaths change over time due to spatial and temporal variability in the ocean environment, making underwater acoustic communication difficult.

As a process to overcome this, the diversity gain that can be obtained through multi-channel combining of a multi-channel receiver can improve communication performance by reducing inter-symbol interference (ISI).

As a related literature, "Spatial diversity in passive time reversal communications" by Song (2006) obtained spatial diversity gain through multi-channel combination of array receivers installed over the entire water depth and derived optimal communication performance by applying time-reversal communication technique. At this time, the channel characteristics are different depending on the depth of each receiver, and there is a depth that shows optimal communication performance (see Fig. 1). Song (2006) derived time-reversal communication performance by increasing the number of receivers starting with receivers located on the sea floor, and when it reached a certain number of receivers, the BER was derived as 0 (see Fig. 2). This result proves that optimal performance can be derived by using only a few receivers with channel characteristics favorable for communication.

Choi (2018)'s "Analysis of Passive Time-Reversal Communication Performance in Shallow Waters with Acoustic Channels" confirmed that when communication signals were received by an array receiver in a shallow water environment with acoustic channels, the 8th receiver (depth 49.75 m) with concentrated energy and relatively good channel characteristics (RMS delay spread ~ 0 ms) showed high communication performance (see Fig. 3). In addition, when communication performance was derived for all cases of arbitrary combinations of four receivers regardless of the receiver order, cases where the 8th receiver with excellent channel characteristics was included showed higher performance than cases where it was not included (see Fig. 4).

Meanwhile, communication signals received from multi-channel receivers may exhibit different performances because each receiver has different acoustic channel characteristics and the characteristics may vary depending on the sea area. Accordingly, when signals from receivers with channel characteristics favorable for communication are included or weighted, the possibility of obtaining optimal communication performance in a given environment increases. Accordingly, the present invention proposes a method of improving communication performance by preemptively analyzing the channel characteristics of communication signals received from each receiver and applying channel characteristic-based weights to the communication signals using the same.

An embodiment of the present invention provides a method for improving communication performance by preemptively analyzing channel characteristics of a communication signal received from a multi-channel receiver and applying channel characteristic-based weights to the communication signal using the same.

Meanwhile, other unspecified purposes of the present invention will be additionally considered within a range that can be easily inferred from the following detailed description and its effects.

A method for improving underwater acoustic communication performance using multi-channel combining of a multi-channel receiver implemented by a processor according to an embodiment of the present invention may include the steps of: obtaining a communication signal through a multi-channel receiver; predicting a baseband underwater channel impulse response of a training symbol interval in the multi-channel receiver; calculating a SINR-based weight and an RMS delay spread-based weight for each channel using the predicted channel impulse response; and applying the weights to the communication signal to reduce energy of a channel that deteriorates communication performance and then applying the communication signal to which the weights are applied to communication demodulation through multi-channel combining.

The above prediction step can use the least squares method.

The above SINR-based weight may be based on a ratio of the multipath energy used for synchronization for demodulation of the communication signal transmitted through multipath, the sum of the energy of the remaining multipaths causing ISI interference, and the background noise energy for the communication signal.

The above SINR-based weight can be determined by the following mathematical formula.

Here, ω _SINR,i is an SINR-based weight for the communication signal received at the ith receiver among the plurality of receivers, P _i is a multipath energy used for synchronization for demodulation for the communication signal received at the ith receiver transmitted through multipaths, I _i is the sum of the energies of the remaining multipaths other than the synchronized path, and N _i is the background noise energy for the communication signal received at the ith receiver.

The above RMS delay spread based weight may be based on the reciprocal of the RMS delay spread which appears as a function of normalized multipath energy and delay time for the communication signal transmitted through multipath.

The above RMS delay spread based weight can be determined by the following mathematical formula.

Here, ω _DS,i may represent the normalized multipath energy for the communication signal received at the ith receiver among the plurality of receivers, σ _τ,i may represent the multipath delay time for the communication signal received at the ith receiver, and TS may represent the symbol period.

As an example of the above multi-channel receiver, the acoustic vector sensor is a device that simultaneously receives an acoustic pressure channel and a particle velocity channel, and in the acquiring step, one or more data sets consisting of acoustic pressure and particle velocities for two or more axes of the X, Y, and Z axes are received, and a combination of the SINR-based weight and the RMS delay spread-based weight can provide a communication signal size correction value for the acoustic pressure (first weight), a communication signal size correction value for one of the two or more axes (second weight), and a communication signal size correction value for one of the two or more axes (third weight).

