KR20200095312A - Method and system for ambient backscatter communication in multi-tag and multi-reader environments - Google Patents

Abstract

A method and system for ambient backscatter communication in a multi-tag and multi-reader environment are disclosed. According to an embodiment of the present invention, a communication method comprises the steps of: receiving a plurality of signals from a plurality of tags; and based on the magnitude of one signal with the largest magnitude among the plurality of signals and the other signals, processing only the one signal or processing the plurality of signals using a soft combining method or a hard decision method.

Description

Ambient backscatter communication method and system in a multi-tag and multi-reader environment {METHOD AND SYSTEM FOR AMBIENT BACKSCATTER COMMUNICATION IN MULTI-TAG AND MULTI-READER ENVIRONMENTS}

The following embodiments relate to a method and system for peripheral backscatter communication in a multiple tag and multiple reader environment.

The IoT market is expected to be more than 10 times that of the existing cellular mobile communication market. In addition, it is predicted that there will be more than 7 billion IoT sensor devices in the future. IoT sensor device environments are expected to be built in a much greater number than AP (Access Point) devices in all environments such as home, company, public period, indoors, outdoors, and transportation.

Ambient Backscatter Communication (ABC) for implementing IoT technology is one of the new communication technologies that allows various devices to communicate using peripheral radio frequency signals without active RF transmission. This technology is one of the 4th industrial revolution technologies, and is effective in solving the problem of sensor network, low-power communication technology, and energy efficiency, which are core technologies of IoT (Internet of Things) applications.

Meanwhile, since peripheral backscatter communication is a communication technology in which a tag utilizes and reflects a peripheral radio frequency signal without active RF transmission, the reliability of the signal cannot be guaranteed. In particular, it is very difficult to improve signal reliability in a peripheral backscatter communication environment composed of a plurality of tags and a plurality of readers.

In embodiments, in the peripheral backscatter communication of a plurality of tags and a plurality of readers, only a signal having a size larger than that of other signals by a certain multiple or more is processed, or in other cases, a plurality of signals are processed by a soft combination method or a hard decision method. It is possible to provide a technology capable of improving the reliability of a tag and/or a plurality of reader signals.

A communication method according to an embodiment includes the steps of receiving a plurality of signals from a plurality of tags, and, among the plurality of signals, one signal having the largest magnitude and the one signal based on the magnitudes of the other signals. Processing only, or processing the plurality of signals using a soft combining method or a hard decision method.

The processing may include processing only the one signal when the magnitude of the one signal is greater than or equal to a predetermined multiple of the magnitude of the largest signal among the other signals.

The processing may include processing the other signals in a soft combination method or a hard decision method when the size of the one signal is less than a certain multiple of the size of the largest signal among the other signals. .

In the case of less than a certain multiple, the processing of the other signals using a soft combination method or a hard decision method may include, if the size of the one signal is less than a certain multiple of the size of the largest signal among the other signals, If the power level is greater than or equal to a certain level, processing the remaining other signals in a soft combination method, and the power level of the other signals while the size of the one signal is less than a certain multiple of the size of the largest signal among the other signals If is less than a predetermined size, processing the other signals in a hard decision method may be included.

The soft combining method may detect the remaining other signals using an energy determination method according to a threshold value.

In the soft combining method, when the other signals are smaller than the threshold value, a signal is detected as 0, and when the other signals are greater than the threshold value, the signal is detected as 1.

A communication device according to an embodiment includes a receiver for receiving a plurality of signals from a plurality of tags, and the one signal based on a signal having the largest magnitude among the plurality of signals and the magnitudes of the other signals. And a controller for processing the plurality of signals by processing only or by a soft combining method or a hard decision method.

The controller may process only one signal when the size of the one signal is greater than or equal to a predetermined multiple of the size of the largest signal among the other signals.

When the size of the one signal is less than a certain multiple of the size of the largest signal among the other signals, the controller may process the other signals in a soft combination method or a hard decision method.

The controller, when the size of the one signal is less than a certain multiple of the size of the largest signal among the other signals and the power level of the other signals is greater than or equal to a certain size, processes the other signals in a soft combination method, If the size of the one signal is less than a certain multiple of the size of the largest signal among the other signals and the power level of the other signals is less than a certain size, the other signals may be processed in a hard decision method.

