KR102480040B1 - Method for transmitting and receiving physical random access channel in communication system - Google Patents

Abstract

A PRACH transmission/reception method in a communication system is disclosed. A method of operating a terminal includes receiving a message including PRACH configuration information indicating a PRACH slot from a base station, determining a start symbol to which the PRACH is mapped from among symbols constituting the PRACH slot based on the type of the PRACH slot. and mapping the PRACH from the starting symbol in the PRACH slot. Accordingly, the performance of the communication system can be improved.

Description

Transmission and reception method of PRACH in communication system {METHOD FOR TRANSMITTING AND RECEIVING PHYSICAL RANDOM ACCESS CHANNEL IN COMMUNICATION SYSTEM}

The present invention relates to a technology for transmitting and receiving a physical random access channel (PRACH), and more particularly, to a technology for mapping a PRACH to a physical resource in a 5G communication system.

Along with the development of information and communication technology, various wireless communication technologies are being developed. Representative wireless communication technologies include long term evolution (LTE) and new radio (NR), which are defined in the 3rd generation partnership project (3GPP) standard. LTE may be one wireless communication technology among 4th generation (4G) wireless communication technologies, and NR may be one wireless communication technology among 5th generation (5G) wireless communication technologies.

For the processing of rapidly increasing wireless data after the commercialization of 4G communication systems (eg, communication systems supporting LTE), the frequency band (eg, frequency bands below 6 GHz) of the 4G communication system as well as the 4G communication system A 5G communication system (eg, a communication system supporting NR) using a frequency band higher than the frequency band (eg, a frequency band of 6 GHz or higher) is being considered. The 5G communication system may support eMBB (enhanced Mobile BroadBand), URLLC (Ultra-Reliable and Low Latency Communication), and mMTC (massive machine type communication).

In 5G communication system, numerology, slot format, frame configuration, SS/PBCH block (synchronization signal/physical broadcast channel block) setting, SS/PBCH block period, preamble The format and the like can be set in various ways, and methods for transmitting and receiving a physical random access channel (PRACH) applicable in a 5G communication system supporting various settings are required.

An object of the present invention to solve the above problems is to provide a method and apparatus for transmitting and receiving a physical random access channel (PRACH) in a communication system.

To achieve the above object, a method of operating a terminal according to a first embodiment of the present invention includes receiving a message including PRACH configuration information indicating a PRACH slot from a base station, the PRACH based on the type of the PRACH slot. Determining a starting symbol to which a PRACH is mapped from among symbols constituting a slot, mapping the PRACH from the starting symbol in the PRACH slot, and transmitting the PRACH mapped to the PRACH slot to the base station. include

Here, the PRACH configuration information may include information indicating a PRACH configuration interval and information indicating the PRACH slot located within the PRACH configuration interval.

Here, the message including the PRACH configuration information may be an SS/PBCH block.

Here, when the type of the PRACH slot is a pure UL slot composed of only UL symbols, the start symbol may be a first symbol among symbols constituting the PRACH slot.

Here, when the type of the PRACH slot is a dominant UL slot including a UL symbol, an unknown symbol, and a DL symbol, the start symbol may be a third symbol among symbols constituting the PRACH slot.

Here, when the terminal operates in the RRC idle state, the type of the PRACH slot may be estimated as a dominant UL slot.

Here, when the terminal operates in an RRC connected state, the type of the PRACH slot may be determined based on the SFI received from the base station.

Here, the PRACH may be multiplexed based on at least one of an FDM scheme and a CDM scheme in the PRACH slot.

Here, information indicating a multiplexing scheme usable in the PRACH slot and the maximum number of PRACHs multiplexed in the PRACH slot may be obtained from the message received from the base station.

To achieve the above object, a method of operating a base station according to a second embodiment of the present invention includes setting a PRACH setting period, setting a PRACH slot located within the PRACH setting period, and the PRACH setting period and the and transmitting a message including information indicating a PRACH slot.

Here, the message may further include information indicating a multiplexing scheme usable in the PRACH slot and the maximum number of PRACHs multiplexed in the PRACH slot, and the multiplexing scheme may be at least one of an FDM scheme and a CDM scheme. .

Here, among the symbols included in the PRACH slot, a start symbol to which the PRACH is mapped may be determined based on the type of the PRACH slot, and the type of the PRACH slot is a pure UL slot consisting of only UL symbols, or the UL symbol, It may be a dominant UL slot including unknown symbols and DL symbols.

Here, the message may be an SS/PBCH block.

To achieve the above object, a terminal according to a third embodiment of the present invention includes a processor and a memory in which one or more instructions executed by the processor are stored, and the one or more instructions include PRACH configuration information indicating a PRACH slot. receiving a message including a message from a base station, determining a starting symbol to which a PRACH is mapped from among symbols constituting the PRACH slot based on a type of the PRACH slot, and mapping the PRACH from the starting symbol in the PRACH slot; and transmits the PRACH mapped to the PRACH slot to the base station.

Here, the PRACH configuration information may include information indicating a PRACH configuration interval and information indicating the PRACH slot located within the PRACH configuration interval.

Here, when the type of the PRACH slot is a pure UL slot composed of only UL symbols, the start symbol may be a first symbol among symbols constituting the PRACH slot.

