KR102539067B1 - Method and apparatus for performing communication using preamble - Google Patents

Abstract

The present disclosure relates to a method and apparatus for performing communication using a preamble. A method according to an embodiment of the present disclosure includes receiving information on a preamble configuration from a base station, obtaining a first preamble and a second preamble corresponding to the first preamble based on the received information on the preamble configuration, A first preamble is transmitted to the base station during a first unit time interval, which is one of each unit time interval to which a predetermined number of symbols are allocated, and a second unit time interval, which is a unit time interval following the first unit time interval, transmits a second preamble to the base station. A preamble and data may be transmitted to the base station.

Description

Method and apparatus for performing communication using a preamble

The present invention relates to a wireless communication system, and more particularly, to a method and apparatus for performing communication using a preamble in a wireless communication system.

Efforts are being made to develop an improved 5G communication system (or NR, New Radio) or pre-5G communication system in order to meet the growing demand for wireless data traffic after the commercialization of the 4G communication system. For this reason, the 5G communication system or pre-5G communication system is called a Beyond 4G Network communication system or a Post LTE system.

In the existing LTE system, a terminal may perform processes such as formation of a radio link with a base station, scheduling request and approval for uplink data transmission. In this process, the terminal and the base station may transmit and receive various control signals to each other.

On the other hand, a method of transmitting and receiving various control signals for data transmission between a terminal and a base station has a problem in that overhead due to control signals occurs in an environment in which a plurality of terminals exist. Accordingly, in a next-generation mobile communication system, research on a grant-free transmission method capable of minimizing a control signal is being actively conducted in order to reduce overhead of a control signal transmitted and received by a terminal to and from a base station.

The present invention can provide a communication method and apparatus for identifying a plurality of terminals using a preamble so that data can be transmitted without responding to terminal access when a plurality of terminals simultaneously attempt to access a base station.

A communication method of a terminal using a preamble according to an embodiment, comprising: receiving information about a preamble configuration from a base station; obtaining a first preamble and a second preamble corresponding to the first preamble based on the received preamble configuration information; Transmitting a first preamble to a base station during a first unit time interval that is one of unit time intervals to which a predetermined number of symbols are allocated; and transmitting a second preamble and data to the base station during a second unit time interval that is a unit time interval following the first unit time interval.

In the communication method of a terminal using a preamble according to an embodiment, the acquiring may include obtaining a second preamble by performing interleaving based on at least some samples among a plurality of sections constituting the first preamble .

In the communication method of a terminal using a preamble according to an embodiment, the obtaining step includes an index of a first preamble obtained from among a plurality of first preambles that can be generated based on information about a preamble configuration and an index of the obtained first preamble. A sequence generated based on the index of the partial interval is obtained as a second preamble, and the partial interval of the first preamble may be at least one of a plurality of intervals generated as a result of dividing the first preamble.

In the communication method of a terminal using a preamble according to an embodiment, an index of a first preamble is generated based on the number of a plurality of first preambles and an identifier of a terminal, and an index of a second preamble is It may be generated based on the number of the plurality of second preambles obtainable based on the preamble and the identifier of the terminal.

In the communication method of a terminal using a preamble according to an embodiment, data may be data modulated based on a multiple access scheme identified based on an index of a first preamble and an index of a second preamble.

The communication method of a terminal using a preamble according to an embodiment may further include receiving an ACK signal notifying that data is demodulated as demodulation of data is completed in a base station.

A communication method of a terminal using a preamble according to an embodiment, when the base station does not demodulate data or the terminal is not detected, a reconstructed first preamble, a second preamble corresponding to the reconstructed first preamble, and data are transmitted to the base station. A step of transmitting may be further included.

In the communication method of a terminal using a preamble according to an embodiment, a first unit time interval and a second unit time interval are included in any one of a plurality of frequency hopping intervals constituting a frequency hopping pattern preset in the terminal, Each of the plurality of frequency hopping intervals may include a unit time interval in which the first preamble is transmitted and a unit time interval in which the second preamble and the data are transmitted.

A communication method of a base station using a preamble according to an embodiment includes detecting a first preamble from a signal received during a first unit time interval, which is one of unit time intervals to which a predetermined number of symbols are allocated; detecting a second preamble corresponding to the first preamble from a signal received during a second unit time interval that is a unit time interval following the first unit time interval; Identifying a terminal based on the first preamble and the second preamble; And as the terminal is identified, demodulating data included in the signal received during a second unit time period, wherein the first preamble and the second preamble are determined by the terminal based on information about a preamble configuration transmitted from the base station. can be obtained from

In the communication method of a base station using a preamble according to an embodiment, the second preamble may be detected according to a result of performing interleaving based on at least some samples among a plurality of sections constituting the first preamble.

In the communication method of a base station using a preamble according to an embodiment, a second preamble includes an index of a first preamble transmitted from a terminal and a transmitted first preamble among a plurality of first preambles that can be generated based on information about a preamble configuration. It includes a sequence generated based on the index of a partial section of the preamble, and the partial section of the first preamble may be at least one of a plurality of sections generated as a result of dividing the first preamble.

In the communication method of a base station using a preamble according to an embodiment, the step of demodulating data may demodulate data according to a multiple access scheme identified based on an index of a first preamble and an index of a second preamble.

The communication method of a base station using a preamble according to an embodiment may further include transmitting an ACK signal informing that data is demodulated as demodulation of data is completed.

In the communication method of a base station using a preamble according to an embodiment, a first unit time interval and a second unit time interval are in a frequency hopping interval that is one of a plurality of frequency hopping intervals constituting a preset frequency hopping pattern in a terminal. The step of demodulating the data includes, as a result of identification based on the first preamble and the second preamble, when data is simultaneously received from another terminal during the frequency hopping period, the data is received in another frequency hopping period among a plurality of frequency hopping periods. The method may further include demodulating data of the terminal based on the received signal.

A terminal performing communication using a preamble according to an embodiment includes a transceiver for receiving information on a preamble configuration from a base station; a memory for storing information about a preamble configuration; and at least one processor for acquiring a first preamble and a second preamble corresponding to the first preamble based on the received preamble configuration information, wherein the transceiver unit is each unit to which a predetermined number of symbols are allocated. A first preamble may be transmitted to the base station during a first unit time interval, which is one of the time intervals, and a second preamble and data may be transmitted to the base station during a second unit time interval, which is a unit time interval following the first unit time interval.

A base station performing communication using a preamble according to an embodiment includes a memory for storing information about a preamble configuration; a transceiver for receiving a signal including a first preamble and a second preamble obtained based on the information on the preamble configuration; and detecting a first preamble from a signal received during a first unit time interval, which is one of unit time intervals to which a predetermined number of symbols are allocated, and performing a second unit time interval following the first unit time interval. A second preamble corresponding to the first preamble is detected from a signal received during the interval, a UE is identified based on the first preamble and the second preamble, and as the UE is identified, a signal received during the second unit time interval is detected. It may include at least one processor for demodulating the included data.

According to an embodiment of the present invention, in a grant-free system that does not require a response for access from a base station, the possibility of identifying a plurality of terminals can be increased by identifying a plurality of terminals using the proposed preamble. In addition, according to an embodiment of the present invention, as a plurality of terminals are identified based on the proposed preamble, a time delay of each terminal is estimated, and data transmitted from each terminal is demodulated to solve a data loss problem. can prevent

1 is a diagram showing the basic structure of a time-frequency resource domain, which is a radio resource domain of a wireless communication system based on CP-OFDM or SC-FDMA.
2 is a diagram for explaining an extensible frame structure of a 5G system according to an embodiment.
3 is a diagram for explaining the structure of a signal transmitted from a terminal to a base station according to an embodiment.
4 is a diagram for explaining a method of allocating resources for preamble and data transmission according to an embodiment.
5A and 5B are diagrams for explaining a method of obtaining a second preamble according to an embodiment.
6 is a diagram for explaining a method in which a base station identifies a plurality of terminals based on a first preamble and a second preamble received from each of a plurality of terminals and estimates a time delay according to an embodiment.
7 is a flowchart illustrating a method for a terminal to perform communication using a preamble according to an embodiment.
8 is a flowchart illustrating a method for a base station to perform communication using a preamble according to an embodiment.
9 is a flowchart illustrating a method of performing communication between a base station and a terminal using a preamble according to an embodiment.
10 is a flowchart illustrating a method for a base station to identify a terminal using a preamble and estimate a time delay according to an embodiment.
11 is a diagram for explaining a method for a base station to demodulate data when a plurality of terminals transmit a signal using a preamble according to a frequency hopping scheme according to an embodiment.
12 is a block diagram of a terminal according to an embodiment.
13 is a block diagram of a base station according to an embodiment.

