CN116527209A

CN116527209A - Method and apparatus for transmitting using parameter set and method and apparatus for scheduling using parameter set

Info

Publication number: CN116527209A
Application number: CN202310721617.1A
Authority: CN
Inventors: 文盛铉; 金哲淳; 金志炯; 朴柱昊; 李濬焕; 金玟贤; 李正薰
Original assignee: Electronics and Telecommunications Research Institute ETRI
Current assignee: Electronics and Telecommunications Research Institute ETRI
Priority date: 2016-07-05
Filing date: 2017-07-05
Publication date: 2023-08-01
Also published as: WO2018008981A1

Abstract

The invention relates to a sending method of a base station, which comprises the following steps: generating a physical channel or physical signal using PRBs as resource allocation units on a frequency axis; and transmitting a physical channel or a physical signal, wherein subcarrier intervals for the plurality of parameter sets are defined differently from each other, the number of subcarriers belonging to a first PRB to which a first parameter set among the plurality of parameter sets is applied is equal to the number of subcarriers belonging to a second PRB to which a second parameter set among the plurality of parameter sets is applied, and a boundary of the first PRB is set at a boundary of the second PRB.

Description

Method and apparatus for transmitting using parameter set and method and apparatus for scheduling using parameter set

The present patent application is a divisional application of a chinese patent application filed on 5/7/2017 with application number 201780042017.5 and the invention name of "transmission method and apparatus using parameter set and scheduling method and apparatus using parameter set".

Technical Field

The present invention relates to a transmission method and apparatus using a parameter set and a scheduling method and apparatus using a parameter set.

Background

Mobile communication systems since Long Term Evolution (LTE), represented by generation 5 (5G), are required to meet various technical requirements for providing high rate data transmission and a wide range of application services and have received much attention in the past. Accordingly, the third generation partnership project (3 GPP) is developing new mobile communication standards that meet the requirements of International Mobile Telecommunications (IMT) -2020. The name of the new mobile communication standard is New Radio (NR). The main application scenarios for NR include providing ultra-high rate data transmission (e.g. enhanced mobile broadband (emmbb)), providing high reliability and low latency (e.g. ultra-reliable low latency communication (URLLC)), and providing large-scale terminal connectivity (e.g. large-scale machine type communication (mctc)).

NR uses a wide frequency range including millimeter wave bands to significantly increase data rates. A frequency band from 1GHz or less to 100GHz is considered as a candidate frequency range for NR. The International Telecommunications Union (ITU) is researching the 24.25 to 86GHz band as a candidate frequency range for IMT-2020.

Systems supporting various services and frequency ranges, such as NR, may have to scale a set of parameters (numerology) for forming the physical signal waveform. For example, in the case of an Orthogonal Frequency Division Multiplexing (OFDM) -based system, a subcarrier spacing suitable for channel characteristics of a transmission band may be used. For example, a subcarrier spacing of 15kHz may be used in a frequency band below 6GHz, and a subcarrier spacing of 120kHz may be used in a frequency band above 6 GHz. In addition, even if the frequency bands are the same, different parameter sets may be used according to the characteristics of the provided service. For example, below 6GHz, a subcarrier spacing of 15kHz may be used for the eMBB transmission and a subcarrier spacing of 60kHz may be used for the URLLC transmission.

Thus, there is a need for a method for supporting flexible transmission and reception using various parameter sets.

Disclosure of Invention

[ problem ]

The present invention is directed to a method and apparatus for supporting flexible transmission and reception using various parameter sets.

Furthermore, the present invention is directed to a method and apparatus for supporting flexible resource allocation (or scheduling) in a next generation communication system.

In addition, the present invention is directed to a method and apparatus for transmitting a signal or channel using a plurality of parameter sets within one carrier.

[ technical solution ]

An exemplary embodiment of the present invention provides a transmission method of a base station. The transmission method of the base station may include: generating a physical channel or physical signal using Physical Resource Blocks (PRBs) as resource allocation units in the frequency domain; and transmitting the physical channel or physical signal.

The subcarrier spacing for the plurality of parameter sets may be defined differently.

The number of subcarriers belonging to a first PRB to which a first parameter set among the plurality of parameter sets is applied may be equal to the number of subcarriers belonging to a second PRB to which a second parameter set among the plurality of parameter sets is applied.

The boundary of the first PRB may be aligned with the boundary of the second PRB.

At least one of the subcarriers belonging to the first PRB may be aligned with at least one of the subcarriers belonging to the second PRB.

The bandwidth of the first PRB may be 2 of the bandwidth of the second PRB ^N Multiple (N is an integer).

There may be a first Direct Current (DC) subcarrier for a first parameter set and a second DC subcarrier for a second parameter set.

The location of the first DC subcarrier may be the same as the location of the second DC subcarrier.

The first parameter set may be a parameter set applied to a downlink synchronization signal for initial access among a plurality of parameter sets.

Based on the first PRB, the number of PRBs included in one carrier may be even regardless of the system bandwidth.

Another exemplary embodiment of the present invention provides a scheduling method of a base station. The scheduling method of the base station may include: configuring a Physical Resource Block (PRB) group for a first terminal; configuring, for the first terminal, a parameter set for a PRB group, which is configured for the first terminal among a plurality of parameter sets defined by a subcarrier spacing and a Cyclic Prefix (CP) length; and scheduling at least one of a plurality of PRBs for the first terminal, the plurality of PRBs being included in a PRB group for the first terminal.

The plurality of PRBs included in the PRB group configured for the first terminal may be contiguous in the frequency domain.

The PRB group configured for the first terminal may be a plurality and the plurality of PRB groups may include a first PRB group and a second PRB group.

The step of configuring the parameter set for the first terminal may comprise: a first parameter set for a first PRB group among a plurality of parameter sets is configured for a first terminal, and a second parameter set for a second PRB group among the plurality of parameter sets is configured for the first terminal.

The PRB group configured for the first terminal may be plural, and the plural PRB groups may include a first PRB group and a second PRB group scheduled for the first terminal through the same Downlink Control Information (DCI).

When the same parameter set is applied to the first PRB group and the second PRB group, an index allocated to a last PRB among the plurality of PRBs included in the first PRB group may be the same as an index allocated to a last PRB among the plurality of PRBs included in the second PRB group.

When the same parameter set is applied to the first PRB group and the second PRB group, the index allocated to the plurality of PRBs included in the second PRB group may be based on the index allocated to the last PRB among the plurality of PRBs included in the first PRB group.

The scheduling method may further include: a PRB bundle index indicating a PRB bundle including at least one PRB is transmitted to a first terminal through Downlink Control Information (DCI).

The number of PRBs included in the PRB group configured for the first terminal may be determined according to a parameter set applied to the PRB group configured for the first terminal.

The scheduling method may further include: configuring a PRB group different from that configured for the first terminal for the second terminal; and configuring a parameter set for the second terminal for a PRB group configured for the second terminal, the parameter set being different from a parameter set for a PRB group configured for the first terminal among the plurality of parameter sets.

The plurality of parameter sets may include a first parameter set and a second parameter set.

The number of PRBs included in the first PRB group to which the first parameter set is applied may be equal to the number of PRBs included in the second PRB group to which the second parameter set is applied.

Still another exemplary embodiment of the present invention provides a method for transmitting a base station, including: generating a first downlink synchronization signal for initial access; and transmitting the downlink synchronization signal.

The first set of sequences for the first downlink synchronization signal may be different from the second set of sequences for the second downlink synchronization signal used for purposes other than initial access.

The generating of the first downlink synchronization signal may include: the first downlink synchronization signal is generated using a second polynomial different from the first polynomial used for the second downlink synchronization signal.

The generating of the first downlink synchronization signal may include: the first downlink synchronization signal is generated using the same polynomial as the polynomial for the second downlink synchronization signal and a cyclic shift value different from the cyclic shift value for the second downlink synchronization signal.

The transmission method may further include: the second downlink synchronization signal is transmitted through a first parameter set among a plurality of parameter sets defined by a subcarrier spacing and a Cyclic Prefix (CP) length.

The transmitting of the first downlink synchronization signal may include: a first downlink synchronization signal is transmitted over a first set of parameters.

The transmitting of the first downlink synchronization signal may include: the first downlink synchronization signal is transmitted through a second parameter set different from the first parameter set among the plurality of parameter sets.

[ beneficial effects ]

According to an exemplary embodiment of the present invention, it is possible to provide a method and apparatus for supporting or performing flexible transmission and reception using various parameter sets.

In addition, according to one exemplary embodiment of the present invention, it is possible to provide a method and apparatus for supporting or performing flexible resource allocation (scheduling) within a next generation communication system.

Drawings

Fig. 1a, 1b, 1c, 1d, 1e, 1f and 1g are diagrams illustrating a method for supporting terminals having heterogeneous parameter set capabilities in the same frequency range according to an exemplary embodiment of the present invention.

Fig. 2a, 2b, 2c, 2d and 2e are diagrams illustrating FRB definitions of NR carriers according to an exemplary embodiment of the present invention.

Fig. 3 is a diagram of an NR carrier based on a basic parameter set according to an exemplary embodiment of the present invention.

Fig. 4 is a diagram showing coexistence of a base parameter set and a sub parameter set.

Fig. 5a, 5b and 5c are diagrams illustrating a method of constructing an anchor point FRB according to an exemplary embodiment of the present invention.

Fig. 6 is a diagram illustrating a subcarrier grid based on method a110 according to an exemplary embodiment of the present invention.

Fig. 7a and 7b are diagrams illustrating a subcarrier grid based on method a111 according to an exemplary embodiment of the present invention.

Fig. 8a and 8b are diagrams of the setting of DC subcarriers based on method a121 and method a122 according to an exemplary embodiment of the present invention.

Fig. 9a and 9b are diagrams illustrating PRB definitions based on method a130 according to an exemplary embodiment of the present invention.

Fig. 10 is a diagram illustrating PRB definition based on method a132 according to an exemplary embodiment of the present invention.

Fig. 11 is a diagram of coexistence with LTE NB-loT when the number of PRBs of the NR carrier is even according to an exemplary embodiment of the present invention.

Fig. 12a and 12b are diagrams illustrating PRB composition based on method a133 according to an exemplary embodiment of the present invention.

Fig. 13 is a diagram illustrating a method of constructing PRBs based on the method 133 for each of a plurality of parameter sets according to an exemplary embodiment of the present invention.

Fig. 14 is a diagram illustrating a method of transmitting a plurality of DC subcarriers based on method a133 according to an exemplary embodiment of the present invention.

Fig. 15 is a diagram illustrating PRB numbers on each parameter set according to an exemplary embodiment of the present invention.

Fig. 16 is a diagram illustrating PRB numbers on each parameter set according to another exemplary embodiment of the present invention.

Fig. 17a and 17b are diagrams illustrating a method for constructing a PRB group for a terminal according to an exemplary embodiment of the present invention.

Fig. 18 is a diagram illustrating full-band PRB numbering according to an exemplary embodiment of the present invention.

Fig. 19a, 19b and 19c are diagrams illustrating a method of configuring a parameter set and a guard band based on method a140 or method a142 according to an exemplary embodiment of the present invention.

Fig. 20a and 20b are diagrams showing FRB composition, parameter set configuration, guard band configuration based on method a100 according to an exemplary embodiment of the present invention.

Fig. 21 is a diagram illustrating PDCCH block setting according to an exemplary embodiment of the present invention.

Fig. 22 is a diagram illustrating a relationship between a PDCCH block and a data region according to an exemplary embodiment of the present invention.

Fig. 23 is a diagram illustrating PDCCH block setting according to another exemplary embodiment of the present invention.

FIG. 24 is a diagram of a computing device according to an exemplary embodiment of the invention.

Detailed Description

In the following detailed description, certain exemplary embodiments of the present invention are shown and described, simply by way of illustration. As will be recognized by those skilled in the art, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive. Like reference numerals designate like elements throughout the specification.

In this specification, repetitive descriptions of the same components will be omitted.

Furthermore, in the present specification, it will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or directly coupled to the other element or be connected or coupled to the other element with the other element interposed therebetween. On the other hand, in the present specification, it is understood that when one component is referred to as being "directly connected to" or "directly coupled to" another element, it can be connected or directly coupled to the other element without the other element interposed therebetween.

In addition, the terminology used in the description presented herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the invention.

Furthermore, in this specification, the singular is intended to include the plural unless the context clearly indicates otherwise.

Furthermore, in the description, the terms "comprises" and "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components, or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof.

Furthermore, in this specification, the term "and/or" includes a combination of a plurality of related items or any item of a plurality of related items. In the present specification, "a or B" may include "a", "B" or "a and B".

In addition, in the present specification, a terminal may refer to a mobile terminal, a mobile station, an advanced mobile station, a high reliability mobile station, a subscriber station, a portable subscriber station, an access terminal, a User Equipment (UE), a machine type communication device (MTC), or the like, and may include all or part of the functions of a mobile terminal, an advanced mobile station, a high reliability mobile station, a subscriber station, a portable subscriber station, an access terminal, a user equipment, MTC, or the like.

Further, in the present specification, a Base Station (BS) may refer to an advanced base station, a high reliability base station (HR-BS), a node B (nodeB), an evolved node B (eNodeB, eNB), a New Radio (NR) node B (e.g., gNB), an access point, a radio access station, a base transceiver station, a mobile multi-hop relay (MMR) -BS, a relay station as a base station, a high reliability relay station as a base station, a relay, a macro base station (macro base station), a small base station (small base station), a femto base station (femto base station), a Home Node B (HNB), a home eNB (HeNB), a pico base station (pico base station), a micro base station (micro base station), and the like, and may further include all or part of the functions of an advanced base station, HR-BS, a node B, eNB, gNB, an access point, a radio access station, a base transceiver station, an MMR-BS, a relay station, a high reliability relay station, a relay (repeater), a macro base station, a small base station, a femto base station, an HNB, a HeNB, a pico base station, and the like.

Hereinafter, a method and apparatus for supporting resource allocation in a wireless communication system will be described. In detail, a method and apparatus for transmitting a signal through a plurality of parameter sets within one carrier will be described.

In a system using Cyclic Prefix (CP) based OFDM (e.g., NR system), a parameter set is basically defined by a subcarrier spacing and a CP length. In this specification, the time domain symbol may be an OFDM symbol. However, this is only one example, and thus the exemplary embodiments of the present invention can be applied even when the time domain symbol is a symbol other than an OFDM symbol.

Table 1 shows an example of a scalable parameter set construction for an OFDM system.

In detail, table 1 shows a case where a total of 5 parameter sets are defined. Each subcarrier spacing of parameter sets a through E is 15kHz, 30kHz, 60kHz, 120kHz, and 240kHz. As one goes from parameter set a to parameter set E, the OFDM symbol length decreases inversely proportional to the subcarrier spacing. The CP overhead is approximately 6.7% for all parameter sets. Thus, the CP length is defined to be proportional to the OFDM symbol length.

Establishing a quadratic, multiple relationship among the subcarrier spacings of parameter set a through parameter set E is suitable for reducing the complexity of NR system implementation or for efficiently supporting operations using multiple heterogeneous parameter sets. The parameter set a of table 1 is the same as the parameter set used for unicast transmission of LTE. Therefore, it is advantageous to coexist with LTE carriers on the same frequency band when using parameter set a.

(Table 1)

One parameter set may be used basically for one cell (or one carrier) and may also be used for specific time-frequency resources within one carrier. Heterogeneous parameter sets may be used for different operating frequency bands and may also be used to support different types of services within the same frequency band and/or the same carrier. As one example of the latter, parameter set a of table 1 may be used for enhanced mobile broadband (eMBB) services for frequency bands below 6GHz, and parameter set C may be used for ultra-reliable low latency communication (URLLC) services for frequency bands below 6 GHz. Meanwhile, in order to support a large machine type communication (mctc) or Multimedia Broadcast Multicast Service (MBMS) service, a parameter set having a subcarrier spacing smaller than that of the base parameter set may be used. For this purpose, a subcarrier spacing of 7.5kHz or 3.75kHz may be considered when the subcarrier spacing of the basic parameter set is 15 kHz.

Hereinafter, a method and apparatus for supporting flexible resource allocation in a wireless communication system will be described. Hereinafter, a method and apparatus for transmitting a signal through a plurality of parameter sets within one carrier will be described. For ease of description, the present invention will be described herein with reference to an NR-based wireless communication system as one example. However, this is merely one example, and thus the present invention is not limited thereto and may be applied to various wireless communication systems. Furthermore, in the present specification, some terms, some units, and some concepts of the LTE system may be equally applied to the NR system. For example, the minimum unit of resource allocation of the NR system is a Resource Element (RE), and one resource element corresponds to one OFDM symbol along the time domain and one subcarrier along the frequency domain. As another example, similar to the LTE system, the subframe length and the radio frame length of the NR system may be 1ms and 10ms. Meanwhile, a Physical Resource Block (PRB) in the LTE system refers to a two-dimensional resource allocation unit composed of 12 subcarriers and 14 time domain symbols in the case where a subcarrier interval is 15 kHz. However, in the present specification, PRBs are used as resource allocation units in the frequency domain, which are independent of the time domain. The method of constructing the PRB will be described in detail below.

In an NR system, a slot may be defined as a scheduling unit in the time domain for uplink and downlink data. The slot length may be defined as an integer number of consecutive OFDM symbols, separately from the subframe length. In addition, in the NR system, a minislot (minislot) may be defined as a minimum scheduling unit having a length shorter than a slot length. For example, micro-slots may be used for Time Division Multiplexing (TDM) usage in frequency bands above 6GHz, partial slot transmission in unlicensed frequency bands or co-existing frequency bands with LTE, URLLC transmission requiring low latency, etc. To support various use cases, the length of the minislots and the starting position of the minislot transmission may be defined as flexibly as possible. For example, if it is assumed that the number of OFDM symbols per slot is M, the number of OFDM symbols per minislot may be configured in a range from 1 to M-1, and the starting position of the minislot-based transmission may be defined as any OFDM symbol within the slot.

