AU2018286373B2 - Method, apparatus, and system for RACH resource configuration and RACH resource selection mechanism - Google Patents

Abstract

A communication method and system for converging a 5th-generation (5G) communication system for supporting higher data rates beyond a 4th-generation (4G) system with a technology for Internet of things (IoT) are provided. The disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. The disclosure provides a method of a terminal, including receiving random access resource configuration information and quasi co-location (QCL) information from a base station, measuring a channel state information-reference signal (CSI-RS), identifying a random access resource based on the CSI-RS, the QCL information and the random access resource configuration information, and transmitting a random access preamble based on the random access resource.

Description

ADVANCE E-MAIL From the INTERNATIONAL BUREAU

PCT To:

YOON & LEE INTERNATIONAL PATENT & LAW NOTIFICATION OF THE RECORDING FIRM OF A CHANGE 3rd Fl, Ace Highend Tower-5 226, Gasan Digital 1-ro, (PCT Rule 92bis.1 and Geumcheon-gu Administrative Instructions, Section 422) Seoul08502 REPUBLIQUE DE COR E fte of mailing (day/month/year) 17 October 2019 (17.10.2019) plicant's or agents file reference IMPORTANT NOTIFICATION F201802-0031IMOTNN IFC IN

ernational application No. International filing date (day/month/year) PCT/KR2018/006687 14 June 2018 (14.06.2018)

The following indications appeared on record concerning:

the applicant the inventor E the agent E the common representative ime and Address State of Nationality State of Residence

NIL, Agiwal o. 104-1902, Telephone No. 33, Hyowon-ro, songtong-gu, Suwon-si, yeonggi-do 16543 Facsimile No. public of Korea E-mail address

The International Bureau hereby notifies the applicant that the following change has been recorded concerning:

the person X the name E the address E the nationality the residence ime and Address State of Nationality State of Residence 1WAL, Anil o. 104-1902, Telephone No. 33, Hyowon-ro, songtong-gu, Suwon-si, Facsimile No. yeonggi-do 16543 public of Korea E-mailaddress Notifications by e-mail authorized

Further observations, if necessary:

A copy of this notification has been sent to: E the International Preliminary Examining Authority the receiving Office o the designated Offices concerned the International Searching Authority the elected Offices concerned F the Authority(ies) specified for supplementary search r other:

The International Bureau of WIPO Authorized officer 34, chemin des Colombettes 12Il Geneva 20, Switzerland Vuagniaux Eric e-mail pct.teaml V arwipo.int Telephone No. +41 22 338 74 01 n PCT/IB/306 (January 2009) 1/SFHV64RKSMWRTO

METHOD, APPARATUS, AND SYSTEM FOR RACH RESOURCE CONFIGURATION AND RACH RESOURCE SELECTION MECHANISM

Technical Field

The disclosure relates to a next-generation wireless communication system and, more

particularly, to a method of configuring a random access channel (RACH) resource in a user

equipment (UE) using different reference signals (RSs) in a beamforming-based system

including one or more evolved node Bs (eNBs) and one or more UEs and a system, method, and

apparatus for a UE to select an RACH resource and to perform an RACH operation.

Background

To meet the demand for wireless data traffic having increased since deployment of

4th-generation (4G) communication systems, efforts have been made to develop an improved

5th-generation (5G) or pre-5G communication system. Therefore, the 5G or pre-5G

communication system is also called a 'beyond 4G network' or a 'post long term evolution

(LTE) system.' The 5G communication system is considered to be implemented in higher

frequency (mmWave) bands, e.g., 60GHz bands, so as to accomplish higher data rates. To

decrease propagation loss of the radio waves and increase the transmission distance, the

beamforming, massive multiple-input multiple-output (MIMO), full dimensional MIMO

(FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are

discussed in 5G communication systems. In addition, in 5G communication systems,

development for system network improvement is under way based on advanced small cells,

cloud radio access networks (RANs), ultra-dense networks, device-to-device (D2D)

communication, wireless backhaul, moving network, cooperative communication, coordinated

18057023_1 (GHMatters) P112258.AU multi-points (CoMP), reception-end interference cancellation and the like. In the 5G system, hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM) modulation

(FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation

(ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and

sparse code multiple access (SCMA) as an advanced access technology have been developed.

The Internet, which is a human centered connectivity network where humans generate

and consume information, is now evolving to the Internet of things (IoT) where distributed

entities, such as things, exchange and process information without human intervention. The

Internet of everything (IoE), which is a combination of the IoT technology and the Big Data

processing technology through connection with a cloud server, has emerged. As technology

elements, such as "sensing technology," "wired/wireless communication and network

infrastructure," "service interface technology," and "security technology" have been demanded

for IoT implementation, a sensor network, a machine-to-machine (M2M) communication,

machine type communication (MTC), and so forth have been recently researched. Such an IoT

environment may provide intelligent Internet technology services that create a new value by

collecting and analyzing data generated among connected things. IoT may be applied to a variety

of fields including a smart home, a smart building, a smart city, a smart car or connected cars, a

smart grid, health care, smart appliances and advanced medical services through convergence

and combination between existing information technology (IT) and various industrial

applications.

In line with this, various attempts have been made to apply 5G communication systems

to IoT networks. For example, technologies such as a sensor network, MTC, and M2M

18057023_1 (GHMatters) P112258.AU communication may be implemented by beamforming, MIMO, and array antennas. Application of a cloud RAN as the above-described Big Data processing technology may also be considered to be as an example of convergence between the 5G technology and the IoT technology.

In order to achieve a high data transfer rate taken into consideration in this patent, an

implementation in an ultra-high frequency (mmWave) band (e.g., 60 GHz band) is taken into

consideration in the 5G communication system. In order to reduce the path loss of a radio wave

and increase the transfer distance of a radio wave in the ultra-high frequency band, in the 5G

communication system, technologies, such as beamforming, massive MIMO, FD-MIMO, an

array antenna, analog beam-forming, and large scale antenna, are discussed.

Furthermore, in the 5G communication system, for the network improvement of the

system, technologies, such as an evolved small cell, an advanced small cell, a cloud RAN, an

ultra-dense network, D2D, a wireless backhaul, a moving network, cooperative communication,

CoMP, and received interference cancellation, are developed.

In addition, in the 5G system, hybrid FQAM and SWSC, that is, ACM schemes, and

FBMC, NOMA, and SCMA, that is, advanced access technologies, are developed.

In the communication system, a user equipment (UE) requires an initial cell selection

method and a cell reselection method in the IDLE mode, wherein the best eNB for access is

selected. Furthermore, for handover for moving to a better cell in the CONNECTED mode, the

UE needs to perform radio resource management (RRM). In order to determine a cell as

described above and for a comparison between types of cell performance, each UE needs to be

able to monitor a measured value that represents each cell or a value derived from measurement.