Hereinafter, the operating principle of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. In addition, 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 a user or operator. Therefore, the definition should be made based on the contents throughout this specification.

The present invention relates to a communication technique and a system for converging a 5G communication system with IoT technology to support a 4G system or a higher data transmission rate after the 4G system. The present disclosure provides intelligent services (e.g., smart home, smart building, smart city, smart car or connected car, health care, digital education, retail, security and safety related services, etc.) based on 5G communication technology and IoT related technology. ) can be applied.

Terms referring to broadcasting information, terms referring to control information, terms referring to messages, terms referring to components of a device, and the like used in the following description are illustrated for convenience of description. Accordingly, the present invention is not limited to the terms described below, and other terms having equivalent technical meanings may be used.

For convenience of description below, some terms and names defined in the 3rd generation partnership project long term evolution (3GPP LTE) standard may be used. However, the present invention is not limited by the above terms and names, and may be equally applied to systems conforming to other standards.

The wireless communication system has moved away from providing voice-oriented services in the early days and, for example, 3GPP's HSPA (High Speed Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2's High Rate Packet Data (HRPD), UMB (Ultra Mobile Broadband), and IEEE's 802.16e, a broadband wireless network that provides high-speed, high-quality packet data services. evolving into a communication system.

As a representative example of the broadband wireless communication system, in the LTE system, an Orthogonal Frequency Division Multiplexing (OFDM) scheme is employed in downlink, and a Single Carrier Frequency Division Multiple Access (SC-FDMA) scheme is employed in uplink. are hiring Uplink refers to a radio link in which a terminal (UE (User Equipment) or MS (Mobile Station)) transmits data or control signals to a base station (eNode B or base station (BS)), and downlink refers to a radio link in which a base station transmits data or a control signal to a terminal. A radio link that transmits data or control signals. The multiple access scheme as described above distinguishes data or control information of each user by allocating and operating time-frequency resources to carry data or control information for each user so as not to overlap each other, that is, to establish orthogonality. do.

As a future communication system after LTE, that is, 5G communication system (or NR), since it should be able to freely reflect various requirements of users and service providers, services that satisfy various requirements must be supported. Services considered for the 5G communication system include enhanced mobile broadband (eMBB), massive machine type communication (mMTC), and ultra reliability low latency communication (URLLC). etc.

eMBB aims to provide a data transmission speed that is more improved than the data transmission speed supported by existing LTE, LTE-A or LTE-Pro.

In order to efficiently provide the Internet of Things, mMTC requires access support for large-scale terminals within a cell, improved coverage of terminals, improved battery time, and reduced terminal cost. Since the Internet of Things is attached to various sensors and various devices to provide communication functions, it must be able to support a large number of terminals (eg, 1,000,000 terminals/km2) in a cell. In addition, terminals supporting mMTC are likely to be located in shadow areas that are not covered by cells, such as the basement of a building due to the nature of the service, so they require wider coverage than other services provided by the 5G communication system. A terminal supporting mMTC must be composed of a low-cost terminal, and since it is difficult to frequently replace a battery of the terminal, a very long battery life time is required.

Finally, in the case of URLLC, as a cellular-based wireless communication service used for a specific purpose (mission-critical), remote control for robots or machinery, industrial automation, As a service used for unmaned aerial vehicles, remote health care, and emergency alerts, it is necessary to provide ultra-low latency and ultra-reliable communication.

The services considered in the 5G communication system described above must be converged and provided based on one framework. That is, for efficient resource management and control, it is preferable that each service is integrated, controlled, and transmitted as one system rather than independently operated.

Hereinafter, frame structures of LTE, LTE-A, and 5G systems will be described with reference to drawings, and a design direction of the 5G system will be described.

1 is a diagram showing the basic structure of a time-frequency resource domain, which is a radio resource domain of a wireless communication system based on CP-OFDM (Cyclic Prefix-Orthogonal Frequency Division Multiplexing) or SC-FDMA (Single Carrier-Frequency Division Multiple Access) am.

Here, the wireless communication system based on CP-OFDM or SC-FDMA may be at least one of LTE, LTE-A and 5G systems, but this is only an example, and wireless communication based on CP-OFDM or SC-FDMA The system is not limited to the above example.

Referring to FIG. 1, in the time-frequency resource domain, the horizontal axis represents the time domain and the vertical axis represents the frequency domain. In this specification, a radio link through which a terminal transmits data or control signals to a base station is referred to as uplink (hereinafter referred to as UL), and a radio link through which a base station transmits data or control signals to a terminal is referred to as downlink (hereinafter referred to as DL). to be explained by

개의 심볼(105)이 모여 하나의 슬롯(115)을 구성할 수 있다. 또한, LTE 및 LTE-A 시스템의 경우 7개의 심볼로 구성된 2개의 슬롯이 하나의 서브프레임(140)을 구성할 수 있다. The minimum transmission unit in the time domain of LTE, LTE-A and 5G systems is an OFDM symbol or an SC-FDMA symbol,

The number of symbols 105 may be gathered to form one slot 115 . In addition, in the case of LTE and LTE-A systems, two slots composed of 7 symbols may constitute one subframe 140.

은 7 또는 14 중 하나의 값으로 설정될 수 있으며, 5G 시스템의 미니슬롯의 경우

은 1, 2, 3, 4, 5, 6 또는 7 중 하나의 값으로 설정될 수 있다.The 5G system can support two types of slot structures: slot and mini-slot (or non-slot). For slots in 5G systems

can be set to either 7 or 14, in the case of a minislot in a 5G system

may be set to one of 1, 2, 3, 4, 5, 6 or 7.

개의 서브캐리어(110)로 구성될 수 있다. 5G 시스템의 유동적 확장형 프레임 구조에 대해, 도 2를 참조하여 보다 구체적으로 후술하도록 한다.Meanwhile, in LTE and LTE-A systems, the length of a slot is 0.5 ms and the length of a subframe 140 is fixed at 1.0 ms. can In the LTE and LTE-A systems, the radio frame 135 is a time domain unit consisting of 10 subframes. In LTE and LTE-A systems, the minimum transmission unit in the frequency domain is a subcarrier in units of 15 kHz (subcarrier spacing = 15 kHz), and the bandwidth of the entire system transmission band is

It may be composed of two subcarriers (110). The flexible scalable frame structure of the 5G system will be described later in more detail with reference to FIG. 2 .

개의 심볼(105, 예를 들어,

개의 심볼 OFDM 심볼 또는

개의 심볼 SC-FDMA 심볼)과 주파수 영역에서

개의 연속된 서브캐리어(125)로 정의될 수 있다. 따라서, 하나의 리소스 블록(120)은

x

개의 리소스 엘리먼트(130)로 구성될 수 있다. A basic unit of resources in the time-frequency domain is a resource element (RE) 130, and the resource element 130 may be represented by at least one of an OFDM symbol index, an SC-FDMA symbol index, and a subcarrier index. The resource block 120 (Resource Block; RB or Physical Resource Block; PRB) is

The number of symbols (105, for example,

symbols OFDM symbols or

symbols SC-FDMA symbols) and in the frequency domain

It can be defined as two consecutive subcarriers (125). Thus, one resource block 120 is

x

It may consist of two resource elements 130 .