The soft combining method may detect the remaining other signals using an energy determination method according to a threshold value.

In the soft combining method, when the other signals are smaller than the threshold value, a signal is detected as 0, and when the other signals are greater than the threshold value, the signal is detected as 1.

1 is a diagram for describing a conventional peripheral backscatter communication.
2 is a diagram showing a communication system according to an embodiment.
3 is a schematic diagram of a plurality of communication devices shown in FIG. 2.
4 is a block diagram schematically illustrating the communication device shown in FIG. 3.
5 and 6 are diagrams schematically showing a multi-tag and multi-reader environment of a communication system.
7 is a flowchart for explaining the operation of the communication system.
8 is a diagram illustrating a data slot for describing an operation protocol performed by a communication device.

이하에서, 첨부된 도면을 참조하여 실시예들을 상세하게 설명한다. 그러나, 실시예들에는 다양한 변경이 가해질 수 있어서 특허출원의 권리 범위가 이러한 실시예들에 의해 제한되거나 한정되는 것은 아니다. 실시예들에 대한 모든 변경, 균등물 내지 대체물이 권리 범위에 포함되는 것으로 이해되어야 한다.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, various changes may be made to the embodiments, and thus the scope of the patent application is not limited or limited by these embodiments. It should be understood that all changes, equivalents, or substitutes to the embodiments are included in the scope of the rights.

The terms used in the examples are used for illustrative purposes only and should not be construed as limiting. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present specification, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof does not preclude in advance.

The terms first or second can be used to describe various components, but the components should not be limited by the terms. The terms are for the purpose of distinguishing one component from another component, for example, without departing from the scope of rights according to the concept of the embodiment, the first component may be referred to as the second component, and similarly The second component may also be referred to as the first component.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person skilled in the art to which the embodiment belongs. Terms, such as those defined in a commonly used dictionary, should be interpreted as having meanings consistent with meanings in the context of related technologies, and should not be interpreted as ideal or excessively formal meanings unless explicitly defined in the present application. Does not.

In addition, in the description with reference to the accompanying drawings, the same reference numerals are assigned to the same components regardless of reference numerals, and redundant descriptions thereof will be omitted. In describing the embodiments, if it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the embodiments, the detailed description thereof will be omitted.

1 is a diagram for describing a conventional peripheral backscatter communication.

The IoT market is expected to be more than 10 times that of the existing cellular mobile communication market. In addition, it is predicted that there will be more than 7 billion IoT sensor devices in the future. IoT sensor device environments are expected to be built in a much greater number than AP (Access Point) devices in all environments such as home, company, public period, indoors, outdoors, and transportation.

Existing peripheral backscatter communication for implementing IoT technology consists of one or more tags and one reader. The communication method of peripheral backscatter communication is a method of reflecting a peripheral radio frequency signal from a tag and transmitting it to a reader.

The signal received by the reader can be calculated through Equation 1.

은 리더가 수신한 신호,

은 신호원에서 리더로 가는 채널,

은 신호원에서 리더로 보낸 신호,

는 태그에서 리더로 가는 채널,

는 태그 내부 페이딩,

는 신호원에서 태그로 가는 채널,

은 태그에서 리더로 보낸 신호,

은 잡음을 의미할 수 있다.

Is the signal received by the reader,

Is the channel from the signal source to the leader,

Is the signal sent from the signal source to the leader,

Is the channel from tag to reader,

Fading inside the tag,

Is the channel from the signal source to the tag,

The signal sent from the tag to the reader,

Can mean noise.

The communication method of the existing peripheral backscatter communication can be divided into three stages. In the first step, the reader calculates the channel power value of each tag.

In the second step, the reader selects the signal with the largest channel power value received for data.

In the last step, the reader receives the data signal from the tag that transmitted the selected signal. The reader may detect '0' and '1' by comparing the power value of the received data.

The reader may detect the data signal through Equation 2.

는 데이터의 신호 전력,

는 신호 전송 길이,

는 태그 전력 계산 길이,

는 태그 선택 길이를 의미할 수 있다.