Each of the above SINR-based weight and the RMS delay spread-based weight may have a positive correlation with the pre-transmission communication performance of the communication signal.

Each of the first to third weights can have a value greater than or equal to 0 and less than or equal to 1.

Additionally, a computer-readable recording medium according to an embodiment of the present invention can store one or more computer programs including commands for performing the above method.

In addition, an underwater acoustic communication performance improvement device for underwater acoustic communication using multi-channel combining of a multi-channel receiver according to an embodiment of the present invention may include: a communication signal obtaining unit for obtaining a communication signal through a multi-channel receiver; a processor for predicting a baseband underwater channel impulse response of a training symbol section in the multi-channel receiver, calculating a channel-specific SINR-based weight and an RMS delay spread-based weight using the predicted channel impulse response, and applying the weights to the communication signal to reduce energy of a channel that deteriorates communication performance, and then applying the communication signal to which the weights are applied to communication demodulation through multi-channel combining; and a display for displaying the performance of the communication signal improved according to the application of the weights as an image.

This technology can provide a method for improving communication performance by preemptively analyzing channel characteristics of communication signals received from a multi-channel receiver and applying channel characteristic-based weights to the communication signals using the same.

Figure 1 shows (a) the BER (Bit Error Rate) and output SNR (Signal-to-Noise Ratio) performance of time-reversal communication according to receiver depth in the prior art, and (b) the communication characteristics at depths of 46 m and 78 m.
Figure 2 shows the performance of acoustic communication before and after reversal as the number of receivers (M) increases, starting with a receiver located on the seabed as shown in the prior art. (a) Output SNR, (b) BER.
Figure 3 shows the signal channel characteristics ((a) input SNR, (b) RMS delay spread) received from a single receiver at each depth in the prior art, and the communication performance derivation result ((c) output SNR).
Figure 4 shows the distribution of acoustic communication performance using four arbitrary receivers in the prior art.
FIG. 5 is a flowchart illustrating a method for improving underwater acoustic communication performance for underwater acoustic communication using multi-channel combining of a multi-channel receiver according to one embodiment of the present invention.
FIG. 6 is a diagram showing components for calculating SINR of a baseband channel impulse response according to an embodiment of the present invention.
FIG. 7 is a diagram showing components for calculating RMS delay spread of a baseband channel impulse response according to an embodiment of the present invention.
FIG. 8 is a diagram showing (a) an experimental schematic diagram according to an embodiment of the present invention, (b) the positions and maximum/minimum distances of a transmitter and a vector sensor moving apart according to distance, and (c) a vertical sound velocity structure measured during the experiment.
FIG. 9 is a diagram showing the correlation between (a) SINR-based weights and (b) RMS delay spread-based weights and time-to-reverse communication performance (output SNR) according to an embodiment of the present invention.
Figure 10 is a diagram showing the results of deriving communication performance by distance before and after applying weights according to an embodiment of the present invention.
FIG. 11 is a diagram showing a channel parameter-based weight (ω _i ) for each receiver according to an embodiment of the present invention and communication signal energy before (γ _i [n]) and after (z _i [n]) applying the weight.
FIG. 12 is a drawing showing an example of a hardware implementation of an underwater acoustic communication performance improvement device according to an embodiment of the present invention.
It is to be understood that the attached drawings are provided for reference only to help understand the technical concept of the present invention, and the scope of the rights of the present invention is not limited thereby.

Specific structural or functional descriptions of the embodiments are disclosed for illustrative purposes only and may be implemented in various forms. Therefore, the actual implemented form is not limited to the specific embodiments disclosed, and the scope of the present disclosure includes modifications, equivalents, or alternatives included in the technical idea described in the embodiments.

Although the terms first or second may be used to describe various components, such terms should be construed only for the purpose of distinguishing one component from another. For example, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component.

When it is said that a component is "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but there may also be other components in between.

Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, the terms "comprises" or "have" should be understood to specify the presence of a described feature, number, step, operation, component, part, or combination thereof, but not to exclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning they have in the context of the relevant art, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

Hereinafter, embodiments will be described in detail with reference to the attached drawings. When describing with reference to the attached drawings, identical components are given the same reference numerals regardless of the drawing numbers, and redundant descriptions thereof will be omitted.