Here, when the type of the PRACH slot is a dominant UL slot including a UL symbol, an unknown symbol, and a DL symbol, the start symbol may be a third symbol among symbols constituting the PRACH slot.

Here, when the terminal operates in the RRC idle state, the type of the PRACH slot may be estimated as a dominant UL slot.

Here, when the terminal operates in an RRC connected state, the type of the PRACH slot may be determined based on the SFI received from the base station.

Here, the PRACH may be multiplexed based on at least one of an FDM scheme and a CDM scheme in the PRACH slot.

According to the present invention, a base station may transmit a message including physical random access channel (PRACH) configuration information to a terminal, and the terminal may map the PRACH to a specific symbol within a PRACH slot indicated by the PRACH configuration information received from the base station. can In addition, PRACH may be multiplexed based on at least one of a time division multiplexing (TDM) method, a frequency division multiplexing (FDM) method, and a code division multiplexing (CDM) method in a PRACH slot indicated by PRACH configuration information.

In addition, a channel state information-reference signal (CSI-RS) may be configured to be associated with a PRACH resource (eg, a PRACH configuration interval, a PRACH slot), and in this case, the UE based on the CSI-RS A PRACH resource may be identified, and a PRACH may be transmitted in the identified PRACH resource. Accordingly, a PRACH transmission/reception procedure can be efficiently performed in a communication system, and performance of the communication system can be improved.

1 is a conceptual diagram illustrating a first embodiment of a communication system.
2 is a block diagram showing a first embodiment of a communication node constituting a communication system.
3 is a conceptual diagram illustrating a first embodiment of an SS/PBCH block in a communication system.
4 is a conceptual diagram illustrating a first embodiment of a candidate SS/PBCH block region in a communication system.
5 is a conceptual diagram illustrating a second embodiment of a candidate SS/PBCH block region in a communication system.
6 is a conceptual diagram illustrating a third embodiment of a candidate SS/PBCH block region in a communication system.
7 is a conceptual diagram illustrating a fourth embodiment of a candidate SS/PBCH block region in a communication system.
8 is a conceptual diagram illustrating a first embodiment of a candidate SS/PBCH block area in a slot in a communication system.
9A is a conceptual diagram illustrating a first embodiment of a short sequence according to a preamble format in a communication system.
9B is a conceptual diagram illustrating a second embodiment of a short sequence according to a preamble format in a communication system.
9C is a conceptual diagram illustrating a third embodiment of a short sequence according to a preamble format in a communication system.
10 is a flowchart illustrating a first embodiment of a method for transmitting and receiving a PRACH in a communication system.
11 is a conceptual diagram illustrating a PRACH configuration interval and a PRACH slot in a communication system.

Since the present invention can make various changes and have various embodiments, specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another. For example, a first element may be termed a second element, and similarly, a second element may be termed a first element, without departing from the scope of the present invention. The terms and/or include any combination of a plurality of related recited items or any of a plurality of related recited items.

It is understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be. On the other hand, when an element is referred to as “directly connected” or “directly connected” to another element, it should be understood that no other element exists in the middle.

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in this application, they should not be interpreted in an ideal or excessively formal meaning. don't

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in more detail. In order to facilitate overall understanding in the description of the present invention, the same reference numerals are used for the same components in the drawings, and redundant descriptions of the same components are omitted.

A communication system to which embodiments according to the present invention are applied will be described. The communication system may be a 4G communication system (eg, a long-term evolution (LTE) communication system, an LTE-A communication system), a 5G communication system (eg, a new radio (NR) communication system), and the like. The 4G communication system can support communication in a frequency band of 6 GHz or less, and the 5G communication system can support communication in a frequency band of 6 GHz or more as well as a frequency band of 6 GHz or less.

Embodiments according to the present invention may be performed in a communication system supporting multi-beam operation as well as single-beam operation. In addition, the communication system to which the embodiments according to the present invention are applied is not limited to the contents described below, and the embodiments according to the present invention can be applied to various communication systems. Here, the communication system may be used in the same sense as a communication network, "LTE" may indicate "4G communication system", "LTE communication system" or "LTE-A communication system", and "NR" may indicate "5G communication system" or "NR communication system".

1 is a conceptual diagram illustrating a first embodiment of a communication system.

Referring to FIG. 1, a communication system 100 includes a plurality of communication nodes 110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, 130-6). In addition, the communication system 100 includes a core network (eg, a serving-gateway (S-GW), a packet data network (PDN)-gateway (P-GW), and a mobility management entity (MME)). can include more. When the communication system 100 is a 5G communication system (eg, a new radio (NR) system), the core network includes an access and mobility management function (AMF), a user plane function (UPF), a session management function (SMF), and the like. can include

The plurality of communication nodes 110 to 130 may support communication protocols (eg, LTE communication protocol, LTE-A communication protocol, NR communication protocol, etc.) defined in the 3rd generation partnership project (3GPP) standard. The plurality of communication nodes 110 to 130 are CDMA (code division multiple access) technology, WCDMA (wideband CDMA) technology, TDMA (time division multiple access) technology, FDMA (frequency division multiple access) technology, OFDM (orthogonal frequency division) multiplexing) technology, filtered OFDM technology, CP (cyclic prefix)-OFDM technology, DFT-s-OFDM (discrete Fourier transform-spread-OFDM) technology, OFDMA (orthogonal frequency division multiple access) technology, SC (single carrier)-FDMA technology, NOMA (Non-orthogonal Multiple Access) technology, GFDM (generalized frequency division multiplexing) technology, FBMC (filter bank multi-carrier) technology, UFMC (universal filtered multi-carrier) technology, SDMA (Space Division Multiple Access) technology, etc. can support Each of the plurality of communication nodes may have the following structure.