In the downlink case, a slot may include a data region and one Physical Downlink Control Channel (PDCCH) region similar to subframes of the LTE system. In the PDCCH region and the data region, a signal may or may not be transmitted. Typically, the PDCCH region and the data region are divided into different time resources (and/or different frequency resources).

For convenience, in this specification, NR signals and NR channels are divided into a first signal set and a second signal set. The first signal set includes signals and channels mainly used to allow a base station or terminal to acquire initial synchronization of Uplink (UL) and Downlink (DL), and the second signal set includes other signals and channels. For example, in the downlink case, the first signal set may include a downlink synchronization signal, a Physical Broadcast Channel (PBCH) and/or a Beam Reference Signal (BRS), and in the uplink case, the first signal set may include a Physical Random Access Channel (PRACH). The first signal set may also be used for purposes other than uplink and downlink synchronization acquisition. For example, the downlink synchronization signal may be used for time and frequency synchronization tracking or Radio Resource Management (RRM) measurements of terminals in a Radio Resource Control (RRC) CONNECTED state, such as terminals in an RRC CONNECTED mode. In some cases, the second signal set may be classified into a 2-1 signal set and a 2-2 signal set. The 2-1 signal set is a set of signals and channels common to several terminals, and the 2-2 signal set is a set of UE-specific (UE-specific) signals and channels. For example, the 2-1 signal set may include a Physical Downlink Shared Channel (PDSCH) on which broadcast information (e.g., system information) is carried, a common search space of a PDCCH, and the like. In addition, in the following, the transmission of the first signal set and the second signal set means the transmission of all or some of the signals and channels comprised by the corresponding sets.

In LTE systems, all terminals except low cost terminals (e.g., reduced bandwidth low complexity (BL)/Coverage Enhanced (CE) UEs) typically support sample rates up to 30.72MHz, support maximum system bandwidth per carrier (e.g., 20 MHz), and support Fast Fourier Transform (FFT)/inverse FFT (IFFT) of up to 2048 size. However, the NR system supports multiple parameter sets and thus the capabilities of the terminal can be subdivided. The capabilities of the NR terminal may be defined based on the maximum sampling rate. For example, the capabilities of terminals supporting Bandwidths (BW) up to 40MHz, 160MHz and 640MHz may be defined as maximum sampling rates of 61.44MHz, 4 x 61.44MHz and 16 x 61.44MHz, respectively. In this case, the terminal may perform transmission using various combinations of FFT/IFFT size and subcarrier spacing within a range not exceeding a sampling rate.

Alternatively, the capabilities of the NR terminal may be defined based on a set of parameter sets supported by the terminal. For example, there may be a terminal supporting all parameter sets and a terminal supporting only some of the parameter sets of the NR system. The capabilities of terminals supporting only some of the parameter sets may be further subdivided. In this case, the terminal may be defined to support the same set of parameter sets for transmitting the first signal set and the second signal set.

Alternatively, the capabilities of the NR terminals may be differentiated according to whether the terminals can simultaneously transmit and receive data using multiple parameter sets. For example, there may be terminals that can simultaneously transmit (and/or receive) a plurality of second signal sets to which different parameter sets are applied, and terminals that cannot simultaneously transmit (or receive) them. The capability of a terminal capable of simultaneously transmitting (and/or receiving) a plurality of second signal sets, to which different parameter sets are applied, within an NR carrier may be similar to the capability of a terminal capable of supporting carrier aggregation to which different parameter sets are applied. Furthermore, there may be terminals that can simultaneously transmit (and/or receive) a first signal set and a second signal set to which different parameter sets are applied, and terminals that cannot simultaneously transmit (or receive) them. The terminal may send capability information to the base station. The capabilities of a low cost terminal for an mctc service may be defined separately from the above-described capabilities.

Meanwhile, terminals supporting URLLC may be divided into terminals requiring both an eMBB service and a URLLC service and terminals requiring only a URLLC service. An example of the former may be a terminal supporting a haptic internet service (e.g., virtual Reality (VR), augmented Reality (AR), game, e-learning, etc.), and an example of the latter may be a terminal installed in a factory automation robot, an operation robot, etc.

As another example, a terminal equipped in an autonomous vehicle may basically require a URLLC service, and a terminal providing a multimedia service in the vehicle may simultaneously require a URLLC service and an eMBB service. At this time, the category or capability of the URLLC dedicated terminal may be defined. Alternatively, the URLLC dedicated terminal is not explicitly separated from the emmbb terminal region, and may be defined by the method for distinguishing capabilities as described above. For example, URLLC dedicated terminals may support small system bandwidths or small parameter sets. Alternatively, the URLLC dedicated terminal may not support the function of simultaneously transmitting (and/or receiving) multiple parameter sets.

[ Parametric set type ]

Two parameter set types may be defined within one NR carrier. One of the two parameter set types is a primary parameter set and the other is a secondary parameter set. The primary and secondary parameter sets may be defined according to terminals and may be different from terminal to terminal. This is similar to the concept that the primary and secondary cells are defined as terminal specific (e.g. UE specific) in LTE systems. The primary parameter set may be a parameter set used when a terminal not in an RRC connected state (e.g., a terminal in an rrc_idle state) initially accesses the NR carrier, or a parameter set configured as a primary parameter set from the base station during an initial access procedure. Alternatively, the main parameter set may be a parameter set configured as a main parameter set from the base station when the terminal is in an RRC CONNECTED state (e.g., a terminal in an rrc_connected state). Alternatively, the main parameter set may be a parameter set used to allow the terminal to perform a specific function other than initial access. For example, the primary parameter set may be used at least for synchronization tracking, radio Resource Management (RRM) measurements, PDCCH monitoring, and/or System Information Block (SIB) reception, etc. of terminals in RRC connected state. The upstream main parameter set and the downstream main parameter set can be distinguished from each other. For example, the terminal may consider a parameter set for receiving the downlink synchronization signal and the PBCH as a downlink main parameter set, and may be configured with an uplink main parameter set from the base station. Alternatively, the main parameter set may be defined only in the case of downstream. Among parameter sets configured for the terminal, the remaining parameter sets other than the primary parameter set may be defined as secondary parameter sets.

[ NR Carrier type ]

The carrier of the LTE system has its own unique cell Identifier (ID) and is defined or configured identically for all terminals except for low cost terminals. That is, parameters or components defining carriers (e.g., system bandwidth, center frequency, parameter set, PRB composition, etc.) are equally applied to the terminal. Meanwhile, in the NR system, one carrier may support a plurality of parameter sets. In this case, the NR carrier can be broadly designed into two types (e.g., a first type NR carrier and a second type NR carrier).

The first type of NR carrier is of the type: where the structure and operation of the individual NR carriers are defined by one representative set of parameters and other sets of parameters may be additionally configured in some or all of the resources. In this case, the first type NR carrier may not operate as an independent carrier using only the additionally configured parameter set. Hereinafter, in the first type NR carrier, a representative parameter set is referred to as a base parameter set (base parameter), and a parameter set that may be additionally configured is referred to as a sub-parameter set (sub-parameter). For example, the basic parameter set may be a parameter set applied to a downlink synchronization signal used for initial access.

The primary and secondary parameter sets are classified from a terminal perspective, while the base and sub-parameter sets are classified from a cell (or system) perspective. In the case of the first type of NR carrier, a terminal in rrc_idle state to be initially accessed to the NR carrier needs to support at least a basic parameter set of the corresponding NR carrier. In addition, in the case of the first type NR carrier, all terminals in the rrc_connected state may use a basic parameter set as a main parameter set.

The second type NR carrier is a type capable of performing independent carrier operation for each parameter set when the NR carrier is composed of a plurality of parameter sets. Alternatively, even if the NR carrier consists of one parameter set, the local frequency portion(s) of the carrier may constitute the independent carrier(s). Hereinafter, the independent carrier constituted by each parameter set (or local frequency portion) is referred to as a self-carrier (self-carrier) to distinguish it from the second type NR carrier. That is, one second type NR carrier includes one or more self-carriers, each of which may perform independent carrier operations. For example, when the NR carrier is composed of the first parameter set and the second parameter set, the NR carrier may operate as an independent NR carrier (e.g., a first self-carrier) by using only a portion of the first parameter set, and may operate as an independent NR carrier (e.g., a second self-carrier) by using only a portion of the second parameter set. When the NR carrier is a carrier supporting initial access, the terminal may initially access the NR carrier using one of the first parameter set and the second parameter set. In addition, the terminal may perform transmission using the NR carrier using one of the first parameter set and the second parameter set as a main parameter set. That is, the primary parameter set may be configured differently for each terminal within the second type NR carrier.

Features of the first type NR carrier and the second type NR carrier may be applied simultaneously within one NR carrier. For example, when the NR carrier is composed of a first parameter set, a second parameter set, and a third parameter set, the first parameter set and the second parameter set each support independent carrier operation, and the NR carrier may not operate as an independent carrier only through the third parameter set. In this case, the first parameter set and the second parameter set may be used as a main parameter set or a sub parameter set, and the third parameter set may be used as a sub parameter set only. The present invention considers a first type NR carrier, a second type NR carrier, and a carrier having a form in which both types are mixed.

Fig. 1a to 1g are diagrams illustrating a method for supporting terminals having heterogeneous parameter set capabilities in the same frequency region according to an exemplary embodiment of the present invention. Fig. 1a to 1g illustrate a method for supporting a plurality of terminals having different parameter set capabilities in the same frequency region. In fig. 1a to 1g, it is assumed that the terminal (UE a) supports only a first parameter set, the terminal (UE B) supports only a second parameter set, and the terminal (UE C) supports both the first parameter set and the second parameter set. For example, the first parameter set may have a subcarrier spacing of 15kHz and the second parameter set may have a subcarrier spacing of 60 kHz. For example, the terminal (UE a) may be a terminal supporting only the eMBB service, the terminal (UE B) may be a terminal supporting only the URLLC service, and the terminal (UE C) may be a terminal supporting both the eMBB service and the URLLC service.

Fig. 1a to 1d and 1g illustrate methods for supporting a terminal (UE a) and a terminal (UE B) through different NR carriers. As shown in fig. 1a to 1d and 1g, a terminal (UE a) is connected to a first carrier to perform transmission through a first parameter set, and a terminal (UE B) is connected to a second carrier to perform transmission through a second parameter set. In detail, fig. 1a to 1d show a case where the frequency range of the second carrier is included in the frequency range of the first carrier. At this time, all overlapping frequency ranges may be used for transmission of the first carrier and the second carrier. This is a different feature from the LTE system. The transmission of the first carrier and the second carrier in the overlapping frequency region may be multiplexed by a method of Frequency Division Multiplexing (FDM), time Division Multiplexing (TDM), code Division Multiplexing (CDM), space Division Multiplexing (SDM), or the like. That is, signals of the terminal (UE a) and the terminal (UE B) in the overlapping frequency region can be transmitted by the above multiplexing method.

Fig. 1a and 1c show the case where some frequency regions of the first carrier overlap with the second carrier, and fig. 1b and 1d show the case where the frequency regions of the first carrier are identical with the frequency regions of the second carrier.

Meanwhile, as a method for supporting the first and second parameter sets for the terminal (UE C), a method for aggregating the first and second carriers (e.g., fig. 1a and 1 b) and a method for supporting the first and second parameter sets (e.g., supporting the mixed parameter sets) within one carrier (e.g., the first carrier) may be used (e.g., fig. 1C and 1 d). The former method (e.g. fig. 1a and 1 b) does not require the use of multiple parameter sets within one carrier and thus has the advantage of a simple design. However, the terminal needs to perform operations such as synchronization acquisition and RRM measurement for each carrier, and thus there is a problem in that the former method (e.g., fig. 1a and 1 b) has higher complexity than the latter method (e.g., fig. 1c and 1 d). When the latter method is used (e.g., fig. 1C and 1 d), the specific frequency region may be configured as a first carrier for the terminal (UE C) and may be configured as a second carrier for the terminal (UE B).

Fig. 1g shows a case where the frequency range of the second carrier is not included in the frequency range of the first carrier. That is, the method shown in fig. 1g is a method in which a terminal (UE B) is not supported in the frequency range of the first carrier. In this case, the first carrier may be a first type NR carrier using the first parameter set as a base parameter set. The terminal (UE a) and the terminal (UE C) support a first set of parameters and may thus be connected to a first carrier. However, the terminal (UE B) supports only the second parameter set, and thus, transmission may not be performed only through the first carrier terminal (UE B). The base station configures a second parameter set in the first carrier (i.e. configures the second parameter set as a sub-parameter set), and thus may use both the first parameter set and the second parameter set (e.g. use a mixed parameter set) for transmission with the terminal (UE C).

The method shown in fig. 1e and 1f is a method of supporting a terminal (UE a) and a terminal (UE B) through the same carrier (e.g., a first carrier). This may correspond to the case where the first carrier is a second type NR carrier. That is, the terminal (UE a) connects to the first carrier to perform transmission using only the first parameter set, and the terminal (UE B) connects to the first carrier to perform only the second parameter set. The main parameter sets of the terminal (UE a) and the terminal (UE B) are a first parameter set and a second parameter set, respectively. In this case, fig. 1e shows a case where the frequency range of the first parameter set belonging to the first carrier and the frequency range of the second parameter set belonging to the first carrier are different. In detail, fig. 1e shows a case where the entire frequency region of the NR carrier and the frequency region for each parameter set may be different. Fig. 1f shows a case where the frequency range of the first parameter set and the frequency range of the second parameter set are the same.

Meanwhile, in the case of fig. 1c and 1d, in order for the first carrier and the second carrier to effectively coexist in the overlapping frequency region, the second carrier and the second parameter set signal region of the first carrier may have an inclusion relationship with each other. That is, the commonly defined second parameter set signal region is configured within a first carrier for the terminal (UE C) and may be configured as a second carrier for the terminal (UE B). For this purpose, the first carrier may be a second type NR carrier. That is, when the first parameter set signal region and the second parameter set signal region of the first carrier each operate as independent carriers, the second parameter set signal region of the first carrier may be configured within the first carrier for the terminal (UE C) and as the second carrier for the terminal (UE B). In this case, the criterion for distinguishing the carriers may be a cell Identifier (ID). In the above case, the method shown in fig. 1c and 1d may not be different from the method shown in fig. 1e and 1f in terms of the physical layer.

【FRB】

In order to use multiple parameter sets within the NR carrier, the system bandwidth (or available bandwidth other than guard bands at both ends of the system bandwidth) may be divided into multiple Frequency Resource Blocks (FRBs). Hereinafter, a method for defining the FRB such that the sum of the FRBs is the system bandwidth is referred to as a 'method a100', and a method for defining the FRB such that the sum of the FRBs is the available bandwidth, that is, a transmission region (transmission region of OFDM subcarriers) other than guard bands at both ends of the system bandwidth is referred to as a 'method a101'. It may be defined such that there is no crossover between FRBs.

The FRB according to method a101 is similar in definition to the subbands of the LTE system. However, the sub-band of the LTE system is a frequency bundle (frequency bundle) for Channel State Information (CSI) related operation, and thus the FRB may be distinguished from the sub-band. For example, a plurality of subbands may be defined in one FRB.

Fig. 2a to 2e are diagrams illustrating FRB definitions of NR carriers according to an exemplary embodiment of the present invention.

Fig. 2a shows method a100 and fig. 2b to 2e show method a101.

As shown in fig. 2a and 2b, all FRBs may have the same bandwidth (e.g., Δf _FRB ). Alternatively, as shown in fig. 2c to 2e, all FRBs may have the same bandwidth, and the bandwidths of the first and/or last FRBs present at both ends of the system bandwidth may be smaller than the bandwidth of each remaining FRB (e.g., Δf _FRB ). Alternatively, all FRBs may have the same bandwidth, and the bandwidth of the first FRB and/or last FRB may be greater than the bandwidth of each remaining FRB (e.g., Δf _FRB )。

Fig. 2c shows a case where FRBs are sequentially allocated from one edge of the available bandwidth, similar to the subband composition of the LTE system, and thus the last FRB of the opposite edge includes a smaller number of subcarriers than each other FRB.

Fig. 2d and 2e show a case where FRBs are sequentially allocated from the center of an available bandwidth such that the FRBs are symmetrical to each other with respect to a center frequency. In detail, fig. 2d and 2e show the case where FRBs existing at both edges of the available bandwidth respectively include a smaller number of subcarriers than other FRBs. In fig. 2d, the number of FRBs is odd, and unpaired FRBs (e.g., center FRBs) exist in the center of the system bandwidth. In fig. 2e, the number of FRBs is even and all FRBs are paired with respect to the center frequency. Fig. 2e shows a case where one Direct Current (DC) subcarrier exists in the center of the system bandwidth and the DC subcarrier is not included in the configuration of the FRB. However, fig. 2e is only an example of an exemplary embodiment. In general, the location of the DC subcarrier may not be the center of the system bandwidth, and the FRB may also be defined such that the DC subcarrier is included in a specific FRB.