To this end, in the existing LTE, different eNBs reserve orthogonal resources in a shared

18057023_1 (GHMatters) P112258.AU frequency band using an omni-beam and transmit a cell-specific RS using the orthogonal resources. A UE is aware of the RS received power (RSRP) of each cell by measuring the cell-specific RS.

Furthermore, in a next-generation communication system in which beamforming is

considered, various methods for different eNBs to alternately transmit cell-and beam-specific

RSs in different resources using different beams and for a UE to derive one representative value

corresponding to a corresponding cell using a measured value of multiple beams transmitted by

one cellhave been researched.

As described above, there was research on RS transmission using one beam and RS

transmission using multiple beams, but a case where each eNB transmits two or more RSs

generated based on different signal generation rules using two or more beams having different

beam areas, coverage, and transmission periodicities has never been researched.

The above information is presented as background information only to assist with an

understanding of the disclosure. No determination has been made, and no assertion is made, as to

whether any of the above might be applicable as prior art with regard to the disclosure.

Summary of Invention

In a next-generation wireless communication system, various random access channel

(RACH) configurations for various purposes may be present. A network needs to provide RACH

information to a required user equipment (UE) in a timely manner so that the UE can efficiently

use the RACH.

Accordingly, an aspect of the disclosure provides a method for a network to allocate an

RACH resource to a UE for handover and other purposes for the efficient RACH use of the UE,

18057023_1 (GHMatters) P112258.AU and a system, method and apparatus for a UE to perform a successful RACH procedure using corresponding information efficiently.

Additional aspects will be set forth in part in the description which follows and, in part,

will be apparent from the description, or may be learned by practice of the presented

embodiments.

In accordance with an aspect of the disclosure, a method of a terminal is provided. The

method includes:

obtaining, by the terminal, random access resource configuration information and quasi

co-location (QCL) information from a base station, the random access resource configuration

information including information on a synchronization signal (SS) and information on a channel

state information-reference signal (CSI-RS);

measuring, by the terminal, a CSI-RS;

identifying, by the terminal, a random access resource based on a measurement result of

the CSI-RS, the QCL information and the random access resource configuration information;

and

transmitting, by the terminal, a random access preamble based on the random access

resource,

wherein the QCL information indicates an SS having a QCL relation with the CSI-RS.

In accordance with another aspect of the disclosure, a terminal is provided. The terminal

includes:

a transceiver configured to transmit and receive signals; and

at least one processor configured to control the terminal to:

18057023_1 (GHMatters) P112258.AU obtain random access resource configuration information and quasi co-location

(QCL) information from a base station, , the random access resource configuration information

including information on a synchronization signal (SS) and information on a channel state

information-reference signal (CSI-RS),

measure a CSI-RS,

identify a random access resource based on a measurement result of the CSI-RS,

the QCL information and the random access resource configuration information, and

transmit a random access preamble based on the random access resource,

wherein the QCL information indicates an SS having a QCL relation with the CSI-RS.

In accordance with another aspect of the disclosure, a method of a base station is

provided. The method includes:

transmitting, by the base station, random access resource configuration information and

quasi co-location (QCL) information to a terminal, the random access resource configuration

information including information on a synchronization signal (SS) and information on a channel

state information-reference signal (CSI-RS);

transmitting, by the base station, a CSI-RS to the terminal;

receiving, by the base station, a random access preamble based on a random access

resource from the terminal; and

transmitting, by the base station, a random access response to the terminal,

wherein the random access resource is determined by the terminal based on a

measurement result of the CSI-RS, the QCL information and the random access resource

configuration information, and

18057023_1 (GHMatters) P112258.AU wherein the QCL information indicates an SS having a QCL relation with the CSI-RS.

In accordance with another aspect of the disclosure, a base station is provided. The base

station includes:

a transceiver configured to transmit and receive signals; and

at least one processor configured to control the base station to:

transmit random access resource configuration information and quasi co-location

(QCL) information to a terminal, the random access resource configuration information

including information on a synchronization signal (SS) and information on a channel state

information-reference signal (CSI-RS),

transmit a CSI-RS to the terminal,

receive a random access preamble based on a random access resource from the

terminal, and

transmit a random access response to the terminal,

wherein the random access resource is determined by the terminal based on a

measurement result of the CSI-RS, the QCL information and the random access resource

configuration information, and

wherein the QCL information indicates an SS having a QCL relation with the CSI-RS.

Other aspects, advantages, and salient features of the disclosure will become apparent to

those skilled in the art from the following detailed description, which, taken in conjunction with

the annexed drawings, discloses various embodiments of the disclosure.

Advantageous Effects of Invention

One or more embodiments of the disclosure may provide a method of performing

18057023_1 (GHMatters) P112258.AU efficient random access.

Furthermore, in accordance with one embodiment of the disclosure, there are advantages

in that in a beamforming-based system including one or more eNBs and one or more UEs, the

eNB can allocate random access-related information based on different RSs to the UE and the

UE can perform mobility management operations, such as neighbor cell access and handover,

using the random access-related information.

Furthermore, in accordance with one embodiment of the disclosure, a UE recognizes

resources in which random access is used and common information, such as the time, frequency,

and direction between different RSs, and minimizes operations unnecessary to select

transmission and reception beams between an eNB and a UE, for example, an operation of

repeating a process of taking turns transmitting/receiving a beam and selecting a beam through

reception signal measurement. Accordingly, there is an advantages in that power of a UE and

time delay can be reduced.

Brief Description of Drawings

The above and other aspects, features, and advantages of certain embodiments of the

disclosure will be more apparent from the following description taken in conjunction with the

accompanying drawings, in which:

FIG. 1 is a diagram showing a relation of a reference signal (RS) and a burst set

according to an embodiment of the disclosure;

FIG. 2 is a diagram showing an RS according to an embodiment of the disclosure;

FIG. 3 is a diagram showing a synchronization signal (SS) according to an embodiment

of the disclosure;

18057023_1 (GHMatters) P112258.AU

FIGS. 4A, 4B, 4C, and 4D are diagrams showing a relation of channel state

information-reference signal (CSI-RS) and random access channel (RACH) configurations

according to an embodiment of the disclosure;

FIGS. 5A, 5B, and 5C are diagrams showing a relation of CSI-RS and RACH

configurations according to an embodiment of the disclosure;

FIGS. 6A and 6B are diagrams showing a relation of SS and RACH configurations

according to an embodiment of the disclosure;

FIG. 7A is an example of a time and frequency segmentation CSI-RS based RACH

configuration method according to an embodiment of the disclosure;

FIG. 7B is an example of a time and sequence segmentation CSI-RS based RACH

configuration method according to an embodiment of the disclosure;

FIG. 7C is an example of a time and sequence segmentation new radio-synchronization

signal (NR-SS)-based RACH configuration method according to an embodiment of the

disclosure;

FIG. 8 is a diagram showing a user equipment (UE) according to an embodiment of the

disclosure;

FIG. 9 is a diagram showing a UE operation according to an embodiment of the

disclosure; and

FIG. 10 is a diagram showing an evolved node B (eNB) according to an embodiment of

the disclosure.