Is the signal power of the data,

Is the signal transmission length,

Is the tag power calculation length,

May mean the tag selection length.

Meanwhile, since peripheral backscatter communication is a communication technology in which a tag utilizes and reflects a peripheral radio frequency signal without active RF transmission, the reliability of the signal cannot be guaranteed. In particular, it is very difficult to improve signal reliability in a peripheral backscatter communication environment composed of a plurality of tags and a plurality of readers.

The embodiments process only signals that are a certain multiple or more larger than other signals in peripheral backscatter communication, or in other cases, by processing signals in a soft combination method or a hard decision method, the reliability of a plurality of tags and a plurality of reader signals We can provide technology that can improve

Hereinafter, embodiments will be described with reference to FIGS. 2 to 7.

2 is a diagram showing a communication system according to an embodiment.

The communication system 20 includes a signal source 100, a plurality of tags 200, and a plurality of communication devices 300.

The communication system 20 may provide a technology capable of improving the reliability of signals of a plurality of tags and a plurality of readers in a peripheral backscatter communication environment consisting of a plurality of tags and a plurality of readers.

The signal source 100 may transmit signals to the plurality of tags 200 and the plurality of communication devices 300.

For example, the signal source 100 may be implemented as a wireless access point (AP). The signal transmitted by the signal source 100 may be an RF signal (Tv tower, FM, Wi-Fi, etc.). However, a form in which the signal source 100 is implemented and a signal to be transmitted are not limited thereto.

The plurality of tags 200 may transmit signals to the plurality of communication devices 300 by using signals (such as RF signals) transmitted from the signal source 100. That is, the plurality of tags 200 may perform peripheral backscatter communication with the plurality of communication devices 300 by reflecting or absorbing the radio signal in the frequency band of the radio signal.

The plurality of tags 200 may receive a tag selection message from the plurality of communication devices 300. The plurality of tags 200 may transmit a response message to the tag selection message.

The plurality of tags 200 may receive a selection completion message for the response message. The plurality of tags 200 may transmit data signals to the communication device that has transmitted the selection completion message.

The plurality of tags 200 may transmit data signals to the plurality of communication devices 300.

The plurality of communication devices 300 may perform peripheral backscatter communication with the plurality of tags 200 by reflecting or absorbing a radio signal in a frequency band of the radio signal.

The plurality of communication devices 300 may receive background radio signals from the plurality of tags 200 and receive only a signal having a size larger than that of other signals by a predetermined multiple or more as a data signal.

The plurality of communication devices 300 may improve reliability of a peripheral backscatter communication signal by detecting a signal using a soft combining method or a hard decision method.

The plurality of communication devices 300 may transmit a tag selection message to receive a data signal from a specific tag among the plurality of tags 200.

The plurality of communication devices 300 may receive a response message. The plurality of communication devices 300 may transmit a selection completion message for the response message.

The plurality of communication devices 300 may receive data signals from the plurality of tags 200. A communication device that has transmitted a selection completion message among the plurality of communication devices 300 may receive a data signal from a tag receiving the selection completion message.

3 is a schematic diagram of a plurality of communication devices 300 shown in FIG. 2.

The plurality of communication devices 300 are implemented in a plurality of communication devices 310. The communication device 310 may receive a signal from the signal source 100 and/or a peripheral backscatter communication signal transmitted by the plurality of tags 200.

The communication device 310 may calculate the received signal through Equation 3.

는 통신 장치(310) 수신 신호,

은 신호원에서 통신 장치(310)로 가는 채널,

는 신호원에서 태그로 가는 채널,

는 태그에서 통신 장치(310)로 가는 채널,

는 태그 내부 페이딩,

는 신호원에서 통신 장치(310)로 보낸 신호,

는 태그에서 통신 장치(310)로 보낸 신호,

는 잡음을 의미할 수 있다.

The communication device 310 receives a signal,

Is a channel from the signal source to the communication device 310,

Is the channel from the signal source to the tag,

Is the channel from the tag to the communication device 310,

Fading inside the tag,

Is a signal sent from the signal source to the communication device 310,

Is the signal sent from the tag to the communication device 310,

Can mean noise.

The communication device 310 may receive a plurality of signals from the plurality of tags 200.

