KR102336143B1 - Apparatus and method for transmitting and receiving in wireless sensor network - Google Patents

Abstract

Disclosed are a transceiving device in a narrowband wireless communication system, and a method thereof. According to an aspect of the present invention, the transceiving device in a narrowband wireless communication system comprises: a general signal transmission processing unit for processing a general signal to be transmitted by using a plurality of channels; a first filtered multi-tone (FMT) transmission unit for generating symbols output from the general signal transmission processing unit as a symbol in a frequency domain; a first emergency signal transmission processing unit for processing an emergency signal to be transmitted; and a combination unit for combining the symbol output from the first FMT transmission unit and the symbol output from the first emergency signal transmission processing unit, and transmitting the same. The first emergency signal transmission processing unit includes: an emergency signal generation unit for obtaining an index for the emergency signal from a predefined index table, and converting the obtained index into binary data; a spreading unit for performing spectrum spread on the binary data on the basis of a Kasami sequence; a modulation unit for generating a symbol by modulating the spectrum-spread binary data; a pulse shaping filter for performing pulse-shaping on the generated symbol in a period based on a transmission period of the general signal and the number of the channels; and an operation unit for operating an insertion level in the pulse-shaped symbol. Therefore, a delay time can be drastically reduced.

Description

Apparatus and method for transmitting and receiving in a narrowband wireless communication system {APPARATUS AND METHOD FOR TRANSMITTING AND RECEIVING IN WIRELESS SENSOR NETWORK}

The present invention relates to a transmission/reception apparatus and method in a narrowband wireless communication system, and more particularly, to a transmission/reception apparatus and method for enabling low-delay signal transmission in a narrowband wireless communication system.

e-WSN (energy-Wireless Sensor Network) is a narrow-band system developed as part of a self-communication network construction plan. Wide coverage due to excellent diffraction*?* permeability of 380Hz UHF (Ultra High Frequency) band, QAM (Quadrature Amplitude Modulation) By using modulation method, it is possible to provide stable communication performance because there is no signal interference problem due to the 15 times faster transmission speed than TRS (Trunked Radio Service) technology in the same frequency and the characteristic of licensed band.

Based on this e-WSN system, it is being used not only for power control where sub-second delay and stability are important, but also for various Internet of Things (IoT) projects. It is expected that the problem of communication failure due to the shaded area can be solved.

However, in general, a wideband system can transmit a signal quickly and thus exhibits low latency characteristics, whereas a narrowband system uses a small channel bandwidth and thus a signal transmission period is long, which leads to a problem in that a transmission delay time is increased.

Accordingly, the e-WSN narrowband system can realize a stable power control communication network, but it needs improvement compared to the smart grid network conditions in terms of minimum transmission delay time.

Background art of the present invention is disclosed in Republic of Korea Patent Publication No. 10-1920467 (2018.11.21. Announcement).

The present invention has been devised to improve the above problems, and an object according to an aspect of the present invention is to satisfy the smart grid network requirements in terms of minimum transmission delay time, and to achieve low transmission delay regardless of the degree of use of network resources. An object of the present invention is to provide an apparatus and method for transmitting and receiving in a narrowband wireless communication system capable of providing a service indicating time.

The problem to be solved by the present invention is not limited to the problem(s) mentioned above, and another problem(s) not mentioned will be clearly understood by those skilled in the art from the following description.

In a narrowband wireless communication system according to an aspect of the present invention, a transmitting apparatus includes a general signal transmission processing unit for processing a general signal to be transmitted using a plurality of channels, and a symbol in a frequency domain for symbols output from the general signal transmission processing unit A first Filtered Multi-Tone (FMT) transmitter that generates an , a first emergency signal transmission processor that processes to transmit an emergency signal, and a symbol output from the first FMT transmitter and a symbol output from the first emergency signal transmission processor and a combiner for combining and transmitting, wherein the first emergency signal transmission processing unit obtains an index for the emergency signal from a predefined index table, and an emergency signal generator for converting the obtained index into binary data; A spreader for spreading the binary data based on a Kasami sequence, a modulator for generating a symbol by modulating the band-spreading binary data, and a transmission period and number of channels for the generated symbol It may include a pulse shaping filter for pulse shaping with a cycle based on , and a calculator for calculating an insertion level in the pulse shaping symbol.

In the present invention, the pulse shaping filter may pulse shaping the modulated symbol with a period of (transmission period/number of channels).

In the present invention, the insertion level may be a value generated based on a power ratio between the emergency signal and the normal signal.

In the present invention, the general signal transmission processing unit includes a serial-to-parallel conversion unit for dividing binary data for the general signal into a plurality of partial binary data corresponding to the number of channels, and channel encoding each of the plurality of partial binary data simultaneously. A plurality of channel encoders, a plurality of interleavers for simultaneously interleaving each of the plurality of channel-encoded binary data, and a plurality of modulators for generating a plurality of modulation symbols by simultaneously modulating each of the plurality of interleaved binary data using a preset modulation method may include

In the present invention, the first FMT transmitter may include an IDFT unit for inverse Fourier transforming the parallel symbols output from the general signal transmission processing unit, and a filter unit for generating a signal in the frequency domain by passing the symbols converted by the IDFT unit. can

In the present invention, the filter unit may be a poly phase filter.