Throughout the drawings, it should be noted that like reference numbers are used to

depict the same or similar elements, features, and structures.

18057023_1 (GHMatters) P112258.AU

Detailed Description of Embodiments of the Invention

The following description with reference to the accompanying drawings is provided to

assist in a comprehensive understanding of various embodiments of the disclosure as defined by

the claims and their equivalents. It includes various specific details to assist in that

understanding but these are to be regarded as merely exemplary. Accordingly, those of

ordinary skill in the art will recognize that various changes and modifications of the various

embodiments described herein can be made without departing from the scope and spirit of the

disclosure. In addition, descriptions of well-known functions and constructions may be omitted

for clarity and conciseness.

The terms and words used in the following description and claims are not limited to the

bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent

understanding of the disclosure. Accordingly, it should be apparent to those skilled in the art that

the following description of various embodiments of the disclosure is provided for illustration

purpose only and not for the purpose of limiting the disclosure as defined by the appended

claims and their equivalents.

It is to be understood that the singular forms "a," "an," and "the" include plural referents

unless the context clearly dictates otherwise. Thus, for example, reference to "a component

surface" includes reference to one or more of such surfaces.

The merits and characteristics of the disclosure and a method of achieving the merits and

characteristics will become more apparent from the embodiments described in detail in

conjunction with the accompanying drawings. However, the disclosure is not limited to the

disclosed embodiments, but may be implemented in various different ways. The embodiments

18057023_1 (GHMatters) P112258.AU are provided to only complete the disclosure and to allow those skilled in the art to fully understand the category of the disclosure. The disclosure is defined by the category of the claims.

The same reference numerals will be used to refer to the same or similar elements throughout the

drawings.

In the disclosure a user equipment (UE) may be referred to as a terminal.

The disclosure relates to a next-generation wireless communication system and, more

particularly, to a method of allocating different types of random access channels (RACHs) to a

UE in a beamforming-based system including one or more evolved node Bs (eNBs) and one or

more UEs, a method of transmitting different random access preambles using the same RACH,

and/or a system, method, and apparatus for performing mobility management operations, such as

cell access and inter-cell handover, using the transmitted different signals.

< LTE RACH configuration for handover>

In long term evolution (LTE), a network provides the following RACH configuration

information for the handover of a UE.

a. Common information (RadioResourceConfigCommon information element (IE))

A serving eNB to which a UE belongs provides the UE with RACH common

information of a target cell on which the UE will perform handover. The common information is

information which may be used by all of UEs not a given UE, and may have included the

following information.

18057023_1 (GHMatters) P112258.AU

RACH-ConfigCornon:: SEQUENCE{ preambleinfo SEQUENCE{ numberOfRA-Preambles ENUMERATED n4,n8,n12,n16,n20,n24,n28, n32,n36,n40, n44,n48,n52,n56, n60, n64

preamblesGroupAConfig SEQUENCE{ sizeOfRA-PreamblesGroupA ENUMERATED{ n4,nS,n12,n16,n20,n24,n28, n32, n36,n40, n44, n48, n52, n56, n60 }, messageSizeGroupA ENUMERATED (b56, b144, b208, b256}, messagePowerOffsetGroupB ENUMERATED { minusinfinity, dBO, dB5, dBS, dB10, dB12, dBl5, dB18

} OPTIONAL -- Need OP } powerRampingParameters PowerRampingParameters, ra-SupervisionInfo SEQUENCE{ preambleTransMax PreambleTransMax, ra-ResponseNVindowSize ENUMERATED (

sf2, sf3, sf4sf5, sf6, sf7,sfS, sfl0 }, mac-ContentionResolutionTimer ENUMERATED sf8, sf16, sf24, sf32, sf40, sf48,sf56, sf64 )

}, maxHARQ-Msg3Tx INTEGER(l..8), } PowerRampingtParameters:::= SEQUENCE{ powerRampingStep ENUMERATED (dB0, dB2,dB4, dB6}, preamblelnitialReceivedTargetPower ENUMERATED { dBm-120,dBm-l8,dBm-116, dBm-114,dBm-112,d~m-Il0, dBm-108,dBm-106,dBm-104, dBm-102,dBm-100,dBm-98,dBm-96, dBm-94, dBm-92, dBm-90 } } PreambleTransMax:::= ENUMERATED n3,n4,n5,n6,n7,nS,n10,n20,n50,n000,n200

-- ASNISTOP

18057023_1 (GHMatters) P112258.AU

Table 1

RACH-ConfigCommon field descriptions mac-ContentionResolutionTimer Timer for contention resolution inTS 36.321 [6]. Value in subframes. Valuesf8 correspondsto 8 subframes, sfl6 corresponds to 16 subframes and so on. maxHiARQ-sg3Tx ~ ~ Maximum number of Msg3 HARQ transmissions in TS 36.321 [6], used for contention based random access. Value is aninteger messagePowerOffsetGroupB Threshold for preamble selection in TS 36321 (6] Value in dB. Value minusininity corresponds to -infinity. Value dBOcorresponds to 0 dB, dB5 corresponds to 5 dB and so on messageSizeGroupA Threshold for preamble selection in TS 36.321 [6] .Value in bits. Value b56 corresponds to 56 bits,b144 corresponds to 144 bits and so on.

numberOfRA-Preambles Number of non-dedicated random access preambles in TS 36321 (6] Value is aniteger Valuen4 corresponds to 4, n8 corresponds to S and so on

powerRampingStep Power ramping factor inTS 36 321 [6]. Value in dB Value dB0 corresponds to 0 dB, dB2 corresponds to 2 dB and so on. preamblelnitiafReceivedTargetPonwer Initial preamble power in TS 36.321 [6] .Value in dBm Value dBm-120 corresponds to -120 dBm, dBm-I18 corresponds to -118 dBm and so on. preamblesGroupAConfig Provides the configuration for preamble grouping inTS 36 321 (6] If the field is not signalled, the size of the random access preambles group A [6] is equal to numberOfRA-Preambles. preambleTransMax, preambleTranm\ax-cE Maximum number of preamble transmission in TS 36.321 [6]. Valueis aninteger, Valuen3 corresponds to 3, n4 corresponds to 4 and so on

ra-ResponseWindowSize Duration of the RA response window in TS 36 321 [6]. Value in subframes Value sf2 corresponds to 2 subftames, sf3 corresponds to 3 subframes and so on. The same value applies for each serving cell (although the associated functionality is performed independently for each cell).

sizeOfRA-PreamblesGroupA Size of the random access preambles group A in TS 36,321 [6]. Value is an integer. Value n4 corresponds to 4 nS corresponds to 8 and so on.

b. Terminal-dedicated information (RACH-ConfigDedicated IE)

Furthermore, a serving eNB to which a UE belongs provides the UE with dedicated

information which may be used by only the UE in a target cell on which the UE may perform

handover. The dedicated information is information which cannot be used by different UEs other

than the corresponding UE, and may have included the following information.