2 is a block diagram showing a first embodiment of a communication node constituting a communication system.

Referring to FIG. 2 , a communication node 200 may include at least one processor 210, a memory 220, and a transceiver 230 connected to a network to perform communication. In addition, the communication node 200 may further include an input interface device 240, an output interface device 250, a storage device 260, and the like. Each component included in the communication node 200 may be connected by a bus 270 to communicate with each other.

The processor 210 may execute a program command stored in at least one of the memory 220 and the storage device 260 . The processor 210 may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present invention are performed. Each of the memory 220 and the storage device 260 may include at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 220 may include at least one of a read only memory (ROM) and a random access memory (RAM).

Referring back to FIG. 1, the communication system 100 includes a plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2), a plurality of terminals 130- 1, 130-2, 130-3, 130-4, 130-5, 130-6). Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may form a macro cell. Each of the fourth base station 120-1 and the fifth base station 120-2 may form a small cell. The fourth base station 120-1, the third terminal 130-3, and the fourth terminal 130-4 may belong to the cell coverage of the first base station 110-1. The second terminal 130-2, the fourth terminal 130-4, and the fifth terminal 130-5 may belong to the cell coverage of the second base station 110-2. The fifth base station 120-2, the fourth terminal 130-4, the fifth terminal 130-5, and the sixth terminal 130-6 may belong to the cell coverage of the third base station 110-3. there is. The first terminal 130-1 may belong to the cell coverage of the fourth base station 120-1. The sixth terminal 130-6 may belong to the cell coverage of the fifth base station 120-2.

Here, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 is a NodeB (NB), an evolved NodeB (eNB), a gNB, an advanced base station (ABS), and a HR -BS (high reliability-base station), BTS (base transceiver station), radio base station, radio transceiver, access point, access node, radio access station (RAS) ), MMR-BS (mobile multihop relay-base station), RS (relay station), ARS (advanced relay station), HR-RS (high reliability-relay station), HNB (home NodeB), HeNB (home eNodeB), It may be referred to as a road side unit (RSU), a radio remote head (RRH), a transmission point (TP), a transmission and reception point (TRP), and the like.

Each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 includes user equipment (UE), terminal equipment (TE), advanced mobile station (AMS), HR-MS (high reliability-mobile station), terminal, access terminal, mobile terminal, station, subscriber station, mobile station, mobile It may be referred to as a portable subscriber station, a node, a device, an on board unit (OBU), and the like.

Meanwhile, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may operate in different frequency bands or may operate in the same frequency band. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to each other through an ideal backhaul link or a non-ideal backhaul link, and , information can be exchanged with each other through an ideal backhaul link or a non-ideal backhaul link. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to the core network through an ideal backhaul link or a non-ideal backhaul link. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 transmits a signal received from the core network to a corresponding terminal 130-1, 130-2, 130-3, and 130 -4, 130-5, 130-6), and signals received from corresponding terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6 are transmitted to the core network can be sent to

In addition, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 transmits MIMO (eg, single user (SU)-MIMO, multi-user (MU)- MIMO, massive MIMO, etc.), coordinated multipoint (CoMP) transmission, carrier aggregation (CA) transmission, transmission in an unlicensed band, direct communication between devices (device to device communication, D2D) (or , proximity services (ProSe)), Internet of Things (IoT) communication, dual connectivity (DC), etc. may be supported. Here, each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 is a base station 110-1, 110-2, 110-3, 120-1 , 120-2) and operations supported by the base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be performed. For example, the second base station 110-2 can transmit a signal to the fourth terminal 130-4 based on the SU-MIMO scheme, and the fourth terminal 130-4 uses the SU-MIMO scheme. A signal may be received from the second base station 110-2. Alternatively, the second base station 110-2 may transmit a signal to the fourth terminal 130-4 and the fifth terminal 130-5 based on the MU-MIMO scheme, and the fourth terminal 130-4 And each of the fifth terminal 130-5 may receive a signal from the second base station 110-2 by the MU-MIMO method.

Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may transmit a signal to the fourth terminal 130-4 based on the CoMP scheme, and The terminal 130-4 may receive signals from the first base station 110-1, the second base station 110-2, and the third base station 110-3 by CoMP. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 includes a terminal 130-1, 130-2, 130-3, and 130-4 belonging to its own cell coverage. , 130-5, 130-6) and a CA method. Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 controls D2D between the fourth terminal 130-4 and the fifth terminal 130-5. and each of the fourth terminal 130-4 and the fifth terminal 130-5 may perform D2D under the control of the second base station 110-2 and the third base station 110-3, respectively. .

Next, methods for transmitting and receiving a physical random access channel (PRACH) in a communication system will be described. Even when a method (for example, transmission or reception of a signal) performed in a first communication node among communication nodes is described, a second communication node corresponding thereto is described as a method performed in the first communication node and a method (eg, signal transmission or reception) For example, receiving or transmitting a signal) may be performed. That is, when the operation of the terminal is described, the corresponding base station may perform an operation corresponding to the operation of the terminal. Conversely, when the operation of the base station is described, a terminal corresponding thereto may perform an operation corresponding to the operation of the base station.