In the case of method a100, the bandwidth of the FRB may be a divisor of the system bandwidth (devisor). For example, when the system bandwidth is 20MHz, the NR carrier may be composed of 4 FRBs having a bandwidth of 5 MHz. As a method described below, when FRB is used as a frequency base unit of parameter set configuration, the method a100 is applied to the second type NR carrier, and thus a plurality of parameter sets may have different system bandwidths. For example, when the second type NR carrier has an entire system bandwidth of 20MHz, the system bandwidth of the first parameter set and the system bandwidth of the second parameter set may be set to 20MHz and 10MHz, respectively. In this case, if the number of FRBs having a bandwidth of 5MHz is 4, the frequency region of the second parameter set may be allocated by two consecutive FRBs. A terminal using a first parameter set as a main parameter set may be configured with two consecutive FRBs of a frequency region for a second parameter set as auxiliary parameter sets or blank resources.

Meanwhile, in the case of method a101, the bandwidth of the FRB may be an integer multiple of the system bandwidth. This is referred to as 'method a102'. Alternatively, the bandwidth of the FRB is a power of 2 times the PRB bandwidth. This is referred to as 'method a103'.

As an example of method a103, each FRB may be configured as 16 PRBs. In this case, when one PRB is composed of 12 subcarriers, one FRB includes 192 (=16×12) subcarriers, similar to the LTE system.

If the number of PRBs per FRB is defined as P in method a102 and method a103, it may be difficult to have P PRBs per FRB. When the number of PRBs is not divided by or less than P, some or all of the FRBs may be composed of a smaller number of PRBs. For example, assume that there are 26 PRBs in a system bandwidth of 5MHz by the method a10p=16. In this case, if it is assumed that 3 FRBs are defined according to the principle of fig. 1d, the first, second, and third FRBs may be composed of 5, 16, and 5 PRBs, respectively. Alternatively, if it is assumed that two FRBs are defined according to the principle of fig. 1e, the first FRB and the second FRB may each consist of 13 PRBs. Meanwhile, when the system bandwidth is small as shown, it may be inefficient to use frequency resources divided into several FRBs. Therefore, if the system bandwidth of the NR carrier is less than a specific value, a method in which the FRB is not specifically defined or one FRB occupies the full band may be considered. The particular value of the bandwidth may be different for each parameter set.

Meanwhile, when the method a100 is used, the boundaries of PRBs and the boundaries of FRBs are not aligned with each other in general, and thus the number of PRBs may be different for each FRB, and even the size of guard bands may be different for each FRB. This may reduce frequency resource utilization efficiency or increase signaling overhead.

On the other hand, when using method a102 and method a103, the boundaries of PRBs and the boundaries of FRBs are aligned with each other, and thus the number of PRBs may be equally defined for each FRB as much as possible and/or the size of guard bands may be equally defined for each FRB as much as possible. In the case of the first type NR carrier, for definition of FRB, method a100 may be used, or methods a101 to a103 may be used. To use the above advantages, methods a101 to a103 can be used for definition of FRB.

[ first type NR Carrier ]

In the first type of NR carrier, the basic parameter set may be defined as a parameter set that all terminals can commonly use within the NR carrier, regardless of RRC connection state. That is, a particular signal or particular channel within the NR carrier may be transmitted at least through the basic set of parameters. The terminal may receive and/or transmit a specific signal (or channel) by default using the basic parameter set as a main parameter set even though the terminal does not receive any parameter set configuration information from the base station.

For example, the first type NR carrier may always have a first signal set (first signal set for downlink) transmitted through a basic parameter set. A terminal not in an RRC connected state may camp on a specific cell or attempt to initially access the specific cell using a first signal set (first signal set for downlink). Furthermore, the first type NR carrier may always have a 2-1 signal set transmitted through a basic parameter set. Alternatively, the base parameter set may be defined as a parameter set for transmitting some of the 2-1 signal sets, irrespective of the first signal set. In this case, a terminal not in the RRC connected state may not know what the basic parameter set of the corresponding cell (or carrier) is. For example, when the terminal in the RRC connected state does not receive the configuration of the individual parameter set, the terminal may periodically monitor the PDCCH using the basic parameter set within the activated NR carrier. If the parameter sets of the first signal set and the 2-1 th signal set (e.g., PDCCH) are different from each other, the terminal may acquire the parameter set of the 2-1 th signal set (e.g., PDCCH) in the course of receiving the first signal set for initial access. Only one parameter set may be used as a base parameter set within one NR carrier.

A parameter set used as a basic parameter set for each frequency band may be predefined. For example, a subcarrier spacing of 15kHz may be used as a base parameter set in a frequency band of 3GHz or less, a subcarrier spacing of 30kHz may be used as a base parameter set in a frequency band of 3 to 6GHz, and a subcarrier spacing of 120kHz may be used as a base parameter set in a frequency band of 6GHz or more. According to this scheme, the terminal attempts cell search using a parameter set preset for each frequency band, thereby reducing complexity of cell search and initial access. On the other hand, the parameter set that can be used as the basic parameter set is not limited, and a method of arbitrarily selecting the parameter set by the base station may be used. For example, a subcarrier spacing of 15kHz and a subcarrier spacing of 30kHz may be used as the basic parameter set in a frequency band of 6GHz or less. According to this scheme, an operator may select a basic parameter set according to an operation scenario to improve flexibility of a technical specification, but a terminal may attempt to receive a synchronization signal through a plurality of parameter sets in an initial cell search of increased complexity.

A terminal not in the RRC connected state may find out a basic parameter set in an initial access procedure to a corresponding carrier. For example, the terminal may find the basic parameter set by receiving the downlink synchronization signal. When the synchronization signal is transmitted only through the basic parameter set, the terminal may attempt to detect the synchronization signal for a plurality of parameter sets and consider a parameter set that successfully receives the synchronization signal as the basic parameter set.

On the other hand, when the synchronization signal is transmitted through several parameter sets within one NR carrier, as a method for acquiring a base parameter set by the terminal, various methods can be considered. For example, the base station may transmit the base parameter set information by carrying the base parameter set information on a first signal set (e.g., a synchronization signal or PBCH). The carrying of the basic parameter set information on the first signal set comprises all methods by which the basic parameter set information can be obtained by the terminal by receiving the first signal set. For example, the mapping (or sequence) of the downlink synchronization signal for the base parameter set may be defined differently from the mapping (or sequence) of the downlink synchronization signal for the parameter set different from the base parameter set.

In this specification, as signaling that a base station can use to transmit control information to a terminal, physical layer signaling (e.g., control information of a physical layer control channel), medium Access Control (MAC) signaling (e.g., MAC Protocol Data Unit (PDU) type control information or MAC header type control information), RRC signaling (e.g., RRC control message or Information Element (IE) type control parameters), etc. may be considered. In general, higher layer signaling includes MAC signaling and RRC signaling. In particular, dynamic resource utilization may be used when control signaling through a physical layer signaling or MAC signaling scheme is composed with or transmitted simultaneously with scheduling information for a corresponding terminal. As another method, a method of notifying configuration information using RRC signaling and dynamically controlling the configuration information configured by RRC through physical layer signaling or MAC signaling may also be used.

The system bandwidth of the first type NR carrier may be defined by a set of base parameters. Alternatively, the candidate values for the system bandwidth of the NR carrier may be defined by a basic parameter set. For example, when the system bandwidths supported by the parameter set a are 5, 10, 20, and 40MHz, the system bandwidth of the NR carrier using the parameter set a as a base parameter set may be one of 5, 10, 20, and 40 MHz. If the parameter set a is used in a system bandwidth wider than 40MHz, a parameter set supporting a wider system bandwidth may be used as a base parameter set, and the parameter set a may be used as a sub-parameter set. The FRB may also be determined by a set of base parameters. This is shown in fig. 3.

Fig. 3 is a diagram illustrating an NR carrier based on a basic parameter set according to an exemplary embodiment of the present invention.

In detail, fig. 3 shows a case where a system bandwidth of a carrier is defined by a basic parameter set and the system bandwidth (or available bandwidth) is divided into 4 FRBs. At this time, for definition of FRB, all of the methods a100 to a103 may be used. For example, when parameter set a is used as the base parameter set and the PRBs of the base parameter set consist of 12 subcarriers, each FRB may consist of 32 PRBs (i.e., 32×12=384 subcarriers) by method a 103.

Alternatively, the bandwidth of the FRB may also have a fixed value, irrespective of the basic parameter set. For example, when using method a100, the bandwidth of the FRB may always have a bandwidth of 5MHz, regardless of the basic parameter set.

Meanwhile, the sub-parameter set may be configured as a sub-parameter set for the terminal. The terminal may receive a configuration of one or more secondary parameter sets within one NR carrier. It may be assumed that the terminal performs transmission and reception using the basic parameter set as a default operation for the configured FRB from the base station. Thereafter, the terminal may receive an RRC message from the base station to receive a configuration of the secondary parameter set for the specific FRB(s). For example, the terminal may assume that the basic parameter set is applied to FRB(s) defined within the system bandwidth while receiving the configuration of the system bandwidth (or frequency domain) of the NR carrier.

As another approach, the terminal may not take any default parameter set for the remaining FRBs other than the FRB(s) that are statically sent the base parameter set. In this case, the terminal may perform transmission using the corresponding parameter set only after it configures the parameter set from the base station.

In detail, fig. 4 shows a case where a base parameter set and a sub-parameter set coexist within one NR carrier. Fig. 4 shows a case where a system bandwidth (or available bandwidth) is divided into 4 FRBs.

The unit in the frequency domain of the sub-parameter set configuration may be FRB. In this case, the minimum unit for the configuration of all parameter sets may be defined as one FRB. The advantage of this scheme is that the parameter set and the resource region can be configured by using a common FRB grid, regardless of the subcarrier spacing of the parameter set. Alternatively, the minimum unit of configuration for each parameter set may be defined differently. For example, the minimum configuration unit may increase in proportion to the subcarrier spacing of the parameter set. As an example thereof, for parameter set a, parameter set B, parameter set C of table 1, 2, and 4 adjacent FRBs may be defined as minimum configuration units in the frequency domain, respectively. Alternatively, the minimum configuration unit of the base parameter set may be one FRB, and the minimum configuration unit of the sub-parameter set(s) having a larger sub-carrier interval than that of the base parameter set may be increased in proportion to the sub-carrier interval. According to this scheme, a predetermined number of PRBs may be always used as a minimum unit in frequency domain resource allocation regardless of a configured parameter set.

As shown in fig. 2c to 2e, when an FRB having a smaller bandwidth than that of a general FRB is defined at an edge of an available bandwidth, spectrum efficiency may be reduced by applying a parameter set different from that of an FRB adjacent to the edge FRB to transmit or receive a signal. This may be more severe when the bandwidth of the edge FRB is very small (e.g. a few PRBs). Thus, the edge FRB may be limited to always have the same parameter set as that of the neighboring FRB. Alternatively, the restriction may be applied only when the bandwidth of the FRB is less than a certain threshold.

The unit in the time domain of the sub-parameter set configuration may be a subframe or a slot. When the unit in the time domain of the parameter set configuration is a slot, the length of the slot may be determined by the base parameter set. For example, when the slot length of the parameter set a is 1ms, the sub-parameter set of the NR carrier using the parameter set a as the base parameter set may be set in units of 1 ms.

Alternatively, a unit smaller than a slot (e.g., an OFDM symbol or a plurality of OFDM symbols) may be a minimum configuration unit of a time domain. The method may be adapted to support URLLC transmissions between heterogeneous parameter sets by a TDM method.

Alternatively, the plurality of slots may be the minimum configuration unit of the time domain. For example, the sub-parameter set is dynamically reconfigured every Z slots (however, Z is a natural number), and the reconfiguration may be valid for Z slots.

Multiple FRBs may be set to have the same sub-parameter set. In this case, the plurality of FRBs may be continuous or discontinuous in the frequency domain. The sub-parameter sets may be semi-statically or dynamically configured. RRC signaling may be used for semi-static configuration and physical layer signaling or MAC signaling may be used for dynamic configuration. Different configuration methods may be applied to the area where the control information is transmitted and the area where the data is transmitted. For example, the PDCCH region may be configured based on a semi-static configuration, and the data region may be configured based on a dynamic or semi-static configuration.

Some of the plurality of FRBs may be defined as anchor points FRB (anchor FRB). An anchor FRB may be defined as an FRB that includes specific time-frequency resources. Here, in a specific time-frequency resource, all terminals expect that the basic parameter set will be used for signaling. For example, a first signal set (e.g., primary Synchronization Signal (PSS)/Secondary Synchronization Signal (SSS), PBCH, and PBCH-DMRS) to which the basic parameter set is applied may be periodically transmitted on a specific time-frequency resource of the anchor point FRB. In addition, the PDCCH region using the basic parameter set may periodically appear in the anchor point FRB. In the case of uplink, a Physical Uplink Control Channel (PUCCH) region using a basic parameter set may periodically appear in the anchor point FRB. The downlink anchor FRB and the uplink anchor FRB may be distinguished from each other and their frequency ranges may be different from each other.

The relative position of anchor point FRB within one carrier may be fixed. Alternatively, the terminal itself may find the location of the anchor point FRB based on a predefined relationship between the anchor point FRB and a specific signal (or a specific channel). Alternatively, the location of the anchor point FRB may be set by the base station. When the location of the anchor point FRB is set by the base station, the location of the anchor point FRB may be transmitted through the PBCH.

For forward compatibility, it is preferable to reduce the number of anchor FRBs. The number of anchor points FRB within one NR carrier may be defined as one or two. The boundary between the location of the first signal set (first signal set for downlink) and the FRB may be considered when designing the number of anchor points FRB and the location of the anchor points FRB in the frequency domain.

Fig. 5a to 5c are diagrams illustrating a method of constructing an anchor point FRB according to an exemplary embodiment of the present invention. Fig. 5a and 5b show the case where the system bandwidth (or available bandwidth) is divided into 4 FRBs. Fig. 5c shows a case where the system bandwidth (or available bandwidth) is divided into 5 FRBs.

In detail, fig. 5a shows a case where the boundary of FRBs is located at the center frequency of a carrier wave and a first signal set is periodically transmitted on two FRBs located at the center. In this case, two FRBs located in the center may be defined as anchor FRBs.

Fig. 5b shows a case where the boundaries of the FRBs are located at the center frequency and the first signal set is periodically transmitted within only one FRB. In this case, one FRB, to which the first signal set is transmitted, may be defined as an anchor FRB.

Fig. 5c shows a case where a center FRB, which is not symmetrical with other FRBs as described above with reference to fig. 2d, exists at the center of the bandwidth. In this case, when the first signal set is periodically transmitted in one FRB located at the center, one FRB located at the center may be defined as an anchor FRB.

According to an exemplary embodiment, the carriers may include both wideband carriers (e.g., 100MHz system bandwidth) and narrowband carriers (e.g., 10MHz system bandwidth). In addition, according to an exemplary embodiment, the carrier may be a self-carrier constituting the above-described second type NR carrier.

The FRB may be used as a unit for distinguishing frequency resources, and may include all resource regions in the time domain.

On the other hand, one FRB may also be defined as a limited frequency resource and a limited time resource. For example, one FRB may include one or more PRBs and slots corresponding to a parameter set applied to the FRB. At this time, the length of the FRB in the time domain may be different for each parameter set or may be common for all parameter sets. For example, the length of the FRB in the time domain may be defined as the length of X slots including the basic parameter set, and the value may be applied to all the FRBs. Alternatively, the length of the FRB in the time domain may be defined as a fixed value (e.g., 10 ms) regardless of the basic parameter set. When the length of the FRB in the time domain is limited, it may be assumed that the terminal does not transmit any signal outside the configured time period of the FRB. Alternatively, it may be assumed that the terminal uses a basic parameter set or a main parameter set outside of the configured FRB period. Alternatively, it may be assumed that the terminal uses a parameter set pre-configured through RRC signaling outside of a configured FRB period.

A method of applying only the basic parameter set to the entire resource region of the anchor point FRB may be considered. Alternatively, a method for statically applying the basic parameter set to only some of the time-frequency resource regions of the anchor point FRB and applying the sub-parameter set (i.e., the terminal's secondary parameter set) to the remaining resource regions may be considered. The first signal set and/or the 2-1 signal set may be transmitted in some of the time-frequency resource regions. In the case of the downlink anchor point FRB, PSS/SSS, PBCH, and PBCH-DMRS may be transmitted in some of the time-frequency resource regions. The latter approach may be used in order to support broadband URLLC transmissions over a set of sub-parameters. Alternatively, a method for scheduling only the basic parameter set for the entire resource region of the anchor point FRB and exceptionally puncturing (puncturing) some of the time resources by grouping (packet) of the sub parameter set may be considered.

[ second type NR Carrier ]

In the case of the first type NR carrier, the frequency region may be defined by a basic parameter set. On the other hand, in the case of the second type NR carrier, a plurality of parameter sets may form each self-carrier within one NR carrier. In general, the entire frequency region of the second type NR carrier may not match the frequency region of each self carrier. The entire frequency region of the second type NR carrier may be defined as a combination of frequency regions of the self-carrier. If there is no restriction between the entire frequency region and the frequency region of the self-carrier, the distinction between the second type NR carrier and the self-carrier may be ambiguous.

Thus, even in the case of the second type NR carrier, a basic parameter set can be defined. The entire frequency range of the second type NR carrier may be matched to the frequency range of the base set of parameters. For example, the second type NR carrier may be composed of a first parameter set occupying a first frequency region and a second parameter set occupying a second frequency region. In this case, if the first parameter set is used as the base parameter set, the entire frequency region of the second type NR carrier may match the first frequency region, and the second frequency region may be some of the first frequency region. According to this method, the roles of the basic parameter sets are the same as in the case of the first-type NR carrier, and the first-type NR carrier and the second-type NR carrier can be distinguished only by whether parameter sets other than the basic parameter sets can be used as the main parameter set.

