KR101785858B1 - Method and apparatus for determining bandwidth based on low power wide area network for internet of things communications - Google Patents

Abstract

A low power wide area network based bandwidth determination method and apparatus for object internet communication is disclosed. A method for determining a bandwidth for signal transmission in a low power wide area network (LPWAN) formed between at least one user terminal belonging to a base station, the method comprising the steps of: determining channel information estimated for an uplink channel from the user terminal to the base station; Determining whether to transmit a signal based on the reference channel gain; determining one of a plurality of bandwidths that is determined to transmit the signal, the bandwidth corresponding to a predetermined reference SNR value; And transmitting the signal to the base station based on the determined bandwidth.

Description

[0001] METHOD AND APPARATUS FOR DETERMINING BANDWIDTH BASED ON LOW POWER WIDE AREA NETWORK FOR INTERNET INTERNET COMMUNICATIONS [0002]

Embodiments of the present invention are directed to techniques for determining bandwidth for signal transmission in low power wide area (LPWA) communication systems.

Internet Of Things (IoT) communication wirelessly exchanges information among a plurality of user terminals operating with only battery power, which is an auxiliary power source, without main power. In this way, it is essential to establish a low power wide area (LPWA) network in the Internet of things because various user terminals communicate with each other based on low power.

The Ultra Narrow Band (UNB) technology, which improves receiver sensitivity by reducing signal bandwidth usage for broadening the communication radius in a low power wide area network (LPWAN), is a low power wide area (LPWA ) Corresponds to a core part of a physical layer in establishing a communication system. In this case, when the Ultra Narrow Band (UNB) is applied to the low power wide area network, the throughput can be reduced due to the bandwidth reduction according to the ultra wide bandwidth technology.

Accordingly, in a low power wide area network (LPWAN) requiring a low power such as a thing Internet communication, a technology for solving the reduction of the throughput that occurs when the ultra low band (UNB) is applied for the broadening of the communication radius . Korean Patent Laid-Open No. 10-2011-0030648 (bandwidth request method and bandwidth allocation method in broadband wireless access system, published March 23, 2011) efficiently requests and allocates uplink resources in a broadband wireless access system Technology discloses a configuration in which a base station provides different bandwidth request channels to terminals in each terminal group.

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a technique for determining a bandwidth for improving signal-to-noise ratio (SNR) in order to reach a target point at a low power in a low-power Internet network based on a Low Power Wide Area Network .

Further, by determining a bandwidth for improving the SNR and transmitting a signal, it is possible to improve the reduction of throughput occurring when applying the UNB technique to a low power wide area network (LPWAN) Technology.

A method for determining a bandwidth for signal transmission in a low power wide area network (LPWAN) formed between at least one user terminal belonging to a base station, the method comprising the steps of: determining channel information estimated for an uplink channel from the user terminal to the base station; Determining whether to transmit a signal based on the reference channel gain; determining one of a plurality of bandwidths that is determined to transmit the signal, the bandwidth corresponding to a predetermined reference SNR value; And transmitting the signal to the base station based on the determined bandwidth.

According to an aspect, the step of determining the bandwidth includes determining a predetermined reference channel gain, a transmit power, a receive noise power density, and a transmit power, for the plurality of bandwidths included in a bandwidth set composed of a discrete number, Extracting at least one bandwidth satisfying a condition less than or equal to a value calculated based on the reference SNR, and determining the largest bandwidth among the extracted bandwidths as the bandwidth.

According to another aspect, determining whether to transmit the signal may determine a time point at which the channel gain is maximum based on the channel gain received from the user terminal and the predetermined reference channel gain (G _TH ).

According to another aspect, determining whether to transmit the signal comprises determining that the signal is transmitted if the channel gain received from the user terminal is greater than or equal to a predetermined reference channel gain (G _TH ) Is less than the reference channel gain, the signal can be kept waiting for a predetermined period of time.

According to another aspect of the present invention, the step of determining whether to transmit the signal may determine whether to transmit the signal by comparing the channel power received after waiting for the predetermined time with the reference channel gain.