3 is a conceptual diagram illustrating a first embodiment of a synchronization signal/physical broadcast channel block (SS/PBCH block) in a communication system.

Referring to FIG. 3, an SS/PBCH block may include a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH). In addition, the SS/PBCH block may further include a demodulation reference signal (DMRS) used for demodulation of the PBCH. The length of the SS/PBCH block on the time axis may be 4 OFDM symbols. In the frequency axis, the size of each of the PSS and SSS included in the SS / PBCH block may be 12 physical resource blocks (PRBs), and the size of the PBCH included in the SS / PBCH block in the frequency axis may be 20 PRBs. However, the size of the PBCH included in the SS / PBCH block in the third symbol (eg, symbol # (n + 2)) among the four OFDM symbols occupied by the SS / PBCH block may be 2 × 4 PRBs. . Here, n may be an integer greater than or equal to 0.

The SS/PBCH block may be used for synchronization, transmission of system information, and the like. The SS/PBCH block may be transmitted by a base station in a broadcast manner. In a communication system, a transmittable position of an SS/PBCH block may be set in advance, and the transmittable position of an SS/PBCH block may be referred to as a "candidate SS/PBCH block area". Candidate SS/PBCH block areas may be set according to subcarrier spacing. The candidate SS/PBCH block area may be set to a radio frame or half frame period. The length of a radio frame may be 10 ms (millisecond) and may include two half frames. A half frame may have a length of 5 ms and may include a plurality of slots. The maximum number of candidate SS/PBCH block regions in one slot may be 2.

4 is a conceptual diagram illustrating a first embodiment of a candidate SS/PBCH block region in a communication system.

Referring to FIG. 4 , in the case of “L=4” in a communication system using a 15 kHz subcarrier interval, candidate SS/PBCH block regions may be subframes #0 to 1 within a half frame. In the case of “L=8” in a communication system in which a 15 kHz subcarrier interval is used, candidate SS/PBCH block regions may be subframes #0 to 3 within a half frame. Here, a subframe may include one slot.

5 is a conceptual diagram illustrating a second embodiment of a candidate SS/PBCH block region in a communication system.

Referring to FIG. 5 , in the case of “L=4” in a communication system using a 30 kHz subcarrier interval, candidate SS/PBCH block regions may be slots #0 to 1 in a half frame. In the case of "L=8" in a communication system in which a 30 kHz subcarrier interval is used, candidate SS/PBCH block areas may be slots #0 to 3 in a half frame. Here, a subframe may include two slots.

6 is a conceptual diagram illustrating a third embodiment of a candidate SS/PBCH block region in a communication system.

Referring to FIG. 6, in the case of “L=64” in a communication system in which a 60 kHz subcarrier interval is used, candidate SS/PBCH block regions include slots #0 to 3, #5 to 8, #10 to 13, and slots within a half frame. #15-18, #20-23, #25-28, #30-33, and #35-38. Here, a subframe may include 8 slots.

7 is a conceptual diagram illustrating a fourth embodiment of a candidate SS/PBCH block region in a communication system.

Referring to FIG. 7, in the case of “L=64” in a communication system using a 120 kHz subcarrier interval, the candidate SS/PBCH block regions include slots #0 to 3, #5 to 8, #10 to 13, and slots in a half frame. #15-18, #20-23, #25-28, #30-33, and #35-38. Here, a subframe may include 16 slots.

Meanwhile, a candidate SS/PBCH block region within a slot may be set as follows.

8 is a conceptual diagram illustrating a first embodiment of a candidate SS/PBCH block area in a slot in a communication system.

Referring to FIG. 8 , one slot may include 14 OFDM symbols, and candidate SS/PBCH block regions may include OFDM symbols #2 to 5 and #8 to 11. That is, candidate SS/PBCH block region #0 may be set in OFDM symbols #2 to 5 in the slot, and candidate SS/PBCH block region #1 may be set in OFDM symbols #8 to 11 in the slot.

는 1.25kHz 및 5kHz 중에서 하나의 값일 수 있다.Meanwhile, sequences used in the random access procedure may be classified into long sequences and short sequences. A long sequence preamble format (eg, preamble formats 0 to 3) may be defined based on Table 1 below. In Table 1, L _RA of the long sequence may be 839,

may be one of 1.25 kHz and 5 kHz.

"가 정의될 수 있고, μ는 0, 1, 2 및 3 중에서 하나의 값일 수 있다.Preamble formats of short sequences (eg, preamble formats A to C) may be defined based on Table 2 below. In Table 2, L _RA of the short sequence may be 139, and "

" can be defined, and μ can be one of 0, 1, 2 and 3.

A long sequence having a preamble format defined in Table 1 can be used in a communication system supporting a frequency band of 6 GHz or less. A short sequence having a preamble format defined in Table 2 can be used in a communication system supporting a frequency band of 6 GHz or higher as well as a frequency band of 6 GHz or lower. In particular, when a 15 kHz or 30 kHz subcarrier interval is used in a communication system supporting a frequency band of 6 GHz or less, a short sequence may be used. When a 60 kHz or 120 kHz subcarrier spacing is used in a communication system supporting a frequency band of 6 GHz or higher, a short sequence may be used. The length of the short sequence according to the preamble format may be as follows.