18057023_1 (GHMatters) P112258.AU

RACH-ConfigDedicated:::= SEQUENCE {

ra-Preamblelndex INTEGER (0..63),

ra-PRACH-Masklndex INTEGER (0..15)

} -- ASNISTOP

Table 2 RACH-ConfigDedicated field descriptions ra-PRACH-MaskIndex Explicitly signalled PRACH Mask Index for RA Resource selection in TS 36.321

[6]. ra-PreambleIndex Explicitly signalled Random Access Preamble for RA Resource selection in TS 36.321[6].

<Different types of RACHs in 3rd generation partnership project (3GPP) NR>

In LTE, two RA methods of contention-based and contention-free have been designed to

be performed on the same single RACH. In accordance with the new radio (NR) standard, in a

next-generation wireless communication system, various types of RACHs may be defined and

used. An example of an RACH in a next-generation wireless communication system may be as

follows.

SS based contention-based RACH

The corresponding RACH is a non-UE-specific RACH which may be used for various

purposes, such as network initial access, network re-access, timing adjustment (TA) for uplink

18057023_1 (GHMattes) P112258.AU synchronization setup, and handover using a synchronization signal (SS). In general, a network may have allocated a given resource for RACH purposes in predetermined periodicity, and may transmit corresponding information through a broadcast/multicast message and also transmit the corresponding information to a UE that has accessed the network through a unicast message, if necessary.

SS based contention-free RACH

The corresponding RACH is a channel which may be limitedly used by a UE that has

already accessed a network when the UE performs a given operation previously configured by

the network, such as re-access or TA, on a corresponding serving eNB or a handover target eNB

upon performing the network re-access, TA for uplink synchronization setup or handover. In

general, a network may previously allocate a unique signal sequence to a UE for a given purpose

within the network, and may configure the unique signal so that it is used within a given RACH

resource. The contention-free RACH resource may be the same resource as a contention-based

RACH resource or may be a resource different from a contention-based RACH resource and may

be a given resource for a UE (or some of UEs or multiple UEs or all of UEs) allocated by an

eNB based on a given report of a UE. In general, the allocation of the contention-free RACH

resource and sequence may be provided in such a way as to provide an accessed UE with

common information through a broadcast message and transmit only UE-specific dedicated

information through a unicast message. A network may provide each UE with all of the pieces of

information in a unicast manner, and a network may provide information on all of UEs to all of

UEs in a broadcast/multicast form.

CSI-RS based contention-based RACH

18057023_1 (GHMatters) P112258.AU

The corresponding RACH is a non-UE-specific RACH which may be used for various

purposes, such as network initial access, network re-access, TA for uplink synchronization setup,

and handover. In general, a network may have allocated a given resource for RACH purposes in

predetermined periodicity, and may transmit corresponding information through a

broadcast/multicast message and also transmit the corresponding information to a UE that has

accessed the network through a unicast message, if necessary.

The channel state information (CSI)-reference signal (-RS) of a contention-based RACH

resource may be the same resource as an NR-SS based RACH resource or may be a resource

different from an NR-SS based RACH, and may be a given resource for a UE (or some of UEs or

multiple UEs or all of UEs) allocated by an eNB based on a given report of a UE.

In this case, the SS based RACH and the CSI-RS based RACH have a physical

difference according to whether the characteristics of a beam used by an eNB in a resource in

which an RACH is performed is based on an NR-SS transmission beam or based on a CSI-RS

transmission beam. Furthermore, the SS based RACH and the CSI-RS based RACH have a

different method for configuring a corresponding RS in a UE. Furthermore, the SS based RACH

and the CSI-RS based RACH have a difference in a method of configuring RACH information

associated with a corresponding RS.

In this case, the CSI-RS may not be an RS having the same name and may be any RS

which may be configured by an eNB.

CSI-RS based contention-free RACH

The corresponding RACH is a channel which may be limitedly used by a UE that has

already accessed a network when the UE performs a given operation previously configured by

18057023_1 (GHMatters) P112258.AU the network, such as re-access or TA, on a corresponding serving eNB or a handover target eNB upon performing the network re-access, TA for uplink synchronization setup or handover. In general, a network may have previously allocated a unique signal sequence to a UE for a given purpose within a network, and may configure the unique signal sequence so that it is used within an RACH resource.

The CSI-RS based contention-free RACH resource may be the same resource as an

NR-SS based RACH resource and/or a CSI-RS based contention-based RACH resource or may

be a resource different from an NR-SS based RACH resource and/or a CSI-RS based contention

-based RACH resource and may be a given resource for a UE (or some of UEs or multiple UEs

or all of UEs) allocated by an eNB based on a given report of a UE.

In general, the allocation of the contention-free RACH resource and sequence may be

provided in such a way as to provide common information to an accessed UE through a

broadcast message and may be provided in such a way as to provide only UE-specific dedicated

information through a unicast message. Furthermore, a network may provide each UE with all of

the pieces of information. Furthermore, a network may provide all of UEs with information on

all of UEs in a broadcast/multicast form.

In this case, the SS based RACH and the CSI-RS based RACH have a physical

difference according to whether the characteristics of a beam used by an eNB in a resource in

which an RACH is performed is based on an NR-SS transmission beam or based on a CSI-RS

transmission beam. Furthermore, the SS based RACH and the CSI-RS based RACH have a

difference in a method for configuring a corresponding RS in a UE. Furthermore, the SS based

RACH and the CSI-RS based RACH have a different method of configuring RACH information

18057023_1 (GHMatters) P112258.AU associated with a corresponding RS.

In this case, the CSI-RS may not be an RS having the same name and may be any RS

which may be configured by an eNB.

As described above, in a next-generation wireless communication system, various

RACH configurations for various purposes may be present. Such a network needs to provide a

required UE with RACH information in a timely manner so that the UE can efficiently use the

RACH.

For the efficient RACH use of a UE, an embodiment of the disclosure provides a method

for a network to allocate a RACH resource to a UE for handover and other purposes and a

system, method and apparatus for a UE to efficiently use corresponding information and to

perform a successful RACH procedure.

Method of providing RACH information

An eNB may provide RACH information available for a UE so that the UE may

selectively use the best RACH. To this end, the eNB may provide the UE with an available

RACH category and required information.

18057023_1 (GHMatters) P112258.AU

Table 3 RACH category definition verl

RACH Type RACH Category ID NR-SS based contention-based RACH 0 NR-SS based contention-free RACH I CSI-RS based contention-basedRACH 2 CSI-RS based contention-free RACH 3

Table 4 RACH category definition ver2

RACH Type RACH Category ID NR-SSbasedRACH 0 CSI-RS based RACH 1

RACH information provided to a UE may have the following form. A network may

provide each UE with each of pieces of RACH information and each RACH resource.