은 심볼간 간섭 방지를 위해 심볼마다 추가되는 CP의 길이에 따라 결정될 수 있다. 예를 들어 일반형 CP가 적용되는 경우,

은 7로 결정되고, 확장형 CP가 적용되는 경우,

은 6으로 결정될 수 있다. 확장형 CP 는 심볼 간 직교성을 유지하기 위해, 일반형 CP 보다 전파 송신 거리가 상대적으로 먼 시스템에 적용될 수 있다. On the other hand, the number of OFDM symbols

may be determined according to the length of a CP added for each symbol to prevent inter-symbol interference. For example, if a general type CP is applied,

is determined to be 7, and when the extended CP is applied,

can be determined as 6. In order to maintain orthogonality between symbols, the extended CP may be applied to a system with a relatively longer propagation transmission distance than the normal CP.

Subcarrier spacing, CP length, etc. are essential information for OFDM transmission and reception, and smooth transmission and reception is possible only when the base station and the terminal recognize a common value.

The frame structures of the aforementioned LTE and LTE-A systems are designed in consideration of normal voice/data communication, and expansion restrictions may follow to satisfy various services and requirements of the 5G system. Therefore, in the 5G system, it is necessary to flexibly define and operate the frame structure in consideration of various services and requirements.

2 is a diagram for explaining an extensible frame structure of a 5G system according to an embodiment.

In the early days when the 5G system is introduced in the future, coexistence or dual mode operation of the 5G system and the existing LTE/LTE-A system is expected. Through this, the existing LTE/LTE-A system can provide stable system operation, and the 5G system can play a role of providing improved services. Therefore, the extended frame structure of the 5G system needs to include at least the frame structure or parameter set of LTE/LTE-A.

In FIG. 2, as essential parameters for defining an extended frame structure, subcarrier intervals, CP lengths, slot lengths, and the like will be described as examples. In addition, in the 5G system, a basic time unit for performing scheduling may be a slot, but this is only an example, and the basic time unit for performing scheduling may be adjusted according to settings.

Referring to FIG. 2, the subcarrier interval is 30 kHz, 14 symbols constitute a 0.5 ms slot, and 12 subcarriers (= 360 kHz = 12x30 kHz) may constitute a PRB.

However, this is only one embodiment, and according to another example, a frame structure in which the subcarrier interval is 60kHz, 14 symbols constitute a 0.25ms slot, and 12 subcarriers (= 720kHz = 12x60kHz) constitutes a PRB is defined It could be. According to another example, a frame structure in which a subcarrier interval is 15 kHz, 14 symbols constitute a 1 ms slot, and 12 subcarriers (180 kHz = 12x15 kHz) constitute a PRB may be defined.

That is, generalizing the above-described frame structure type with reference to FIG. 2, the 5G wireless communication system according to an embodiment has a relationship of integer multiples to each other for each frame structure type, such as a subcarrier interval, CP length, slot length, etc., which are essential parameter sets. By determining to have, high scalability can be provided.

Meanwhile, in the 5G wireless communication system, in order to reduce overhead due to a control signal between a terminal and a base station, a grant-free transmission technology may be used. Grant-free transmission techniques can be classified according to which control signals are omitted.

In the SP scheduling (semi-persistent scheduling) technique, which is one of the grant-free transmission techniques, the base station issues a scheduling command to the terminal once every a plurality of subframes, rather than determining scheduling for each subframe. The base station can reduce signaling overhead due to a scheduling control signal by issuing a scheduling command for each of a plurality of subframes.

In addition, as another example, after entering a radio resource control (RRC) connection state by forming a radio link between a terminal and a base station, a technology for transmitting data without exchanging a scheduling request and approval signal between the terminal and the base station is a grant-free transmission technology can be used.

As another example, a short message service (SMS) technology that enables transmission of a short data signal together with a preamble in RACH resources for initial access only when the base station successfully detects the preamble can be used as a grant-free transmission technology. there is.

As another example, a technique of transmitting uplink data immediately after the terminal transmits a random access preamble indicating an access attempt may be used as a grant-free transmission technique. In this case, the terminal can directly transmit data without waiting for a random access response to the preamble from the base station. However, when data is transmitted through uplink without receiving a response from the base station, signals of the terminals may overlap because the terminals cannot receive individual scheduling from the base station. Non-orthogonal multiple access (NOMA) may be considered as one of the methods for separately receiving signals of overlapping terminals. The non-orthogonal multiple access scheme is a technique for effectively overlapping signals by utilizing multiple access signatures such as codebooks, sequences, and interleavers.

An embodiment of the present invention may provide a method for transmitting a signal using a preamble in order to recover a signal of the terminals in an environment in which the terminal transmits data without waiting for a response from the base station to the preamble. This will be described later in more detail with reference to FIGS. 3 to 13 .

3 is a diagram for explaining the structure of a signal transmitted from a terminal to a base station according to an embodiment.

Referring to FIG. 3 , a terminal may transmit at least one data symbol to a base station using a first preamble 330 and a second preamble 350 . In this embodiment, the first preamble 330 may be a signal having a length of one slot including a cyclic prefix (CP) 330, a first preamble sequence 340, and a guard interval 350. For example, the first preamble 330 may be a random access preamble transmitted through a Physical Random Access Channel (PRACH) resource in an LTE system. Also, in this embodiment, the second preamble 350 may be a sequence allocated to at least a part of a predetermined number of symbol intervals constituting one slot. Here, the second preamble may be a signal having a relatively shorter length than the first preamble.

A terminal according to an embodiment may transmit a first preamble 330, a data symbol 340, and a second preamble 350 to the base station during each unit time interval composed of a preset number of symbols. Although the unit time interval is described as a slot in this embodiment, this is only an example, and the unit time interval is not limited to the slot. For example, the terminal may transmit the first preamble 330 composed of the CP 332, the first preamble sequence 334, and the guard period 336 to the base station in slot #k 310. Also, the terminal may transmit a plurality of data symbols and the second preamble 350 in slot #k+1 320 . Here, the terminal may request access to the base station by transmitting the first preamble 330 and the second preamble 350. In addition, in this embodiment, as the terminal is not required to receive a random access response to the access request, the terminal is located at any position between a plurality of data symbols in slot #k+1 (320). A signal in which 2 preambles 350 are inserted can be transmitted.

The second preamble 350 according to an embodiment can be used to identify a plurality of terminals when a collision between preambles occurs as a plurality of terminals attempt access to a base station using the first preamble 330. . Specifically, when the base station receives the first preamble 330 from a plurality of terminals, the base station identifies only that the first preamble 330 has been received, and may not identify each of the plurality of terminals attempting access. Also, as it becomes difficult to identify a plurality of terminals, the base station may not be able to estimate the time delay of each of the plurality of terminals. Accordingly, the terminal may additionally transmit the second preamble 350 to the base station in addition to the first preamble 330 so that the base station can identify the signal of the terminal among the signals of the plurality of terminals.

Upon receiving a signal from the terminal, the base station can identify the terminal that has transmitted the signal through detection of the first preamble 330 and the second preamble 350 . In addition, the base station may demodulate the data of the identified terminal.

As described above, the terminal according to an embodiment additionally transmits the second preamble 350 to the base station in addition to the first preamble 330, thereby preamble collision that may occur in a grant-free transmission technique. collision) problem can be solved.

In this specification, for convenience of explanation, a period composed of the CP 332, the first preamble sequence 334, and the guard period 336 is defined as a preamble slot, and a period composed of a plurality of data symbols and the second preamble 350 Let the section be defined as a data slot. A preamble slot and a data slot may have the same length.

In addition, a preamble slot may be allocated within random access resources, and data slots following the preamble slot may be allocated within resources for uplink data transmission. For example, a signal constituting a preamble slot is transmitted through a resource to which a physical random access channel (PRACH) in an LTE system is allocated, and a signal constituting a data slot is a physical uplink shared channel (PUSCH) in an LTE system. It can be transmitted through the allocated resource.