In the following, for convenience, the parameter set(s) different from the base parameter set will be referred to as sub-parameter set even in the case of the second type NR carrier. According to this method, the method for constructing the FRB and the anchor FRB can be equally applied even to the second type NR carrier. In the case of the second type NR carrier, the bandwidth of the FRB may have a fixed value regardless of the parameter set. For example, method a100 is used for configuration of FRB, and the bandwidth of FRB may always be 5MHz regardless of parameter set. In addition, in the case of the second type NR carrier, there may be an anchor point FRB for each self carrier. Alternatively, the anchor point FRB may exist at least for all parameter sets used as main parameter sets of the terminal, regardless of the parameter set type.

In case of the second type NR carrier, the first signal set and/or the 2-1 th signal set may be always transmitted at least for all parameter sets used as a main parameter set of the terminal, regardless of the parameter set type. When the first signal set and/or the 2-1 th signal set is transmitted through a specific parameter set, a terminal using the specific parameter set as a secondary parameter set may be configured with the presence of the signal set from the base station to find the presence of the signal set.

[ subcarrier grid ]

Hereinafter, consecutive OFDM subcarriers or a set of frequency positions thereof is referred to as a 'subcarrier grid'. OFDM subcarriers may be transmitted in frequencies corresponding to each of the predefined subcarrier bins. When multiple parameter sets are used within one NR carrier, a subcarrier grid may be defined for each parameter set. When subcarrier spacings of parameter sets differ from each other by a power of 2, subcarrier grid points of parameter sets having large subcarrier spacings may be aligned on subcarrier grid points of parameter sets having small subcarrier spacings. That is, the previous grid point and the subsequent grid point may have the same frequency value. This is shown in fig. 6, 8a and 8b, 9a and 9b and 10. The subcarrier grid for each parameter set may be defined as one or several within the system bandwidth (or available bandwidth other than the guard band in the system bandwidth) of the NR carrier. OFDM modulation and demodulation may be performed for each subcarrier grid.

The method that allows each parameter set within the NR carrier to have one full sub-carrier grid is called 'method a110'. Fig. 6 shows method a110.

In detail, fig. 6 shows that the base parameter set and the sub-parameter set each have one full sub-carrier grid, the sub-parameter set having a subcarrier spacing twice as large as the subcarrier spacing (e.g., af) of the base parameter set. As shown in fig. 6, subcarrier grid points of the subcarrier sets may be aligned over subcarrier grid points of the base parameter set.

The method a110 has an advantage in that the terminal can perform the FFT/IFFT operation only once for each parameter set regardless of the configuration form of the parameter sets. When using method a110, the center frequency of the subcarrier grid for the parameter sets may be the same for all parameter sets, and the bandwidth of the subcarrier grid for the parameter sets may be the same for all parameter sets. When defining the DC sub-carriers for all parameter sets, the positions of the DC sub-carriers may be the same for all parameter sets. Method a110 may be more suitable for the first type NR carrier.

Meanwhile, the base parameter set may have one full sub-carrier grid, and the sub-parameter set may have one or more sub-carrier grids. This is called 'method a111'. Fig. 7a and 7b show method a111.

In detail, fig. 7a shows a case where a sub-parameter set has a plurality of sub-carrier meshes, and fig. 7b shows a case where a sub-parameter set has one sub-carrier mesh. Fig. 7a and 7b show the case where the subcarrier spacing of the subcarrier sets is twice as large as the subcarrier spacing (af) of the base parameter set.

When using method a111, a subcarrier grid of parameter sets may be defined within each FRB. For example, when the NR carrier consists of 4 FRBs, the subcarrier grid for each subcarrier set may be up to 4.

Alternatively, when using method a111, the size of the subcarrier grid of the subcarrier set may be defined to include the minimum bandwidth of all frequency regions configured by the subcarrier set. One sub-carrier grid for a sub-parameter set may comprise full-band. When the sub-parameter sets are configured in units of FRBs in the frequency domain, a subcarrier grid of the corresponding sub-parameter set may be defined in a plurality of consecutive FRBs. The method may be more suitable for the second type NR carrier.

When using method a111, the subcarrier grid of the subcarrier sets may be designed such that the interval between subcarriers belonging to different grids is an integer multiple of the basic subcarrier interval for the corresponding parameter set. By doing so, interference between subcarrier grids can be eliminated.

Even when the method a111 is used, subcarrier grid points having a parameter set of a large subcarrier spacing can be aligned on subcarrier grid points having a parameter set of a small subcarrier spacing.

Meanwhile, a method for defining a DC subcarrier and using the DC subcarrier as a null subcarrier (null subcarrier) may reduce implementation complexity of an OFDM receiver. In the LTE system, a DC subcarrier exists at a center frequency of a carrier in the case of downlink, and no DC subcarrier exists in the case of uplink. In the case of NR carriers, the presence or absence of DC subcarriers may be defined for each parameter set type. This is referred to as 'method a120'.

As detailed methods for the method a120, the method a121, the method a122, and the method a123 can be used.

Method a121 is a method of using a DC carrier for transmission of a basic parameter set and not using a DC subcarrier for transmission of a sub-parameter set.

Method a122 is a method of using a DC subcarrier for both transmission of a base parameter set and transmission of a sub-parameter set.

Method a123 is a method of not using a DC subcarrier for both transmission of a base parameter set and transmission of a sub-parameter set.

When a DC subcarrier for blanking (nulling) is not defined in the technical specification, the terminal may process noise around DC in the implementation.

When there are DC subcarriers in the parameter sets for nulling, the DC subcarriers may be defined for each subcarrier grid at a center frequency of a frequency region occupied by each subcarrier grid belonging to the corresponding parameter set. Alternatively, the location of the DC subcarrier may not be predefined in the technical specification, the base station nulls out any particular subcarrier, and the nulled particular subcarrier may be used for the DC subcarrier of the terminal.

Fig. 8a and 8b show method a121 and method a122.

In detail, in fig. 8a and 8b, a case is assumed in which the method a110 is used and the base parameter set and the sub-parameter set have the same center frequency.

Fig. 8a and 8b show one basic parameter set and 3 sub-parameter sets (first sub-parameter set, second sub-parameter set, third sub-parameter set). The subcarrier spacing of the first set of subcarriers is as large as 0.5 times the subcarrier spacing of the base set of parameters (e.g., Δf), the subcarrier spacing of the second set of subcarriers is as large as 2 times the subcarrier spacing of the base set of parameters (e.g., Δf), and the subcarrier spacing of the third set of subcarriers is as large as 4 times the subcarrier spacing of the base set of parameters (e.g., Δf).

Fig. 8a shows the case where the DC sub-carriers are only present in the base parameter set and not in the sub-parameter set by method a121 DC. That is, the DC subcarrier is used only for transmission of the basic parameter set (i.e., transmission based on the basic parameter set representing a plurality of parameter sets).

Fig. 8b shows the case where the DC sub-carriers are present in both the base parameter set and the sub-parameter set by method a122. That is, the DC subcarrier is used to transmit all parameter sets (i.e., based on the transmission of all parameter sets).

Meanwhile, in the NR system, the setting of the DC sub-carriers of the downlink and the uplink may be the same. For example, in the case of both downlink and uplink, method a121 may be used or method a122 may be used. When the method a121 or the method a122 is also applied to the uplink, there is a problem. In case of LTE uplink, there is no DC subcarrier. Thus, the DC subcarrier is disposed in the NR uplink carrier, and thus may be difficult to coexist with the 'LTE in-band Narrowband (NB) -internet of things (IoT) carrier'. On the other hand, DC subcarriers are used even for uplink transmission, and thus the implementation complexity of the receiver can be reduced when a low-cost node other than the base station receives an uplink signal.

Meanwhile, the setting of the DC sub-carriers of the downlink and uplink may also be independently designed. For example, method a121 or method 122 may be applied to the downlink and method a123 may be applied to the uplink. By doing so, the NR carrier is prone to coexist with the LTE NB-IoT carrier in both uplink and downlink cases.

【PRB】

Hereinafter, a method for configuring PRBs on a frequency basis will be mainly described. In NR carriers, a PRB may also be defined as a set of M consecutive subcarriers in the frequency domain (however, M is a natural number). There is no cross-over between PRBs and the sum of PRBs may include all available subcarriers.

PRBs of NR carriers may be defined for each parameter set. Hereinafter, PRBs of the basic parameter set are referred to as 'basic PRBs'. For example, when the parameter set a of table 1 is used as the basic parameter set, the basic PRB of the corresponding carrier may be composed of 12 subcarriers and a bandwidth of 180kHz, similar to the case of a subcarrier spacing of 15kHz for the LTE system. All basic PRBs may have the same number of subcarriers. For this purpose, the total number of subcarriers per NR carrier may be an integer multiple of the 'number of subcarriers per basic PRB'.

Hereinafter, PRBs of the sub-parameter set are referred to as 'sub-PRBs'. The sub-PRBs may have the same bandwidth as the base PRBs. This is referred to as 'method a130'. Fig. 9a and 9b show method a130.

In detail, fig. 9a and 9b show a case where the basic PRB consists of 12 subcarriers. Fig. 9a shows a case where there are an even number of PRBs in one carrier, and fig. 9b shows a case where there are an odd number of PRBs in one carrier. Fig. 9a and 9b show one basic parameter set and 3 sub-parameter sets (first sub-parameter set, second sub-parameter set, third sub-parameter set). Fig. 9a and 9b show the case where DC sub-carriers exist in both the base parameter set and the sub-parameter set by method a 122.

If the subcarrier spacing of the base parameter set is assumed to be Δf, each of the subcarrier spacing of the first, second, and third subcarrier spacings is 0.5, 2, and 4. Here, Δf may be 15kHz.

With method a130, the sub-PRBs have the same bandwidth as the base PRBs. Thus, each of the PRBs of the first, second and third sub-parameter sets (i.e., the first, second and third sub-PRBs) has 24, 6 and 3 subcarriers. In addition, in fig. 9a and 9b, a method is used in which boundaries between PRBs are aligned with each other with respect to parameter sets.

As shown in fig. 9b, when the basic PRB is odd (i.e., when there is one center PRB), the center PRB of the third sub-parameter set does not have 3 available subcarriers, but only has two available subcarriers.

Meanwhile, if it is assumed that a fourth sub-parameter set having a sub-carrier interval of 8×Δf is added and the fourth sub-parameter set can be used for the same carrier, a PRB of the fourth sub-parameter set (i.e., a fourth sub-PRB) mathematically has 1.5 sub-carriers through the method a 130. As a result, it may be difficult to configure all sub-PRBs to have an integer number of sub-carriers.

In order to solve the above-described problem, when the basic PRB for the NR carrier is composed of 12 subcarriers, a method for limiting the maximum value of the subcarrier spacing of the subcarrier set to 4×Δf may be used. In other words, if it is assumed that the basic PRB is composed of M subcarriers (however, M is a natural number), and each of the subcarrier spacing of the basic parameter set and the subcarrier spacing of the subcarrier set is Δf and n×Δf (however, N is a natural number), a method of restricting the use of the parameter set and making N a divisor of M may be used. The method does not exclude the use of a sub-parameter set having a sub-carrier spacing (e.g. 1/N x af) smaller than the sub-carrier spacing of the base parameter set.

On the other hand, the PRBs of the sub-parameter set may have different bandwidths than the underlying PRBs. This is referred to as 'method a131'. In detail, the PRB bandwidth may be defined to be proportional to the subcarrier spacing of the corresponding parameter set. In other words, the 'number of subcarriers per PRB' of all parameter sets may be equally defined. This is referred to as 'method a132'. Fig. 10 shows method a132.

In detail, in fig. 10, a set of parameter sets identical to the set of parameter sets shown in fig. 9a and 9b is considered. Fig. 10 shows one basic parameter set and 3 sub-parameter sets (first sub-parameter set, second sub-parameter set, third sub-parameter set). Fig. 10 shows the case where DC sub-carriers exist in both the base parameter set and the sub-parameter set by method a 122.

As shown in fig. 10, the basic PRB and the PRBs of the first to third sub-parameter sets (i.e., each of the first, second, and third sub-PRBs) are each composed of 12 subcarriers. Furthermore, the bandwidths of the first to third sub-PRBs are respectively as large as 0.5, 2 and 4 times the bandwidth of the base PRB. In fig. 10, a method of allowing the boundary between sub-PRBs to be aligned with the boundary between basic PRBs is also used. In this case, the PRB bandwidths of the parameter sets have 2 to each other ^N The difference of times (however, N is an integer), and thus a nested structure can be satisfied as shown in fig. 10. That is, one PRB having a subcarrier spacing of 2×Δf may occupy the frequency range of two consecutive PRBs having a subcarrier spacing of Δf, and one PRB having a subcarrier spacing of 4×Δf may occupy the frequency range of two consecutive PRBs having a subcarrier spacing of 2×Δf. Furthermore, one PRB with a subcarrier spacing of Δf may occupy the frequency of two consecutive PRBs with a subcarrier spacing of 1/2×ΔfA range of rates. For example, the number of subcarriers (e.g., 12) belonging to a PRB to which a basic parameter set among a plurality of parameter sets is applied may be equal to the number of subcarriers belonging to a PRB to which a first sub-parameter set is applied, and the boundary with a PRB to which a basic parameter set is applied may be aligned with the boundary with a PRB to which a first sub-parameter set is applied. In detail, at least one of subcarriers (e.g., subcarrier No. 0) belonging to a PRB to which the basic parameter set is applied may be aligned with at least one of subcarriers (e.g., subcarrier No. 0) belonging to a PRB to which the first sub parameter set is applied. In fig. 12, the peaks of the subcarriers mean positions of the subcarriers, and the alignment of the subcarriers belonging to the heterogeneous parameter set means alignment of the peaks belonging to the heterogeneous parameter set. A physical channel (or physical signal) using the PRBs thus defined may be generated and transmitted by a base station.

However, the bandwidth of the first sub-PRB is smaller than the bandwidth of the base PRB, and thus all boundaries between sub-PRBs may not be aligned with boundaries between base PRBs. The method for aligning PRB boundaries as much as possible across parameter sets reduces the number of cases for parameter set configuration and guard band configuration, thereby simplifying signaling.

In fig. 10, a case is assumed in which a well-defined DC subcarrier is defined in each parameter set. However, as described above, a method for aligning boundaries between PRBs of heterogeneous parameter sets may be used regardless of the presence or absence of DC subcarriers.

The above methods a130 to a132 are methods in which the PRB bandwidth for each parameter set has a fixed value. Meanwhile, a method of setting a PRB bandwidth for a terminal by a base station may be used. As the most flexible method for this, there is a method in which the base station sets PRB bandwidths of all parameter sets. However, this approach typically increases the signaling overhead of the terminal. In addition, when bandwidth information of a basic PRB is transmitted through a PBCH, there is a problem in that a PBCH resource region is required to be wide. As another method, there is a method in which the bandwidth of the base PRB has a fixed value and the base station can set the bandwidth of the sub PRB. In this case, the bandwidths of the sub-PRBs and the base PRBs may have a relationship of integer multiples of each other. As described above, when the PRB bandwidth is variable, a method for configuring resources supporting the PRB bandwidth may be complex.

Meanwhile, in case of the LTE system, the number of PRBs may be even or odd depending on the system bandwidth of the carrier. When the number of PRBs is odd, there is one center PRB. Similarly, even NR systems can support both even and odd number of PRBs. However, if it is assumed that the number of PRBs is odd and there is one center PRB, when one FRB is scheduled to be located at the center of the bandwidth as shown in fig. 2d, the center FRB may have an odd number of PRBs. Thus, the FRB bandwidth cannot be composed of an even number of PRBs, which is the case for all FRBs. That is, it is not possible to use both method a103 and the principle of fig. 2 d. In addition, when the FRBs are configured as shown in fig. 2e, one center PRB may not be included in any one of the FRBs. Further, as shown in fig. 9b, the center PRB may have a different number of subcarriers from the number of subcarriers of other PRBs.

To solve the above problem, the number of basic PRBs for NR carriers may be always even regardless of the basic parameter set and the system bandwidth. That is, the number of basic PRBs included in one NR carrier may be even. When the number of PRBs is even, the center frequency of the NR carrier may be located at the boundary between two PRBs located in the middle. For example, an LTE carrier with a 5MHz system bandwidth has 25 PRBs. At this time, if it is assumed that the parameter set has a subcarrier spacing of 15kHz in the same system bandwidth (e.g., 5 MHz) and that the 'number of subcarriers per PRB' is 12, as a method of allowing the NR carrier to have an even number of PRBs, there are a method for defining 24 PRBs obtained by subtracting one PRB from 25 PRBs and a method for defining 26 PRBs obtained by adding one PRB to 25 PRBs. In the latter case, if the bandwidths of all PRBs have the same size as before, the guard band needs to be reduced in size, which may be possible or impossible depending on the characteristics of the NR waveform. As a method for defining an even number of PRBs without reducing the size of the guard band, there is a method for defining PRBs such that the number of subcarriers of some PRBs is different from the number of subcarriers of each other PRB. For example, one or two PRBs of the PRBs at both ends adjacent to the system guard band may be composed of a smaller number of subcarriers or a larger number of subcarriers than the number of subcarriers of each other PRB. In the above example using a system bandwidth of 5MHz and a subcarrier spacing of 15kHz, the total number of subcarriers remains the same, and two PRBs at both ends adjacent to the guard band among 26 PRBs may include six subcarriers. That is, at least one of the even number of basic PRBs included in one NR carrier may have a bandwidth smaller than that of each remaining PRB.

Fig. 11 is a diagram illustrating coexistence with LTE NB-IoT when the number of PRBs of the NR carrier is even according to an exemplary embodiment of the present invention. In fig. 11, the subcarrier spacing of the LTE DL carrier is 15kHz and the subcarrier spacing of the NR DL carrier is 15kHz.