In a narrowband wireless communication system according to another aspect of the present invention, a transmitting apparatus includes a general signal transmission processing unit processing a general signal to be transmitted using a plurality of channels, a second emergency signal transmission processing unit processing to transmit an emergency signal, and a second Filtered Multi-Tone (FMT) transmitter for generating symbols output from the general signal transmission processor and the symbols output from the second emergency signal transmission processor as symbols in a frequency domain; and the second FMT transmitter for output Comprising a calculator for calculating and transmitting the insertion level to the symbol, wherein the second emergency signal transmission processing unit, obtains an index for the emergency signal from a predefined index table, and converts the obtained index into binary data An emergency signal generator, a spreader for spreading the binary data based on a Kasami sequence, a modulator for generating a symbol by modulating the band-spreading binary data, and the number of channels using the generated symbols It may include a repeater to repeat the number of times corresponding to the input to the second FMT transmitter.

In the present invention, the general signal transmission processing unit includes a serial-to-parallel conversion unit for dividing binary data for the general signal into a plurality of partial binary data corresponding to the number of channels, and channel encoding each of the plurality of partial binary data simultaneously. A plurality of channel encoders, a plurality of interleavers for simultaneously interleaving each of the plurality of channel-encoded binary data, and a plurality of modulators for generating a plurality of modulation symbols by simultaneously modulating each of the plurality of interleaved binary data using a preset modulation method; may include

In the present invention, the second FMT transmitter may output the emergency signal at each period of the transmission period/number of channels of the general signal, and output the general signal through each channel at each transmission period of the general signal.

In the present invention, the second FMT transmitter includes an IDFT unit that converts symbols in the frequency domain output from the general signal transmission processing unit and the second emergency signal transmission processing unit into symbols in the time domain, and the symbols converted by the IDFT unit It may include a filter unit for generating a signal in the frequency domain by passing the .

In the present invention, the filter unit may be a poly phase filter.

In the present invention, the insertion level may be a value generated based on a power ratio between the emergency signal and the normal signal.

In a narrowband wireless communication system according to another aspect of the present invention, a reception apparatus includes a first emergency signal reception processing unit for estimating an emergency signal from a received signal, and a first for demultiplexing the received signal into a plurality of data. An FMT receiver and a general signal reception processor for recovering a normal signal from a plurality of data output from the first FMT receiver, wherein the first emergency signal reception processor is a filter matching a pulse shaping filter of a transmitter, and A matched filter that filters data pulse-shaped by the pulse shaping filter, a demodulator that demodulates the filtered data using a preset demodulation method, a despreader that despreads the demodulated data, It may include an emergency signal estimator that checks the index from the index table and estimates the emergency signal based on the checked index.

In the present invention, the general signal reception processing unit includes a plurality of demodulators for simultaneously demodulating each of the plurality of data by a preset demodulation method, a plurality of deinterleavers for simultaneously deinterleaving each of the plurality of demodulated data, and the plurality of deinterleaving It may include a plurality of channel decoders for channel-decoding each of the data at the same time, and a parallel-to-serial converter for serially converting the plurality of channel-decoded data to output binary data for a normal signal.

In the narrowband wireless communication system according to another aspect of the present invention, the receiving apparatus includes a second FMT receiver that demultiplexes a received signal and separates it into a symbol for a normal signal and a symbol for an emergency signal, the second FMT receiver A general signal reception processing unit for recovering a general signal from a symbol for the output general signal, and a second emergency signal reception processing unit for estimating an emergency signal from the symbol for the emergency signal output from the second FMT reception unit, wherein the second The emergency signal reception processing unit includes a demodulator for demodulating a symbol for the emergency signal output from the second FMT reception using a preset demodulation method, a despreading unit for despreading the demodulated data, and a corresponding to the despreading data. It may include an emergency signal estimator that checks the index from the index table and estimates the emergency signal based on the checked index.

In the present invention, the second FMT receiver may output the emergency signal at each period of the general signal reception period/number of channels, and output the general signal through each channel at each general signal reception period.

In a transmission method in a narrowband wireless communication system according to another aspect of the present invention, an emergency signal generator obtains an index for an emergency signal from a predefined index table, converts the obtained index into binary data, and spreading Band-spreading the binary data based on a Kasami sequence, a modulator modulating the band-spreading binary data to generate a symbol, a pulse shaping filter converting the generated symbol to a transmission period of a general signal and performing pulse shaping with a period based on the number of channels, and allowing an operation unit to calculate an insertion level on the pulse-formed symbol to be transmitted.

In the present invention, in the pulse shaping step, the pulse shaping filter may pulse shaping the modulated symbol with a period of (transmission period/number of channels).

In the present invention, the insertion level may be a value generated based on a power ratio between the emergency signal and the normal signal.