4 is a diagram for explaining a method of allocating resources for preamble and data transmission according to an embodiment.

Referring to FIG. 4 , a terminal may transmit (410) a first preamble during a specific unit time interval and transmit (420) a second preamble and data in a unit time interval following the specific unit time interval. In this embodiment, the unit time interval is described as a slot, but this is only an embodiment, and the unit time interval is not limited to the slot. According to another example, the unit time interval may be a mini slot.

After transmitting the first preamble 410, the terminal can use resources more effectively by transmitting the second preamble 420 and data without responding to the transmission of the first preamble 410.

5A and 5B are diagrams for explaining a method of obtaining a second preamble 550 according to an embodiment.

Referring to FIG. 5A , the terminal may select a part of the section constituting the first preamble 530 allocated to slot #k 510 . Here, the first preamble 530 may consist of a plurality of sections. In this specification, each of a plurality of sections constituting the first preamble 530 is defined as a preamble section. The number of preamble sections constituting the first preamble 530 may be defined according to Equation 1 below.

[Equation 1]

는 제 1 프리앰블(530)을 구성하는 프리앰블 구간의 개수,

은 하나의 슬롯의 길이,

는 프리앰블 구간의 길이를 의미한다. 프리앰블 구간의 길이는 무선 통신 시스템에서 기 설정된 심볼의 길이와 대응될 수 있다. In Equation 1 above,

Is the number of preamble sections constituting the first preamble 530,

is the length of one slot,

denotes the length of the preamble section. The length of the preamble period may correspond to the length of a preset symbol in a wireless communication system.

개의 제 2 프리앰블(550)이 획득될 수 있다. When the UE acquires the second preamble 550 based on one preamble section, the total

Two second preambles 550 may be obtained.

는

중 하나일 수 있다. 여기에서, 선택 가능한 프리앰블 구간의 인덱스

는 제 2 프리앰블(550)의 인덱스를 의미할 수도 있다. 단말은

개의 인덱스 중 선택된 프리앰블 구간의 인덱스인 구체적으로, 단말이 선택 가능한 프리앰블 구간의 인덱스

는

중 하나일 수 있다. 여기에서, 선택 가능한 프리앰블 구간의 인덱스

는 제 2 프리앰블(550)의 인덱스를 의미할 수도 있다. 단말은

개의 인덱스 중 선택된 프리앰블 구간의 인덱스인

의 샘플(534a)을 추출할 수 있다. 또한, 단말은

에 할당된 인터리버(interleaver) 패턴에 따라 추출된 샘플(534a)을 인터리빙하여 제 2 프리앰블(550)을 획득할 수 있다. 전술한 인터리버 패턴은 기지국과 단말 간에 기 설정될 수 있다. Specifically, the index of the preamble section selectable by the UE

Is

can be one of Here, the index of the selectable preamble section

may mean the index of the second preamble 550. the terminal

Specifically, the index of the preamble section selectable by the UE, which is the index of the preamble section selected from among the indexes.

Is

can be one of Here, the index of the selectable preamble section

may mean the index of the second preamble 550. the terminal

The index of the preamble section selected among the indexes

A sample 534a of can be extracted. In addition, the terminal

The second preamble 550 may be obtained by interleaving the extracted sample 534a according to an interleaver pattern assigned to . The aforementioned interleaver pattern may be preset between the base station and the terminal.

와 대응되는 구간에 제 2 프리앰블(550)을 삽입할 수 있다. 또한, 단말은 슬롯#k+1(520)에서 제 2 프리앰블(550)이 삽입된 구간 이외의 다른 구간에 단말이 기지국에 송신하고자 하는 데이터 심볼(540)을 삽입할 수 있다. In slot #k+1 (520), the terminal is in the preamble section of slot #k (510).

The second preamble 550 may be inserted in a section corresponding to . In addition, the terminal may insert the data symbol 540 that the terminal intends to transmit to the base station in a section other than the section in which the second preamble 550 is inserted in slot #k+1 520 .

Accordingly, the UE uses the first preamble 530 including the CP 532 allocated to the slot #k 510, the first preamble sequence 534, and the guard period 536 and the slot #k+1 520 A signal composed of the data symbol 540 allocated to and the second preamble 550 may be transmitted to the base station.

Meanwhile, when a plurality of terminals use the same first preamble and the same second preamble, a collision between the first preambles and a collision between the second preambles occur simultaneously, and thus the base station may not be able to identify each of the plurality of terminals. The base station may transmit a plurality of second preambles in order to increase identification probability of a plurality of terminals. This will be described in detail with reference to FIG. 5B.

개의 제 2 프리앰블을 획득할 수 있다. 여기에서, 단말이 선택한

개의 제 2 프리앰블은 제 2 프리앰블 세트로 정의한다. 단말은 제 1 프리앰블(530)을 구성하는

개의 프리앰블 구간 중

개의 프리앰블 구간(534a, 534b)을 선택할 수 있다. 단말이

개의 프리앰블 구간 중

개의 프리앰블 구간(534a, 534b)을 선택하는 경우, 다음의 수학식 2에 기초하여,

개의 제 2 프리앰블이 획득될 수 있다. Referring to Figure 5b, the terminal

It is possible to obtain two second preambles. Here, the terminal selected

The number of second preambles is defined as a second preamble set. The terminal configures the first preamble 530

of the preamble sections

Two preamble sections 534a and 534b can be selected. Terminal

of the preamble sections

In the case of selecting two preamble sections 534a and 534b, based on Equation 2 below,

A number of second preambles may be obtained.

[Equation 2]

=

=

인 경우,

일 수 있다. 단말에서 선택한 프리앰블 구간의 인덱스가

인 경우, 단말은

구간의 샘플을 추출하고, 기 설정된 인터리버 패턴에 따라 추출된 샘플을 인터리빙하여,

개의 제 2 프리앰블을 획득할 수 있다. 여기에서, k개의 제 2 프리앰블로 구성된 각각의 제 2 프리앰블 세트의 인덱스

는

중 하나일 수 있다. In Equation 2 above,

If

can be The index of the preamble section selected by the terminal is

If , the terminal

Samples of the interval are extracted, and the extracted samples are interleaved according to a preset interleaver pattern,

It is possible to obtain two second preambles. Here, the index of each second preamble set consisting of k second preambles

Is

can be one of

와 각각 대응되는 구간에 k개의 제 2 프리앰블을 삽입할 수 있다. 또한, 단말은 슬롯#k+1(520)에서 k개의 제 2 프리앰블이 삽입된 구간 이외의 다른 구간에 단말이 기지국에 송신하고자 하는 데이터 심볼(540)을 삽입할 수 있다.In slot #k+1 (520), the UE selects the preamble section of slot #k (510).

K second preambles may be inserted into sections corresponding to . In addition, the terminal may insert the data symbol 540 that the terminal intends to transmit to the base station in slot #k+1 520 in a section other than the section in which the k second preambles are inserted.

As described above with reference to FIG. 5B, a UE according to an embodiment can reduce the possibility of collision between preambles of a plurality of UEs by increasing the number of second preambles in an environment with a large number of concurrently transmitting UEs. According to another embodiment, the terminal may reduce the number of second preambles or may not use the second preamble in an environment where the number of simultaneous transmission terminals is small. This can be determined by considering the number of simultaneous terminals in the base station. Meanwhile, information on whether the second preamble is used or the number of second preambles may be transmitted from the base station to the terminal in advance as information on the preamble configuration.

According to another embodiment, the second preamble may be obtained based on a sequence allocated according to a combination of the first preamble index and the second preamble index. For example, based on the index of the first preamble and the index of the second preamble, the terminal generates a Zadoff-chu sequence having a symbol length according to Equation 3 below, and converts the generated sequence to the second preamble. It can be used as a preamble.