9A is a conceptual diagram illustrating a first embodiment of a short sequence according to a preamble format in a communication system.

Referring to FIG. 9A, 14 short sequences (P #0 to 13) having a preamble format A0 may be set in one subframe (eg, a subframe having a length of 1 ms), and one subframe 7 short sequences (P #0 to 6) having a preamble format A1 can be set. Three short sequences (P #0 to 2) having preamble format A2 may be set in one subframe, and two short sequences (P #0 to 1) having preamble format A3 may be set in one subframe. It can be.

9B is a conceptual diagram illustrating a second embodiment of a short sequence according to a preamble format in a communication system.

Referring to FIG. 9B, 7 short sequences (P #0 to 6) having a preamble format B1 may be set in one subframe (eg, a subframe having a length of 1 ms), and one subframe 3 short sequences (P #0 to 2) having a preamble format B2 can be set. Two short sequences (P #0 to 1) having preamble format B3 may be set in one subframe, and one short sequence (P #0) having preamble format B4 may be set in one subframe. there is.

9C is a conceptual diagram illustrating a third embodiment of a short sequence according to a preamble format in a communication system.

Referring to FIG. 9C, 9 short sequences (P #0 to 8) having a preamble format C0 may be set in one subframe (eg, a subframe having a length of 1 ms), and one subframe In , three short sequences (P #0 to 2) having a preamble format C2 can be set.

Meanwhile, the PRB size allocated for PRACH may vary according to the numerology (eg, PRACH subcarrier spacing (SCS)). For example, the PRB size (eg, number) allocated for PRACH may be defined based on Table 3 below. "PRACH SCS" may be a subcarrier interval applied to PRACH, "UL (uplink) SCS" may be a subcarrier interval used for uplink transmission, and "PRACH PRB size" may be a PRB allocated for PRACH. may be the number of

In addition, the minimum number and maximum number of PRBs may vary according to numerology (eg, subcarrier spacing) in a communication system. For example, the minimum number and maximum number of PRBs may be defined based on Table 4 below.

는 하향링크에서 RB(예를 들어, PRB)의 최소 개수를 지시할 수 있고,

는 하향링크에서 RB(예를 들어, PRB)의 최대 개수를 지시할 수 있다.

는 상향링크에서 RB(예를 들어, PRB)의 최소 개수를 지시할 수 있고,

는 상향링크에서 RB(예를 들어, PRB)의 최대 개수를 지시할 수 있다.

May indicate the minimum number of RBs (eg, PRBs) in downlink,

may indicate the maximum number of RBs (eg, PRBs) in downlink.

May indicate the minimum number of RBs (eg, PRBs) in uplink,

may indicate the maximum number of RBs (eg, PRBs) in uplink.

■ in the time domain PRACH to physical resources mapping method

10 is a flowchart illustrating a first embodiment of a method for transmitting and receiving a PRACH in a communication system.

Referring to FIG. 10 , a communication system may include a base station, a terminal, and the like, and each base station and terminal may be configured identically or similarly to the communication node 200 shown in FIG. 2 . The base station may generate PRACH configuration information and may transmit a message including the generated PRACH configuration information (S1001). PRACH configuration information may be transmitted through the PBCH included in the SS/PBCH block. The PRACH configuration information includes the sequence type (eg, long sequence or short sequence) used in the random access procedure, the preamble format of the sequence, the PRACH configuration period, and the resource information of the PRACH slot (eg, the time the PRACH slot is allocated). frequency resources, the number of PRACH slots, etc.), a PRACH configuration table, and the like. Alternatively, the PRACH configuration table may be preset in the base station and terminal. The PRACH configuration interval and PRACH slot may be configured as follows.

11 is a conceptual diagram illustrating a PRACH configuration interval and a PRACH slot in a communication system.

Referring to FIG. 11, a PRACH configuration interval may be configured periodically or aperiodically, and one or more PRACH slots may be configured within the PRACH configuration interval. The PRACH configuration period may be set in units of subframes, half frames, or radio frames. A PRACH slot may be used for transmission and reception of a sequence having a preamble format defined in Table 1 or Table 2. A PRACH slot may consist of one or more slots. When a PRACH slot includes a plurality of slots, corresponding slots may be continuously positioned on the time axis. The PRACH configuration interval and the PRACH slot may be configured according to numerology (eg, subcarrier interval).

The type of PRACH slot can be classified into a pure UL slot and a dominant UL slot. A pure UL slot may indicate a slot composed of only UL symbols. The dominant UL slot may indicate a slot including a UL symbol, a downlink (DL) symbol, and an unknown symbol. For example, the dominant UL slot may indicate a slot that satisfies at least one of the following conditions. Here, the type of PRACH slot may be determined based on slot format indication (SFI).

-Condition #1: "Number of UL symbols included in a slot" > "Number of DL symbols included in a slot"

- Condition #2: "Number of UL symbols included in slot" > "Number of unknown symbols included in slot"

-Condition #3: "Number of UL symbols included in a slot" > "Number of DL symbols included in a slot + Number of unknown symbols included in a slot"

Referring back to FIG. 10 , a PRACH configuration table for a long sequence may be "Table 1 + Table 5". Table 5 may indicate the length of a PRACH slot (eg, the length of an available PRACH slot) for each long sequence preamble format.