Alternatively, a network may divide common parameters and information different (e.g.,

resource location) based on each resource when configuring RACH resources of a given

category, may configure common parameters as a common part by grouping the common

parameters, and may configure uncommon parameters as a dedicated part by grouping the

uncommon parameters.

Alternatively, a parameter that is common within a given configuration, for example,

RACH-ConfigDedicated may be allocated as a single parameter, and uncommon parameters may

have different values in a list form.

In this case, a category identifier (ID) list included in corresponding RACH

Configuration may indicate RACH types supported by a corresponding RACH configuration. A

UE may select or check whether to transmit which random access (RA) using a corresponding

resource in a specific manner based on the RACH types. A network may allocate an RACH

18057023_1 (GHMattes) P112258.AU resource of a different category to a UE or may allocate RACH resources at the same time with respect to one or more categories.

Table 5

RACHconfigList::= SEQUENCE(SIZE(.maxRACH-configs))OFRACH-config

RACH-config:: SEQUENCE { rach-configlD INTEGER(O...maxRACHconfigD), rach-categoryD-List RACH-categorylD-List, radioResourceConfigConumon RadioResourceConfigConnon, rach-ConfigDedicated-List RACH-ConfigDedicated-List } RACH-ConfigDedicated-List::= SEQUENCE (SIZE (1..maxRACH-dedicated)) OF RACH-ConfigDedicated,

RadioResourceConfigConmon::= SEQUENCE { rach-ConfigCommon RACH-ConfigCommon, pdsch-ConfigCommon PDSCH-ConfigCommnon pusch-ConfigCommon PUSCH-ConfigConmmonr phich-Config PHICH-Config, pucch-ConfigCommon PUCCH-ConfigCommon,

RACH-ConfigConunon::= SEQUENCE preambleInfo SEQUENCE nunberofRA-Preambles ENUMERATED (n4, n. n12...} preamblesGroupACnxfig SEQUENCE{ sizeOfRA-PreamblesGroupA ENUMERATED (n4,n8, n12...} messageSizeGroupA ENUMERATED {b56,.bl44, b208, b256}, messagePowerOffsetGroupB ENUVMERATED {minusinfinity, dBO. dBS, dBS ,

OPTIONAL -- Need OP )

powerRampingParameters PowerRamnpingParameters, ra-SupervisionInfo SEQUENCE{ preambleTransMax PreambleTransMax. ra-ResponseWindowSize ENUMERATED {sf2. sf3, sf4, } mac-ContentionResolutionTimer ENUMERATED {sf sf 6. sf24...)

maxHARQ-Msg3Tx INTEGER(1..8), rach-categoryll-List RACH-categorylD-List, prach-Config-List PRACH-Config-List, prach-QCLInfo-List PRACH-QCLInfo-List, }

18057023_1(GHMatters) P112258.AU

RACH-ConfigDedicated:= SEQUENCE rach-categoryID-List RACH-categorylD-List, prach-Config-List PRACH-Config-List. ra-PreamblcIndex INTEGER (0-63), ra-PRACH-MaskIndex INTEGER (0..15) N. css . pss INTEGER (0..maxCSIpSS), N 'mMss cSIMas INTEGER (0m..axSSpCSI), N.m esIas m egTaS INTEGER (0.maxCSIpCSI), Naw INTEGER (0..maxrap), } PRACH-Config-List ::=SEQUENCE (SIZE (I..maxRACH-resourceConfigs)) OF PRACH-Config

PRACH-Config::= SEQUENCE (

rach-categoryID-List RACH-categoryID-List, rootSequencelndex INTEGER (0..837). prach-ConfigInfo PRACH-Configlnfo prach-QCLInfo PRACH-QCLInfo } PRACH-Configinfo:= SEQUENCE{ rach-eategoryID RACH-categorylD, prach-timelnfo PRACH-timeinrfo, prach-freqlnfo PRACH-freqinfo prach-periodicityInfo PRACH-periodicityinfo prach-numerologylnfo PRACH-numerologylnfo prach-hoppinginfo PRACH-hoppinglnfo prach-QCLInfo PRACH-QCLInfo } PRACH-QCLInfo::= SEQUENCE{ nr-SS-block-ID-List NR-SS-block-ID-List, nr-CSI-RS-beam-ID-List NR-CSI-RS-beam-ID-List, nr-QCL-ID-List NR-QCL-ID-List, } RACH-categoryID-List::=SEQUENCE(SIZE(1..maxracheat))OF RACH-categoryID RACH-caregoryID ::=INTEGER(0...MaxRACHCategory)

NR-CSI-RS-beam-ID-List::= SEQUENCE (SIZE (1..maxcsirs))OF NR-CSI-RS-bean-mID

18057023_1 (GHMatters) P112258.AU

Table 6

RACH-categoryID Categories (NR-SS based Contention-based, NR-SS based contention free, CSI-RS based Contention based, CSI-RS based contention free, etc.)to which a corresponding RACH belongs

maxRACH-dedicated A maximumnumber of dedicated RACH allocations that may be configured

PRACH-timelnfo Time information of a PRACH resource. The following information may be included: prachConfigtimeIndex (= prach-ConfigIndex in LTE) which is the table mapping of fixed frames associated with index, time offset from Radio frame boundary, time offset from a fixed SFN reference, time offset from a NR-SS(PSS/SSS.PBCH) boundary, time offset from a the CSI-RS boundary,

PRACH-freqInfo Frequency information ofa PRACH resource. The following information: prach-ConfigfreqIndex which is the table mapping of fixed frequency subarriers associated with index frequency offset from reference frequency derived from NR-SS (center frequency, min. center frequency, max. center frequency..) frequency offset from reference frequency derived from the CSI-RS (center frequency, mia center frequencymax. center frequency..),

PRACH-periodicityInfo Periodicity informationofPRACH resource. The following information may be included: Integer periodicity of the same PRACH channel in terms of # of subframes. time (ms, us), 4# of symbols # of hybrid automatic repeat request (HARQ) time to trigger (TT or any other time unit used in the system.