와 제 2 프리앰블 인덱스

를 파라미터로 사용하여 쟈도추 시퀀스를 생성할 수 있다. Each terminal selects the first preamble index

and a second preamble index

You can create a Jadochu sequence by using as a parameter.

[Equation 3]

는 제 1 프리앰블 인덱스를 나타내고,

는 제 2 프리앰블 인덱스를 나타낼 수 있다. 또한, 수학식 3에서,

는 심볼의 길이에 해당하는

보다 큰 소수로 정의될 수 있다. 수학식 3에 기초하여, 생성된 시퀀스는 슬롯 내에서 제 2 프리앰블 인덱스에 해당하는 심볼 위치에 삽입될 수 있다. 단말이 제 1 프리앰블 인덱스와 제 2 프리앰블 인덱스를 기초로 제 2 프리앰블을 생성하는 경우에도 단말은 복수개의 제 2 프리앰블을 획득할 수 있다. 단말은 슬롯에서 프리앰블 생성에 이용된 복수의 제 2 프리앰블 인덱스 각각에 대응되는 심볼 위치에 복수개의 제 2 프리앰블 각각을 삽입할 수 있다. In Equation 3 above,

denotes a first preamble index,

may indicate the second preamble index. Also, in Equation 3,

is the length of the symbol

can be defined as a larger prime number. Based on Equation 3, the generated sequence may be inserted at a symbol position corresponding to the second preamble index within the slot. Even when the UE generates the second preamble based on the first preamble index and the second preamble index, the UE can obtain a plurality of second preambles. The terminal may insert each of the plurality of second preambles in the slot at a symbol position corresponding to each of the plurality of second preamble indices used for preamble generation.

Meanwhile, in the foregoing examples, the length of the second preamble has been described as one symbol, but this is only an example, and the length of the second preamble is not limited to a symbol unit. The length of the second preamble obtained from the terminal and the number of used second preambles may be determined according to configuration information defined in a base station to which the terminal intends to access.

Configuration information on the second preamble may be transmitted from the base station to each of the terminals through a broadcasting channel. However, this is only one embodiment, and according to another embodiment, the base station may transmit configuration information about the second preamble to each of the terminals through RRC signaling. For example, the base station may include configuration information of the second preamble in SIB-2, which is one of system information blocks (SIBs) of LTE, and transmit the same. Accordingly, the UE may obtain the second preamble by referring to SIB-2. Table 1 below shows information included in the configuration information of the second preamble.

Information included in the configuration information of the second preamble Information elements Description Resources for Grant-Free Transmission Location of resources capable of transmitting preamble-based terminal signals for grant-free transmission Number of second preambles The number of uses of the second preamble of each terminal
0 (not used), 1, 2, 3, ? Length of the second preamble Length of the second preamble
1, 2, 3, 4, ? (unit: symbol length)

6 is for explaining a method in which a base station identifies a plurality of terminals based on a first preamble 630 and a second preamble 650 received from each of a plurality of terminals and estimates a time delay according to an embodiment. it is a drawing

In this embodiment, it is assumed that the process of adjusting the uplink timing of each of a plurality of terminals is omitted. Accordingly, signals of each of a plurality of terminals may be received by the base station at different times.

Referring to FIG. 6, each terminal may transmit a first preamble 630 in a random access resource that is a first unit time interval and transmit a second preamble 650 in a second unit time interval that is a data transmission resource. . Here, the random access resource and the data transmission resource may each correspond to one slot.

A base station according to an embodiment may detect a first preamble 630 from a first random access resource 605 . Here, the base station can estimate the time delay of the signal transmitted from the terminal based on the first preamble 630 detected in the first random access resource 605 . On the other hand, when both terminal 1 and terminal 2 included in the plurality of terminals transmit the first preamble 630, the base station only detects the first preamble 630, and the plurality of terminals that have transmitted the first preamble 630 The terminal may not be identified. Also, since the plurality of terminals are not identified, the base station may not be able to estimate a time delay for each of the plurality of terminals.

Accordingly, the base station can identify terminal 1 and terminal 2 by additionally detecting the second preamble 650 transmitted through the first data transmission resource 610 in addition to the first preamble 630 . When several second preambles are detected for the same first preamble, the base station can confirm that a plurality of terminals that have transmitted the same first preamble have accessed. In addition, the base station can estimate the time delays 682 and 684 respectively generated in terminal 1 and terminal 2 by comparing the insertion position of the preset second preamble 650 and the detected position of the second preamble 650. there is.

As the terminal is identified through detection of the first preamble 630 and the second preamble 650, the base station according to an embodiment may demodulate the data symbol transmitted through the second data transmission resource 610.

Meanwhile, according to another embodiment, after the first preamble 630 received through the second random access resource is detected, the base station transmits one second preamble 650 through the second data transmission resource 620. When detected, it may be determined that access is performed from one terminal. For example, the base station may determine that access is performed from terminal 3 and estimate a time delay 686 of terminal 3 based on the detected first preamble.

Also, the base station may demodulate data symbols received through the second data transmission resource 620 . However, when a plurality of terminals transmit the same first preamble and the same second preamble, identification of the plurality of terminals may be difficult as the base station determines that one terminal rather than a plurality of terminals attempted access.

As an example of the data demodulation of the present invention, a case in which a plurality of terminals transmit data using non-orthogonal multiple access technology may be considered. In this case, the base station may request information on a multiple access signature (MA signature) used by each terminal to demodulate data of each of a plurality of terminals. Information on the multi-access signature may be transmitted from the terminal to the base station using additional signaling, but according to the present embodiment, the multi-access signature of the terminal may be obtained based on the first preamble index and the second preamble index.

For example, as the first preamble index and the second preamble index of the terminal are detected, the base station may obtain the multi-access signature based on Equation 4 below. The base station may demodulate data based on a multiple access scheme indicated by the obtained multiple access signature.

[Equation 4]

는 단말 i의 다중 접속 시그니처 인덱스,

는 단말 i가 이용한 제 1 프리앰블 인덱스,

는 단말 i가 이용한 제 2 프리앰블 인덱스, M은 각 단말이 선택 가능한 다중 접속 시그니처의 총 개수,

는 임의의 함수를 의미한다. 여기에서, 임의의 함수는 사칙 연산들로 구성된 함수일 수 있으나 이는 일 예일 뿐, 임의의 함수가 전술한 예에 한정되는 것은 아니다. In Equation 4 above,

Is the multi-access signature index of terminal i,

Is the first preamble index used by terminal i,

is the second preamble index used by terminal i, M is the total number of multiple access signatures that each terminal can select,

represents an arbitrary function. Here, the arbitrary function may be a function composed of four arithmetic operations, but this is only an example, and the arbitrary function is not limited to the above example.

According to another example, the base station may determine the multi-access signature index based on Equation 5 below.

[Equation 5]

는 단말 i의 다중 접속 시그니처 인덱스,

는 단말 i가 이용한 제 1 프리앰블의 인덱스,

는 단말 i가 이용한 제 2 프리앰블의 인덱스,

은 셀의 ID,

는 임의의 함수를 의미한다. In Equation 5 above,

Is the multi-access signature index of terminal i,

Is the index of the first preamble used by terminal i,

Is the index of the second preamble used by terminal i,

is the ID of the cell,

represents an arbitrary function.

However, this is only an example, and the method for determining the multiple access signature index by the base station is not limited to the above example.

Meanwhile, the terminal according to an embodiment may transmit information about the identifier of the terminal to the base station through the index of the first preamble and the index of the second preamble. For example, when the information on the identifier of each terminal is associated with the index of the first preamble and the index of the second preamble as shown in Equation 6 below, the base station may use the preamble index for terminal identification. For example, the base station may check an identifier of the terminal such as a radio network temporary identifier (RNTI) using the preamble index.