The communication device 310 processes only one signal having the largest size or soft combining, based on a signal having the largest size among a plurality of signals received from the plurality of tags 200 and the other signals. ) Method or hard decision method to process a plurality of signals.

The communication device 310 may select a tag for receiving a data signal from among the plurality of tags 200. The communication device 310 may select a tag through Equations 4 and 5.

은 번째 태그를 지나 번째 리더로 수신된 신호의 전력,

는 신호의 샘플 개수,

은 인덱스,

는 태그의 개수,

은

째 통신 장치가 받은 수신 신호를 의미할 수 있다.

Is the power of the signal received by the reader through the second tag,

Is the number of samples in the signal,

Is the index,

Is the number of tags,

silver

It may mean a received signal received by the fourth communication device.

는 선택된 태그,

는 태그의 개수,

는 태그의 총 개수,

은 통신 장치의 개수,

은 통신 장치의 총 개수,

은 k번째 태그를 지나 번째 통신 장치로 수신된 신호의 전력,

는 신호원 신호의 전력을 의미할 수 있다.

Is the selected tag,

Is the number of tags,

Is the total number of tags,

Is the number of communication devices,

Is the total number of communication devices,

Is the power of the signal received by the communication device after the kth tag,

May mean the power of the signal source signal.

의 차이가 난다면 태그가 'zone' 안에 존재한다고 판단할 수 있다. 'zone'은 통신 장치(310)로부터 일정 영역을 의미할 수 있다.Communication device 310 in the tag selection process

If there is a difference, it can be determined that the tag exists in the'zone'. 'zone' may mean a certain area from the communication device 310.

When the tag exists in the'zone', the communication device 310 may receive the data signal only from the tag in the'zone'.

The communication device 310 may transmit a tag selection message to a tag selected to receive a data signal. The communication device 310 may receive a response message to the tag selection message from the selected tag.

When receiving the response message, the communication device 310 may transmit a selection completion message to the selected tag. The communication device 310 may receive a data signal from a tag that has received the selection completion message.

The communication device 310 may process data signals. That is, the communication device 310 may detect the data signal as 0 or 1.

The communication device 310 may detect the data signal through Equation (5).

는 통신 장치(310)가 검출한 데이터 신호,

는 데이터 신호의 전력,

는 신호기(100)에서 통신 장치(310)로 송신된 신호의 전력,

는 선택된 태그에서 보낸 신호의 전력(즉, 신호기(100)의 신호 전력 + 선택된 태그의 신호 전력)을 의미할 수 있다.

Is the data signal detected by the communication device 310,

Is the power of the data signal,

Is the power of the signal transmitted from the beacon 100 to the communication device 310,

May mean power of a signal transmitted from the selected tag (ie, signal power of the beacon 100 + signal power of the selected tag).

와

의 거리가 가까울 경우에는 0을 검출하고,

와

의 거리가 가까울 경우에는 1을 검출할 수 있다.For example, the communication device 310

Wow

If the distance of is close, 0 is detected,

Wow

If the distance of is close, 1 can be detected.

That is, the communication device 310 may determine '0' and '1' for the data signal by detecting the data signal in the'energy determination method' according to the threshold.

4 is a block diagram schematically illustrating the communication device shown in FIG. 3.

The communication device 310 includes a receiver 311 and a controller 315.

The receiver 311 may receive a plurality of signals from the plurality of tags 200. The receiver 311 may transmit a plurality of signals to the controller 315.

The receiver 311 may transmit a tag selection message. The receiver 311 may receive a response message. The receiver 311 may transmit a selection completion message. The receiver 311 may receive a data signal.

The controller 315 processes only one signal with the largest magnitude based on the magnitudes of one signal with the largest magnitude and other signals among a plurality of signals, or a soft combining method or a hard decision method. You can process multiple signals.

The controller 315 may measure the magnitude of each of the plurality of signals. If the received signal is greater than or equal to a certain size, the controller 315 may determine that a tag that has transmitted a signal greater than or equal to the certain size exists in a certain area'zone' from the communication device 310.

If the received signal is less than a certain size, the controller 315 may determine that a tag that has transmitted a signal less than the certain size exists outside a certain area'zone' from the communication device 310.