18057023_1 (GHMatters) P112258.AU

PRACH-numerologyInfo Numerology infonnation in which a PRACH resource is transmitted. The following information may be included: Numerology ID, Sub carrier spacing, mini slotID/order/ratio,

PRACH-hoppinginfo Coverage level specific frequency hopping configurationforPRACH,

PRACH-QCLInfo An RS different from an RS in which a PRACHresource is transmitted or QCL association infonnation that may have a bean association with a different resource A UE may identify whether which eNB transmission resource (NR-SS, CSI-RS. PRACH, PDCCH or PDSCH)may be received through which UE beam based on corresponding information. The corresponding information may include the following information QCLed NR-SS ID, QCLed the CSI-RS ID, QCLed subframe;#, QCLed radio frane #,QCLed SFN QCLed NR-SS beam ID. QCLed the CSI-RS beam ID, QCLed UE beam ID,.

ra-PRACH-MaskIndex Explicitly signalled PRACH Mask Index for RA Resource selection in TS 38.321.

ra-PreanibleIndex Explicitly signalled Random Access Preamble for RA Resource selection in TS 38.32L This could be replaced with a list of ra-PreambleIndex. such as ra-PreambleIndex::=SEQUENCE(SIZE(1 maxrachat))OF RACH-categoryID

Multiple configurations, such as an unnecessarily redundant parameter and list, are

included in the embodiment modified in the table. In the practical operation of the standard or

the network, only parameters that belong to the redundant parameters and that are important and

suitable for desired purposes may be selected and implemented. Alternatively, a network may

divide a dedicated physical RACH (PRACH) configuration into an NR-SS and a CSI-RS as

follows and allocate them.

18057023_1 (GHMatters) P112258.AU

Table 7

RACH-ConfigDedicated-SS ::=SEQUENCE { rach-categoryID-List RACH-categoryID-List, prach-Config-List PRACH-Config-List, ra-PreambleIndex INTEGER (0.63), ra-PRACH-MaskIndex INTEGER (0..15), Nnum CSI-RS pe NR-SS INTEGER (0..maxCSIpSS), N..NR-SS pa CSI-XS INTEGER (0..maxSSpCSI), Naum CSI-RS esi-as INTEGER (0..maxCSIpCSI), NRAP INTEGER (0..maxrap),

RACH-ConfigDedicated-CSI-RS ::=SEQUENCE{ rach-categoryID-List RACH-categoryID-List, prach-Config-List PRACH-Config-List, ra-PreambleIndex INTEGER (0..63), ra-PRACH-MaskIndex INTEGER (0.15), Num CSI-RS per NR-SS INTEGER (O..maxCSIpSS), Nnum NR-SS per csi-as INTEGER (0..maxSSpCSI), Nnum CSI-RS per CSI-RS INTEGER (0.maxCSIpCSI), NRAP INTEGER (0..maxrap),

An eNB may selectively transmit only some of the RACH information depending on an

operation of a given UE's condition. In general, a UE selects only one RACH transmission

method at a time and performs handover. Although all of pieces of RACH resource information

is provided to a UE as described above, only one RACH transmission method and resource may

be actually used like an RACH resource that first reaches an available period, for example. If

such a case is taken into consideration, to provide a UE with all of pieces of RACH resource

information all the time as described above may cause unnecessary transmission overhead.

In an embodiment of the disclosure, quasi co-location (QCL) indicates that given

characteristics are the same between two different signals. Time QCL indicates that time

synchronization is the same (or almost similar), frequency QCL indicates that frequency

synchronization is the same (or almost similar), and spatial QCL indicates that

18057023_1 (GHMatters) P112258.AU transmission/reception directions are similar. In two different signals having the same time, frequency and spatial QCL, it may be assumed that the transmission/reception stages of the corresponding signals are present in the same physical location and use directional antenna configurations and beams having the same direction. In an embodiment of the disclosure, QCL is defined as a correlation between signals that may be transmitted/received using such an identical beam.

In an embodiment of the disclosure, a UE may measure RSs transmitted by eNBs

through a beam sweeping configuration in which the eNBs take turns transmitting a beam using

different antenna configurations. A RS that is taken into consideration includes a SS and a

CSI-RS, but may not be essentially limited thereto.

The RACH configuration may be included in a handover request acknowledgement (or

handover acknowledgement) message that is transmitted from a handover target cell to the

serving cell of a UE as a response to a handover request for the successful handover of the UE or

may be included in a handover command (or mobilityControllnfo or

RRCConnectionReconfiguration) message transmitted from a serving cell to a UE in order to

perform handover.

FIG. 1 is a diagram showing a relation of an RS and a burst set according to an

embodiment of the disclosure.

Referring to FIG. 1, in one embodiment of the disclosure, as in FIG. 1, an RS may have

included a burst set transmitted in given periodicity, may have included bursts transmitted

continuously or at given intervals within a corresponding burst set, and may have included

blocks transmitted continuously or at given intervals within a corresponding burst. In this case,

18057023_1 (GHMatters) P112258.AU beamformed signal information using different antenna configurations or the same antenna configuration may be transmitted in the blocks. As described above, a unit of beam sweeping in which an RS is transmitted while changing a beam as described above may be a block, burst or burst set.

FIG. 2 is a diagram showing an RS according to an embodiment of the disclosure.

Referring to FIG. 2, different types of RSs may be transmitted on different time and

frequency resources in independent, different periodicity without a correlation. FIG. 2 shows one

embodiment in which RSs are transmitted in the same frequency band on different time

resources with different periodicity.

FIG. 3 is a diagram showing an SS according to an embodiment of the disclosure.

Referring to FIG. 3, in one embodiment of the disclosure, an NR-SS may have included

a burst set transmitted in given periodicity, may have included bursts transmitted continuously or

at given intervals within a corresponding burst set, and may have included blocks transmitted

continuously or at given intervals within a corresponding burst, as in FIG. 1. In this case, the

blocks may transmit beamformed signal information using different antenna configurations or

the same antenna configurations. A unit of beam sweeping in which an RS is transmitted while

such a beam is changed may be a block, burst or burst set. An eNB may configure the interval in

which the eNB receives an uplink random access preamble from a UE while sweeping the uplink

random access preamble using a beam in which an NR-SS is transmitted as described above. In

an embodiment of the disclosure, such a configuration interval is defined as an NR-SS based

RACH. Corresponding resources may have a close associative relation with the transmission

beam of an NR-SS.

18057023_1 (GHMatters) P112258.AU

In order to notify a UE of a beam association between the NR-SS and the NR-SS based

RACH transmission resource as a QCL correlation, a network may include NR-SS beam

information (e.g., a beam ID, resource location, time/frequency offset, beam sequence, and QCL

ID) having a QCL correlation within a corresponding RACH resource in NR-SS based RACH

configuration information. In this case, the UE is aware of the received eNB beam information to

be used by an eNB in the corresponding RACH resource using corresponding information. When

the UE transmits an RA preamble using the corresponding RACH resource, the best UE

transmission beam information may also be checked.

Referring to FIG. 3, an eNB may configure NR-SS based RACH resources, may include

NR-SS-related QCL information indicating whether an eNB beam in which each RACH

resource will be received has a correlation with a given NR-SS transmission beam in an RACH

resource configuration, and may transmit the RACH resource configuration. A UE for which

NR-SS based RACH resources including the NR-SS-related QCL information have been

configured may receive NR-SS based RACH resources that belong to the NR-SS based RACH

resources and may be transmitted by the UE and received by the eNB based on the downlink

measurement results of NR-SSs having a QCL relation. Furthermore, the UE may previously

select a UE transmission beam in which an RA preamble will be transmitted in the selected

NR-SS based RACH resources based on the downlink measurement results of the NR-SSs

having a QCL relation, and may directly transmit an RA preamble using an optimal beam

without procedures, such as a separate NR-SS measurement and UE beam sweeping.