[Equation 6]

는 단말 i가 이용한 제 1 프리앰블의 인덱스,

는 단말 i가 이용한 제 2 프리앰블의 인덱스,

는 단말 i의 식별자, P는 단말이 선택 가능한 제 1 프리앰블의 총 개수, S는 단말이 선택 가능한 제 2 프리앰블의 총 개수,

와

는 임의의 함수를 의미한다. 기지국은 단말 i의 식별자를 수신한 경우, 단말 i가 이용한 제 1 프리앰블의 인덱스, 단말 i가 이용한 제 2 프리앰블의 인덱스, 단말 i의 식별자, 단말이 선택 가능한 제 1 프리앰블의 총 개수 및 단말이 선택 가능한 제 2 프리앰블의 총 개수를 전술한 함수

와

에 입력하여, 단말의 식별자를 확인할 수 있다. 또 다른 예에 따라, 단말의 식별자와 프리앰블 인덱스는 다음의 수학식 7에 따라 연관될 수도 있다.In Equation 6 above,

Is the index of the first preamble used by terminal i,

Is the index of the second preamble used by terminal i,

Is the identifier of UE i, P is the total number of first preambles selectable by the UE, S is the total number of second preambles selectable by the UE,

and

represents an arbitrary function. When the base station receives the identifier of terminal i, the index of the first preamble used by terminal i, the index of the second preamble used by terminal i, the identifier of terminal i, the total number of first preambles selectable by the terminal, and the terminal selected The above function for calculating the total number of possible second preambles

and

By entering in, you can check the identifier of the terminal. According to another example, the identifier of the terminal and the preamble index may be associated according to Equation 7 below.

[Equation 7]

는 단말 i가 이용한 제 1 프리앰블의 인덱스,

는 단말 i가 이용한 제 2 프리앰블의 인덱스,

는 단말 i의 식별자,

은 셀의 ID, P는 단말이 선택 가능한 제 1 프리앰블의 총 개수, S는 단말이 선택 가능한 제 2 프리앰블의 총 개수,

와

는 임의의 함수를 의미한다. 상기의 수학식 7에 따라, 단말은 단말이 접속한 셀의 ID와 단말의 식별자 기초로 제 1 프리앰블의 인덱스 및 제 2 프리앰블의 인덱스를 결정할 수 있다. In Equation 7 above,

Is the index of the first preamble used by terminal i,

Is the index of the second preamble used by terminal i,

Is the identifier of terminal i,

is the cell ID, P is the total number of first preambles selectable by the UE, S is the total number of second preambles selectable by the UE,

and

represents an arbitrary function. According to Equation 7 above, the terminal can determine the index of the first preamble and the index of the second preamble based on the ID of the cell accessed by the terminal and the identifier of the terminal.

Meanwhile, the above-described example is only an example for explaining the relationship between the terminal identifier and the preamble, and the method of determining the index of the preamble according to an embodiment is not limited to the above-described example.

7 is a flowchart illustrating a method for a terminal to perform communication using a preamble according to an embodiment.

In step 710, the terminal may receive information about the preamble configuration from the base station. The terminal can receive information about the preamble configuration broadcasted from the base station. Information on the preamble configuration according to an embodiment may include information on the location of a resource capable of transmitting a preamble-based signal, the length and number of the first preamble, and the length and number of the second preamble.

In step 720, the terminal may obtain a first preamble and a second preamble corresponding to the first preamble based on the received preamble configuration information. Here, the first preamble may include a CP, a first preamble sequence, and a guard period, but this is only an example and the configuration of the first preamble is not limited to the above example.

According to an embodiment, a UE may acquire a second preamble by interleaving at least some of a plurality of sections constituting the first preamble sequence included in the first preamble according to a preset interleaver pattern. According to another embodiment, the terminal may obtain a sequence generated based on the index of the first preamble and the index of the second preamble as the second preamble.

In step 730, the terminal may transmit a first preamble to the base station during a first unit time interval, which is one of unit time intervals to which a predetermined number of symbols are allocated. The first unit time interval may be, for example, a random access resource.

In step 740, the terminal may transmit a second preamble and data during a second unit time interval that is a unit time interval following the first unit time interval. The second unit time may be, for example, a data transmission resource.

The UE may transmit the second preamble and data to the base station by inserting the second preamble into at least one of a plurality of symbol positions constituting the second unit time interval and inserting data into the remaining symbol positions.

8 is a flowchart illustrating a method for a base station to perform communication using a preamble according to an embodiment.

In step 810, the base station may detect a first preamble from a signal received during a first unit time interval, which is a unit time interval to which a predetermined number of symbols are allocated.

In step 820, the base station may detect a second preamble corresponding to the first preamble from a signal received during a second unit time interval following the first unit time interval.

Meanwhile, the first preamble and the second preamble may be acquired by the terminal based on information about the preamble configuration broadcasted from the base station. The information on the preamble configuration may include information about the location of a resource capable of transmitting a preamble-based signal, the length and number of the first preamble, and the length and number of the second preamble.

In step 830, the base station can identify the terminal based on the first preamble and the second preamble.

After detecting the first preamble, the base station can confirm that a plurality of terminals attempted access when a plurality of second preambles are detected as a result of detecting the second preamble. The base station can identify each of a plurality of terminals based on the different second preambles.

In step 840, the base station may demodulate data included in the signal received during the second unit time interval as the terminal is identified.

A base station according to an embodiment may obtain a multi-access signature for data demodulation based on the detected index of the first preamble and the index of the second preamble. The base station may demodulate data based on a multiple access scheme indicated by the obtained multiple access signature. However, this is only one embodiment, and the base station may obtain information about the multiple access scheme used in the terminal through other control signals or higher layer signaling.

9 is a flowchart illustrating a method of performing communication between a base station and a terminal using a preamble according to an embodiment.

In step 910, the base station may transmit information about the preamble configuration to the terminal. The information on the preamble configuration may include information about the location of a resource capable of transmitting a preamble-based signal, the length and number of the first preamble, and the length and number of the second preamble.

In step 920, the terminal may acquire a first preamble and a second preamble based on the information on the preamble configuration. A method of obtaining the first preamble and the second preamble by the UE may correspond to the method described above with reference to FIGS. 3 to 5B.

In step 930, the terminal may transmit data using the obtained preamble. A terminal according to an embodiment may transmit a first preamble to a base station during a first unit time period to which a predetermined number of symbols are allocated. In addition, the terminal may transmit data and a second preamble corresponding to the first preamble to the base station during a second unit time interval that is a unit time interval following the first unit time interval.

In step 940, the base station can identify the terminal based on the first preamble and the second preamble. When a signal is received, the base station may detect the first preamble and detect the second preamble after detecting the first preamble. The base station may identify at least one terminal attempting to access the base station based on the first preamble and the second preamble.

In step 950, the base station may demodulate the data of the terminal. As the UE is identified, the base station according to an embodiment may demodulate at least one data symbol received along with the second preamble during the second unit time period.

In step 960, the base station may transmit an ACK signal as data demodulation of the terminal is completed. The base station may not transmit an ACK signal when data demodulation of the terminal is not completed. However, this is only an example, and the base station may transmit a NACK signal for notifying that the data demodulation of the terminal is not completed.

10 is a flowchart illustrating a method for a base station to identify a terminal using a preamble and estimate a time delay according to an embodiment.

In step 1005, the base station may receive a signal in which a preamble and data are combined from at least one terminal.

In step 1010, the base station may determine whether the first preamble is detected in the received signal. Here, it is assumed that the information on the length and number of the first preamble is previously shared between the base station and the terminal.

In step 1015, when the first preamble is not detected in the received signal, the base station may determine that the terminal attempting access does not exist. In addition, the base station may not perform second preamble detection and data demodulation as it is determined that the terminal attempting access does not exist.

In step 1020, the base station can confirm that the ACK timer has expired. As the ACK timer expires, the base station may again perform the process of receiving a signal in which a preamble and data are combined from at least one terminal described above in step 1005 .

In step 1025, the base station can determine whether a second preamble is detected when the first preamble is detected in the received signal. The second preamble according to an embodiment may be obtained as a result of interleaving at least some samples among a plurality of sections constituting the first preamble. The second preamble according to another embodiment may be obtained based on a sequence generated based on the index of the first preamble and the index of the second preamble. Here, it is assumed that the information on the length and number of the second preamble is previously shared between the base station and the terminal.