In an embodiment of the present invention, a method is proposed to improve communication performance by applying weights using channel characteristics closely related to communication performance. Channel parameters for weights used in the embodiment of the present invention are SINR (Signal-to-Interference plus Noise Ratio) and RMS delay spread (Root Mean Squared delay spread). By considering relative weights based on underwater acoustic communication channel characteristics, underwater acoustic communication performance is improved in underwater acoustic communication demodulation using multi-channel combining of a multi-channel receiver.

FIG. 5 is a flowchart illustrating a method for improving underwater acoustic communication performance for underwater acoustic communication using multi-channel combining of a multi-channel receiver according to an embodiment of the present invention. As illustrated in FIG. 5, the method for improving underwater acoustic communication performance for underwater acoustic communication using multi-channel combining of a multi-channel receiver (hereinafter simply referred to as “underwater acoustic communication performance improving method”) includes a step of obtaining a communication signal (S10), a step of predicting a baseband underwater impulse response (S20), a step of calculating weights (S30), and a step of applying the same to communication demodulation through multi-channel combining (4S0).

In step (S10), a communication signal is acquired through a multi-channel receiver. The multi-channel receiver may be an array receiver or a vector sensor.

The array receiver includes a plurality of receivers having a predetermined array. Each receiver receives an acoustic pressure channel. One receiver functions as a single-channel receiver, and multiple receivers are combined to form a multi-channel receiver. The vector sensor simultaneously receives an acoustic pressure channel and a particle velocity channel. That is, the vector sensor can receive acoustic pressure and particle velocity for two or more axes among the X, Y, and Z axes. For example, the vector sensor can receive acoustic pressure and particle velocity for the X and Y axes, in which case one vector sensor forms a three-channel receiver. For another example, the vector sensor can receive acoustic pressure and particle velocity for the X, Y, and Z axes, in which case one vector sensor forms a four-channel receiver. Hereinafter, a description will be given focusing on an embodiment in which a multi-channel receiver according to one embodiment is a four-channel vector sensor.

In one embodiment, the transmitter may transmit the communication signal from a point a certain distance away from the vector sensor and moving further away. For example, the receiver may receive the communication signal 48 times, and thus obtain 48 data sets, although the number of receptions is not limited.

In the following, the description will focus on communication signals received by one receiver, but is not limited thereto, and the same process can be applied to communication signals received by other receivers.

In step (S20), the baseband channel impulse response of the training symbol interval is predicted in the multi-channel receiver. The baseband channel impulse response is predicted to calculate the parameters described below. The impulse response can be estimated using training symbols and the least square method can be used.

FIG. 6 shows components for calculating SINR of a baseband channel impulse response according to one embodiment, and FIG. 7 shows components for calculating RMS delay spread of a baseband channel impulse response according to one embodiment.

Underwater acoustic communication performance varies not only depending on the ratio of received signal energy to noise energy, but also depending on which path is used for synchronization and demodulation when transmitted through multiple paths. In addition, other than the synchronized path, the remaining multipaths cause ISI and reduce communication performance. SINR can be expressed as the ratio of the multipath energy (P) used for synchronization, the sum of the energy of the remaining multipaths causing interference (I), and the background noise energy (N), as shown in the following mathematical expression 1 (see Figure 6).

RMS delay spread represents the time dispersion characteristics of the channel and is an important parameter that can predict the occurrence of ISI. RMS delay spread (σ _τ ) can be expressed as a function of normalized multipath energy (relative intensity) (h ² _k ) and delay time (relative delay time) (τ _k ), as shown in the following mathematical expression 2 (see Figure 7).

The channel impulse response for calculating the above parameters can be estimated using training symbols as described above and the least squares method can be used.

In step (S30), the SINR-based weight and the RMS delay spread-based weight are calculated for each channel using the channel impulse response predicted in step (S20). Specifically, the SINR-based weight and the RMS delay spread-based weight are calculated using the SINR and RMS delay spread of the channel received by the multi-channel receiver.

The SINR-based weight (ω _SINR,i ) and RMS delay spread-based weight (ω _DS,i ) of the channel received at the ith receiver can be calculated as shown in the mathematical expression 3 below.