When an NR carrier co-exists with an 'LTE in-band NB-IoT carrier', an LTE NB-IoT DL carrier (e.g., occupying 180kHz bandwidth) may be set on two PRBs of the NR DL carrier if the system bandwidth of the NR carrier is one of 3MHz, 5MHz, and 15MHz of existing LTE as shown in fig. 11. Thus, when resource allocation in PRB units is used, additional resource loss of one PRB may occur. In case that the boundary of the LTE PRB and the boundary of the NR PRB are not aligned with each other, a problem may occur in that the frequency resource region of the LTE NB-IoT carrier is not aligned in one NR PRB. The above-described problem may be solved by a method of semi-statically configuring a frequency region, where NB-IoT is configured as a blank resource on which no signal is transmitted, and resources are allocated only to the remaining region of PRBs including the blank resource. That is, data transmission of PRBs including the blank resource may be rate-matched around the blank resource. The configuration information of the blank resources may be broadcast through SIB or may be transmitted to the terminal through RRC signaling. Alternatively, if the PRB bandwidth is configurable, the above problem can be solved by adjusting the size of the PRB bandwidth.

According to the above-described exemplary embodiments, it is assumed that the DC subcarrier is not included in any PRBs. Meanwhile, a method for configuring PRBs such that DC subcarriers are included in the PRBs may be used. This is referred to as 'method a133'.

Method a133 is a method of including DC subcarriers in the 'number of subcarriers per PRB'. Thus, when the 'number of subcarriers per PRB' for a specific parameter set is regularly constructed, the sum of the number of DC subcarriers and the number of subcarriers other than DC subcarriers is constant for each PRB.

In detail, fig. 12a and 12b show a case where one DC subcarrier exists at the center of a carrier bandwidth and one DC subcarrier is included in a specific PRB.

Fig. 12a shows the case where if there are a total of 2*N (however, N is a natural number) PRBs (e.g., PRB No.0, PRB No.1,..and PRB No. (2*N-1)), PRB No. N includes one DC subcarrier. Fig. 12b shows the case that if there are a total of (2 x n+1) (however, N is a natural number) PRBs (e.g., prbno.0, PRB No.1, PRB No. (2*N)), then PRB No. N-1 includes one DC subcarrier. In fig. 12a and 12b, it is assumed that each PRB is composed of the same number (e.g., 12) of subcarriers, regardless of whether each PRB includes DC subcarriers or not. When using method a133, the DC subcarrier may be transmitted at a fixed location. For example, as shown in fig. 12a and 12b, the DC sub-carriers may be transmitted at a regular center of the carrier bandwidth.

Meanwhile, when a plurality of parameter sets are used within the NR carrier, the method a133 may be applied to each parameter set.

Fig. 13 is a diagram illustrating a method for constructing PRBs based on the method 133 for each of a plurality of parameter sets according to an exemplary embodiment of the present invention. Fig. 13 shows three parameter sets (e.g., a first parameter set, a second parameter set, and a third parameter set). In fig. 13, it is assumed that the first parameter set has a subcarrier spacing of Δf, the second parameter set has a subcarrier spacing of 2×Δf, and the third parameter set has a subcarrier spacing of 4×Δf.

In detail, fig. 13 shows a case where method a132 for PRB bandwidth scaling between parameter sets is used and PRB boundaries are aligned between parameter sets.

As shown in fig. 13, when the position of the DC subcarrier for each parameter set is fixed at the regular center of the carrier bandwidth, the DC subcarrier for each parameter set may be included in one of two center PRBs. In this case, unlike the exemplary embodiments of fig. 8a to 10, the frequency positions of the DC subcarriers for the parameter sets are different and there may be a slight offset (e.g., 0.5 Δf-1.5 Δf) between them. Further, subcarrier grid points of parameter sets may not be aligned with each other among the parameter sets. That is, as shown in fig. 13, subcarrier grid points (i.e., frequency values of subcarriers) of a parameter set (e.g., second parameter set) having a large subcarrier spacing are not aligned on subcarrier grid points of a parameter set (e.g., first parameter set) having a small subcarrier spacing, and for the latter (e.g., first parameter set), there is an offset corresponding to half of the subcarrier grid point spacing. This is a feature that differs from the exemplary embodiment of fig. 8a to 10 described above.

When using method a133, a plurality of DC subcarriers may be defined for one NR carrier and one parameter set. This may be useful when the system intends to simultaneously support terminals with various bandwidth capabilities over one NR carrier.

Fig. 14 is a diagram illustrating a method for transmitting a plurality of DC subcarriers based on method a133 according to an exemplary embodiment of the present invention.

In detail, fig. 14 shows a case where method a133 for one NR carrier and one parameter set is applied to a plurality of DC subcarriers and the plurality of DC subcarriers are included in a PRB.

In fig. 14, 3 DC subcarriers (e.g., a first DC subcarrier, a second DC subcarrier, and a third DC subcarrier) are assumed. The frequency distance between the first DC subcarrier and the second DC subcarrier is defined as d ₁ And the frequency distance between the second DC subcarrier and the third DC subcarrier is defined as d ₂ . The frequency locations of the DC sub-carriers and the relative frequency distances between them (e.g. d ₁ 、d ₂ ). In this case, the DC subcarriers may be set at regular intervals in the frequency domain. That is, the frequency distances between all two adjacent DC sub-carriers may be equal (e.g., d ₁ ＝d ₂ ). Alternatively, the frequency distance between two adjacent DC sub-carriers may be equal to or larger than the frequency bandwidth size occupied by one synchronization signal sequence. For synchronization signal transmission, this may be required for each DC subcarrier. At the same time or separately, the frequency distance between two adjacent DC subcarriers may be an integer multiple of the PRB bandwidth as shown in fig. 14.

Meanwhile, the frequency positions of the DC subcarriers and the relative frequency distances therebetween are variable, and the base station selects any one or more of the subcarriers, and the selected subcarrier(s) may also be used for the DC subcarriers.

Alternatively, a group of subcarriers that can be used as DC subcarriers is predefined, the base station selects one or more subcarriers from among the subcarriers included in the group, and the selected subcarrier(s) can also be used for DC subcarriers.

Alternatively, the position of one DC subcarrier of the plurality of DC subcarriers is fixed, and the positions of the remaining DC subcarriers may be variable. Here, one DC subcarrier having a fixed position may exist in the center of the carrier bandwidth. Here, the positions of the remaining DC subcarriers having the changed positions may be arbitrarily determined by the base station.

Meanwhile, when a plurality of DC subcarriers exist in one NR carrier, some of the plurality of DC subcarriers are defined at fixed positions not to be included in any PRB, and the method a133 may also be applied to the remaining DC subcarriers. For example, when one parameter set has a plurality of DC subcarriers, one of the DC subcarriers to which the method a133 is not applied exists at the center of the carrier bandwidth, and the remaining DC subcarriers to which the method a133 is applied may be allocated at different frequency positions from the center of the carrier bandwidth.

Meanwhile, when the method a133 is used, the terminal can acquire the position of the DC subcarrier in the course of receiving the downlink synchronization signal even if the position of the DC subcarrier within the carrier bandwidth is not defined in advance. For example, a specific subcarrier (e.g., one subcarrier located at the center of a frequency region) among subcarriers constituting a frequency region to which a sequence of a downlink synchronization signal is mapped may be defined as a DC subcarrier. Therefore, even if a downlink synchronization signal is transmitted from any frequency region within the carrier bandwidth, the terminal can acquire the position of the DC subcarrier according to the above rule while successfully receiving the synchronization signal. In this case, if it is assumed that the synchronization signal is transmitted through the basic parameter set, the terminal may acquire the position of one DC subcarrier among the one or more DC subcarriers for the basic parameter set. If the terminal needs to find out the positions of other DC sub-carriers of the same parameter set or of the DC sub-carrier(s) of the other parameter set, the terminal is configured with corresponding position information from the base station or similar to the above method the terminal uses the corresponding parameter set to search for a synchronization signal, thereby obtaining the positions of the DC sub-carriers. The former method is more effective in view of the reception complexity of the terminal.

Meanwhile, when the method a133 is used, if the positions of the same DC subcarriers are assumed, an offset (e.g., Δf) may occur between the boundary of the LTE PRB and the boundary of the NR PRB. Thus, the problem of misalignment of the frequency resource regions of LTE NB-IoT carriers disposed within the NR carrier bandwidth in one NR PRB may similarly occur. To solve this problem, the above-described method can also be used.

In detail, fig. 15 shows a case where PRB bandwidths of a plurality of parameter sets are defined by the method a132, and a nested structure (for example, the nested structure shown in fig. 10) is applied between PRB grids of the plurality of parameter sets.

The subcarrier spacing of f1 is as large as twice the subcarrier spacing of f0 and the subcarrier spacing of f2 is as large as four times the subcarrier spacing of f 0. Thus, the PRB bandwidth of parameter set f1 is as large as twice the PRB bandwidth of parameter set f0, and the PRB bandwidth of parameter set f2 is as large as four times the PRB bandwidth of parameter set f 0. One of the 3 parameter sets (e.g., f0, f1, and f 2) may be defined as a base parameter set.

With method a102, one FRB consists of an integer number of consecutive PRBs in the frequency domain. In fig. 15, it is assumed that one PRB group constitutes one FRB, and one FRB includes 8 PRBs for the parameter set f 0. This is equivalent to the case where one PRB group includes 4 PRBs for the parameter set f1 and the case where one PRB group includes two PRBs for the parameter set f 2. That is, the number of PRBs included in the PRB group may be determined according to a parameter set applied to the PRB group.

In fig. 15, it is assumed that PRB group No.0 to PRB group No.3 correspond to FRB No.0 to FRB No.3, respectively. The PRB group number is only a cell-specific number for distinguishing PRB groups, and PRB group number(s) different therefrom may be allocated to the terminal. In addition, typically one PRB group may be configured as one or more FRBs.

A terminal may use only one parameter set within one PRB group to transmit or receive a signal. For example, the terminal may use only the parameter set f0 in the PRB group No.0 and the PRB group No.3, use only the parameter set f2 in the PRB group No.1, and use only the parameter set f1 in the PRB group No. 2. In the case of a downlink PRB group, a signal received by a terminal using a single parameter set may include at least PDCCH and PDSCH and may further include reference signals (e.g., DMRS, CSI-RS). In the case of an uplink PRB group, a signal transmitted by a terminal using a single parameter set may include at least PUCCH and PUSCH and may further include reference signals (e.g., DMRS, sounding Reference Signals (SRS)).

In this case, the PRB number may be defined within each PRB group. This is referred to as 'method a134'. As shown in fig. 15, since 8 PRBs for the parameter set f0 exist within the PRB group No.0, the 8 PRBs (consecutive PRBs in the frequency domain) may be numbered as PRB No.0 to PRB No.7. Further, since 8 PRBs for the parameter set f0 exist within the PRB group No.3, the 8 PRBs may be numbered by PRB No.0 to PRB No.7. For example, when the base station allocates resources to the terminal using a plurality of PRB groups configured for the terminal by the same Downlink Control Information (DCI) (e.g., PRB group No.0 and PRB group No.3 to which the same parameter set f0 is applied), an index allocated to a first PRB (or a last PRB) included in the PRB group No.0 to which the parameter set f0 is applied may be the same as an index allocated to a first PRB (or a last PRB) among 8 PRBs included in the PRB group No.3 to which the parameter set f0 is applied. In addition, since 2 PRBs for the parameter set f2 exist within the PRB group No.1, the 2 PRBs may be numbered as PRB No.0 and PRB No.1. Further, since 4 PRBs for the parameter set f1 exist within the PRB group No.2, the 4 PRBs may be numbered as PRB No.0 to PRB No.3.

Alternatively, the PRB numbers may be defined within all or some of the PRB groups corresponding to each parameter set. This is referred to as 'method a135'. According to method a134, PRB group No.3 shown in fig. 15 has PRB No.0 to PRB No.7. On the other hand, according to method a135, PRB group No.3 may have PRB No.8 to PRB No.15 after the PRB number of PRB group No. 0. For example, when a base station allocates resources to a terminal using a plurality of PRB groups configured for the terminal by the same DCI (e.g., PRB group No.0 and PRB No.3 to which the same parameter set f0 is applied), an index allocated to 8 PRBs included in PRB group No.3 may be based on an index allocated to a last PRB of 8 PRBs included in PRB group No. 0.

The base station may allocate data transmission resources (e.g., PDSCH resources, PUSCH resources) to the terminal in PRB units (or PRB bundle units) by a PRB number representing a PRB within a PRB group, or a PRB bundle number representing a PRB bundle within a PRB group (and/or a PRB group number representing a PRB group). This is referred to as 'method a136'. In the case of method a136, the use of PRB numbers representing PRBs within a PRB group for data resource allocation may mean that the scheduling information included in the DCI explicitly includes the PRB number(s), or that the scheduling information included in the DCI is generated based on the PRB number(s). In the latter case, the terminal may acquire the scheduled PRB number(s) within the PRB group based on the scheduling information of the DCI. In method a136, the use of PRB group numbers representing PRB groups may have the same meaning as described above.

For example, the first terminal may be configured to use the parameter set f0 within the PRB group No.0 and PRB group No. 3. For a terminal, the base station may schedule PRB No.0 through PRB No.3 within PRB group No.0 as a data transmission region. In detail, the base station may configure at least one PRB group (e.g., PRB group No. 0) for the terminal, configure at least one parameter set (e.g., parameter set f 0) for the at least one PRB group (e.g., PRB group No. 0) among the plurality of parameter sets for the terminal, and schedule at least one PRB (e.g., PRB nos. 0, 1, 2, and 3) among the plurality of PRBs included in the at least one PRB group (e.g., PRB group No. 0) for the terminal. When the base station configures a plurality of PRB groups for the same terminal, different parameter sets may also be applied to the plurality of PRB groups configured for the terminal. In this case, the base station may transmit the PRB number(s) or PRB bundle number(s) (and/or PRB group number (s)) as scheduling information of the PDSCH (or PUSCH) to the terminal through physical layer signaling, e.g., downlink Control Information (DCI). In this case, as described above, the transmission of the PRB number(s) may mean that the scheduling information included in the physical layer signaling (e.g., DCI) explicitly includes the PRB number(s). For example, the resource allocation information of DCI in the frequency domain may include a bitmap in PRB units. Alternatively, the transmission of the PRB number may mean generating scheduling information included in physical layer signaling (e.g., DCI) based on the PRB number(s). For example, the resource allocation information of DCI in the frequency domain includes a bitmap in PRB bundles, and the PRB bundles may be composed of a plurality of consecutive PRBs. For example, when one PRB bundle is configured as two PRBs, PRB No.0 and PRB No.1 within PRB group No.0 are defined as PRB bundle No.0, and PRB No.2 and PRB No.3 within PRB group No.0 may be defined as PRB bundle No.1. In this case, the base station may inform the terminal of the PRB bundle No.0 and PRB bundle No.1 within the PRB group No.0 through DCI, and the terminal may know that the PRB nos. 0 to 3 within the PRB group No.0 are scheduled through the received DCI. Meanwhile, the terminal may also be configured with a PRB group number through higher layer signaling, such as RRC signaling or MAC Control Element (CE). The PRB group number may mean a PRB group index, the PRB number may mean a PRB index, and the PRB bundle number may mean a PRB bundle index. Here, the PRB group number transmitted to the terminal by the base station does not necessarily have to be 0, but may be a number allocated specifically to the terminal (e.g., UE-specific).

As another example, the second terminal may be configured to use the parameter set f1 within the PRB group No. 2. For a terminal, the base station may schedule PRB No.2 through PRB No.3 within PRB group No.2 as a data transmission region. In this case, the base station may transmit the PRB number(s) or PRB bundle number(s) (and/or PRB group number (s)) to the terminal through physical layer signaling. Here, the PRB group number transmitted to the terminal by the base station does not necessarily have to be 2, but may be a number allocated specifically to the terminal (e.g., UE-specific). The terminal may receive information from the base station and transmit or receive data through a parameter set configured for a corresponding PRB group. As described above, when a frequency region in which a specific parameter set is used is configured restrictively and resources within the configured frequency region are allocated to a terminal, the number of PRBs for scheduling is reduced as compared with the case in which the parameter set can be used within the entire system bandwidth. Thus, signaling overhead for allowing the base station to notify the terminal of the resource allocation information in PRB units (or PRB bundle units) can be reduced. In particular, unlike the LTE system, the NR system needs to support a very wide system bandwidth (e.g., up to 400 MHz), and thus limiting a frequency region for the scheduling can be helpful when the amount of traffic to be transmitted is not large.

The exemplary embodiment shown in fig. 16 is similar to the exemplary embodiment shown in fig. 15. However, fig. 16 shows a case where bandwidths of PRB groups are defined differently for each parameter set.

That is, one PRB group may be defined by K consecutive PRBs in the frequency domain (however, K is a natural number) regardless of the parameter set. For example, in fig. 16, one PRB group includes 8 consecutive PRBs. For example, the number of PRBs included in the PRB group No.0 to which the parameter set f0 is applied is equal to the number of PRBs included in the PRB group No.1 to which the parameter set f1 is applied.

Thus, the bandwidth of the PRB group for parameter set f1 is as large as twice the bandwidth of the PRB group for parameter set f0, and the bandwidth of the PRB group for parameter set f2 is as large as four times the bandwidth of the PRB group for parameter set f 0. Fig. 16 shows PRB groups for parameter set f0 (e.g., PRB group No.0 through PRB group No. 3), PRB groups for parameter set f1 (e.g., PRB group No.0 and PRB group No. 1), and PRB groups for parameter set f2 (e.g., PRB group N.0). In this case, fig. 16 shows that the method a134 can also be applied.