When the length of one slot is 1 ms and preamble formats 0 and 3 of Table 5 are used, the PRACH slot may consist of one slot. When the length of one slot is 1 ms and the preamble format 1 of Table 5 is used, the PRACH slot may consist of 3 slots. When the length of one slot is 1 ms and the preamble format 2 of Table 5 is used, the PRACH slot may consist of 4 slots.

A PRACH configuration table for a short sequence may be configured in the same manner as the previously described PRACH configuration table for a long sequence. For example, the PRACH configuration table for a short sequence may be “Table 2 + PRACH slot length for each preamble format”.

Meanwhile, the terminal may receive the SS/PBCH block from the base station and check information (eg, PRACH configuration information) included in the SS/PBCH block. The UE may map PRACH to physical resources based on PRACH configuration information included in the SS/PBCH block (S1002).

For example, when a short sequence is used in a random access procedure, the UE can determine the type of PRACH slot indicated by the PRACH configuration information. The type of PRACH slot may be determined based on SFI. A terminal operating in a radio resource control (RRC) connected state may receive SFI from a base station and may determine a PRACH slot type as a pure UL slot or a dominant UL slot based on the SFI. On the other hand, since a terminal operating in an RRC idle state does not receive SFI from the base station, the terminal can estimate the PRACH slot type indicated by the PRACH configuration information as a dominant UL slot.

When the PRACH slot type is determined to be a pure UL slot, the UE may map the PRACH from the first symbol in the PRACH slot indicated by the PRACH configuration information. That is, when a pure UL slot is used, the PRACH mapping start symbol may be the first symbol in the PRACH slot. Alternatively, when the PRACH slot type is determined to be the dominant UL slot, the UE may map the PRACH from a preset symbol (eg, a third symbol) within the PRACH slot indicated by the PRACH configuration information. For example, when a dominant UL slot is used, a mapping start symbol of PRACH may be a third symbol in the PRACH slot. A preset symbol in the PRACH slot may be one symbol among symbols constituting the PRACH slot except for the first symbol.

Alternatively, when a long sequence is used in the random access procedure, the UE may determine the type of the PRACH slot indicated by the PRACH configuration information as a pure UL slot. When the long sequence is transmitted only in the pure UL slot, the UE may determine the type of the PRACH slot as the pure UL slot regardless of SFI. Therefore, the UE can map the PRACH from the first symbol in the PRACH slot indicated by the PRACH configuration information.

The UE may map the PRACH to physical resources and transmit the PRACH mapped to the physical resources to the base station (S1003). The base station can receive the PRACH from the terminal by monitoring the resource indicated by the PRACH configuration information transmitted in step S1001.

The aforementioned PRACH transmission/reception method (eg, random access procedure) may be applied to a beam failure recovery request procedure, an on-demand system information request procedure, and the like.

■ P in the frequency/code domain rach to physical resources mapping method

Meanwhile, in order to support all "PRACH transmission occasions" in a communication system supporting a time division multiplexing (TDM) scheme, a PRACH configuration interval and PRACH slots (eg, the number of PRACH slots) allocated by a base station ) may not be sufficient. The PRACH transmission location may indicate an area in which PRACH transmission occurs. For example, when a long sequence having preamble formats 1 or 2 and a short sequence having preamble formats A3, B3, B4, or C2 are used, the PRACH configuration period and PRACH slot allocated by the base station are composed of the corresponding sequences. It may not be sufficient for transmission of PRACH. In this case, the PRACH may be multiplexed based on at least one of a frequency division multiplexing (FDM) scheme and a code division multiplexing (CDM) scheme.

는 FDM 방식으로 다중화 가능한 PRACH(예를 들어, PRACH를 구성하는 시퀀스)의 최대 개수를 지시할 수 있다.When a long sequence is used, PRACH multiplexing can be performed based on Table 6 below. When a short sequence is used, PRACH multiplexing can be performed based on Table 7 below.

may indicate the maximum number of PRACHs (eg, sequences constituting the PRACH) that can be multiplexed in the FDM scheme.

Each of Tables 6 and 7 may be referred to as a "PRACH configuration table". Information listed in Tables 6 and 7 (eg, a PRACH configuration table) may be preset in the base station and the terminal. Alternatively, the base station may transmit SS/PBCH blocks including the information listed in Tables 6 and 7, and the terminal may check the information listed in Tables 6 and 7 based on the SS/PBCH blocks received from the base station.

는 "PRB의 최소 개수(24)/PRACH PRB 크기(4)"일 수 있다. 즉,

는 6일 수 있다. 이와 동일한 방식으로, 표 6 및 표 7에 기재된

가 결정될 수 있다.Referring to Tables 4 and 6, when the minimum number of PRBs for 15kHz UL SCS is 24 and the PRACH PRB size is 6,

may be "minimum number of PRBs (24)/PRACH PRB size (4)". in other words,

may be 6. In the same way, as shown in Tables 6 and 7

can be determined.