In a transmission method in a narrowband wireless communication system according to another aspect of the present invention, an emergency signal generator obtains an index for an emergency signal from a predefined index table, and converts the obtained index into binary data; The upper part spreads the binary data based on a Kasami sequence, the modulator modulates the band-spread binary data to generate a symbol, and the repeater applies the generated symbol to the number of channels. Repeatedly transmitting the number of times to the second FMT transmitter, the second FMT transmitter outputting the symbol every period of the transmission period/channel number of the general signal, and the operation unit to the symbol output from the second FMT transmitter and calculating the insertion level and transmitting it.

In the present invention, the insertion level may be a value generated based on a power ratio between the emergency signal and the normal signal.

In a reception method in a narrowband wireless communication system according to another aspect of the present invention, when a symbol for an emergency signal is received, a matched filter filters data pulse-shaped by a pulse-shaping filter, and a demodulator converts the filtered data Demodulating using a preset demodulation method, a despreading unit despreading the demodulated data, and an emergency signal estimating unit checking an index corresponding to the despreading data from an index table, and an emergency signal based on the checked index estimating.

In a reception method in a narrowband wireless communication system according to another aspect of the present invention, a second FMT receiver outputs a symbol for an emergency signal at each period of a general signal reception period/number of channels, and a demodulator includes the second FMT Demodulating a symbol output from a receiver, despreading the demodulated data by a despreading unit, and an emergency signal estimating unit checking an index corresponding to the despreading data from an index table, and based on the checked index estimating the signal.

An apparatus and method for transmitting and receiving in a narrowband wireless communication system according to an embodiment of the present invention, while satisfying the smart grid network requirements in terms of minimum transmission delay time, a service that exhibits a low transmission delay time regardless of the degree of use of network resources can provide

The apparatus and method for transmitting and receiving in a narrowband wireless communication system according to an embodiment of the present invention can be applied to an emergency signal transmission mode of an e-WSN to dramatically reduce a delay time.

A transmission/reception apparatus and method in a narrowband wireless communication system according to an embodiment of the present invention use a multi-channel-based transmission technique, so that a signal can be transmitted faster to achieve a transmission delay time that meets the requirements, By applying the spreading technique, a signal can be directly transmitted without a resource allocation process, so there is no waiting delay due to resource allocation.

An apparatus and method for transmitting and receiving in a narrowband wireless communication system according to an embodiment of the present invention manage essential control signals transmitted in a service as an index, and transmit only index information to an emergency signal wirelessly to minimize the delay time in the radio can do.

In the case of an emergency signal, an apparatus and method for transmitting and receiving in a narrowband wireless communication system according to an embodiment of the present invention appropriately adjust a spreading factor and a signal insertion level during a band spreading process to minimize the effect on the existing e-WSN system. It is possible to transmit

On the other hand, the effects of the present invention are not limited to the above-mentioned effects, and various effects may be included within the range apparent to those skilled in the art from the description below.

1 is a diagram for explaining a transmitting apparatus in a narrowband wireless communication system according to an embodiment of the present invention.
FIG. 2 is a view for explaining the pulse shaping filter shown in FIG. 1 .
3 is an exemplary diagram illustrating a spectrum of a transmission signal according to an embodiment of the present invention.
4 is a diagram for explaining a transmitting apparatus in a narrowband wireless communication system according to another embodiment of the present invention.
5 is a diagram for explaining a receiving apparatus in a narrowband wireless communication system according to an embodiment of the present invention.
6 is a diagram for explaining a receiving apparatus in a narrowband wireless communication system according to another embodiment of the present invention.
7 and 8 are diagrams for explaining an index transmission method for an emergency signal according to an embodiment of the present invention.
9 and 10 are exemplary diagrams for explaining performance according to an emergency signal insertion level according to an embodiment of the present invention.

Hereinafter, an apparatus and method for transmitting and receiving in a narrowband wireless communication system according to an embodiment of the present invention will be described with reference to the accompanying drawings. In this process, the thickness of the lines or the size of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, the terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of the user or operator. Therefore, definitions of these terms should be made based on the content throughout this specification.

Implementations described herein may be implemented in, for example, a method or process, an apparatus, a software program, a data stream, or a signal. Although discussed only in the context of a single form of implementation (eg, discussed only as a method), implementations of the discussed features may also be implemented in other forms (eg, as an apparatus or program). The apparatus may be implemented in suitable hardware, software and firmware, and the like. A method may be implemented in an apparatus such as, for example, a processor, which generally refers to a computer, a microprocessor, a processing device, including an integrated circuit or programmable logic device, or the like. Processors also include communication devices such as computers, cell phones, portable/personal digital assistants (“PDA”) and other devices that facilitate communication of information between end-users.

1 is a diagram for explaining a transmitting apparatus in a narrowband wireless communication system according to an embodiment of the present invention, FIG. 2 is a diagram for explaining the pulse shaping filter shown in FIG. 1, and FIG. 3 is an embodiment of the present invention It is an exemplary diagram showing a spectrum of a transmission signal according to an example.

Referring to FIG. 1 , in a narrowband wireless communication system according to an embodiment of the present invention, a transmitting apparatus 100 includes a general signal transmission processing unit 110 , a first Filtered Multi-Tone (FMT) transmitting unit 120 , and a first It may include an emergency signal transmission processing unit 130 and a coupling unit 140 .