For example, there are 8 PRBs in PRB group No.0 and PRB No.1 for parameter set f0, respectively, and thus these 8 PRBs may be numbered as PRB No.0 through PRB No.7. Furthermore, there are 8 PRBs in PRB group 1 for parameter set f1, and thus these 8 PRBs may be numbered as PRB No.0 through PRB No.7. The base station may allocate data transmission resources to the terminals in PRB units (or PRB bundle units), and according to method a136, the base station may signal the PRB number(s) within the PRB group or the PRB bundle number(s) (and/or PRB group number (s)) within the PRB group to the terminals.

Meanwhile, it is appreciated that frequency diversity gain in transmission of a data channel, frequency hopping may be applied to an NR PDSCH or a Physical Uplink Shared Channel (PUSCH). Here, frequency hopping means that data channels allocated to terminals are transmitted through different frequency resource regions in time. The frequency hopping of the NR PDSCH or the NR PUSCH may be performed by a predetermined pattern in PRB units (or PRB bundle units).

In addition, as described above, when a plurality of parameter sets are used within one carrier and the areas where each parameter set is used are separated for each parameter set, frequency hopping can be limited to be performed only within the resource areas where the same parameter set is configured. For example, when the parameter set is configured as shown in fig. 15, frequency hopping may be applied between the frequency resource of PRB group No.0 and the frequency resource of PRB group No. 3. That is, some or all of PRBs belonging to a data channel configured in one terminal may exist in PRB group No.0 at time t1 and PRB group No.3 at time t 2. However, according to the above rule, frequency hopping may not be applied between the frequency resource of the PRB group No.0 and the frequency resource of the PRB group No.1, and frequency hopping may not be applied between the frequency resource of the PRB group No.0 and the frequency resource of the PRB group No. 2.

As described above, PRB groups may be distinguished from FRBs. For example, FRBs are defined by the above-described methods a100 to a103, and one PRB group may correspond to one or more FRBs. According to the above definition, it may be assumed that a PRB group is a group of consecutive PRBs in the frequency domain for the allocated parameter set. In this case, according to methods a101 to a103, one PRB group may be composed of one FRB or consecutive FRBs in the frequency domain. Meanwhile, when the method a100 is used, one PRB group may also be composed of one FRB or consecutive FRBs in the frequency domain.

However, when using method a100, unlike methods a101 to a103, the boundary of the FRB in the frequency domain is not aligned with the PRB boundary, but may be located on a specific PRB. That is, the FRB may include an integer number of PRBs, and may additionally include one or two partial or partial PRBs. Thus, when using method a100, a PRB group may be defined as a complete PRB existing within one or more consecutive FRBs. That is, a PRB group may be composed of one or more FRBs. In this case, the terminal may consider only the complete PRBs within the corresponding region as a PRB group.

Fig. 17a and 17b are diagrams illustrating a method for constructing a PRB group for a terminal according to an exemplary embodiment of the present invention. In detail, fig. 17a and 17b show some frequency regions within the system bandwidth.

Fig. 17a shows a case where FRB is defined by method a 101. One FRB consists of N (however, N is a natural number) consecutive PRBs. In this case, according to the above method, the terminal may be configured with one or more FRBs as PRB groups. That is, as shown in fig. 17a, the base station may configure a first FRB as a PRB group for a first terminal (e.g., a first UE), a second FRB as a PRB group for a second terminal (e.g., a second UE), and the first and second FRBs as PRB groups for a third terminal (e.g., a third UE). Thus, a first terminal (e.g., a first UE) may consider N PRBs constituting a first FRB as a PRB group, a second terminal (e.g., a second UE) may consider N PRBs constituting a second FRB as a PRB group, and a third terminal (e.g., a third UE) may consider 2*N PRBs constituting the first FRB and the second FRB as a PRB group.

Fig. 17b shows a case where FRB is defined by the method a 100. An FRB consists of a length L [ MHz ] in the frequency domain]Is a continuous RB composition of (L is, however, a divisor of the size of the system bandwidth). In FIG. 17b, it is assumed that the first FRB includes M ₁ A complete PRB, and the second FRB includes M ₂ And the complete PRBs. In this case, according to the above method, the terminal may be configured with one or more FRBs as PRB groups. That is, as shown in fig. 17b, the base station may configure the first FRB as a PRB group for a first terminal (e.g., a first UE), configure the second FRB as a PRB group for a second terminal (e.g., a second UE), and configure the first and second FRBs as a PRB group for a third terminal (e.g., a third UE). Thus, a first terminal (e.g., a first UE) may include M in a first FRB ₁ The complete PRBs are considered to be PRB groups, and a second terminal (e.g., a second UE) may consider M included in a second FRB ₂ The complete PRBs are regarded as PRBs, and a third terminal (e.g., a third UE) may treat M included in the first and second FRBs ₁ +M ₂ +1 complete PRBs are considered as PRB groups.

Meanwhile, a plurality of PRB groups may be configured for the terminal. Multiple PRB groups may be considered for various use examples. In this case, frequency regions of a plurality of PRB groups configured for the terminal may need to overlap with each other.

Meanwhile, data transmitted to a terminal through a PDSCH may be classified into common data and terminal-specific (e.g., UE-specific) data. The common data is data that a plurality of terminals can commonly receive, and may be, for example, system information, paging messages, or the like. PDSCH for transmitting common data may be generally scheduled by common control information (e.g., DCI). That is, a plurality of terminals may receive the same DCI and may decode common data by receiving the same PDSCH corresponding thereto.

According to the above method, the base station may configure a PRB group for the terminal and allocate PDSCH or PUSCH resources using PRB indexes (or PRB numbers) defined within the PRB group. When a plurality of terminals are configured with different PRB groups, the terminals may operate in different frequency regions or may take different PRB indexes for the same PRB. Therefore, when data to be transmitted through the PDSCH or PUSCH is common data, there may be a problem in that a plurality of terminals may differently understand resource allocation information of DCI for the common PDSCH. Accordingly, it may be difficult for a base station to transmit common data to a plurality of terminals having different PRB group configurations through a common PDSCH.

In order to solve the above-described problems, PRB groups for common data transmission may be individually configured for terminals. That is, the base station may configure each PRB group for common data transmission (hereinafter, 'common PRB group') and PRB group for terminal-specific (e.g., UE-specific) data transmission (hereinafter, 'terminal-specific PRB group') for terminal. In this case, the common data may be transmitted substantially in a common PRB group. However, a method for allowing terminal-specific data to be transmitted in a common PRB group may be used. Up to one common PRB group may be configured for a terminal.

Alternatively, the common PRB group may not be defined separately, some PRBs within a specific PRB group configured for the terminal may be configured as a sub-group, and the PRB index may be defined separately for only PRBs configured as a sub-group. For example, when a terminal is configured with a PRB group consisting of 32 consecutive PRBs, some of the 32 PRBs (e.g., 16 PRBs) may be configured as a sub-group, and the PRBs configuring the sub-group may have an index from 0 to 15. When there is a common frequency region among PRB groups of terminals, subgroups may be identically configured for a plurality of terminals within the common frequency region. The base station may allocate resources of the PDSCH including the common data to the terminals using PRB indexes from 0 to 15.

Meanwhile, the region in which each parameter set is used may be defined as being used over the entire system bandwidth, without being divided in units of FRBs or PRB groups. Even in this case, the positions and boundaries between 'PRBs' for each parameter set may have a fixed nesting structure as described above. However, in this case, as shown in fig. 18, it may be necessary to define PRB numbers (e.g., PRB No.0, PRB No.1, and PRB No. 2) for each parameter set (e.g., f0, f1, and f 2) within the entire operation bandwidth or the entire system bandwidth of the terminal.

Fig. 18 is a diagram illustrating full-band PRB numbering according to an exemplary embodiment of the present invention. In fig. 18, the subcarrier spacing of the parameter set f1 is twice as large as that of the parameter set f0, and the subcarrier spacing of the parameter set f2 is four times as large as that of the parameter set f 0. The PRB bandwidth for parameter set f1 is twice as large as the PRB bandwidth for parameter set f0, and the PRB bandwidth for parameter set f2 is four times as large as the PRB bandwidth for parameter set f 0.

The base station may use the full band PRB number to schedule data for the terminal over a desired frequency region and a desired parameter set. In this case, the frequency region of the control channel may be configured based on a smaller unit than in the case where the concept of the FRB or PRB group is used. For example, a frequency region of an NR PDCCH in which the first parameter set is used may be configured using PRBs of the first parameter set as a minimum unit. Referring to fig. 18 as an example, the NR PDCCH may use a parameter set f0 and occupy frequency regions of PRB No.8 through PRB No.23 for the parameter set f 0. When NR carriers supporting multiple parameter sets are used, the uplink control channel and the downlink control channel may also be transmitted through the multiple parameter sets.

Meanwhile, in the LTE system, a concept of Virtual Resource Blocks (VRBs) is used. The VRB means a logical RB mapped to a physical contiguous PRB according to a predetermined mapping rule when the base station performs resource allocation. In this specification, the term PRB is used as meaning of RB without distinguishing concepts of PRB and VRB. If PRBs and VRBs are distinguished from each other in an NR system, the PRBs described in the present specification may mean PRBs of LTE or VRBs of LTE according to what is described in the present specification. In detail, in the context described in the present specification, if PRBs are used as units when performing resource allocation of a base station, the PRBs may be interpreted as VRBs. For example, the PRBs shown in fig. 15 and 16 may be interpreted as VRBs, and the VRBs may be mapped to PRBs having an actual physical meaning according to a predefined mapping rule.

Meanwhile, the NR system needs to support terminals having various transmission bandwidth capabilities within one carrier. That is, a terminal that can use the entire system bandwidth of the NR carrier and a terminal that can use only a portion of the system bandwidth of the NR carrier can coexist. The terminal needs to report its own transmission bandwidth capabilities to the base station. The base station receives a report of this transmission bandwidth capability in the process of establishing an RRC connection with the terminal and can set the operating frequency bandwidth of the terminal within the NR carrier based thereon. In this case, to facilitate configuration, the base station may inform the terminal of the system bandwidth and center frequency of the NR carrier. The point in time when the base station transmits information about the system bandwidth and the center frequency to the terminal may be no later than the point in time when the base station configures an operating frequency bandwidth for the terminal.

For example, the terminal may acquire the center frequency location and the system bandwidth information by receiving a downlink synchronization signal and/or broadcast information during an initial access period. In this case, the terminal may acquire the basic parameter set information together, and thus acquire the PRB grid of the basic parameter set (e.g., the total number of PRBs, the number of subcarriers per PRB, the location of the PRB boundary, etc.). In addition, if the configuration information of the FRB or the configuration information of the PRB group is defined, the terminal may find the configuration information of the FRB or the configuration information of the PRB group based on the configuration information of the PRB grid. Accordingly, the base station can configure a desired frequency region within the system bandwidth as an operation frequency bandwidth of the terminal, and the terminal can find out to which position the frequency region configured for the terminal belongs from the system perspective. The terminal may perform transmission of control information, transmission of data, transmission of pilot, time-frequency synchronization and beam management, RRM measurement and RRM reporting, CSI measurement, CSI reporting, etc. within the configured operating band. The terminal may perform a backoff operation if link performance is poor in an operating band, for example, when a Radio Link Failure (RLF) occurs. In detail, the terminal may transmit or receive signals (e.g., an initial access signal and an initial access channel) from an area outside the operating frequency area and perform synchronization and beam acquisition again or transmit PRACH again. In this case, the base station may reconfigure the operating frequency band for the terminal.

[ guard band ]

When heterogeneous parameter sets are multiplexed by FDM within one NR carrier, a guard band may be inserted in order to mitigate interference between heterogeneous parameter sets. Basically, the signal is not transmitted in the guard band, but if necessary, a narrowband signal of the NR system or a system separate from the NR system may be transmitted in the guard band. For example, the LTE NB-IoT carrier may be transmitted in a guard band.

As described above, when the parameter set is configured in the frequency domain using one or more FRBs as a basic unit, the FRBs may be references for setting guard bands. For example, guard bands may be inserted at both ends of the frequency region occupied by each FRB. Hereinafter, a method for setting a guard band between parameter sets using FRB as a basic unit within an NR carrier will be described.

First, a set of FRBs in which guard bands can be set may be defined. Method a140 and method a141 are methods of dividing FRBs into anchor FRBs and non-anchor FRBs.

In detail, the method a140 is a method that can set guard bands for all FRBs including the anchor FRB, and the method a140 provides the most flexible resource allocation method. However, the method a140 has a disadvantage in that a terminal that has used the anchor point FRB for transmission needs to be reconfigured with an effective frequency resource region for the anchor point FRB whenever the setting of the guard band for the anchor point FRB is changed.

The method a141 is a method in which a guard band can be set only for the remaining FRBs other than the anchor FRB among the FRBs, and has an advantage in that the effective resource area of the anchor FRB is not changed.

Method a140 and method a141 may be applied to both the first type NR carrier and the second type NR carrier. In the case of the second type NR carrier, as described above, there may be several anchor points FRB. In this case, guard bands may not be defined for all anchor FRBs.

Method a142 and method a143 are methods of distinguishing FRBs using the configured parameter set type.

In detail, the method a142 is a method in which a guard band can be set only for FRBs configured as a sub-parameter set. Similar to method a141, method a142 has a disadvantage in that the available resource area of the FRB configured as the base parameter set is not changed. In particular, this helps the terminal monitor the PDCCH used by the basic parameter set using the basic parameter set as the main parameter set. However, in the case of the second type NR carrier, there may be a terminal using a sub-parameter set as a main parameter set, and thus the method a142 may be applied to the first type NR carrier.

Method a143 is a method in which a guard band can be set only for FRBs configured as a base parameter set. Method a143 may effectively allocate PRBs of the sub-parameter set.

Meanwhile, when a plurality of parameter sets are multiplexed by TDM within one FRB, a guard band may be differently defined or set for each parameter set.

Meanwhile, when a guard band is set between two FRBs using two different parameter sets, the guard band may be generally set only for any one of the two FRBs. For example, the guard band may be set only for FRBs in which parameter sets having smaller subcarrier intervals are used. This is referred to as 'method a144'. As another example, the guard band may be set only for FRBs in which parameter sets having a larger subcarrier spacing are used. This is referred to as 'method a145'.

Method a144 and method a145 may be used by combining with methods a140 to a 143. For example, if it is assumed that the method a144 and the method a141 are combined with each other, the method a144 may be applied to the remaining FRBs other than the anchor FRB among the FRBs. As another example, if it is assumed that the method a144 and the method a142 are combined with each other, the method a144 is applied to set a guard band between FRBs configured as sub-parameter sets, and if one of two adjacent heterogeneous parameter sets is a base parameter set, according to the method a142, a guard band may be set for the FRBs configured as sub-parameter sets.

Fig. 19a to 19c show method a142.

Fig. 19a to 19c are diagrams illustrating a method for configuring a parameter set and a guard band based on method a140 or method a142 according to an exemplary embodiment of the present invention.

In detail, fig. 19a to 19c show multiplexing of two heterogeneous parameter sets by FDM within an NR carrier, and guard bands are set between the parameter sets.

In fig. 19a to 19c, it is assumed that the subcarrier grid for each parameter set is defined by method a110, the center frequency position of the parameter set is the same for all parameter sets, and the position of the DC subcarriers of the parameter set is the same for all parameter sets.

In fig. 19a to 19c, it is assumed that one FRB is composed of 4 basic PRBs by method a103, and that a PRB of a parameter set is composed of 12 subcarriers for all parameter sets by method a 132. The composition of the FRB shown in fig. 19a to 19c may be applied to the first type NR vector as described above.

In fig. 19a to 19c, it is assumed that a basic parameter set is applied to a first FRB and a sub parameter set is applied to a second FRB and a third FRB.

When the method a142 is used, the first FRB to which the basic parameter set is applied does not have a guard band. Thus, all 4 basic PRBs belonging to the first FRB may be used for transmission.

On the other hand, guard bands are inserted into the second and third FRBs. Since the same parameter set is applied to the second and third FRBs, the guard band may not be disposed in the direction of the boundary between the second and third FRBs, but may be inserted in opposite directions of the second and third FRBs, respectively. In fig. 19a to 19c, if the first FRB is considered as an anchor FRB, it can be interpreted that method a140 is used.

In fig. 19a, the subcarrier spacing of the first sub-parameter set is twice as large as the subcarrier spacing (e.g., Δf) of the basic parameter set, and the first sub-PRB, which is a PRB of the first sub-parameter set, consists of two basic PRBs. Thus, as shown in fig. 19a, among 8 basic PRBs belonging to the second and third FRBs, the first basic PRB may be configured as a guard band, the second to seventh basic PRBs may be configured as 3 first sub-PRBs, and the last basic PRB may be configured as a guard band.

In fig. 19b and 19c, the subcarrier spacing of the second sub-parameter set is four times as large as the subcarrier spacing (e.g., Δf) of the basic parameter set, and the second sub-PRB, which is a PRB of the second sub-parameter set, is composed of four basic PRBs. Thus, as shown in fig. 19b, among 8 basic PRBs belonging to the second and third FRBs, two first basic PRBs may be configured as a guard band, the third to sixth basic PRBs may be configured as one second sub-PRB, and the last two basic PRBs may be configured as a guard band.