FIGS. 4A, 4B, 4C, and 4D are diagrams showing a relation of CSI-RS and RACH

configurations according to an embodiment of the disclosure.

18057023_1 (GHMatters) P112258.AU

Referring to FIGS. 4A to 4D, an eNB configures CSI-RS based RACH resources, may

include CSI-RS-related QCL information indicating whether an eNB beam in which each RACH

resource will be received has a correlation with which CSI-RS transmission beam in an RACH

resource configuration, and may transmit the RACH resource configuration. A UE for which the

CSI-RS based RACH resources including the CSI-RS-related QCL information have been

configured may select CSI-RS based RACH resources that belong to the CSI-RS based RACH

resources and that may be transmitted by the UE and received by the eNB based on the downlink

measurement results of CSI-RSs having a QCL relation. Furthermore, the UE may previously

select a UE transmission beam in which an RA preamble will be transmitted in the selected

CSI-RS based RACH resources based on the downlink measurement results of the CSI-RSs

having a QCL relation, and may directly transmit the RA preamble using an optimal beam

without procedures, such as separate CSI-RS measurement and UE beam sweeping.

In a more detailed embodiment, referring to FIG. 4A, a CSI-RS based RACH resource

has the same beam sweeping pattern (i.e., base station CSI-RS transmission beam sweeping =

RACH reception beam sweeping) as a CSI-RS, and may be configured orthogonally with respect

to a time axis. In this case, the CSI-RS based RACH resource may be configured through

mapping for a CSI-RS orthogonally present with respect to the time axis.

In another embodiment, referring to FIG. 4B, a CSI-RS based RACH resource has the

same beam sweeping pattern (i.e., base station CSI-RS transmission beam sweeping = RACH

reception beam sweeping) as a CSI-RS, and may be configured through mapping for a CSI-RS

based RACH resource orthogonally present with respect to a time axis and a corresponding

CSI-RS resource orthogonally present with respect to time and frequency axes. In this case, the

18057023_1 (GHMatters) P112258.AU

CSI-RS based RACH resource may be configured through mapping for a CSI-RS orthogonally

present with respect to the time and frequency axis.

In another embodiment, referring to FIG. 4C, a CSI-RS based RACH resource has the

same beam sweeping pattern (i.e., base station CSI-RS transmission beam sweeping = RACH

reception beam sweeping) as a CSI-RS, and may be configured through mapping for a CSI-RS

based RACH resource orthogonally present with respect to time and frequency axes and a

corresponding CSI-RS resource orthogonally present with respect to the time and frequency axes.

In this case, the CSI-RS based RACH resource may be configured through mapping for a

CSI-RS having the same beam sweeping pattern (i.e., CSI-RS a transmission beam sweeping=

RACH reception beam sweeping).

In another embodiment, referring to FIG. 4D, a CSI-RS based RACH resource has the

same beam sweeping pattern (i.e., base station CSI-RS transmission beam sweeping = RACH

reception beam sweeping) as a CSI-RS, and may be configured through mapping for a CSI-RS

based RACH resource orthogonally present with respect to a time axis and a corresponding

CSI-RS resource orthogonally present with respect to the time and frequency axes. In this case,

the CSI-RS based RACH resource may be configured through mapping for a CSI-RS based

RACH resource orthogonally present with respect to the time and frequency axes and a

corresponding CSI-RS.

In this case, the CSI-RS based RACH resource may have a QCL relation with one or

more CSI-RSs. In such a case, a UE may classify transmitted preamble sequences and notify an

eNB to identify the best CSI-RS.

The eNB may notify the UE of the correlation between the preamble sequence and the

18057023_1 (GHMatters) P112258.AU

CSI-RS using the following method or the eNB and the UE may implicitly be aware of the

correlation. For the sake of convenience, a CSI-RS is identified as RS2, and an NR-SS is

identified as RS1. In this case, the RS1 and RS2 may be an NR-SS, a CSI-RS or an RS

transmitted by an eNB.

Notification or recognition method in table form

The determination of which preamble sequence (or a set of preamble sequences) is

mapped to RS2 may be announced in a table form using a UE-specific

unicast/multicast/broadcast radio resource control (RRC)/media access control (MAC)/physical

layer (PHY) message.

Alternatively, a UE and an eNB may each store the corresponding table when the device

is fabricated. In such a case, various tables are stored by the UE and the eNB. The UE and the

eNB may be notified of which table will be referred by an indicator, such as a number

identifying the corresponding table, is fabricated and the indicator is exchanged or announced

using a UE-specific unicast/multicast/broadcast RRC/MAC/PHY message. The UE and the eNB

may select a preamble sequence using the corresponding table.

Table 8 Example 1: RS2 and preamble sequence (or set of preamble sequences) mapping

RS2 ID Set of Random Access Preamble (RAP) sequence index QCLed (or RS2 beam ID) RSIID 0 (o... RAP} 0 1 {RA-r1 ... RAP2) 0

CIDI (RAPcID-i --RAPcms,-s) 0 CIDI-1 (RAPcmjI -1RAPcm.j) I

CIDK (RAPcM-1 ... RAPcmI)

Max-RS2-ID K'

The parameters may include a series of rules or may be values randomly determined by

an eNB or a UE according to circumstances and a transmission/reception form.

18057023_1 (GHMattes) P112258.AU

Furthermore, if a rule is present, the following table may be written based on the rule

and transmitted.

Table 9 Example 2: RS2 ID and preamble sequence (or set of preamble sequences) mapping RS2 index within Set of Random Access Preamble sequence QCLed QCLed RS2s of RSI index RS1 ID 0 {0 ... Nma m/Nnum rsperw rs1} 0 1 (Nmax /Nmn rse p r 0 .. 2*Nax w/Nnum rs2 me rsrl1)

Nn=m r Wer1 {Nm. w-Nm RP/Nm r m,,+1 0 . . Nma N RAP -1} 0 {0 ..Nax w/Nnn= rs- persi-rl} 1 {NmaxR A/Num rs2 1rs1 2*Nma w/Nnum ra w rl}

Nn rpe r {Nmax w-Nmax /Nanum rsI+1 1

Nam ~Na rs -1}l-I

The RS2 index configured by listing Nnumrs2_per-rs1 RS2s that belong to RS2s

having a QCL relation with an RS1 other than an RS2 unique ID announced and transmitted by a

network and that has an index from a UE having an ID of the smallest value as 0.