The general signal transmission processing unit 110 may process the general signal to be transmitted using a plurality of channels. The general signal transmission processor 110 may include a serial-to-parallel converter 112 , a plurality of channel encoders 114 , a plurality of interleavers 116 , and a plurality of modulators 118 .

The serial-to-parallel converter 112 may divide binary data for a serially input normal signal into a plurality of partial binary data, and transmit the plurality of partial binary data to a plurality of channel encoders, respectively. For example, the serial-to-parallel converter 112 divides binary data for a normal signal into N pieces of partial binary data, and each partial binary data may include k bits.

The plurality of channel encoders 114 may channel-code input partial binary data and output channel-encoded binary data. In this case, the channel encoder 114 may be the same channel encoder. For example, if the code rate of the channel encoder 114 is k/n, n encoded bits may be output for k bits.

The plurality of interleavers 116 may interleave the channel-encoded binary data output from the channel encoder 114, respectively, and transmit the interleaved data to the plurality of modulators. The interleaving of the interleaver 116 serves to mix the channel-encoded binary data according to a predetermined rule.

The plurality of modulators 118 may generate a plurality of modulation symbols by modulating the interleaved binary data using a preset modulation method, and transmit the plurality of generated modulation symbols to the first FMT transmitter 120 . Here, the modulation method may be, for example, PSK, QAM, or the like. That is, the modulator 118 may generate a digital modulation symbol by performing digital modulation on a data symbol composed of binary data to be transmitted through a channel.

The first FMT transmitter 120 may generate the symbols output from the general signal transmission processor 110 as symbols in the frequency domain. In this case, the first FMT transmitter 120 may perform inverse Fourier transform and filtering on the parallel symbols output from the general signal transmission processor 110 . Accordingly, the first FMT transmitter 120 may include an Inverse Discrete Fourier Transform (IDFT) unit 122 and a filter unit 124 .

The IDFT unit 122 may convert a symbol in the frequency domain into a symbol in the time domain. When using M subchannels, symbols to be transmitted on the M subchannels to be used are inputted in parallel to the points of the IDFT unit 122, and the IDFT unit 122 uses the inputted M subchannel transmission symbols. Thus, the IDFT operation can be performed to output M complex time-domain results.

Meanwhile, in the embodiment of the present invention, IDFT is configured, but FFT (Fast Fourier Transform) operation may be used instead of IDFT.

The filter unit 124 may generate a symbol in the frequency domain by passing the symbol (signal) converted by the IDFT unit 122 . In this case, the filter unit may be implemented as a poly phase filter.

The first emergency signal transmission processing unit 130 may include an emergency signal generation unit 131 , a diffusion unit 132 , a modulation unit 133 , a pulse shaping filter 134 , and an operation unit 135 . have.

The emergency signal generator 131 obtains an index for the emergency signal from a predefined index table, converts the obtained index into binary data, and transmits the converted binary data to the spreader. Here, the emergency signal may transmit only index information corresponding to the emergency signal in a predefined index table.

The spreader 132 may spread the binary data for the emergency signal generated by the emergency signal generator 131 according to a Kasami sequence, and then transmit it to the modulator 133 .

은

의 값을 갖는다. Kasami 수열은 'Large set'과 'Small set'으로 분류되며 'Large set'은 모ㄷ드든 'Small set'을 포함한다. Large set의 family size는

또는

이며 'small set'의 family size는

을 갖는다. 즉, Kasami 수열은 많은 family size를 가질 뿐만 아니라 Large set 및 Small set의 family size에 포함되어 있는 수열들의 자기상관 및 상호상관 특성이 매우 우수하다. 본 발명의 실시예에서 정의된 Kasami 수열은 생성다항식의 차수가

인 수열을 사용하며 디바이스들에는 'Small set' 내의 서로 다른 수열이 할당된다. The emergency signal is transmitted by spreading the bandwidth, and the Kasami sequence with excellent auto-correlation and cross-correlation characteristics can be used during the spread process. The Kasami sequence, which is a binary sequence, exists only when the order n of the generator polynomial is even, and then the length of the sequence is

silver

has a value of The Kasami sequence is classified into 'Large set' and 'Small set', and 'Large set' includes all 'Small set'. The family size of the large set is

or

and the family size of 'small set' is

has That is, the Kasami sequence not only has many family sizes, but also has very excellent autocorrelation and cross-correlation characteristics of sequences included in the family sizes of large and small sets. The Kasami sequence defined in the embodiment of the present invention is the order of the generative polynomial.

It uses an argument sequence, and devices are assigned different sequences in the 'Small set'.

The modulator 133 may perform binary phase shift keying (BPSK) modulation on the binary data spread by the spreader 132 , and transmit it to the pulse shaping filter 134 .

The pulse shaping filter 134 may pulse shaping the data modulated by the modulator 133 with a period based on the transmission period (Ts) of the general signal and the number of channels (N). That is, the pulse shaping filter 134 may pulse shaping the data modulated by the modulator 133 with a period of (transmission period/number of channels).