는 최댓값보다 작은 값으로 설정될 수 있다. 예를 들어, 표 6에서 1.25kHz PRACH SCS가 사용되는 경우,

는 4보다 작은 값(예를 들어, 1, 2 또는 3)으로 설정될 수 있다. 이 경우, 표 6은 아래 표 8로 다시 정의될 수 있고, 표 7은 아래 표 9로 다시 정의될 수 있다.On the other hand, in order to reduce the size of the PRACH setting table (eg, Tables 6 and 7),

may be set to a value smaller than the maximum value. For example, if 1.25 kHz PRACH SCS is used in Table 6,

may be set to a value less than 4 (eg, 1, 2 or 3). In this case, Table 6 may be redefined as Table 8 below, and Table 7 may be redefined as Table 9 below.

Meanwhile, even when PRACHs are multiplexed based on the TDM scheme and the FDM scheme, the number of PRACH slots in the PRACH configuration interval may not be sufficient to transmit the PRACH. In this case, the PRACHs can be multiplexed in the CDM scheme, and the maximum number of PRACHs (eg, sequences included in the PRACH) that can be multiplexed in the CDM scheme can be predefined.

For example, if up to 32 sequences are configured for different cells and the maximum number of sequences that can be set for each cell is 64, the maximum number of PRACHs that can be multiplexed in the CDM scheme in the same time-frequency resource is 2. . Here, a cell may be an area covered by one SS/PBCH block, and the maximum number of sequences configurable for each cell may be variously set.

■ PRACH based on the setting table PRACH to physical resources mapping method

In a communication system, the number of transmissions of SS/PBCH blocks can be very large, and PRACH slots can be configured regardless of transmission of SS/PBCH blocks. When a long sequence is used, a collision problem between the PRACH slot and the SS/PBCH block may not occur because the long sequence is transmitted in a pure UL slot. On the other hand, when a short sequence is transmitted in the dominant UL slot, a collision between the PRACH slot and the SS/PBCH block may occur.

A UE operating in an RRC idle state may check an actual transmission location of an SS/PBCH block based on a bitmap included in remaining minimum system information (RMSI). A terminal operating in an RRC connected state may check an actual transmission location of an SS/PBCH block based on an RRC message or a handover command. Accordingly, the UE can check the actual transmission location of the SS/PBCH block before performing the random access procedure.

When it is determined that a long sequence is used and the PRACH slot overlaps with the actual transmission position of the SS/PBCH block, the UE transmits the PRACH (eg, including the long sequence) in the PRACH slot overlapping with the actual transmission position of the SS/PBCH block. PRACH) may not be transmitted. In this case, the UE may determine that a PRACH to be transmitted in a PRACH slot overlapping an actual transmission location is transmitted based on a multiplexing method with another PRACH in the next PRACH slot.

In addition, when a short sequence having a preamble format A3, B3 or B4 is used and it is determined that the PRACH slot overlaps with the actual transmission position of the SS/PBCH block, the UE transmits the PRACH slot overlapping with the actual transmission position of the SS/PBCH block. A PRACH (eg, a PRACH including a short sequence having a preamble format A3, B3 or B4) may not be transmitted. In this case, the UE may determine that a PRACH to be transmitted in a PRACH slot overlapping an actual transmission location is transmitted based on a multiplexing method with another PRACH in the next PRACH slot.

In addition, when a short sequence having a preamble format A0, A1, A2, B1, B2, C0 or C2 is used and it is determined that the PRACH slot overlaps with the actual transmission position of the SS/PBCH block, the UE PRACH (e.g. PRACH containing a short sequence having preamble format A0, A1, A2, B1, B2, C0 or C2) in a PRACH slot (e.g. half slot within a PRACH slot) overlapping the actual transmission position may not transmit. In this case, the UE may determine that a PRACH to be transmitted in a PRACH slot overlapping with an actual transmission location is transmitted based on a multiplexing method with another PRACH in the next PRACH slot.

For example, when a long sequence having a preamble format 0 is set in the UE, the UE can first check the type of the PRACH slot (eg, a pure UL slot or a dominant UL slot). If the PRACH slot type is a dominant UL slot, the UE may not use the corresponding PRACH slot, and may determine that the PRACH to be transmitted in the corresponding PRACH slot is transmitted based on a multiplexing method with another PRACH in another PRACH slot. .

■ CSI- RS (channel state information-reference signal) and PRACH association between resources

In order to report a beam index in a random access procedure, association between an SS/PBCH block and a PRACH resource (eg, PRACH configuration information, PRACH slot) may be required. In addition, association between CSI-RS and PRACH resources may also be required. Here, the SS/PBCH block index may be indicated by CSI-RS. Accordingly, the association between the CSI-RS and the PRACH resource may be established based on the association between the SS/PBCH block and the PRACH resource. A sequence transmitted through PRACH resources related to the SS/PBCH block may be different from a sequence transmitted through PRACH resources related to CSI-RS.

For example, the PRACH resource associated with the SS/PBCH block is the same as the PRACH resource associated with the CSI-RS, and the first sequence transmitted through the PRACH resource associated with the SS/PBCH block is transmitted through the PRACH resource associated with the CSI-RS. If different from the second sequence to be used, the first sequence may be multiplexed with the second sequence based on at least one of the TDM method, the FDM method, and the CDM method in the corresponding PRACH resource.

Meanwhile, the SS/PBCH block index may be indicated based on the following methods.