For example, the controller 315 may generate a tag selection message in order to receive only a signal of a tag determined to be in the'zone' as a data signal.

The controller 315 may process only one signal having the largest size when the size of one of the plurality of signals is greater than or equal to a predetermined multiple of the size of the largest signal among other signals.

For example, if the size of the signal received from the tag in the'zone' is more than a certain multiple of the size of the largest signal among other signals received from the tags outside the'zone', the controller 315 In order to receive only the signal received from the tag in the'zone' as a data signal, a tag selection message can be generated.

The controller 315 determines that the size of one of the signals of the tag determined to be in the'zone' with the largest size is equal to or greater than a certain multiple of the size of the largest signal among other signals received from tags outside the'zone'. In this case, a tag selection message can be generated in order to receive a data signal only from a tag that transmits one signal having the largest size.

The controller 315 receives a data signal only from a tag that transmits a signal with an extreme signal level when a tag with an extreme signal size exists (for example, when the distance between the tag and the reader is close). Reliability of a signal as much as a signal is received from all of the plurality of tags 200 can be secured, and a signal transmission speed can also be increased.

The controller 315 may transmit a tag selection message to the receiver 311. The controller 315 may generate a selection completion message when receiving the response message. The controller 315 may transmit a selection completion message to the receiver 311.

The controller 315 may process a data signal.

The controller 315 may process the remaining other signals in a soft combination method or a hard decision method when the size of one of the plurality of signals is less than a certain multiple of the size of the largest signal among other signals.

For example, through a soft coupling method, the controller 315 may sample the received signal. The controller 315 may process the sampled signal using a'energy determination method' according to a threshold.

That is, the controller 315 may process the signal in a manner that detects the signal as '0' when the sampled signal is less than the threshold value and determines as '1' when the sampled signal is greater than the threshold value.

The controller 315 processes the signals in a soft combination method, so that as the number of readers increases, a faster decision can be made. In addition, when the controller 315 processes a signal in a soft coupling method, if the time axis is fixed, the reliability of the transmission signal may be more secured than in the conventional method.

Through the hard decision method, the controller 315 may select one tag and process the signal in the'AND or OR rule selection method' when the received signal is in a situation where both channels have the same or low power. The controller 315 may bring about a result of improving reliability close to the soft coupling method through the hard decision method.

The controller 315 may perform signal processing in a hard decision selection method, thereby performing a faster determination of a transmission signal than a soft combining method and securing better reliability than a conventional peripheral backscatter communication method.

5 and 6 are diagrams schematically showing a multi-tag and multi-reader environment of a communication system.

5 is a diagram illustrating that a plurality of tags 200 are arranged and distributed, respectively. 6 is a diagram illustrating that a plurality of tags 200 are sporadically distributed in various places like a general home network situation.

When a plurality of tags 200 are arranged and distributed as shown in FIG. 5, it may be difficult to have an extremely large signal size among signals received by any one of the plurality of communication devices 300.

When a plurality of tags 200 are distributed in several places as shown in FIG. 6, tag 1 may be located in a'zone' of the communication devices 310 and R1.

That is, the communication devices 310 and R1 may receive a signal transmitted from tag 1 with a signal size greater than or equal to a predetermined multiple of other tags (tag 2 to tag k).

The communication devices 310 and R1 may receive only the signal of tag 1 in the'zone' area as a data signal.

7 is a flowchart for explaining the operation of the communication system.

The signal source 100 may transmit signals to the plurality of tags 200 and the plurality of communication devices 300 (710).

The plurality of tags 200 may transmit signals to the plurality of communication devices 300 by using the signals transmitted from the signal source 100 (715 ).

Among the plurality of communication devices 300, any one communication device 310 may measure whether the size of the received signal is greater than or equal to a predetermined size (720 ).

When the size of the received signal is greater than or equal to a certain size, the communication device 310 is a signal having the largest signal size among the plurality of signals received from the plurality of tags 200 and the largest signal among other signals. It may be determined whether or not a certain multiple (α times) of the size of is greater than (725).

The communication device 310 is a tag that transmits one signal with the largest size when the size of one of the plurality of signals is greater than or equal to a certain multiple (α times) of the size of the largest signal among other signals It is possible to receive a data signal only from (730).