주기마다 직교하는 특성이 있다. 따라서 긴급신호는 일반적인 FMT 기법을 사용한 경우 T_s마다 신호를 전송하지만, 본 발명에서는

주기마다 신호를 전송할 수 있다. 따라서 일반적인 FMT 기법이 적용된 경우보다

배 만큼 신호를 빠르게 전송할 수 있어 낮은 전송지연시간을 나타낼 수 있다. The pulse shaping filter 134 has the same spectral characteristics as in the case of using N channels in Filtered Multi-Tone (FMT), and a time domain generated when all 1s are input to the N channel inputs of the FMT as shown in FIG. 2 . It has the same shape as the signal. The FMT output signal in the general signal transmission mode has a characteristic that is orthogonal to each _{transmission period (T s} ), so that the signal is transmitted every _{T s.}

Each period has a characteristic that is orthogonal. _{Therefore, the emergency signal is transmitted every T s} when the general FMT technique is used, but in the present invention

A signal can be transmitted every cycle. Therefore, compared to the case where the general FMT technique is applied

A signal can be transmitted twice as fast, which can indicate a low transmission delay time.

The operation unit 135 may perform an operation of multiplying the data pulse-shaped by the pulse shaping filter 134 by the insertion level. Here, the insertion level may be a value generated based on the power ratio of the emergency signal and the normal signal.

That is, the insertion level can be expressed using a bury ratio (BR), which is a power ratio between the emergency signal and the normal signal, and BR can be expressed as in Equation 1 below.

[Equation 1]

,

및

는 각각 시간 인덱스 k에서의 일반신호, BPSK 변조된 긴급신호 및 삽입 레벨을 나타낸다. 일반신호는 QPSK ~ 64-QAM이 사용되며 이때 평균 에너지는 1이고, 긴급신호의 평균 에너지는 1로 가정한다. 따라서 삽입 레벨

는 아래 수학식 2와 같이 나타낼 수 있다. here,

,

and

denotes a normal signal, a BPSK-modulated emergency signal, and an insertion level at time index k, respectively. For general signals, QPSK ~ 64-QAM are used, and it is assumed that the average energy is 1 and the average energy of the emergency signal is 1. So the insertion level

can be expressed as in Equation 2 below.

[Equation 2]

On the other hand, for backward compatibility of the narrowband wireless communication system, the power of the emergency signal should be sufficiently lower than the power of the general signal.

FIG. 3 shows a spectrum of a signal when transmitting a signal using four channels having a 25 kHz bandwidth in succession, and FIG. 3A shows a spectrum mask of the pulse shaping filter 134 . When the emergency signal is transmitted to the corresponding pulse shaping filter 134 , it can be confirmed that the spectrum of the signal has the same spectrum shape as in the case of transmitting a general e-WSN signal, as shown in FIG. 3B .

The combiner 140 may combine the data output from the first FMT transmitter 120 and the data output from the first emergency signal transmission processor and transmit the combined. In this case, the combiner 140 may transmit the combined symbol to the receiving device through a channel through a radio frequency (RF) unit (not shown).

The transmitting apparatus 100 configured as described above may be included in the gateway and the device. At this time, in order to prevent collision of emergency signals, different Kasami sequences are assigned to devices, and thus devices can transmit emergency signals without considering collision. If there are separate uplink and downlink frequencies of the narrowband wireless communication system, since there are a total of 512 'Small sets' in the sequence, a maximum of 512 devices can be operated in one gateway. You can use the same sequence as the Kasami sequence used in . When the uplink and downlink frequencies of the narrowband wireless communication system are the same, 256 Kasami sequences can be assigned to each device and gateway, so that up to 256 devices can be operated.

4 is a diagram for explaining a transmitting apparatus in a narrowband wireless communication system according to another embodiment of the present invention.

Referring to FIG. 4 , in the narrowband wireless communication system according to another embodiment of the present invention, the transmission apparatus 200 includes a general signal transmission processing unit 210 , a second Filtered Multi-Tone (FMT) transmission unit 220 , and a second It may include an emergency signal transmission processing unit 230 and an operation unit 240 .

The general signal transmission processing unit 210 is configured to process a general signal to be transmitted using a plurality of channels, and is the same as the general signal transmission processing unit 110 illustrated in FIG. 1 , and thus a description thereof will be omitted.

The second emergency signal transmission processing unit 230 may process to transmit the emergency signal.

The second emergency signal transmission processor 230 may include an emergency signal generator 231 , a spreader 232 , a modulator 233 , and a repeater 234 .

The emergency signal generator 231 obtains an index for the emergency signal from a predefined index table, converts the obtained index into binary data, and transmits the converted binary data to the spreader. Here, the emergency signal may transmit only index information corresponding to the emergency signal in a predefined index table.

The spreader 232 may spread the binary data for the emergency signal generated by the emergency signal generator 231 according to a Kasami sequence, and then transmit it to the modulator.

The modulator 233 may perform binary phase shift keying (BPSK) modulation on the binary data spread by the spreader 232 and transmit it to the repeater 234 .

The repeater 234 may repeat the data modulated by the modulator 233 a number of times corresponding to the number of channels and transmit it to the second FMT transmitter 220 .