- CSI-RS may be generated based on sequences indicating different SS/PBCH blocks (or different SS/PBCH block groups). Here, the SS/PBCH block group may include one or more SS/PBCH blocks.

- CSI-RS can be generated based on sequences belonging to sequence groups indicating different SS/PBCH blocks (or different SS/PBCH block groups).

- The transmission location of the CSI-RS may indicate different SS/PBCH blocks (or different SS/PBCH block groups).

- CSI-RS may be coded/scrambled based on sequences indicating different SS/PBCH blocks (or different SS/PBCH block groups).

Here, the CSI-RS may indicate one or more SS/PBCH block indexes (or one or more SS/PBCH block group indexes). Alternatively, a plurality of CSI-RSs may indicate the same SS/PBCH block index (or the same SS/PBCH block group index). The number of PRACH resources associated with the CSI-RS may be different from the number of PRACH resources associated with the SS/PBCH block.

Therefore, based on the CSI-RS received from the base station, the UE can check the SS / PBCH block associated with the corresponding CSI-RS, can check the PRACH resource associated with the checked SS / PBCH block, and can use the PRACH in the checked PRACH resource. can transmit

The methods according to the present invention may be implemented in the form of program instructions that can be executed by various computer means and recorded on a computer readable medium. Computer readable media may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on a computer readable medium may be specially designed and configured for the present invention or may be known and usable to those skilled in computer software.

Examples of computer readable media include hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include high-level language codes that can be executed by a computer using an interpreter or the like as well as machine language codes generated by a compiler. The hardware device described above may be configured to operate with at least one software module to perform the operations of the present invention, and vice versa.

Although described with reference to the above embodiments, those skilled in the art will understand that the present invention can be variously modified and changed without departing from the spirit and scope of the present invention described in the claims below. You will be able to.

Claims (20)

As a method of operating a terminal in a communication system,
Receiving from a base station a message including PRACH configuration information including information indicating the number of physical random access channel (PRACH) slots configured in the time domain and information indicating the number of PRACHs multiplexed in the frequency domain;
determining a physical resource through which the PRACH is transmitted based on the PRACH configuration information; and
And transmitting the PRACH to the base station in the physical resource. The method of claim 1,
The PRACH configuration information further includes information indicating a PRACH configuration interval. The method of claim 1,
The message including the PRACH configuration information is an SS/PBCH block (synchronization signal/physical broadcast channel block). The method of claim 1,
When the type of the PRACH slot is a pure UL slot consisting of only uplink (UL) symbols, the starting symbol to which the PRACH is mapped is a first symbol among symbols constituting the PRACH slot. The method of claim 1,
When the type of the PRACH slot is a dominant UL slot including a UL symbol, an unknown symbol, and a downlink (DL) symbol, the starting symbol to which the PRACH is mapped is three among symbols constituting the PRACH slot. The operation method of the terminal, which is the th symbol. The method of claim 1,
When the terminal operates in a radio resource control (RRC) idle state, the type of the PRACH slot is assumed to be a dominant UL slot. The method of claim 1,
When the terminal operates in an RRC connected state, the type of the PRACH slot is determined based on a slot format indication (SFI) received from the base station. delete delete As a method of operating a base station in a communication system,
setting a physical random access channel (PRACH) slot in the time domain;
Determining the number of PRACHs multiplexed in the frequency domain; and
and transmitting a message including information indicating the number of PRACH slots configured in the time domain and information indicating the number of PRACHs multiplexed in the frequency domain. delete The method of claim 10,
Among the symbols included in the PRACH slot, a start symbol to which the PRACH is mapped is determined based on the type of the PRACH slot, and the type of the PRACH slot is a pure UL slot consisting of only uplink (UL) symbols, or A method of operating a base station, which is a dominant UL slot including the UL symbol, an unknown symbol, and a downlink (DL) symbol. The method of claim 10,
The message is an SS / PBCH block (synchronization signal / physical broadcast channel block), a method of operating a base station. As a terminal in a communication system,
processor; and
including a memory in which one or more instructions executed by the processor are stored;
The one or more commands,
Receiving a message from a base station including PRACH configuration information including information indicating the number of physical random access channel (PRACH) slots configured in the time domain and information indicating the number of PRACHs multiplexed in the frequency domain;
determining a physical resource through which the PRACH is transmitted based on the PRACH configuration information; And
A terminal configured to transmit the PRACH to the base station in the physical resource. The method of claim 14,
The PRACH configuration information further includes information indicating a PRACH configuration interval. The method of claim 14,
If the type of the PRACH slot is a pure UL slot consisting of only uplink (UL) symbols, the starting symbol to which the PRACH is mapped is a first symbol among symbols constituting the PRACH slot. The method of claim 14,
When the type of the PRACH slot is a dominant UL slot including a UL symbol, an unknown symbol, and a downlink (DL) symbol, the starting symbol to which the PRACH is mapped is three among symbols constituting the PRACH slot. The second symbol, terminal. The method of claim 14,
When the terminal operates in a radio resource control (RRC) idle state, the type of the PRACH slot is assumed to be a dominant UL slot. The method of claim 14,
When the terminal operates in an RRC connected state, the type of the PRACH slot is determined based on a slot format indication (SFI) received from the base station. delete

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