The communication device 310 is a data signal from a plurality of other communication devices 400 when the size of one signal having the largest size among the plurality of signals is less than a certain multiple (α times) of the size of the largest signal among other signals. Can receive (735, 740).

When receiving data signals from a plurality of other communication devices 400, the communication device 310 may detect the signal using a soft combination method or a hard decision method (750 ).

When the size of the received signal is less than a predetermined size, the communication device 310 may receive data signals from the plurality of tags 800 (755, 760).

The communication device 310 may detect the data signals received from the plurality of tags 800 in a soft combination method or a hard decision method (750).

8 is a diagram illustrating a data slot for describing an operation protocol performed by a communication device.

The communication device 310 may receive the data slot 800 from the plurality of tags 200 through peripheral backscatter communication. The data slot 800 may be divided into a signal size measurement period 810, a tag selection period 830, and a data signal reception period 850.

The communication device 310 may measure all the sizes of signals transmitted by the plurality of tags 200 in the signal size measurement section 810.

The communication device 310 may select a tag for receiving a data signal based on the magnitudes of signals measured in the tag selection section 830.

The communication device 310 may transmit a tag selection message 831 to select a tag for receiving a data signal.

The communication device 310 may receive a response message 835 for the tag selection message 831 from the selected tag.

When receiving the response message 835, the communication device 310 may transmit a selection completion message 839 to the selected tag.

The communication device 310 may receive the data signal 850 from the selected tag.

The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, or the like alone or in combination. The program instructions recorded on the medium may be specially designed and constructed for the embodiments or may be known and usable by those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs, DVDs, and magnetic media such as floptical disks. -Hardware devices specifically configured to store and execute program instructions such as magneto-optical media, and ROM, RAM, flash memory, and the like. Examples of program instructions include high-level language code that can be executed by a computer using an interpreter, etc., as well as machine language codes produced by a compiler. The hardware device described above may be configured to operate as one or more software modules to perform the operation of the embodiment, and vice versa.

The software may include a computer program, code, instruction, or a combination of one or more of these, and configure the processing device to operate as desired, or process independently or collectively You can command the device. Software and/or data may be interpreted by a processing device or to provide instructions or data to a processing device, of any type of machine, component, physical device, virtual equipment, computer storage medium or device. , Or may be permanently or temporarily embodied in the transmitted signal wave. The software may be distributed on networked computer systems, and stored or executed in a distributed manner. Software and data may be stored in one or more computer-readable recording media.

As described above, although the embodiments have been described by the limited drawings, those skilled in the art can apply various technical modifications and variations based on the above. For example, 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 from the described method, or other components Alternatively, even if replaced or substituted by equivalents, appropriate results can be achieved.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

Claims (6)

Receiving a plurality of signals from a plurality of tags;
One signal with the largest magnitude among the plurality of signals and the other signals are processed based on the magnitudes of the other signals, or the plurality of signals are processed by a soft combining method or a hard decision method. Steps to
Communication method comprising a.
The method of claim 1,
The processing step,
Processing only the one signal when the size of the one signal is greater than a certain multiple of the size of the largest signal among the other signals
Communication method comprising a.
The method of claim 1,
The processing step,
If the size of the one signal is less than a certain multiple of the size of the largest signal among the other signals, processing the other signals in a soft combination method or a hard decision method
Communication method comprising a.
The method of claim 3,
If it is less than the predetermined multiple, processing the other signals in a soft combination method or a hard decision method,
Processing the other signals in a soft combining method when the size of the one signal is less than a certain multiple of the size of the largest signal among the other signals and the power level of the other signals is greater than or equal to a certain level; And
If the size of the one signal is less than a certain multiple of the size of the largest signal among the other signals and the power level of the other signals is less than a certain size, processing the other signals in a hard decision method
Communication method comprising a.
The method of claim 3,
The soft combining method,
The remaining other signals are detected using an energy determination method according to a threshold value.
Communication method.
The method of claim 5,
The soft combining method,
If the other signals are less than the threshold value, the signal is detected as 0, and if the other signals are greater than the threshold value, the signal is detected as 1.
Communication method.

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