In step 1030, the base station may perform UE identification and time delay estimation based on the first preamble.

When the first preamble is detected, the base station can check whether the second preamble is used. When the base station is configured not to use the second preamble, the base station can identify the terminal based on the first preamble and estimate a time delay.

Meanwhile, the base station can identify the terminal based on the first preamble and estimate the time delay even when the second preamble is configured to be used, but the second preamble is not detected in the received signal. For example, the base station may not be able to detect the second preamble due to interference generated as a plurality of terminals transmit signals during the same unit time period. When the first preamble is detected and the second preamble is not detected, the base station may estimate UE identification and time delay based on the first preamble.

In step 1035, the base station may perform UE identification and time delay estimation based on the first preamble and the second preamble.

In step 1040, the base station may demodulate data. For example, the base station may perform UE identification and time delay estimation based on the first preamble and the second preamble, and then demodulate the received data symbol together with the second preamble. According to another example, the base station may demodulate data symbols received after the first preamble after performing UE identification and time delay estimation based on the first preamble.

In step 1045, the base station may transmit an ACK signal as the data is demodulated.

In step 1050, the base station can confirm that the ACK timer of the terminal has expired when data demodulation is not completed.

Although the base station identifies the terminal by detecting the preamble, there may be a case where the base station cannot properly demodulate the data of the identified terminal. The base station can check whether the data of the terminal has been recovered without errors through a cyclic redundancy check (CRC) check or the like. The base station may transmit a NACK or not transmit an ACK signal when an error occurs.

As the ACK timer expires, the base station may repeat the process of receiving a signal in which a preamble and data are combined from at least one terminal described above in step 1005 . In addition, when an ACK signal is not received from the base station, the terminal may reconstruct a signal in which the preamble and data are combined during another unit time period and transmit the signal to the base station.

Meanwhile, according to another example, when the same first preamble and the same second preamble are transmitted, since the base station cannot identify each of a plurality of terminals, a problem in that data is not properly demodulated may occur. In this case, the base station performs data demodulation by determining that there is only one terminal that has transmitted the first preamble and the second preamble, and thus data demodulation may not be completed. Accordingly, a plurality of terminals may not be able to receive an ACK signal from the base station. Therefore, a plurality of terminals can reconstruct a signal in which a preamble and data are combined during a new unit time period and transmit the signal to the base station.

11 is a diagram for explaining a method for a base station to demodulate data when a plurality of terminals transmit a signal using a preamble according to a frequency hopping scheme according to an embodiment.

In this embodiment, it is assumed that each terminal transmits a preamble and data to the base station according to a preset frequency hopping pattern. The frequency hopping pattern preset for each terminal may include a plurality of frequency hopping intervals, and each of the plurality of frequency hopping intervals may consist of two unit time intervals.

Referring to FIG. 11 , device 1 and device 2 may transmit a signal in which a preamble and data are combined according to a preset frequency hopping pattern 1110 of device 1 and a frequency hopping pattern 1120 of device 2, respectively. For example, terminal 1 transmits a first preamble during a first unit time interval of each of a plurality of frequency hopping intervals constituting the frequency hopping pattern 1110 of terminal 1, and transmits data and a first preamble during a second unit time interval. A second preamble corresponding to can be transmitted. In addition, terminal 2 transmits a first preamble during a first unit time interval of each of a plurality of frequency hopping intervals constituting the frequency hopping pattern 1120 of terminal 2, and corresponds to data and the first preamble during a second unit time interval. A second preamble may be transmitted.

Meanwhile, when the first preamble and the second preamble set in each of terminal 1 and terminal 2 are transmitted in the same frequency hopping interval, data demodulation may be impossible due to interference. In this case, the base station can determine whether hopping patterns of terminals collide through preamble detection, and demodulate data based on signals received in frequency hopping intervals other than the frequency hopping interval in which collision occurs.

According to another embodiment, as a result of determining the number of terminals using the corresponding resource through preamble detection, the base station identifies the terminal because the number of terminals using a specific frequency hopping interval exceeds the extent that the base station can accommodate (multiple If -user detection (MUD) cannot be performed, the base station can demodulate data of each terminal using signals received in the remaining frequency hopping intervals except for the corresponding frequency hopping interval.

12 is a block diagram of a terminal 1200 according to an embodiment.

Referring to FIG. 12 , a terminal 1200 may include a transceiver 1210, a processor 1220, and a memory 1230. According to the signal transmission method using the preamble proposed in the above embodiments, the transceiver 1210, the processor 1220, and the memory 1230 of the terminal 1200 can operate. However, components of the terminal 1200 according to an embodiment are not limited to the above-described example. According to another embodiment, the terminal 1200 may include more or fewer components than the aforementioned components. In addition, in a specific case, the transceiver 1210, the processor 1220, and the memory 1230 may be implemented as a single chip.

The transceiver 1210 may transmit and receive signals to and from the base station. Here, the signal may include a first preamble, a second preamble, and data. Also, according to another example, the signal may include information about a preamble configuration or an ACK signal. To this end, the transceiver 1210 may include an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that amplifies a received signal with low noise and down-converts its frequency. However, this is only one embodiment, and components of the transceiver 1210 are not limited to the RF transmitter and the RF receiver.

Also, the transceiver 1210 may receive a signal through a wireless channel, output the signal to the processor 1220, and transmit the signal output from the processor 1220 through a wireless channel.

The processor 1220 may control a series of processes so that the terminal 1200 may operate according to the above-described embodiment. For example, the processor 1220 may obtain a first preamble and a second preamble corresponding to the first preamble based on information about the preamble configuration received from the base station through the transceiver 1210.

The memory 1230 may store information about a preamble configuration, control information, or data included in a signal obtained from the terminal 1200, data necessary for the control of the processor 1220, and generated during control by the processor 1220. It may have an area for storing data and the like. The memory 1230 may be configured in various forms such as a ROM or/and a RAM or/and a hard disk or/and a CD-ROM or/and a DVD.

13 is a block diagram of a base station 1300 according to an embodiment.

Referring to FIG. 13 , a base station 1300 may include a transceiver 1310, a processor 1320, and a memory 1330. According to the signal reception method using the preamble proposed in the above embodiments, the transceiver 1310, the processor 1320, and the memory 1330 of the base station 1300 can operate. However, components of the base station 1300 according to an embodiment are not limited to the above example. According to another embodiment, the base station 1300 may include more or fewer components than the aforementioned components. In addition, in a specific case, the transceiver 1310, the processor 1320, and the memory 1330 may be implemented as a single chip.

The transmitting and receiving unit 1310 may transmit and receive signals to and from the terminal. Here, the signal may include a first preamble, a second preamble, and data. Also, according to another example, the signal may include information about a preamble configuration or an ACK signal. To this end, the transceiver 1310 may include an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that amplifies a received signal with low noise and down-converts its frequency. However, this is only one embodiment, and components of the transceiver 1310 are not limited to the RF transmitter and the RF receiver.

In addition, the transceiver 1310 may receive a signal through a wireless channel, output the signal to the processor 1320, and transmit the signal output from the processor 1320 through a wireless channel.

The processor 1320 may control a series of processes so that the base station 1300 can operate according to the above-described embodiment. For example, the processor 1320 may broadcast information about the preamble configuration through the transceiver 1310. Also, the processor 1320 may detect the first preamble and the second preamble from the signal received from the terminal. The processor 1320 may identify a terminal based on the detected first preamble and second preamble, and demodulate data received together with the second preamble in a predetermined unit time interval as the terminal is identified.

The memory 1330 may store information on a preamble configuration, control information, or data, and may have an area for storing data necessary for controlling the processor 1320 and data generated during control by the processor 1320. . The memory 1330 may be configured in various forms, such as a ROM or/and a RAM or/and a hard disk or/and a CD-ROM or/and a DVD.