The normal signal is input to the second FMT transmitter 220 at each transmission period (Ts), the number of normal signals input to the second FMT transmitter 220 and the number of emergency signals input to the second FMT transmitter 220 are should be the same Accordingly, the repeater must repeat N times corresponding to the number of channels in order to match the number of normal signals input to the second FMT transmitter 220 and the number of emergency signals input to the second FMT transmitter 220 . A period input to the FMT transmitter 220 may be Ts.

The second FMT transmitter 220 may generate a symbol output from the general signal transmission processor 210 and a symbol output from the second emergency signal transmission processor 230 as a signal in the frequency domain. In this case, the second FMT transmitter 220 may perform inverse Fourier transform and filtering on the parallel symbols output from the general signal transmission processing unit 210 and the second emergency signal transmission processing unit 230 . Accordingly, the second FMT transmitter 220 may include an Inverse Discrete Fourier Transform (IDFT) unit 222 and a filter unit 224 . Here, it may be implemented as a poly phase filter.

The calculator 230 may perform an operation of multiplying the symbol output from the second FMT transmitter 220 by the insertion level. Here, the insertion level may be a value generated based on the power ratio of the emergency signal and the normal signal.

주기마다 직교하는 특성이 있다. 따라서 낮은 전송지연시간을 갖는 긴급신호 전송이 가능하다.On the other hand, the transmitter 100 of FIG. 1 transmits an emergency signal using a separate pulse shaping filter 134, but the transmitter 200 of FIG. 4 uses the FMT of the existing narrowband wireless communication system, When a signal is transmitted, the transmission of a general signal may be suspended. After the emergency signal is converted into binary data, each binary data is spread by the Kasami sequence in the spreader 232, is BPSK-modulated, and is input to the second FMT transmitter 220 after the signal is repeated N times, repeated A signal may be allocated to N channels and transmitted. Here, since the same signal is transmitted to the parallel input of the second FMT transmitter 220, the output signal of the second FMT transmitter 220 is similar to the transmitter of FIG.

Each period has a characteristic that is orthogonal. Therefore, it is possible to transmit an emergency signal with a low transmission delay time.

5 is a diagram for explaining a receiving apparatus in a narrowband wireless communication system according to an embodiment of the present invention.

Referring to FIG. 5 , in the narrowband wireless communication system according to an embodiment of the present invention, the reception device 300 includes a first FMT reception unit 310 , a general signal reception processing unit 320 , and a first emergency signal reception processing unit 330 . ) may be included.

The first FMT receiver 310 may demultiplex the received signal and separate it into a plurality of data. In this case, the first FMT receiver 310 may output a general signal through N channels at every transmission period (Ts). The first FMT receiving unit 310 may include a filter unit 312 and a DFT unit 314 .

The filter unit 312 may generate a predetermined number of sampled signals by sampling the received signal at predetermined frequency intervals. That is, the filter unit 312 may generate a signal in the frequency domain with respect to the received signal.

The filter unit 312 may generate M parallel signals based on the signals received by the RF receiver (not shown). Here, the filter unit 312 may be implemented as a poly phase filter.

The DFT unit 314 may spread the signals generated by the filter unit 312 by using a discrete Fourier transform (DFT).

Meanwhile, although the embodiment of the present invention has been described as using the IDFT, since a Fast Fourier Transform (FFT) operation can be used instead of the IDFT, a modulator can be implemented more efficiently.

The general signal reception processing unit 320 may restore a general signal from a plurality of data output from the first FMT reception unit 310 .

The general signal reception processing unit 320 may include a plurality of demodulators 322 , a plurality of deinterleavers 324 , a plurality of channel decoders 326 , and a parallel-to-serial converter 328 .

The plurality of demodulators 322 may generate a plurality of binary data by simultaneously demodulating each of a plurality of symbols using a preset demodulation method.

The plurality of deinterleavers 324 may simultaneously deinterleave each of the plurality of demodulated binary data.

The plurality of channel decoders 326 may simultaneously channel-decode each of the plurality of deinterleaved binary data.

The parallel-to-serial converter 328 may serially convert the plurality of channel-decoded binary data to output binary data for a general signal.

The first emergency signal reception processing unit 330 may estimate the emergency signal from the received signal.

The first emergency signal reception processor 330 may include a matched filter 332 , a demodulator 334 , a despreader 336 , and an emergency signal estimator 338 .

The matched filter 332 is a filter matched to the pulse shaping filter 134 of the transmitter 100 , and may filter data pulse shaped by the pulse shaping filter 134 .

The demodulator 334 may demodulate the data filtered by the matched filter 332 using a preset demodulation method.

The despreader 336 may despread the data demodulated by the demodulator 334 .

The emergency signal estimator 338 may check an index corresponding to the despread data from the index table, and estimate the emergency signal based on the checked index.

6 is a diagram for explaining a receiving apparatus in a narrowband wireless communication system according to another embodiment of the present invention.

Referring to FIG. 6 , in the narrowband wireless communication system according to another embodiment of the present invention, the reception apparatus 400 includes a second FMT reception unit 410 , a general signal reception processing unit 420 , and a second emergency signal reception processing unit 430 . ) may be included.