According to another aspect, in a physical layer frame structure used for signal transmission between the base station and the user terminal, a channel measurement interval may be located before a data transmission period.

1. A bandwidth determining apparatus belonging to a base station forming a low power wide area network (LPWAN), the apparatus comprising: a channel estimating unit for estimating, based on channel information estimated for an uplink channel from a bandwidth determining apparatus to a base station, A bandwidth determining unit that determines a bandwidth corresponding to a predetermined reference SNR value among a plurality of allocatable bandwidths as determined to transmit the signal, and a bandwidth determining unit that determines the bandwidth And a transmitting / receiving unit for transmitting the signal to the base station based on the received signal.

According to an aspect of the present invention, the bandwidth determining unit may determine the predetermined reference channel gain, the transmission power, the reception noise power density, and the reference SNR for the plurality of bandwidths included in a bandwidth set composed of a discrete number Extracting at least one bandwidth satisfying a condition less than or equal to the calculated value based on the bandwidth, and determining the largest bandwidth among the extracted bandwidths as the bandwidth.

According to another aspect, the signal transmission determination unit may determine a time point at which the channel gain is maximum based on the channel gain received from the user terminal and the predetermined reference channel gain ( _GTH ).

According to another aspect of the present invention, the signal transmission determination unit determines that the channel gain received from the user terminal is greater than or equal to a predetermined reference channel gain (G _TH ), and that the channel power is higher than the reference channel gain The signal can be kept waiting for a predetermined period of time.

According to another aspect of the present invention, the signal transmission determination unit may determine whether to transmit the signal by comparing the channel power received after waiting for the predetermined time with the reference channel gain.

According to another aspect, in a physical layer frame structure used for signal transmission between the base station and the user terminal, a channel measurement interval may be located before a data transmission period.

A signal processing method in a receiving apparatus having at least one user terminal and a low power wide area network (LPWAN), the method comprising the steps of: transmitting a signal to be transmitted from the user terminal to an uplink The method comprising: transmitting a reference signal for estimating an uplink channel to the user terminal; feeding back channel information corresponding to the uplink estimated based on the reference signal to the user terminal; As it is determined to transmit the signal based on the predetermined reference channel gain, the signal is received from the user terminal using any bandwidth corresponding to a predetermined reference SNR value among a plurality of allocatable bandwidths .

A receiving apparatus forming a low power wide area network (LPWAN) with at least one user terminal, the receiving apparatus comprising: an uplink channel estimation unit for estimating an uplink channel from the user terminal to the receiver before transmitting a signal to be transmitted from the user terminal; And a channel estimator for feeding back the channel information corresponding to the uplink estimated based on the reference signal to the user terminal, wherein the transmitter / And determining whether to transmit the signal using any one of bandwidths corresponding to a predetermined reference SNR value among a plurality of allocatable bandwidths as the signal is determined to be transmitted based on the channel information and the predetermined reference channel gain, Can be received from the user terminal.

According to the present invention, in a low power wide area network (LPWAN), a bandwidth for improving SNR (Signal to Noise Ratio) is determined, so that a signal can reach a desired target point with low power. That is, the communication radius can be enlarged by adaptively determining the bandwidth.

Further, by determining a bandwidth for improving the SNR and transmitting a signal, it is possible to improve a decrease in throughput caused when an ultra low bandwidth (UNB) technique is applied to a low power wide area network (LPWAN) .