Here, ω _SINR,i is a SINR-based weight for a communication signal received at the ith receiver among multiple receivers, P _i is a multipath energy used for synchronization for demodulation for a communication signal received at the ith receiver transmitted through multiple paths, I _i is the sum of the energies of the remaining multipaths excluding the synchronized paths, and N _i represents background noise energy for the communication signal received at the ith receiver. In addition, ω _DS,i is a normalized multipath energy for the communication signal received at the ith receiver among multiple receivers, σ _τ,i is a multipath delay time for the communication signal received at the ith receiver, and TS represents a symbol period, respectively.

Here, it is noted that ω _SINR,i and ω _DS,i have a positive correlation with the communication performance. They generally have a linear positive correlation. This makes the application of weighting factors considering channel characteristics in multi-channels more intuitive. According to one embodiment, by utilizing a vector sensor, at least four channel environments (P, X, Y, Z) including acoustic pressure, particle velocities in the X, Y, and Z axes are considered, and it is more advantageous in the process of reducing the energy of the signal of the corresponding channel that may deteriorate the communication performance for these multi-channels. For example, when the Z channel has the worst communication performance, the lowest weighting factor can be assigned to the Z channel, and a proportional weighting factor can be assigned to each channel having relatively good communication performance. For example, if the communication performance deteriorates in the order of P, X, Y, and Z, the P channel can be given a weight of 0.9 as the highest weighting factor, the X channel can be given a weight of 0.8 as the next, the Y channel can be given a weight of 0.7 as the next, and the Z channel can be given a weight of 0.5 as the lowest weighting factor.

If the weights described above according to one embodiment do not have a linear positive relationship with the communication performance, for example, if they have an exponential relationship, it is not easy to apply the proportional weighting factor described above. For example, consider that the weight interval between the channel with the highest communication performance and the next highest channel becomes very narrow, making it difficult to distinguish between them.

In step (S40), the weights calculated in step (S30) are applied to the acquired communication signal to reduce the energy of the channel that deteriorates the communication performance, and then the communication signal with the weights applied is applied to communication demodulation through multi-channel combining.

In order to apply the two weights described above (i.e., the SINR-based weight and the RMS delay spread-based weight) according to one embodiment, the two weights can be combined. For example, the two weights can be combined to generate a single weight (ω _i ).

When the single weights to be applied to each channel are, in order, a first weight, a second weight, a third weight, and a fourth weight, the SINR-based weight and the RMS delay spread-based weight of the P channel can be combined to create the first weight, the SINR-based weight and the RMS delay spread-based weight of the X channel can be combined to create the second weight, the SINR-based weight and the RMS delay spread-based weight of the Y channel can be combined to create the third weight, and the SINR-based weight and the RMS delay spread-based weight of the Z channel can be combined to create the fourth weight.

This combination may be such that each of the first to fourth weights has a specific value within a range from a lower bound of 0 to an upper bound of 1. In a positive correlation, a proportionally low weight may be specified for a relatively low channel, and a proportionally high weight may be specified for a relatively high channel. However, this is not limited to the range of the upper and lower bounds of the weights, and a range is sufficient in which a high weight is applied to a relatively high channel and a low weight is applied to a relatively low channel.

In one embodiment, the energy of a signal that may deteriorate communication performance is reduced by multiplying the received signal (γ _i [n]) by a weight (ω _i ) calculated using channel parameters for the signal received at the ith receiver to derive a weighted signal (z _i [n]). This is then used for communication demodulation through multi-channel combining.

<Experimental example>

The effectiveness of the present invention was verified through a sea experiment. Fig. 8 is a communication experiment conducted in domestic waters (South Sea) in which a vector sensor was used as a receiver to receive a communication signal. The transmitter transmitted a communication signal while moving from a distance of 143 m to 670 m from the vector sensor and received it with the vector sensor. The vector sensor can receive acoustic pressure and particle velocity in the X, Y, and Z axes, and each channel characteristic is different. Fig. 9 is a result of comparing the SINR-based weight and the RMS delay spread-based weight of each component of the vector sensor with the communication performance, and it can be seen that there is a positive correlation.

Fig. 10 is a time-reversal communication performance derived using four components of a vector sensor, and it can be confirmed that in most cases, the communication performance is improved after applying the weights than before. The channel parameters used for the weights in the present invention are SINR and RMS delay spread, and a value obtained by combining these can be used as the weights.

Figure 11 shows an example of communication signal energy before and after weighting and weighting based on RMS delay spread, and it can be confirmed that the energy of a signal with relatively poor channel characteristics is reduced by applying weighting.