Alternatively, as shown in fig. 19c, among 8 basic PRBs belonging to the second and third FRBs, the first basic PRB may be configured as a guard band, the second to seventh basic PRBs may be configured as two second sub-PRBs, and the last basic PRB may be configured as a guard band. Here, the number of basic PRBs allocated as the second sub-PRB is 6, but not a multiple of 4. Thus, the first of the two second sub-PRBs consists of four basic PRBs, while the second sub-PRB (i.e. the last second sub-PRB) consists of two (=6 and 4-th-sum) basic PRBs.

The exemplary embodiments of fig. 19a and 19b are summarized as follows. That is, if the subcarrier spacing of the basic parameter set is Δf, the size of the guard band of the FRB to which the subcarrier spacing n×Δf (however, N is a natural number) of the subcarrier set is applied may be defined as log ₂ Bandwidth of N basic PRBs. This is referred to as 'method a150'. In detail, method a150 may be summarized as follows. That is, the size of the guard band for the corresponding FRB may be defined as log based on PRBs corresponding to the parameter set configured in the FRB ₂ N PRBs. However, this method has a problem in that the guard band is set too wide when the difference between the subcarrier intervals is large.

Alternatively, the exemplary embodiments of fig. 19a and 19c are summarized as follows. That is, the size of the guard band for the FRB to which the sub-parameter set is applied may be defined to always have a fixed value. This is called "method a151". The exemplary embodiments of fig. 19a and 19c correspond to the case where the size of the guard band is defined as 1 basic PRB. When using method a151, as shown in fig. 19c, the bandwidths of particular sub-PRBs (e.g., the last sub-PRB) may be respectively smaller than those of other sub-PRBs. Alternatively, the size of the guard band for the corresponding FRB may be defined as N PRBs based on the PRBs corresponding to the parameter set configured in the FRB. This is referred to as 'method a152'. For example, N may be fixed to 1.

Meanwhile, the guard band for the FRB to which the parameter set having the subcarrier interval smaller than that of the basic parameter set is applied may be one basic PRB or one PRB for the corresponding subcarrier set. The former is referred to as 'method a153', and the latter is referred to as 'method a154'. For example, it is assumed that one PRB is composed of 12 subcarriers, and an FRB (front FRB) to which a basic parameter set having a subcarrier interval of 15kHz is applied and an FRB (rear FRB) to which a subcarrier interval of 7.5kHz is applied are adjacent to each other. According to method a153, a guard band of 180kHz (=12×15 kHz) may be inserted into the following FRB, or according to method a154, a guard band of 90kHz (=12×7.5 kHz) may be inserted into the following FRB.

Alternatively, the guard band for FRBs to which parameter sets having a subcarrier spacing smaller than that of the base parameter set are applied may be a plurality of base PRBs or a plurality of PRBs for the corresponding subcarrier sets.

Method a153 and method a154 may be used by combining with method a150 and method a 151. For example, the base parameter set and/or the sub-parameter set having a larger sub-carrier interval than that of the base parameter set may apply method a151, and the sub-parameter set having a smaller sub-carrier interval than that of the base parameter set may apply method a153 or method a154.

In the exemplary embodiment of fig. 19a to 19c, it is assumed that method a103 is applied to the case of FRB configuration. Each FRB consists of an integer number of PRBs. Therefore, in the configuration of the guard band, the methods a140 to a143 may be used, and the guard band may be configured in units of integer multiples of PRBs.

However, when the method a100 is applied to the FRB composition, it may be difficult to use the methods a140 to a143.

In detail, fig. 20a and 20b show a case where heterogeneous parameter sets coexist in one carrier by FDM.

In the exemplary embodiment of fig. 20a and 20b, the case of FRB is assumed to be defined by method a 100. Thus, each FRB is not composed of an integer number of PRBs, but subcarrier(s) excluded from PRBs may be present in each FRB. For example, there are 51 subcarriers in the first FRB shown in fig. 20a, where 48 of the 51 subcarriers are composed of four basic PRBs, and the remaining 3 subcarriers are maintained without constituting PRBs. The remaining subcarrier(s) excluded from the PRB composition may be generated at the boundary between FRBs to which different parameter sets are applied. In this case, the remaining subcarrier(s) may be used as guard bands between heterogeneous parameter sets.

In the exemplary embodiment of fig. 20a and 20b, it is assumed that the basic parameter set is configured in the first FRB, the first sub-parameter set is configured in the second FRB and the third FRB, and by the case where the method a132, the basic PRB, and the first sub-PRB are each composed of 12 subcarriers. The subcarrier spacing of the first sub-parameter set is twice as large as the subcarrier spacing (e.g., af) of the basic parameter set, and the first sub-PRB (PRB of the first sub-parameter set) consists of two basic PRBs.

In the exemplary embodiment of fig. 20a, it is assumed that the subcarrier grid is defined by method a110, the center frequency positions of the parameter sets are the same for all parameter sets, and the positions of the DC subcarriers of the parameter sets are the same for all parameter sets. 7 basic PRBs included in the frequency regions of the second and third FRBs are used as 4 first sub-PRBs. The remaining subcarriers excluded from the PRB composition are configured as guard bands. In this case, similar to the exemplary embodiment of the present invention, the number of basic PRBs in the frequency region of the second and third FRBs is not divided by 2. Thus, each of the 3 first sub-PRBs has 12 subcarriers, and the remaining 1 first sub-PRBs has 6 subcarriers. If all the sub-PRBs are configured to have the same bandwidth, the remaining 1 first sub-PRBs are not defined and the frequency region of the remaining 1 first sub-PRBs may be used as a guard band.

In the exemplary embodiment in fig. 20b, it is assumed that the subcarrier grid is defined by method a111, the frequency region of the subcarrier grid is different for the base parameter set and the subcarrier set, and the positions of the DC subcarriers are different for the base parameter set and the subcarrier set. In this case, the first sub-PRB is not defined by the base PRB and is defined independently on a separate subcarrier grid. Fig. 20b illustrates a case in which 4 first sub-PRBs are defined in the frequency region of the second FRB and the third FRB. Fig. 20b shows a case where the DC subcarrier of the first sub-parameter set is located at the center of the frequency regions of the second and third FRBs. However, if the number of carrier grid points is considered flexible, it may be difficult for the DC sub-carriers to be located at the center of the frequency regions of the second and third FRBs.

The above-described method is a method for predefining the presence or absence of a guard band, the size of the guard band, and/or the position of the guard band. Meanwhile, the guard band may be variably configured by the base station, and information about the guard band may be signaled to the terminal. In addition, one or more methods for configuring the guard band (e.g., method a140 to method a 154) may be defined in the technical specification, and the one or more methods for configuring the guard band (e.g., method a140 to method a 154) may be signaled to the terminal.

[ PDCCH resource region ]

The PDCCH of the LTE system is transmitted in full band within the active portion of the system bandwidth. Meanwhile, in the case of the NR system, one carrier needs to support a plurality of parameter sets or to have forward compatibility, and thus a PDCCH resource region needs to be limited to a specific region in the frequency domain and in some cases to a specific region in the time domain. For this purpose, a PDCCH block may be defined.

A PDCCH block is a time-frequency resource that may transmit one or more PDCCHs. The PDCCH block may consist of X FRBs and Y OFDM symbols. If one PDCCH block is composed of a plurality of FRBs, the FRBs may be contiguous or non-contiguous in the frequency domain. Alternatively, the PDCCH block may consist of Z PRBs and Y OFDM symbols. If one PDCCH block is composed of a plurality of PRBs, the PRBs may be contiguous or non-contiguous in the frequency domain.

In this case, a PDCCH search space may be defined for each PDCCH block. The PDCCH block may repeatedly occur every predetermined period within the FRB(s) occupied by the PDCCH block. For example, a PDCCH block may exist in each subframe within the corresponding FRB(s). That is, a subframe of the NR system may be defined as a period in which a PDCCH resource region occurs. In this case, the position of the OFDM symbol from which the PDCCH block starts may be the same in each subframe. Thus, the terminal may periodically monitor the PDCCH blocks, but may transmit or not transmit signals in each PDCCH block.

To reduce the PDCCH monitoring complexity of the terminal, the base station may configure a time resource region (e.g., other service transmission section) for the terminal that does not transmit the PDCCH, and the terminal may skip PDCCH monitoring in the configured section. In case of the LTE system, a PDCCH region (full-band PDCCH region) existing in each subframe may correspond to 1 PDCCH block. However, the NR carrier may have a plurality of FRBs, and thus, there may be a plurality of PDCCH blocks in the frequency domain.

Fig. 21 shows a method for setting a PDCCH block in an NR carrier.

In detail, fig. 21 shows a case where 3 PDCCH blocks (e.g., a first PDCCH block, a second PDCCH block, and a third PDCCH block) are provided among 4 FRBs (e.g., a first FRB, a second FRB, a third FRB, and a fourth FRB).

The first PDCCH block is configured in the first and second FRBs (i.e., x=2), the second PDCCH block is configured in the third FRB (i.e., x=1), and the third PDCCH block is configured in the fourth FRB (i.e., x=1).

The first PDCCH block consists of 2 consecutive OFDM symbols (i.e., y=2), the second PDCCH block consists of 3 consecutive OFDM symbols (i.e., y=3), and the third PDCCH block consists of 2 consecutive OFDM symbols (i.e., y=2).

In the exemplary embodiment of fig. 21, a case in which a first parameter set is applied to a first PDCCH block and a second parameter set is applied to a third PDCCH block is assumed. Each PDCCH block may be repeatedly set according to a predetermined period (e.g., subframe) based on time. If the OFDM symbol length of the second parameter set is shorter than the OFDM symbol length of the first parameter set, the setup period of the third PDDCH block in the time domain may be shorter than the setup period of each of the remaining PDCCH blocks.

The guard band may be inserted at both ends or one end of the frequency region occupied by the PDCCH block. In this case, the method for inserting the guard band may be equally used. In the exemplary embodiment of fig. 21, the same parameter set is applied to the first PDCCH block and the second PDCCH block, and thus the guard band is not configured between the first PDCCH block and the second PDCCH block. In the exemplary embodiment of fig. 21, heterogeneous parameter sets are applied between the second PDCCH block and the third PDCCH block, and thus guard bands are configured between the second PDCCH block and the third PDCCH block. In addition, since the exemplary embodiment of fig. 21 assumes that the method a141 is used, the second PDCCH block existing in the third FRB as the anchor FRB completely occupies the bandwidth of the third FRB without guard bands.

Fig. 22 is a diagram illustrating a relationship between a PDCCH block and a data region according to an exemplary embodiment of the present invention. In fig. 22, a slot for a PDCCH block and a data region may be a subframe.

As shown in fig. 22, within the corresponding FRB(s), the bandwidth occupied by the PDCCH block (e.g., the available bandwidth) may be the same as the bandwidth occupied by the data region. That is, the same guard band may be applied to the PDCCH region and the data region for each FRB.

Fig. 22 shows a case where a PDCCH block is configured within one FRB. The same parameter set may be applied to the PDCCH block and the data region corresponding to the PDCCH block within the same FRB. Alternatively, the same parameter set may be applied to the PDCCH block for at least the same subframe and the data region corresponding to the PDCCH block within the same FRB. However, as shown in fig. 22, the possibility that signals transmitted through other parameter sets may puncture the PDCCH region of the FRB or the data region of the FRB is not excluded. If the bandwidth occupied by the FRB or the data region in the set of FRBs is composed of a plurality of PRBs, even the PDCCH region may be composed of a plurality of PRBs according to this method. In the data region, uplink, downlink, and side link (sidelink) data may be transmitted.

On the other hand, if different parameter sets are applied to the PDCCH region and the data region within the same FRB, different guard bands may be applied to the PDCCH region and the data region. For example, the same parameter set as that for the same time region of the adjacent FRB is applied to the PDCCH region in any FRB, and thus the guard band is not set in the PDCCH region, and a different parameter set from that for the same time domain of the adjacent FRB is applied, and thus the guard band may be set in the data region.

Meanwhile, one PDCCH block may include only the anchor point(s) FRB or only FRBs that are not anchor points. This is referred to as 'method a162'. Alternatively, a PDCCH block consisting of at least anchor point(s) FRB may be defined within the NR carrier. This is referred to as 'method a163'.

If the terminal knows only the anchor FRB, methods (e.g., method a162 and method a 163) may receive downlink control information using a PDCCH block located and defined in the anchor FRB. If there are multiple anchor FRBs for one parameter set, one PDCCH block may also be defined to include all the anchor FRBs, and may also be defined for each anchor FRB. The former method can widen the bandwidth of the PDCCH block to increase the frequency diversity gain. If there is an anchor FRB for each parameter set, method A162 and method A163 may be used for each parameter set.

Meanwhile, the PDCCH blocks within the anchor FRB may be fixedly allocated regardless of whether the base station configures the PDCCH blocks. Hereinafter, the PDCCH block is referred to as a 'fixed PDCCH block' having the above-described features within the anchor point FRB. If a fixed PDCCH block is defined, the terminal may use the fixed PDCCH block to receive downlink control information when the terminal not in the RRC connected state initially accesses the NR carrier. The terminal may periodically monitor the fixed PDCCH blocks within the anchor point FRB according to a predetermined period (e.g., every subframe of the primary parameter set).

Meanwhile, if the PDCCH block is composed of only anchor point(s) FRBs, it may be difficult to secure a sufficient PDCCH search space due to bandwidth limitations. In order to solve the above-described problem, a configuration method for allowing the basic PDCCH block including the anchor FRB to further include the non-anchor FRB may be used. In this case, information of a frequency resource region for the basic PDCCH block may be signaled from the base station to the terminal in the RRC connected state. A terminal not in an RRC connected state may receive a first signal set to learn information of a frequency resource region for a basic PDCCH block before performing PDCCH monitoring.

Meanwhile, a PDCCH block in the FRB(s) that is not an anchor point may be configured for the terminal by the base station. The configuration information of the PDCCH block may be transmitted as broadcast information or RRC parameters. In detail, configuration information (e.g., resource locations and/or parameter sets) of the PDCCH block may be explicitly or implicitly signaled from the base station to the terminal. As an example of the latter implicitly signaling, the terminal may receive signaling of parameter set configuration information of FRB(s) that are not anchor, and then derive PDCCH block configuration information in the corresponding FRB(s) from a predefined relationship with the signaled parameter set configuration. For example, in the exemplary embodiment of fig. 21, if it is assumed that after the terminal receives the configuration of the first parameter set of the first and second FRBs, there is a PDCCH block using the first parameter set for each predetermined period within the first and second FRBs based on the configuration, the terminal may perform PDCCH monitoring. The location of the configured PDCCH blocks in the time domain in the FRB(s) that are not anchor may be defined by fixing the location of the PDCCH blocks in the time domain as described above.

Meanwhile, as described in the exemplary embodiment in fig. 18, a case where all parameter sets are used in a full band without distinguishing FRBs (or PRB groups) may be considered. In this case, the parameter set of the data area may be dynamically configured by the base station, and the parameter set of the control area may be fixedly configured in the terminal in advance.

In detail, fig. 23 shows a case where a first PDCCH block using a first parameter set and a second PDCCH block using a second parameter set are configured within one NR carrier. Here, the first parameter set may be used as a basic parameter set, and the first PDCCH block may be fixedly transmitted at all times. In fig. 23, the time slots for the second parameter set may be shorter than the time slots of the first parameter set.

The terminal may receive the configuration of all or some PDCCH blocks. For example, if the terminal monitors the first PDCCH block, the terminal receives downlink control information transmitted on the first PDCCH block, and thus may receive scheduling of PDSCH (e.g., first PDSCH, second PDSCH, and third PDSCH) within an operation bandwidth of the terminal. The first PDSCH is transmitted in a frequency region in which the first PDCCH block is transmitted. The second PDSCH is transmitted in a frequency region where PDCCH blocks are not configured. The third PDSCH is transmitted in the frequency region in which the second PDCCH block is transmitted.

In this case, the starting position of the PDSCH may be different according to the frequency region in which the PDSCH is scheduled. For example, the second PDSCH in the above example may be scheduled from as much time as the number of OFDM symbols occupied by the first PDCCH block earlier than the first PDSCH and the third PDSCH. As described above, the OFDM symbol position at which the data channel transmission starts may be different according to the frequency region in which the data channel is scheduled. Accordingly, if the base station schedules a data channel for a terminal through Downlink Control Information (DCI), the base station can transmit the number of OFDM symbols that become a starting position of the corresponding data channel.

Meanwhile, as described above, a PDCCH search space may be defined for each PDCCH block. In this case, a method for defining a PDCCH search space over the entire PDCCH block (the former method) and a method for defining a PDCCH search space separately for each OFDM symbol configuring the PDCCH block (the latter method) may be used. The former method is referred to as 'method a170', and the latter method is referred to as 'method a171'.

If the PDCCH block is composed of a plurality of OFDM symbols, method a170 has one wide PDCCH search space and method a171 has a plurality of narrow PDCCH search spaces.

If the method a170 is used, the terminal needs to know in advance the number of OFDM symbols occupied by the PDCCH block (i.e., the value of Y or information corresponding to the value of Y) before receiving the PDCCH block. The base station may notify the terminal of the value of Y in a similar method to the LTE system. For example, the base station may notify the terminal of the value of Y using a separate channel (hereinafter referred to as PCFICH) similar to the physical control format indicator channel (physical control format indicator channel, PCFICH).

On the other hand, even if the method a171 is used, the terminal does not know the value of Y, and may attempt PDCCH reception at least in the search space of the first OFDM symbol among the OFDM symbols belonging to the PDCCH block. In this case, therefore, the value of Y may be transmitted to the terminal by more various methods. For example, PCFICH is defined for each OFDM symbol configuring the PDCCH block, and the base station may inform the terminal whether the PDCCH block includes the next OFDM symbol through each PCFICH. In each OFDM symbol, the PCFICH may be multiplexed with the PDCCH by FDM. Alternatively, the base station may inform the terminal whether the PDCCH block includes the next OFDM symbol through the PDCCH configuring each OFDM symbol of the PDCCH block. For this purpose, a dedicated DCI format may be defined for transmitting a 1-bit payload (payload) indicating whether a PDCCH block includes the next OFDM symbol.