On the other hand, as described above, a computer-readable storage medium, which may be a computer-readable storage medium included in a base station or terminal, is provided, or the computer-readable storage medium exists individually rather than being fitted at any end. One or more computer programs stored on a computer readable storage medium exist, and at least one processor executes one or more computer programs to perform communication using a preamble.

Embodiments of the present invention disclosed in this specification and drawings are only presented as specific examples to easily explain the technical content of the present invention and help understanding of the present invention, and are not intended to limit the scope of the present invention. That is, it is obvious to those skilled in the art that other modifications based on the technical idea of the present invention can be implemented. In addition, each of the above embodiments is classified for convenience of explanation, and can be operated in combination with each other as needed.

Claims (29)

In the communication method of the terminal using the preamble,
Receiving information about a preamble configuration from a base station;
obtaining a first preamble and a plurality of second preambles corresponding to the first preamble, based on the received preamble configuration information;
transmitting the first preamble to the base station during a first unit time interval that is one of unit time intervals to which a predetermined number of symbols are allocated; and
Transmitting the plurality of second preambles and data to the base station during a second unit time interval that is a unit time interval following the first unit time interval;
The data is modulated data based on a multiple access signature selected on the basis of an index of the first preamble and an index of a second preamble set composed of the plurality of second preambles among a plurality of multiple access signatures used in non-orthogonal multiple access. ego,
Obtaining the plurality of second preambles,
identifying the number of second preambles from the received preamble configuration information; and
selecting k sections from among a plurality of sections constituting the first preamble when the number of second preambles is k;
and obtaining the plurality of second preambles by performing interleaving on a plurality of samples included in the selected k intervals according to a preset interleaver pattern. delete delete According to claim 1,
wherein the index of the first preamble is generated based on the number of the plurality of first preambles and an identifier of the terminal. delete According to claim 1,
Further comprising receiving an ACK signal indicating that the data is demodulated as demodulation of the data is completed in the base station. According to claim 1,
When the data is not demodulated or the terminal is not detected by the base station, transmitting a reconstructed first preamble, a second preamble corresponding to the reconstructed first preamble, and the data to the base station Further comprising, Terminal communication method. According to claim 1,
The first unit time interval and the second unit time interval,
Included in any one of a plurality of frequency hopping intervals constituting a frequency hopping pattern preset in the terminal,
Each of the plurality of frequency hopping sections,
A communication method of a terminal comprising a unit time interval in which the first preamble is transmitted and a unit time interval in which the plurality of second preambles and the data are transmitted. In the communication method of a base station using a preamble,
detecting a first preamble from a signal received during a first unit time interval, which is one of unit time intervals to which a predetermined number of symbols are allocated;
detecting a plurality of second preambles corresponding to the first preamble from signals received during a second unit time interval that is a unit time interval following the first unit time interval;
identifying a terminal based on the first preamble and the plurality of second preambles; and
Demodulating data included in a signal received during the second unit time interval as the terminal is identified;
The first preamble and the plurality of second preambles are obtained from the terminal based on information about a preamble configuration transmitted from the base station,
The data is modulated data based on a multiple access signature selected on the basis of an index of the first preamble and an index of a second preamble set composed of the plurality of second preambles among a plurality of multiple access signatures used in non-orthogonal multiple access. ego,
The information on the preamble configuration includes information on the number of second preambles,
When the number of second preambles is k, as a result of performing interleaving according to a preset interleaver pattern on a plurality of samples included in k sections selected by the terminal among a plurality of sections constituting the first preamble, the plurality of samples are interleaved. The second preamble of is obtained, the communication method of the base station. delete delete delete According to claim 9,
When the demodulation of the data is completed, transmitting an ACK signal indicating that the data is demodulated. According to claim 9,
The first unit time interval and the second unit time interval,
Included in a frequency hopping section, which is one of a plurality of frequency hopping sections constituting a preset frequency hopping pattern in the terminal;
Demodulating the data,
As a result of identification based on the first preamble and the plurality of second preambles, when data is simultaneously received from another terminal during the frequency hopping interval, based on a signal received in another frequency hopping interval among the plurality of frequency hopping intervals Further comprising the step of demodulating the data of the terminal with , the communication method of the base station. In a terminal performing communication using a preamble,
transceiver; and
and at least one processor connected to the transceiver, wherein the at least one processor,
Receiving information about a preamble configuration from a base station;
A first preamble and a plurality of second preambles corresponding to the first preamble are obtained based on the information on the received preamble configuration, and a first preamble is one of unit time intervals to which a predetermined number of symbols are allocated. Transmitting the first preamble to the base station during a unit time interval;
Transmitting the plurality of second preambles and data to the base station during a second unit time interval that is a unit time interval following the first unit time interval;
The data is modulated data based on a multiple access signature selected on the basis of an index of the first preamble and an index of a second preamble set composed of the plurality of second preambles among a plurality of multiple access signatures used in non-orthogonal multiple access. is,
The information on the preamble configuration includes information on the number of second preambles,
When the number of second preambles is k, as a result of performing interleaving according to a preset interleaver pattern on a plurality of samples included in k sections selected by the terminal among a plurality of sections constituting the first preamble, the plurality of samples are interleaved. A second preamble of is obtained. delete delete According to claim 15,
The index of the first preamble is generated based on the number of the plurality of first preambles and an identifier of the terminal. delete The method of claim 15, wherein the at least one processor,
Upon completion of demodulation of the data in the base station, receiving an ACK signal indicating that the data is demodulated. The method of claim 15, wherein the at least one processor,
When the data is not demodulated at the base station or the terminal is not detected, transmitting a reconstructed first preamble, a second preamble corresponding to the reconstructed first preamble, and the data to the base station. According to claim 15,
The first unit time interval and the second unit time interval,
Included in any one of a plurality of frequency hopping intervals constituting a frequency hopping pattern preset in the terminal,
Each of the plurality of frequency hopping sections,
It is composed of a unit time interval in which the first preamble is transmitted and a unit time interval in which the plurality of second preambles and the data are transmitted. In a base station performing communication using a preamble,
transceiver; and
and at least one processor connected to the transceiver, wherein the at least one processor:
Detecting a first preamble from a signal received during a first unit time interval, which is one of each unit time interval to which a predetermined number of symbols are allocated;
detecting a plurality of second preambles corresponding to the first preamble from a signal received during a second unit time interval that is a unit time interval following the first unit time interval;
Identifying a terminal based on the first preamble and the plurality of second preambles;
As the terminal is identified, demodulating data included in a signal received during the second unit time interval;
The first preamble and the plurality of second preambles are obtained from the terminal based on information about a preamble configuration transmitted from the base station,
The data is modulated data based on a multiple access signature selected on the basis of an index of the first preamble and an index of a second preamble set composed of the plurality of second preambles among a plurality of multiple access signatures used in non-orthogonal multiple access. ego,
The information on the preamble configuration includes information on the number of second preambles,
When the number of the second preambles is k, as a result of performing interleaving according to a preset interleaver pattern on a plurality of samples included in k sections selected by the terminal among a plurality of sections constituting the first preamble, the plurality of samples are interleaved. Where the second preamble of is obtained, the base station. delete delete delete The method of claim 23, wherein the transceiver,
When the demodulation of the data is completed, the base station transmits an ACK signal indicating that the data is demodulated. 24. The method of claim 23,
The first unit time interval and the second unit time interval,
Included in a frequency hopping section, which is one of a plurality of frequency hopping sections constituting a preset frequency hopping pattern in the terminal;
The at least one processor,
As a result of identification based on the first preamble and the plurality of second preambles, when data is simultaneously received from another terminal during the frequency hopping interval, based on a signal received in another frequency hopping interval among the plurality of frequency hopping intervals To demodulate the data of the terminal with, the base station. Claims 1, 4, 6 to 9, 13 and 14, a computer-readable recording medium recording a program for executing any one of the methods in a computer.

Images