1 is a conceptual diagram showing a low power wide area network (LPWAN) in an embodiment of the present invention.
2 is a diagram illustrating a frame structure of a physical layer used for signal transmission in an LPWAN network according to an embodiment of the present invention.
3 is a flow diagram illustrating an operation for adaptively determining a bandwidth in an LPWAN, according to an embodiment of the present invention.
4 is a block diagram illustrating an internal configuration of a bandwidth determination apparatus according to an embodiment of the present invention.
FIG. 5 is a graph illustrating an effect of improving a transmission rate according to adaptive bandwidth allocation in a low power wide area communication network in an embodiment of the present invention.
FIG. 6 is a flowchart illustrating an operation of processing a signal transmitted using a bandwidth determined by a user terminal in a base station, which is a receiving apparatus, according to an exemplary embodiment of the present invention.
7 is a block diagram illustrating an internal configuration of a base station serving as a receiving apparatus, according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present embodiments are directed to the construction of a communication network capable of Ubiquitous connection of various types of application media in a low-power wide area network (LPWAN) -based inter-things (IoT) network And introduces Ultra Narrow Band (UNB) technology to expand the communication radius. Particularly, the embodiments of the present invention can be applied to 3GPP LTE / LTE-A and 3GPP LTE / LTE-A among the 3GPP LTE / LTE-A and Long Range Alliance (LoRa) To a technique for improving the reduction of throughput due to the introduction of modulation techniques.

The embodiments of the present invention can reduce the noise power by reducing the bandwidth, thereby determining the transmission time point based on the reference value while improving the signal-to-noise ratio (SNR) And to a technique for improving the reduction of the transmission speed caused by the transmission. That is, the present invention relates to a technique of reducing noise by decreasing a bandwidth to reduce a noise represented by a product of a noise power density and a bandwidth in determining a bandwidth used for transmitting a signal from a user terminal to a base station. In other words, it relates to a technique of varying the bandwidth to reduce the noise to improve the SNR and transmit the signal to the wide area.

In this embodiment, the user terminal may represent an electronic device (i. E., A thing Internet device) forming an IoT such as a smart phone, a PC (personal computer), a smart TV, a smart refrigerator, May be expressed as a bandwidth determining apparatus that determines a bandwidth (BW) used in signal transmission using an uplink channel. In the present embodiments, the user terminal may be referred to as a transmitting apparatus, and the base station as a receiving apparatus.

1 is a conceptual diagram showing a low power wide area network (LPWAN) in an embodiment of the present invention.

Referring to FIG. 1, a low power wide area network (LPWAN) may include a base station (BS) and at least one user terminal. Here, the user terminal may be represented by a bandwidth determining device.

One or more user terminals may be connected to one of the base stations 110 by wire or wirelessly to form the Internet of interest (IoT). At this time, when connected to the low power wide area network, the user terminal 120 and the base station 110 can perform wide area communication with ultra low power. That is, communication can be performed up to a predetermined target arrival point set by only the ultra low power.

2 is a diagram illustrating a frame structure of a physical layer used for signal transmission in an LPWAN network according to an embodiment of the present invention.

2, a channel estimation for an uplink channel from the bandwidth determining apparatus 120 to the base station 110 is first performed in the base station 110, and a channel estimation for an uplink channel The channel information can be fed back. The bandwidth decision unit 120 may determine the bandwidth for signal transmission to the base station 110 based on the channel information on the fed-back uplink channel. That is, the transmitting apparatus may be the bandwidth determining apparatus 120, and the receiving apparatus may be the base station 110.

In the low power wide area network (LPWAN), the reception signal y of the base station 110 with respect to the transmission signal x to be transmitted from the bandwidth determiner 120, which is a user terminal, to the base station 110 can be expressed as Equation have.

[Equation 1]

이고, P_T는 송신 신호의 전력(power), h는 대역폭 결정 장치에서 기지국까지의 상향 링크 무선 채널의 채널 정보(예컨대, 채널 계수), n은 수신 장치 잡음(즉, 기지국에서의 수신 잡음)을 나타낼 수 있다.In Equation (1), the average power of the transmission signal x

And, P _T is the power (power), h is the channel information of the uplink radio channel in the bandwidth determining device to the base station (e.g., a channel coefficient), n is the receiving device noise (receive in other words, the base station noise) of the transmitted signal Lt; / RTI >

The signal-to-noise ratio (SNR) of the received signal y in Equation (1) can be expressed by Equation (2) below.