Alternatively, a cyclic redundancy check or scrambling identifier (scrambling identifier, ID) applied to the PDCCH may be distinguished according to whether the PDCCH block includes the next OFDM symbol. In this case, if the terminal receives the PDCCH, the terminal may perform blind decoding on the plurality of CRCs (or the plurality of scrambling identifiers) to learn whether the PDCCH block includes the next OFDM symbol.

If the above method is used, the PCFICH or DCI is not defined in the last OFDM symbol configuring the PDCCH block, or the terminal may not perform blind decoding on the last OFDM symbol configuring the PDCCH block. The length in the time domain may be different in each PDCCH block, and thus PCFICH or DCI may be defined for each PDCCH block. Meanwhile, even when the method a171 is used, the terminal may first acquire the value of Y by receiving the PCFICH before receiving the PDCCH block, similar to the method a 170.

Method a170 and method a171 may be used in combination. For example, a first OFDM symbol belonging to an OFDM symbol of a PDCCH block configures one PDCCH search space, and the remaining OFDM symbols belonging to the OFDM symbol of the PDCCH block may configure another PDCCH search space. In this case, in the case of a PDCCH block including a PDCCH common search space, the PDCCH search space on at least the first OFDM symbol may include a PDCCH common search space. In this case, the value of Y may be transmitted through the PDCCH common search space on the first OFDM symbol.

In the PDCCH block, a Reference Signal (RS) or other control channel may also be transmitted. For example, the PDCCH block may include a demodulation RS (DMRS) for decoding the PDCCH, a physical hybrid automatic repeat request indicator channel (PHICH), a PCFICH, a preamble signal, and the like.

[ first Signal set ]

As described above, the first signal set may include a downlink synchronization signal, PBCH, BRS, and/or an uplink PRACH. In this case, for a frequency resource region in which a first signal set to which a base parameter set is applied in an NR carrier is transmitted, method a180, method a181, or method a182 may be applied.

Method a180 is a method for including a center frequency of an NR carrier (i.e., a center of a subcarrier grid for a basic parameter set) in a frequency resource area where a first signal set to which the basic parameter set is applied is transmitted. According to method a180, the frequency region in which the first signal set is transmitted is fixed, and thus there may be restrictions on the parameter set configuration and the resource configuration in the corresponding frequency region. However, the reception complexity of the terminal for the first signal set is low, and only low cost terminals (e.g. LTE, MTC terminals, NR MTC terminals) capable of receiving a narrow bandwidth can use the basic parameter set to connect to the same NR carrier.

Method a181 is a method for including one or more predefined carrier grid points in a frequency resource region in which a first signal set to which a base parameter set is applied is transmitted. If method a181 is used, the set of carrier grid points includes the center frequency of the NR carrier.

Method a182 is a method for including one or more predefined carrier grid points in a frequency resource region in which a first signal set to which a base parameter set is applied is transmitted. If method a182 is used, then the set of carrier grid points does not include the center frequency of the NR carrier.

According to the method a181 and the method a182, if a frequency resource region to which the first signal set of the basic parameter set is transmitted includes a plurality of carrier grid points, a plurality of first signal sets may be transmitted in the frequency resource region. According to the method a181 and the method a182, the position of the center frequency or the position of the DC subcarrier can be transmitted by transmission of the first signal set. In this case, if all of the plurality of first signal sets include DC subcarriers, each DC subcarrier may not be included in any PRB, as described above, or may be included in any RPB of the PRBs according to method a 133.

According to method a181, the first signal set may include a DC subcarrier if the first signal set is transmitted in the center of the bandwidth, and the first signal set may not include a DC subcarrier if the first signal set is transmitted in a frequency domain other than the center of the bandwidth. In this case, when the terminal receives the synchronization signal, it is necessary to assume a case where the DC subcarrier is included in the synchronization signal and a case where the DC subcarrier is not included in the synchronization signal. Thus, the reception complexity may increase. In order to solve the above-described problem, if the first signal set is transmitted in a frequency region other than the center of the bandwidth, a method for including one subcarrier for performing virtual DC subcarrier in the synchronization signal and using the one subcarrier as a null subcarrier at the time of transmitting at least the synchronization signal may be considered. According to the method, the terminal can receive the synchronization signal using the same receiver regardless of the frequency region in which the synchronization signal is transmitted.

On the other hand, if there are a plurality of first signal sets to which the same parameter set is applied within one NR carrier, only some of the plurality of first signal sets may be used for initial access of the terminal. That is, the first signal set(s) for initial access and the first signal set(s) not for initial access may be distinguished from each other. The same parameter set may be a base parameter set. That is, the first signal set(s) for initial access and the first signal set(s) not for initial access may be transmitted by the base station through the same parameter set (e.g., the base parameter set).

In detail, a sequence (or a sequence set) of a downlink synchronization signal for initial access and a sequence (or a sequence set) of a downlink synchronization signal not for initial access may be differently defined. That is, if the base station generates and transmits a downlink synchronization signal for initial access, a sequence (or a sequence set) for initial access may be different from a sequence (or a sequence set) for a purpose different from that of the downlink synchronization signal used for initial access.

If the downlink synchronization signal is composed of PSS and SSS, the terminal may first receive PSS and then SSS, so that the above method may be sufficiently applied to PSS. That is, the PSS used for the initial access and the PSS not used for the initial access may be distinguished from each other by different sequences (or sequence sets), and the SSS used for the initial access and the SSS not used for the initial access may not be distinguished from each other. Meanwhile, if the environment of the radio channel is poor, even if the base station transmits PSS which is not used for initial access, the terminal may successfully detect the PSS and may misunderstand it as PSS for initial access. In this case, it may be helpful to apply the above method to both PSS and SSS. That is, the probability of simultaneously erroneously detecting both PSS and SSS not used for initial access is relatively lower than the probability of erroneously detecting PSS not used for initial access by the terminal.

For example, if a downlink synchronization signal (e.g., PSS) is generated through an m-sequence, the sequence length of the synchronization signal for initial access and the sequence length of the synchronization signal not for initial access are the same, but a different polynomial may be applied to the sequence generation. That is, the base station may generate a synchronization signal for initial access and a synchronization signal not for initial access using different polynomials.

Alternatively, if a downlink synchronization signal (e.g., PSS) is generated through an m-sequence, a sequence of the synchronization signal for initial access and a sequence of the synchronization signal not for initial access have the same length and are generated through the same polynomial, but different cyclic shift values may be applied to the two sequences. That is, the base station may generate a synchronization signal for initial access and a synchronization signal not for initial access using different cyclic shift values.

Alternatively, different resource mappings may be applied to the downlink synchronization signal for initial access and the downlink synchronization signal not for initial access.

Here, the different resource mappings may include different numbers of sequence mapped resource elements, different arrangements of resource elements, and/or different OFDM symbol positions. According to this method, since the terminal only takes a sequence (and/or resource map) of a synchronization signal for initial access and searches for the synchronization signal, it is highly likely that the terminal receives the synchronization signal for initial access and attempts initial access based on the received synchronization signal. On the other hand, it is unlikely that the terminal receives a synchronization signal not used for initial access and erroneously attempts initial access based on the received synchronization signal.

The number and/or frequency location of synchronization signals for initial access are fixed and the number and/or frequency location of synchronization signals not for initial access may be variable. For example, only 1 downlink synchronization signal is used for initial access of the terminal, and the 1 downlink synchronization signal for initial access of the terminal may be fixedly located at the center of the carrier bandwidth.

The synchronization signal for initial access is always fixedly transmitted, and if necessary, the synchronization signal not used for initial access may be configured for the terminal by the base station. The above method can be applied to each parameter set if the NR carrier is composed of a plurality of parameter sets.

Meanwhile, if the first signal set is composed of two or more signals (or channels), each signal (or channel) may be transmitted in a different frequency region. For example, the downlink synchronization signal and the PBCH may be multiplexed by FDM. Alternatively, the downlink synchronization signal and the PBCH may be transmitted in the same frequency band, or the PRACH may be transmitted in a different frequency band from the same. In this case, method a180 or method a182 may be applied to only some signals (or channels) configuring the first signal set. For example, the methods a180 to a182 may be applied only to the downlink synchronization signal, and the resource areas of the remaining signals (or channels) constituting the first signal set may be defined by a relationship with the resource areas for the downlink synchronization signal and may be configured by the base station.

Meanwhile, for the parameter set type for transmission of the first signal set in the first type NR carrier, the method a183 and the method a184 may be applied.

Method a183 is a method of transmitting the first signal set only through the base parameter set. According to method a183, all terminals need to use the basic parameter set (i.e. the main parameter set) for reception (and/or transmission) of the first signal set. Thus, even a terminal that uses the secondary parameter set to transmit data may have to use the base parameter set for synchronization acquisition, broadcast information acquisition, beam acquisition and beam estimation, random access, and the like. The complexity of the transceiver of the terminal may increase if the terminal supports the case of using the main parameter set and the auxiliary parameter set simultaneously in parallel.

Method a184 is a method for transmitting a first set of signals over a base set of parameters and also transmitting some or all of the first set of signals over a sub-set of parameters. In order to support initial access by the terminal using the secondary parameter set, all signals (or channels) constituting the first signal set may also have to be transmitted through the secondary parameter set. For example, if the first signal set is composed of a downlink synchronization signal, PBCH, BRS, and PRACH, all elements of the first signal set may be transmitted through the base parameter set and the sub-parameter set. On the other hand, if the initial access of the terminal can be made only through the main parameter set and the auxiliary parameter set needs to be used for time-frequency synchronization tracking and the like of the terminal in the RRC connected state, only some of the first signal set can be transmitted through the sub-parameter set. For example, if it is assumed that the first signal set is composed of a downlink synchronization signal, a PBCH, and a PRACH, the downlink synchronization signal may be transmitted through the basic parameter set and the sub-parameter set, and the PBCH and the PRACH may be transmitted through only the basic parameter set.

If method a184 is used, some or all of the first set of signals may be transmitted for all of the set of sub-parameters configured in the NR carrier, or for some of the set of sub-parameters configured in the NR carrier. The first signal set used by the base parameter set is always fixedly transmitted, and the first signal set used by the sub-parameter set may or may not be transmitted according to the configuration of the base station.

According to method a184, the terminal may receive (and/or transmit) both the first signal set and the second signal set using only one sub-parameter set, and thus method a184 may have a lower transmission/reception complexity than method a 183. On the other hand, the first signal set needs to be transmitted through different parameter sets multiple times, and thus the overhead of the control signal may increase. In addition, when a plurality of parameter sets are applied to transmission of the synchronization signal, the amount of information to be transmitted to the terminal through the synchronization signal may increase or the synchronization signal design may be complicated. Further, a case is assumed in which the first signal set is transmitted through heterogeneous parameter sets over the same period of time. If the number of transceiver units (TXRUs) of the base station is small, it may be difficult to accurately form beams in other directions for each parameter set when forming the transmit beam of the first signal set.

Meanwhile, if method a184 is used in the first type NR carrier and all the first signal sets are also transmitted through the sub-parameter sets, there is a possibility that the terminal may initially access the NR carrier using the corresponding sub-parameter set. In this case, a method in which the terminal uses the sub-parameter set to not perform initial access may be considered. That is, the first signal set(s) for initial access and the first signal set(s) not for initial access may be transmitted by the base station through different parameter sets (e.g., base parameter set, sub-parameter set). For this purpose, a distinction can be defined between synchronization signals for the basic parameter set and synchronization signals for the sub-parameter set. For example, the sequence of the synchronization signal, the resource element mapping, etc. may be defined differently for the base parameter set and the sub-parameter set. The terminal may know the discriminated elements in advance and detect only the synchronization signal corresponding to the basic parameter set to perform initial access through the basic parameter set.

On the other hand, in the case of the first type NR carrier, a method in which the terminal performs initial access using a sub-parameter set may be considered. In this case, the terminal needs to know whether the parameter set used by the terminal for initial access is a basic parameter set or a sub-parameter set. The terminal may acquire the parameter set type information by receiving a downlink signal (or channel) of the first signal set. For example, the mapping (or sequence) of the downlink synchronization signal may be defined differently for the base parameter set and the sub-parameter set, and the terminal may attempt blind detection of multiple mappings (or sequences) upon receiving the synchronization signal. As another example, the parameter set type information may be transmitted through the PBCH. When the parameter set acquired by the terminal during the initial access is a sub-parameter set, the terminal may use the sub-parameter set acquired during the initial access as a main parameter set until a configuration of other parameter sets for performing the next procedure and operation (e.g., PDCCH monitoring, data and pilot transmission/reception, CSI/RRM measurement and reporting) is received from the base station.

Meanwhile, in the case of the second type NR carrier, as described above, the terminal is allowed to perform initial access using the sub-parameter set. In this case, the terminal does not need to know whether the parameter set used by the terminal for initial access is a base parameter set or a sub-parameter set. The terminal may use the parameter set acquired during the initial access as a main parameter set until a configuration of other parameter sets for performing the next procedure and operation (e.g., PDCCH monitoring, data and pilot transmission/reception, CSI/RRM measurement and reporting) is received from the base station.

FIG. 24 is a diagram illustrating a computing device according to an exemplary embodiment of the present invention. The computing device TN100 of fig. 24 may be a base station or a terminal or the like described in the present specification. Alternatively, the computing device TN100 of FIG. 24 may be a wireless device, a communication node, a transmitter, or a receiver.

In the exemplary embodiment of fig. 24, the computing device TN100 may include at least one processor TN110, a transmitting/receiving apparatus TN120 connected to a network to perform communication, and a memory TN130. Furthermore, the computing device TN100 may also include a storage device TN140, an input interface device TN150, an output interface device 160, and the like. Components included in computing device TN100 may be connected to each other through bus TN170 to communicate with each other.

The processor TN110 may execute program commands stored in at least one of the memory TN130 and the storage device TN 140. The processor TN110 may mean a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), or a dedicated processor performing a method according to an exemplary embodiment of the present invention. The processor TN110 may be configured to implement the procedures, functions, and methods described with reference to the exemplary embodiments of the present invention. The processor TN110 may control each component of the computing device TN 100.

Memory TN130 and storage TN140 may each store various information associated with the operation of processor TN 110. The memory TN130 and the storage TN140 may each be configured by at least one of a volatile storage medium and a nonvolatile storage medium. For example, the memory TN130 may be configured by at least one of a Read Only Memory (ROM) and a Random Access Memory (RAM).

The transmitting/receiving device TN120 may transmit or receive wired signals or wireless signals. Furthermore, the computing device TN100 may have a single antenna or multiple antennas.

The exemplary embodiments of the present invention are not only realized by the apparatus and/or method as described above, but also by a program realizing functions corresponding to the configuration of the exemplary embodiments of the present invention, or a recording medium recording the program, which can be easily realized by one of ordinary skill in the art from the foregoing description of the exemplary embodiments of the present invention.

Although the exemplary embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto. That is, several modifications and variations made by those skilled in the art using the basic concept of the invention as defined in the claims fall within the scope of the invention.

Claims

1. A method of a first terminal, comprising:

receiving information on a first FRB and a parameter set for the first FRB from a base station, the first FRB including PRBs to which the parameter set is applied, the FRB representing a frequency resource block, the PRBs representing a physical resource block;

determining a PRB sub-group including one or more PRBs among PRBs included in the first FRB, the one or more PRBs within the PRB sub-group being allocated with a local index;

identifying PDSCH resources for PDSCH scheduled by a base station, the PDSCH resources being allocated within the PRB subset based on the local index, PDSCH representing a physical downlink shared channel; and

and receiving the PDSCH from the base station through the PDSCH resource.

2. The method of claim 1, wherein the first FRB is specifically configured for the first terminal and the PRB sub-groups are commonly configured for a terminal group to which the first terminal belongs.

3. The method of claim 1, wherein the PDSCH is scheduled to a terminal group to which the first terminal belongs by the same downlink control information.

4. A method according to claim 3, wherein the local index is interpreted jointly by terminals belonging to the terminal group.

5. The method of claim 1, wherein the PDSCH comprises common data for a terminal group to which the first terminal belongs.

6. The method of claim 1, wherein the PRB subset is determined based on configuration information provided by the base station.

7. A method of a base station, comprising:

transmitting information about a first FRB and a parameter set for the first FRB to a first terminal, the first FRB including PRBs to which the parameter set is applied, the FRB representing a frequency resource block, the PRBs representing a physical resource block;

transmitting configuration information to the first terminal, wherein the configuration information indicates a PRB subgroup, the PRB subgroup comprises one or more PRBs (physical resource blocks) among PRBs included in the first FRB, and local indexes are allocated to the one or more PRBs in the PRB subgroup;

allocating PDSCH resources for PDSCH scheduled to the first terminal within the PRB sub-group based on the local index, the PDSCH representing a physical downlink shared channel; and

And transmitting the PDSCH to the first terminal through the PDSCH resource.

8. The method of claim 7, wherein the first FRB is specifically configured for the first terminal and the PRB sub-groups are commonly configured for a terminal group to which the first terminal belongs.

9. The method of claim 7, wherein the PDSCH is scheduled to a terminal group to which the first terminal belongs by the same downlink control information.

10. The method of claim 9, wherein the local index is commonly interpreted by terminals belonging to the terminal group.

11. The method of claim 7, wherein the PDSCH comprises common data for a terminal group to which the first terminal belongs.