주기마다 긴급신호를 출력할 수 있고, 전송주기마다 N개의 채널을 통해 일반신호를 출력할 수 있다. The second FMT receiver 410 may demultiplex the received signal and separate it into a plurality of data. The second FMT receiver 410 is

It is possible to output an emergency signal at every cycle, and a general signal through N channels at every transmission cycle.

The second FMT receiver 410 may include a filter unit 412 and a DFT unit 414 .

Since the general signal reception processing unit 420 is the same as the general signal reception processing unit 320 shown in FIG. 5 , a description thereof will be omitted.

The second emergency signal reception processing unit 430 may estimate the emergency signal from data on the emergency signal output from the second FMT reception unit 410 .

The second emergency signal reception processor 430 may include a demodulator 432 , a despreader 434 , and an emergency signal estimator 436 .

The demodulator 432 may demodulate the data for the emergency signal output from the second FMT receiver 410 using a preset demodulation method.

The despreader 434 may despread the data demodulated by the demodulator 432 .

The emergency signal estimator 436 may check an index corresponding to the despread data from the index table, and estimate the emergency signal based on the checked index.

7 and 8 are diagrams for explaining an index transmission method for an emergency signal according to an embodiment of the present invention.

The emergency signal is defined in advance in the service to which the narrowband wireless communication system is applied. As shown in Table 1 below, M emergency signals transmitted from the gateway (GW) to the device and from the device to the gateway (GW) are each defined, and the ) and in the device's memory.

" 전송이 요청되면, 게이트웨이는 표 1과 같이 사전에 정의된 인덱스 테이블을 확인하고, 해당 인덱스 번호

을 긴급신호 송신 처리부를 이용하여 전송할 수 있다. 디바이스는 게이트웨이에서 전송된 긴급신호를 수신할 수 있고, 디바이스는 수신된 긴급신호를 인덱스 테이블에서 확인한 후 서비스로 전송할 수 있다. 이는 전력제어가 중요한 배전자동화 시스템에 적용될 경우 디바이스를 제어하기 위한 선로 개폐, 단말 잠금 풀림, 및 BI(Binary Input) 등의 제어 메시지 전송에 활용할 수 있다. 7 is a diagram for explaining a method of transmitting an emergency signal from a gateway GW to a device. Referring to FIG. 7, the emergency signal "GW_data" in the service

" When transmission is requested, the gateway checks the predefined index table as shown in Table 1, and the corresponding index number

can be transmitted using the emergency signal transmission processing unit. The device may receive the emergency signal transmitted from the gateway, and the device may check the received emergency signal in the index table and then transmit it to the service. When applied to a distribution automation system where power control is important, it can be used to open and close a line to control a device, unlock a terminal, and transmit control messages such as BI (Binary Input).

" 전송이 요청되면, 디바이스는 사전에 정의된 인덱스 테이블을 확인하고, 해당 인덱스 번호

을 긴급신호 송신 처리부를 이용하여 전송할 수 있다. 게이트웨이는 디바이스로부터의 긴급신호를 수신할 수 있고, 게이트웨이는 수신한 긴급신호를 인덱스 테이블에서 확인한 후, 서비스로 전송할 수 있다. 이는 전력제어가 중요한 배전자동화 시스템에 적용될 경우 디바이스에서 긴급을 요하는 고장정보 (Fault Indicator, FI), 순간고장, 일시고장, 및 단선/결상 등을 매핑하여 활용할 수 있다. 8 is a diagram for explaining a method of transmitting an emergency signal from a device to a gateway. Referring to FIG. 8, in the service, the emergency signal "Device_data

" When transmission is requested, the device checks the predefined index table and

can be transmitted using the emergency signal transmission processing unit. The gateway may receive the emergency signal from the device, and after checking the received emergency signal in the index table, the gateway may transmit the received emergency signal to the service. This can be used by mapping emergency information (Fault Indicator, FI), instantaneous failure, temporary failure, and disconnection/phase loss in devices when applied to a distribution automation system where power control is important.

As described above, in the emergency signal transmission mode in the narrowband wireless communication system, signals requiring urgency in the service are managed as indexes, and only index information can be wirelessly transmitted when the emergency signal is transmitted. Therefore, it is possible to minimize the transmission delay time by minimizing the amount of data to be transmitted for data requiring urgency.

9 and 10 are exemplary diagrams for explaining performance according to an emergency signal insertion level according to an embodiment of the present invention.

In the narrowband wireless communication system, modulation schemes such as QPSK, 16QAM, and 64QAM can be used. When the signal uses 64-QAM in the narrowband wireless communication system, the performance of the e-WSN signal according to the insertion level may be as shown in FIG. 9 . Referring to FIG. 9 , it can be seen that when the emergency signal is not transmitted, the e-WSN signal operates at a carrier-to-noise ratio (CNR) of 16 dB, and when the emergency signal is inserted at -20 dB, the value of 0.4 dB It can be seen that performance degradation occurs.

When the e-WSN signal uses QPSK, the performance of the e-WSN signal according to the insertion level may be as shown in FIG. 10 . Referring to FIG. 10 , it can be confirmed that the e-WSN signal operates at a CNR of 4 dB when the emergency signal is not transmitted, and performance degradation of 0.1 dB occurs when the emergency signal is inserted at -10 dB. have. Therefore, it can be confirmed that in order to transmit a signal while maintaining backward compatibility with the existing e-WSN, it is enough to set the BR to -20 dB or less.