 &Quot; (2) "

로 표현하고, 미리 정의될 수 있다. 즉, 대역폭 결정 장치(120)와 기지국(110) 간에 신호대 잡음비(SNR)는 아래의 수학식 3을 만족해야 초저전력으로 기정의된 목표 지점까지 광역으로 신호를 전송할 수 있다.In Equation (2), N ₀ is the noise power spectral density of the receiver, W is the signal bandwidth, and σ ² is the variance. The transmission distance of a signal in a communication system can be determined by a minimum signal-to-noise ratio (SNR) at which a receiving device (e.g., a base station) can recover a message without error, i.e., a signal. Accordingly, a reference SNR representing a minimum signal-to-noise ratio (SNR) capable of restoring a message without error at a maximum communication distance

And can be defined in advance. That is, the signal-to-noise ratio (SNR) between the bandwidth decision unit 120 and the base station 110 must satisfy Equation (3) below to transmit the signal to a predetermined target point with ultra low power.

&Quot; (3) "

가 감소될 수 있으므로 기지국으로부터 피드백된 채널 정보에 기반하여 채널 이득이 최대가 되는 시점을 결정하고, 채널 이득이 최대가 되는 시점에 신호를 전송할 수 있다. 즉, 대역폭 결정 장치(120)는 채널 이득이 최대가 되는 시점에 가장 적합한 대역폭을 결정하여 신호를 전송할 수 있다. That is, when applying an unbalanced band (UNB) modulation technique to a low power wide area network (LPWAN) to transmit a signal to a predetermined target point set at an ultra low power, the bandwidth determining apparatus 120 satisfies Equation The SNR can be improved by adaptively adjusting the signal bandwidth. At this time, when the SNR is increased by reducing the signal bandwidth, the transmission rate, that is,

The time point at which the channel gain becomes maximum can be determined based on the channel information fed back from the base station and the signal can be transmitted at the time when the channel gain becomes maximum. That is, the bandwidth determining apparatus 120 can determine a most suitable bandwidth at the time when the channel gain becomes maximum, and transmit the signal.

(h_max는 채널 이득이 최대일 때의 채널 계수)가 되는 시점이 신호 전송을 위해 결정될 수 있다. 이때, 채널 이득, 즉, 채널 계수가 최대인 신호 전송 시점을 결정할 때, 신호 대역폭은 아래의 수학식 4와 같이 표현될 수 있다.For example, the uplink radio channel from the bandwidth decision unit 120 to the base station 110 is monitored and the time when the gain of the uplink channel becomes maximum, that is,

(h _max is the channel coefficient when the channel gain is the maximum) can be determined for signal transmission. At this time, when determining the channel gain, that is, the signal transmission time point at which the channel coefficient is maximum, the signal bandwidth can be expressed by Equation (4) below.

&Quot; (4) "

As described above, in order to transmit a signal using the bandwidth determined by Equation (4) at the time when the channel gain becomes maximum, the channel information may be acquired before data transmission.

Referring to FIG. 2, the physical layer frame structure 200 may have a channel measurement 210 before a data transmission period 220. That is, channel estimation may be performed before data transmission. At this time, the operation of the channel estimation section 210 can be variously operated according to a duplex scheme. That is, the BS 110 can estimate the state of the uplink channel through various methods.

For example, when a time division duplex (TDD) is used, the base station 110, which is a receiving apparatus during a channel estimation interval 210, transmits a reference signal for channel estimation to a bandwidth determiner 120). Then, the bandwidth determining apparatus 120 estimates the downlink channel from the base station 110 to the bandwidth determining apparatus 120 using the reference signal, and based on the uplink / downlink channel reciprocity The channel information for the uplink channel can be obtained.

As another example, when a frequency division duplex (FDD) is used, the bandwidth determining apparatus 120, which is a user terminal, can transmit a reference signal to the base station 110. [ The base station 110 may perform channel estimation based on the reference signal and may feedback the estimated channel information to the bandwidth determining apparatus 120. [ Then, the bandwidth determining apparatus 120 can determine the time and bandwidth for signal transmission based on the channel information for the fed-back uplink channel. At this time, up to the process of estimating the channel information from the base station to the bandwidth determining apparatus 120 may be included in the channel estimation section 210.