The method according to the embodiment of the present invention described above can be applied to the field of underwater communication using a plurality of receiver channels (array receivers, vector sensors, etc.), the field of channel parameter-based weighting, the demodulation algorithm of an underwater acoustic communication modem using diversity gain, the underwater acoustic communication reception signal weighting application algorithm according to time-varying channel characteristics, and the receiver design.

Fig. 12 is a diagram illustrating an example of a hardware implementation of an underwater acoustic communication performance improvement device according to an embodiment of the present invention. An underwater acoustic communication performance improvement device (1000) according to one embodiment may include a communication signal acquisition unit (1010), a processor (1020), a memory (1030), and a display (1040).

The communication signal acquisition unit (1010) can acquire a communication signal through a multi-channel receiver. The communication signal acquisition unit (1010) can include a wired/wireless communication module, etc. for acquiring a communication signal received by the multi-channel receiver.

The processor (1020) can calculate weights to be applied to the acquired communication signal using the underwater acoustic communication performance improvement model stored in the memory (1030). For example, the processor (1020) can predict a baseband underwater channel impulse response from the acquired communication signal and calculate an SINR-based weight and an RMS delay spread-based weight using the same. Then, the processor (1020) can apply the calculated weights to the acquired communication signal to perform a correction to reduce signal energy that may deteriorate communication performance in the communication signal, and then apply the correction to communication demodulation through multi-channel combining. However, the operation of the processor (1020) is not limited thereto, and the operations described in FIGS. 5 to 11 may be performed.

The memory (1030) can store an underwater acoustic communication performance improvement model. The memory (1030) can temporarily or permanently store data required to perform an underwater acoustic communication performance improvement method according to one embodiment. For example, the memory can also store an acquired communication signal, a predicted baseband underwater channel impulse response, a SINR-based weight and an RMS delay spread-based weight, a communication signal to which weights are applied, and a communication signal demodulated through multi-channel combining.

The display (1040) can display the performance of improved communication signals as an image according to the application of weights. The display (1040) can also visualize the acquired communication signals, predicted baseband underwater channel impulse responses, SINR-based weights and RMS delay spread-based weights, communication signals with weights applied, and communication signals demodulated through multi-channel combining.

The embodiments described above may be implemented as hardware components, software components, and/or a combination of hardware components and software components. For example, the devices, methods, and components described in the embodiments may be implemented using a general-purpose computer or a special-purpose computer, such as, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a programmable logic unit (PLU), a microprocessor, or any other device capable of executing instructions and responding to them. The processing device may execute an operating system (OS) and software applications running on the OS. In addition, the processing device may access, store, manipulate, process, and generate data in response to the execution of the software. For ease of understanding, the processing device is sometimes described as being used alone, but those skilled in the art will appreciate that the processing device may include multiple processing elements and/or multiple types of processing elements. For example, a processing device may include multiple processors, or a processor and a controller. Other processing configurations, such as parallel processors, are also possible.

The software may include a computer program, code, instructions, or a combination of one or more of these, which may configure a processing device or, independently or collectively, command the processing device to perform a desired operation. The software and/or data may be permanently or temporarily embodied in any type of machine, component, physical device, virtual equipment, computer storage medium or device, or transmitted signal waves, for interpretation by the processing device or for providing instructions or data to the processing device. The software may be distributed over network-connected computer systems and stored or executed in a distributed manner. The software and data may be stored on a computer-readable recording medium.

The method according to the embodiment may be implemented in the form of a program command that can be executed through various computer means and may be recorded on a computer-readable medium. The computer-readable medium may store program commands, data files, data structures, etc., singly or in combination, and the program commands recorded on the medium may be those specially designed and configured for the embodiment or may be those known to and usable by those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic media such as a hard disk, a floppy disk, and a magnetic tape, optical media such as a CD-ROM, a DVD, magneto-optical media such as a floptical disk, and hardware devices specially configured to store and execute program commands such as a ROM, a RAM, a flash memory, and the like. Examples of program instructions include machine language code, such as that produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc.

The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

Although the embodiments have been described with limited drawings as described above, those skilled in the art can apply various technical modifications and variations based on them. For example, even if the described techniques are performed in a different order than the described method, and/or the components of the described system, structure, device, circuit, etc. are combined or combined in a different form than the described method, or are replaced or substituted by other components or equivalents, appropriate results can be achieved.