Meanwhile, the emergency signal performance (CNR) can be calculated using Equation 3 below.

[Equation 3]

9.6dB에서

의 BER (Bit Error Rate)을 달성한다. 삽입레벨인 BR이 -20dB인 경우 긴급신호의 동작 CNR이 -20dB 이하인 영역에서 동작한다. 따라서 확산 수열의 길이가 1023 이상을 사용하면 긴급신호가 정상적으로 동작한다. Since BPSK modulation is used for emergency signals,

at 9.6 dB

BER (Bit Error Rate) is achieved. When the insertion level BR is -20dB, it operates in the region where the operating CNR of the emergency signal is -20dB or less. Therefore, if the length of the spread sequence is 1023 or more, the emergency signal operates normally.

The number of channels, the length of a sequence, and index information set in consideration of the performance degradation of the e-WSN system according to the insertion level of -20dB and the performance of the emergency signal may be as shown in Table 2 below.

As can be seen in Table 2, when the length of the sequence is 1024 and the number of channels is set to 6 and 12, it can be confirmed that the types of emergency signals that can be transmitted are 4 and 8, respectively. It can be seen that the grid requirements can achieve a transmission delay of less than 20 ms.

As described above, the apparatus and method for transmitting and receiving in a narrowband wireless communication system according to an embodiment of the present invention satisfy the smart grid network requirements in terms of minimum transmission delay time, and low transmission irrespective of the degree of use of network resources. A service indicating the delay time can be provided.

The apparatus and method for transmitting and receiving in a narrowband wireless communication system according to an embodiment of the present invention can be applied to an emergency signal transmission mode of an e-WSN to dramatically reduce a delay time.

A transmission/reception apparatus and method in a narrowband wireless communication system according to an embodiment of the present invention use a multi-channel-based transmission technique, so that a signal can be transmitted faster to achieve a transmission delay time that meets the requirements, By applying the spreading technique, a signal can be directly transmitted without a resource allocation process, so there is no waiting delay due to resource allocation.

An apparatus and method for transmitting and receiving in a narrowband wireless communication system according to an embodiment of the present invention manage essential control signals transmitted in a service as an index, and transmit only index information to an emergency signal wirelessly to minimize the delay time in the radio can do.

In the case of an emergency signal, an apparatus and method for transmitting and receiving in a narrowband wireless communication system according to an embodiment of the present invention appropriately adjust a spreading factor and a signal insertion level during a bandwidth spreading process to minimize the effect on the existing e-WSN system. It is possible to transmit

Although the present invention has been described with reference to the embodiment shown in the drawings, this is merely an example, and those skilled in the art to which various modifications and equivalent other embodiments are possible. will understand

Accordingly, the true technical protection scope of the present invention should be defined by the following claims.

100, 200: Transmitting device
110, 210: general signal transmission processing unit
112: serial-to-parallel conversion unit
114: channel encoder
116: interleaver
118: modulator
120: first FMT transmitter
122: IDFT unit
124: filter unit
130: first emergency signal transmission processing unit
131: emergency signal generator
132: diffuser
133: modulator
134: pulse shaping filter
135: arithmetic unit
140: coupling part
220: second FMT transmitter
230: second emergency signal transmission processing unit
234: repeat
300, 400: receiving device
310: first FMT receiver
314: DFT unit
320: general signal reception processing unit
322: demodulator
324: deinterleaver
326: channel decoder
328: parallel-to-serial conversion unit
330: first emergency signal reception processing unit
332: matched filter
334: demodulator
336: despreading unit
338: emergency signal estimation unit
410: second FMT receiver
430: second emergency signal reception processing unit

Claims (1)

a general signal transmission processing unit for processing a general signal to be transmitted using a plurality of channels;
a second emergency signal transmission processor configured to transmit an emergency signal;
a second Filtered Multi-Tone (FMT) transmitter for generating symbols output from the general signal transmission processing unit and symbols output from the second emergency signal transmission processing unit as symbols in a frequency domain; and
Comprising a calculator for calculating and transmitting the insertion level on the symbol output from the second FMT transmitter,
The second emergency signal transmission processing unit,
an emergency signal generator for obtaining an index for the emergency signal from a predefined index table and converting the obtained index into binary data;
a spreader that spreads the binary data based on a Kasami sequence;
a modulator for generating a symbol by modulating the band-spread binary data; and
and a repeater for repeating the generated symbol a number of times corresponding to the number of channels and inputting it to the second FMT transmitter;
The general signal transmission processing unit,
a serial-to-parallel converter for dividing the binary data of the general signal into a plurality of partial binary data corresponding to the number of channels;
a plurality of channel encoders for channel-coding each of the plurality of partial binary data simultaneously;
a plurality of interleavers for simultaneously interleaving each of the plurality of channel-encoded binary data; and
and a plurality of modulators for generating a plurality of modulation symbols by simultaneously modulating each of the plurality of interleaved binary data using a preset modulation method.

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