At this time, even if the bandwidth determiner 120 acquires channel information for the uplink channel in advance before transmitting the signal according to the physical layer frame structure of FIG. 2, the channel information alone indicates whether the corresponding time point is an optimal transmission time point . ≪ / RTI > Accordingly, not only the channel information at a specific time point but also the channel information until a fixed predetermined period after the specific time point should be known. That is, the transmission time point at which the channel gain becomes maximum can be determined by predicting the channel information corresponding to the time interval corresponding to the future time period after the specific point in time.

FIG. 3 is a flowchart illustrating an operation of adaptively determining a bandwidth in an LPWAN according to an embodiment of the present invention. FIG. 4 is a block diagram illustrating an internal configuration of a bandwidth determination apparatus according to an embodiment of the present invention. .

4, the bandwidth determination apparatus 400 may include a transmission / reception unit 410, a signal transmission determination unit 420, and a bandwidth determination unit 430.

Each of the steps 310 to 330 of FIG. 3 is performed by the transmission / reception unit 410, the signal transmission determination unit 420, and the bandwidth determination unit 430, which are components of the bandwidth determination apparatus 400 of FIG. .

3 and 4, the bandwidth determining apparatus 400 may obtain channel information on the uplink channel in the physical layer frame structure 200 of FIG. 2, in particular, the channel estimation section 210. In this case, when estimating the channel information in the bandwidth determining apparatus 400, the bandwidth determining apparatus 400 may further include a channel estimating unit (not shown). When estimating the channel information in the base station 401, The channel information can be fed back from the base station 401 to the base station 401.

In step 310, the signal transmission determining unit 420 may determine whether to transmit a signal based on the uplink channel information (i.e., the channel gain information h | in Equation 3) and the predetermined reference channel gain G _TH have.

For example, when the uplink channel information satisfies the condition of Equation (5) below, the signal transmission determining unit 420 determines to transmit the signal, and if the condition of Equation (6) is satisfied, And to wait for the signal for a predetermined period of time.

&Quot; (5) "

&Quot; (6) "

In Equations (5) and (6), h may represent the channel coefficient of the uplink channel, and G _TH may be predefined as the reference channel gain.

According to Equation (5), the channel coefficient, that is, the channel power | h | ² is greater than or equal to the reference channel gain G _TH , the signal transmission determination unit 420 may determine that the channel gain at that point in time is the maximum. Accordingly, the signal transmission determining unit 420 may determine to transmit the signal at a time when the channel power is equal to or greater than the reference channel gain G _TH .

Then, as shown in Equation (6), | h | ² is smaller than the reference channel gain G _TH , the signal transmission determining unit 420 may determine to temporarily wait without transmitting a signal. For example, the signal transmission determination unit 420 may determine that the signal is temporarily stored in the buffer, the storage unit (not shown) or the like for a predetermined period of time, and waits for transmission of the signal. At this time, the signal transmission determination unit 420 determines that | h | |, which is obtained based on the channel information acquired based on the channel information acquired at the next time, ² is greater than or equal to the reference channel gain G _TH . That is, whether or not the channel power corresponding to the channel information obtained later is greater than or equal to the reference channel gain G _TH can be compared again, and the channel gain is maximized through a process of comparing again after waiting for a predetermined time The signal can be determined to be transmitted at the time point.

In step 320, it is determined that the signal is transmitted. Accordingly, the bandwidth determining unit 430 transmits a signal to the base station 401, which is one bandwidth corresponding to the predetermined reference SNR value among the plurality of bandwidths that can be allocated Can be determined by the bandwidth to be used.

At this time, the bandwidth determining unit 430 can determine a bandwidth in a bandwidth set composed of a continuous number as shown in Equation (4). Then, the bandwidth determining unit 430 may determine the bandwidth in a bandwidth set composed of a discrete number so as to be suitable for an actual commercial communication system.