Therefore, other implementations, other embodiments, and equivalents to the claims are also included in the scope of the claims described below.

1000: Underwater Acoustic Communication Performance Improvement Device
1010: Communication signal acquisition unit
1020 : Processor
1030 : Memory
1040 : Display

Claims (11)

A method for improving underwater acoustic communication performance for underwater acoustic communication demodulation using multi-channel combining of a multi-channel receiver implemented by a processor,
A step of acquiring a communication signal through a multi-channel receiver;
A step of predicting a baseband underwater channel impulse response of a training symbol interval in the above multi-channel receiver;
A step of calculating a channel-specific SINR-based weight and an RMS delay spread-based weight using the predicted channel impulse response; and
A step of applying the weights to the communication signal to reduce the energy of the channel that deteriorates the communication performance, and then applying the communication signal to which the weights are applied to communication demodulation through multi-channel combining; is included.
A method for improving underwater acoustic communication performance, wherein the SINR-based weighting is based on the ratio of the multipath energy used for synchronization for demodulation of the communication signal transmitted through multipath, the sum of the energy of the remaining multipaths causing ISI interference, and the background noise energy to the communication signal. In the first paragraph,
The above-mentioned predicting step is a method for improving underwater acoustic communication performance using the least squares method. delete In the first paragraph,
A method for improving underwater acoustic communication performance, wherein the SINR-based weight is determined by the following mathematical formula.

Here, ω _SINR,i is an SINR-based weight for the communication signal received at the ith receiver among a plurality of receivers, P _i is a multipath energy used for synchronization for demodulation for the communication signal received at the ith receiver transmitted through multipaths, I _i is the sum of the energies of the remaining multipaths other than the synchronized path, and N _i represents background noise energy for the communication signal received at the ith receiver. In the first paragraph,
A method for improving underwater acoustic communication performance, wherein the above RMS delay spread-based weight is based on the inverse of the RMS delay spread, which appears as a function of normalized multipath energy and delay time for the communication signal transmitted through multipath. In paragraph 5,
A method for improving underwater acoustic communication performance, wherein the above RMS delay spread-based weight is determined by the following mathematical formula.

Here, ω _DS,i represents the normalized multipath energy for the communication signal received at the ith receiver among a plurality of receivers, σ _τ,i represents the multipath delay time for the communication signal received at the ith receiver, and TS represents the symbol period. In the first paragraph,
The above multi-channel receiver has an array receiver comprising an array of receivers for receiving an acoustic pressure channel and a vector sensor for receiving an acoustic pressure channel and particle velocity channels for two or more axes among the X, Y, and Z axes.
A method for improving underwater acoustic communication performance, wherein a combination of the SINR-based weight and the RMS delay spread-based weight using a vector sensor as an example provides a communication signal size correction value (first weight) for the acoustic pressure, a communication signal size correction value (second weight) for one of the two or more axes, and a communication signal size correction value (third weight) for the other of the two or more axes. In Article 7,
A method for improving underwater acoustic communication performance, wherein each of the SINR-based weight and the RMS delay spread-based weight has a positive correlation with the pre-transmission communication performance of the communication signal. In Article 8,
A method for improving underwater acoustic communication performance, wherein each of the first to third weights has a value greater than or equal to 0 and less than or equal to 1. A computer-readable recording medium storing one or more computer programs including commands for performing the method of any one of claims 1, 2, and 4 to 9. As a device for improving underwater acoustic communication performance for underwater acoustic communication using multi-channel combination of a multi-channel receiver,
A communication signal acquisition unit that acquires a communication signal through a multi-channel receiver;
A processor for predicting a baseband underwater channel impulse response of a training symbol interval in the multi-channel receiver, calculating a channel-specific SINR-based weight and an RMS delay spread-based weight using the predicted channel impulse response, applying the weights to the communication signal to reduce energy of a channel that deteriorates communication performance, and then applying the communication signal to which the weights are applied to communication demodulation through multi-channel combining; and
A display that displays the performance of a communication signal improved according to the application of the above weights as an image;
The above SINR-based weighting is based on the ratio of the multipath energy used for synchronization for demodulation of the communication signal transmitted through multipath, the sum of the energy of the remaining multipaths causing ISI interference, and the background noise energy to the communication signal.

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