인 경우, 대역폭 결정부(430)는 아래의 수학식 7에 기초하여 신호를 전송하기 위한 대역폭을 적응적으로 결정할 수 있다.A set of bandwidths of size N

, The bandwidth determining unit 430 may adaptively determine a bandwidth for transmitting a signal based on Equation (7) below.

&Quot; (7) "

보다 작거나 같은 조건을 만족하는 대역폭이 추출될 수 있다. 예컨대, W₁, W₂, W₃가 추출된 경우, 대역폭 결정부(430)는 W₁, W₂, W₃ 중 대역폭이 최대(MAX)인 대역폭(예컨대, W₁)을 신호 전송을 위한 대역폭으로 결정할 수 있다.According to Equation (7), the bandwidth determining unit 430 determines the channel information obtained from the plurality of bandwidths and the bandwidths that are less than or equal to the value calculated based on the predetermined reference channel gain G _TH and the reference SNR (SNR _TH ) Can be extracted. The bandwidth determining unit 430 may determine the maximum bandwidth among the extracted bandwidths as the bandwidth for signal transmission. For example, among W ₁ , W ₂ , ..., W _N

A bandwidth satisfying a condition less than or equal to a bandwidth can be extracted. For example, in the case where W _1, W _2, W ₃ extracted, the bandwidth determining unit 430 is W _1, W _2, W ₃ of the bandwidth, a maximum (MAX) of the bandwidth (e.g., W ₁₎ a to the signal transmission Can be determined by the bandwidth.

That is, the operation of adaptively determining the bandwidth for transmitting a signal in the set of bandwidths composed of discontinuous numbers according to Equations (5) to (7) can be performed according to the algorithm described in Table 1 below.

According to Table 2 above, in step 2, it can be seen that the SNR increases as the bandwidth W decreases. Since the bandwidth is predetermined according to the state of the communication system, each of W ₁ to W _N is substituted into Equation (7), and the channel coefficient h obtained based on the channel information, the received power noise density N _0, P _T , a W satisfying the condition of Equation (7) among W ₁ to W _N can be determined based on a predefined reference SNR value.

Accordingly, among the plurality of bandwidths, W having a small bandwidth W satisfying the condition of the reference SNR _TH is extracted, and the largest bandwidth among the plurality of bandwidths can be determined as the bandwidth for signal transmission. That is, the transmission bandwidth can be improved by determining the largest bandwidth among the bandwidths satisfying the condition of the reference SNR _TH among the bandwidths included in the bandwidth set as the bandwidth for the signal transmission.

In step 330, the transceiver 410 may transmit a signal to the base station 401 based on the determined bandwidth.

FIG. 5 is a graph illustrating an effect of improving a transmission rate according to adaptive bandwidth allocation in a low power wide area communication network in an embodiment of the present invention.

5 illustrates a case where a signal is transmitted from a terminal to a base station using a fixed bandwidth without varying a bandwidth in a low power wide area communication network (LPWAN) (510), a case where a bandwidth is varied and a signal is transmitted from a terminal to a base station (Throughput) of the mobile station.

Referring to FIG. 5, it can be seen that the transmission rate is improved compared to the case of transmitting a signal with variable bandwidth without changing the bandwidth (520) when the bandwidth is varied. In particular, it can be seen that as the distance increases, the transmission speed improves more. That is, the bandwidth at which the reference SNR is satisfied is determined at the time when the channel gain becomes maximum, and as the signal is transmitted using the determined bandwidth, not only the far-low power can be transmitted to the wide area but also the transmission speed is improved Can be confirmed.

FIG. 6 is a flowchart illustrating an operation of processing a signal transmitted using a bandwidth determined by a user terminal in a base station serving as a receiving apparatus according to an exemplary embodiment of the present invention. FIG. 2 is a block diagram illustrating an internal configuration of a base station that is a device.

7, the receiving apparatus 700 indicates a base station forming the LPWAN, and may include a transmitting / receiving unit 710, and a channel estimating unit 720.

The steps 610 to 630 of FIG. 6 may be performed by the transmitting / receiving unit 710, which is a component of the receiving apparatus 700 of FIG. 7, and the channel estimating unit 720.

In step 610, the transmission / reception unit 710 estimates the uplink channel from the user terminal to the reception apparatus before transmitting the signal to be transmitted from the base station, that is, the user terminal belonging to the reception apparatus 700 And transmit the reference signal to the user terminal.

For example, a reference signal may be transmitted to a user terminal in a channel estimation 210 of FIG.

In operation 620, the channel estimation unit 720 may estimate the state of the uplink channel from the user terminal to the reception apparatus based on the reference signal, and may feedback the channel information corresponding to the estimated uplink to the user terminal can do. At this time, FDD or the like can be used for the channel estimation, and duplicated description will be omitted since it has already been described above.

In step 630, the transceiver 710 determines that the user terminal is to transmit a signal based on the feedback channel information and the predetermined reference channel gain, The user terminal can receive a signal transmitted from the user terminal using any one of the bandwidths.

For example, the transmitter / receiver 710 can receive a signal transmitted from the user terminal using the bandwidth determined based on Equation (7) at a time point when the channel gain of the uplink channel is maximum.

The method according to the above embodiments may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions to be recorded on the medium may be those specially designed and configured for the embodiments or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. 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.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. For example, it is to be understood that the techniques described may be performed in a different order than the described methods, and / or that components of the described systems, structures, devices, circuits, Lt; / RTI > or equivalents, even if it is replaced or replaced.

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

Claims (14)

A bandwidth determining method for transmitting a signal through a low power wide area network (LPWAN) based Internet (IoT) network formed between at least one user terminal belonging to a base station,
Determining whether to transmit a signal based on channel information estimated for an uplink channel from the user terminal to the base station and a predetermined reference channel gain;
Determining any bandwidth corresponding to a predetermined reference SNR value among the plurality of allocatable bandwidths as determined to transmit the signal; And
Transmitting the signal to the base station based on the determined bandwidth;
Lt; / RTI >
Wherein determining the bandwidth comprises:
Wherein when the channel gain received from the user terminal is equal to or greater than a predetermined reference channel gain (G _TH ), the channel information and the transmission power are transmitted to the plurality of bandwidths included in a bandwidth set composed of a discrete number Extracting a bandwidth corresponding to a value obtained by dividing the product of the reception noise power density and the bandwidth of any one of the plurality of bandwidths by more than a predetermined reference SNR value; And
Determining a largest bandwidth among the extracted bandwidths as a bandwidth corresponding to the reference SNR value
(LPWAN). ≪ / RTI > delete The method according to claim 1,
Wherein the step of determining whether to transmit the signal comprises:
Determining a time point at which the channel gain is maximum based on the channel gain received from the user terminal and the predetermined reference channel gain (G _TH )
Gt; (LPWAN) < / RTI > The method according to claim 1,
Wherein the step of determining whether to transmit the signal comprises:
Determining that the signal is transmitted if the channel gain received from the user terminal is greater than or equal to a predetermined reference channel gain (G _TH )
And if the channel gain is less than the reference channel gain, waiting the predetermined period of time for the signal
Gt; (LPWAN) < / RTI > 5. The method of claim 4,
Wherein the step of determining whether to transmit the signal comprises:
Determining whether to transmit the signal by comparing the received channel gain with the reference channel gain after waiting for the predetermined time
Gt; (LPWAN) < / RTI > The method according to claim 1,
A physical layer frame structure used for signal transmission between the base station and the user terminal includes a channel measurement section before a data transmission period
Gt; (LPWAN) < / RTI > 1. A bandwidth determining apparatus belonging to a base station forming a low-power wide area network (LPWAN) based Internet (IoT) network,
A signal transmission determination unit for determining whether to transmit a signal based on channel information estimated for an uplink channel from a bandwidth determining apparatus to a base station and a predetermined reference channel gain;
A bandwidth determining unit that determines a bandwidth corresponding to a predetermined reference SNR value among a plurality of allocatable bandwidths as determined to transmit the signal; And
A transmission / reception unit for transmitting the signal to the base station based on the determined bandwidth;
Lt; / RTI >
Wherein the bandwidth determining unit comprises:
The method of claim 1, wherein when the channel gain received from the user terminal is equal to or greater than a predetermined reference channel gain (G _TH ), the channel information and the transmission power of the plurality of bandwidths included in the bandwidth set composed of a discrete number Extracting a bandwidth corresponding to a value obtained by dividing a product by a reception noise power density and a bandwidth of any one of the plurality of bandwidths equal to or greater than a predetermined reference SNR value and comparing the largest bandwidth among the extracted bandwidths with the reference SNR value The bandwidth to be determined
(LPWAN). ≪ / RTI > delete 8. The method of claim 7,
The signal transmission determination unit may determine,
Determining a time point at which the channel gain is maximum based on the channel gain received from the user terminal and the predetermined reference channel gain (G _TH )
(LPWAN). ≪ / RTI > 8. The method of claim 7,
The signal transmission determination unit may determine,
Determining to transmit the signal if the channel gain received from the user terminal is greater than or equal to a predetermined reference channel gain (G _TH )
And if the channel gain is less than the reference channel gain, waiting the predetermined period of time for the signal
(LPWAN). ≪ / RTI > 11. The method of claim 10,
The signal transmission determination unit may determine,
Determining whether to transmit the signal by comparing the received channel gain with the reference channel gain after waiting for the predetermined time
(LPWAN). ≪ / RTI > 8. The method of claim 7,
The physical layer frame structure used for signal transmission between the base station and the user terminal includes a channel measurement section before a data transmission period
(LPWAN). ≪ / RTI > A signal processing method in a receiving apparatus forming at least one user terminal and a low power wide area network (LPWAN) based Internet (IoT) network,
Transmitting a reference signal for estimating an uplink channel from the user terminal to the reception terminal to the user terminal before transmitting the signal to be transmitted from the user terminal;
Feeding back channel information corresponding to the uplink estimated based on the reference signal to the user terminal; And
As the signal is determined to be transmitted based on the feedback channel information and the predefined reference channel gain, any one of bandwidths corresponding to a predetermined reference SNR value among a plurality of allocatable bandwidths is used to transmit the signal From the user terminal
Lt; / RTI >
If there is more than any of the bandwidth is based on the channel gain is a channel gain, received from the user terminal a predefined (G _TH) that corresponds to the reference SNR value, wherein the plurality includes a bandwidth set consisting of a discontinuous number (discrete number) And a maximum SNR value of the extracted bandwidth corresponding to a value obtained by dividing the product of the channel information and the transmission power by the reception noise power density and the bandwidth of any one of the plurality of bandwidths, To represent bandwidth
(LPWAN). ≪ / RTI > 1. A receiving apparatus for forming at least one user terminal and a low power wide area network (LPWAN) based Internet (IoT) network,
A transmitter and a receiver for transmitting a reference signal for estimating an uplink channel from the user terminal to the receiver before transmitting the signal to be transmitted from the user terminal to the user terminal; And
And a channel estimator for feeding back channel information corresponding to the uplink estimated based on the reference signal to the user terminal,
Lt; / RTI >
The transmitting /
As the signal is determined to be transmitted based on the feedback channel information and the predefined reference channel gain, any one of bandwidths corresponding to a predetermined reference SNR value among a plurality of allocatable bandwidths is used to transmit the signal From the user terminal,
Wherein one of the bandwidths corresponding to the reference SNR value is a bandwidth of the user equipment when the channel gain received from the user terminal is equal to or greater than a predetermined reference channel gain ( _GTH ) The method of claim 1, wherein the plurality of bandwidths are divided into a product of the channel information and a transmission power by a noise power density and a bandwidth of the plurality of bandwidths, To represent a large bandwidth
(LPWAN). ≪ / RTI >

Images