18057023_1 (GHMattes) P112258.AU

Table 10 Example 3: RS2 ID and preamble sequence (or a set of preamble sequences) mapping RS2 index within Set of Random Access Preamble sequence QCLed QCLed RS2s of RS1 index RS1 index 0 {0 ... N6N 2 -l} 1 0 1 {N= X-an .2 In a 0

Ns= 2 i - {N. -N. iAPNa .2 .1 0 N= W -1} NaM %2De a {0 ... N= RNa. -2 . si-1} 1 Nam s 2 e a1+1 {Na RNnu=s2 ve si 1 . 2*N= RNm f2 w f-1}

2*Nt= 2 {N= Ap-N x. pNz z2 e s+1 1 .N. RA -1}

Max-RS2-index ... _K

The RS2 index configured by listing Nnumrs2_per-rs1 RS2s that belong to RS2s

having a QCL relation with an RS1 other than an RS2 unique ID announced and transmitted by a

network and that has an index from a UE having an ID of the smallest value as 0.

Table 11 Example 4: RS2 ID and dedicated preamble sequence mapping

RS2 index within QCLed UE dedicated Random Access Preamble QCLed RS2sofRSl sequenceindex RS1 index 0 ID0 0 1 IDI 0 1 Nnum rs2 per rsIr IDNnmrs2 w rsl-l 0 Nnum rs2 Par rsl ID.,nurm Is2 per ]rsl I Nnum is' P&! 111+1 IDNnumf rs2I per 151-1 I

2*N 2 p 1-1 ID2Nm 2 p - I

Max-RS2-index ... K

A UE has only to use an allocated preamble sequence based on desired RS2

transmission in such a manner that a network allocates the RS2 index to the UE regarding that

which dedicated preamble sequence will be used for which RS2 transmission.

18057023_1 (GHMattes) P112258.AU

Announcement method using rule and parameter of rule

A parameter necessary for a rule or calculation regarding that which preamble sequence

(or set of preamble sequences) is mapped to which RS2 may be notified in the form of a rule

using a UE-specific unicast/multicast/broadcast RRC/MAC/PHY message.

The following parameters may be considered as the parameter that may be notified.

- NmaxRAP: the number of random access preamble sequences (max sequence ID)

- Nnum rs2_per rs: a maximum/configured number of RS2s having a QCL relation

with one RS1

- Max-RS2-ID: a maximum number of transmittable RS2s (or a maximum ID or the

number of configured transmission RS2s) or ID

- K: the greatest RS1 ID of RS2s having a QCL relation (or a maximum RS1 ID)

Rules that may be considered are as follows.

- Method of calculating an RS2 index

-> A UE classifies RS2 having a QCL relation with the same RS1 within configured

RS2 configuration information, lines the corresponding RS2s up from the smallest ID to the

greatest ID, and assigns indices that increase from 0 by 1 to the respective RS2.

-> Alternatively, an eNB includes an RS2 index in an RS2 configuration and announces

the RS2 configuration.

- Method of determining random access preamble sequence set (or pool

When a UE selects a given RS2 and attempts RACH transmission using the eNB

reception beam and UE transmission beam of the given RS2, an RAP sequence set available for

the UE may be the same as one of the followings:

18057023_1 (GHMatters) P112258.AU

->{RS2_index*Nmax_RAP/Nnum rs2per rsi ... (RS 2 _index+)*NmaxRAP/Nnum rs2per rsl-1}

->(RS2_index mod Nnum rs2per rs)*Nmax_RAP/Nnum rs2per rsl ... (RS2_index mod

Nnum rs2per rs1 +1)*NmaxRAP/Nnum rs2per rs1-1}

FIGS. 5A, 5B, and 5C are diagrams showing a relation of CSI-RS and RACH

configurations according to an embodiment of the disclosure.

Referring to FIGS. 5A, 5B, and 5C, an eNB may configure CSI-RS based RACH

resources, may include NR-SS-related QCL information indicating that an eNB beam in which

each RACH resource will be received has a correlation with which NR-SS transmission beam in

an RACH resource configuration, and may transmit the RACH resource configuration. A UE for

which the CSI-RS based RACH resources including the NR-SS-related QCL information have

been configured may select some CSI-RS based RACH resources that belong to the CSI-RS

based RACH resources and that may be transmitted by the UE and received by the eNB based on

downlink measurement results of NR-SSs having a QCL relation. Furthermore, the UE may

previously select a UE transmission beam in which an RA preamble will be transmitted in the

selected CSI-RS based RACH resource based on the downlink measurement results of NR-SSs

having a QCL relation, and may directly transmit the RA preamble using an optimal beam

without procedures, such as separate CSI-RS measurement and UE beam sweeping.

In a more detailed embodiment, referring to FIG. 5A, a CSI-RS based RACH resource

has the same beam sweeping pattern (i.e., base station NR-SS transmission beam sweeping=

RACH reception beam sweeping) as an NR-SS, and may be configured orthogonally with

respect to a time axis. In this case, the CSI-RS based RACH resource may be configured through

mapping for an NR-SS orthogonally present with respect to the time axis.

18057023_1 (GHMatters) P112258.AU

In another embodiment, referring to FIG. 5B, a CSI-RS based RACH resource has the

same beam sweeping pattern (i.e., base station NR-SS transmission beam sweeping = RACH

reception beam sweeping) as an NR-SS, and may be configured orthogonally with respect to

time and frequency axes. In this case, the CSI-RS based RACH resource may be configured

through mapping for a CSI-RS based RACH resource orthogonally present with respect to the

time axis and a corresponding NR-SS.

In another embodiment, referring to FIG. 5C, a CSI-RS based RACH resource has the

same beam sweeping pattern (i.e., base station NR-SS transmission beam sweeping = RACH

reception beam sweeping) as an NR-SS, and may be configured through mapping for a CSI-RS

based RACH resource orthogonally present with respect to a time axis and a corresponding

NR-SS resource orthogonally present with respect to the time and frequency axes. In this case,

the CSI-RS based RACH resource may be configured through mapping for an NR-SS

orthogonally with respect to the time and frequency axes.

In this case, the CSI-RS based RACH resource may have a QCL relation with one or

more NR-SSs. In such a case, a UE may classify transmitted preamble sequences and notify an

eNB whether which NR-SS is the best.

An eNB may notify a UE of the correlation between the preamble sequence and the

NR-SS using the following method or the eNB and the UE may implicitly be aware of the

correlation. Some or one of the various schemes included in the description of FIG. 4D may be

used as a detailed relation configuration and preamble sequence selection scheme.

If the technologies proposed in FIGS. 4A, 4B, 4C, and 4D and 5A, 5B, and 5C are used

at the same time, there is an advantage in that a UE and an eNB can perform both an RACH

18057023_1 (GHMatters) P112258.AU based on NR-SS measurement and an RACH based on CSI-RS measurement using a CSI-RS based RACH channel.

FIGS. 6A and 6B are diagrams showing a relation of SS and RACH configurations

according to an embodiment of the disclosure.

Referring to FIGS. 6A and 6B, an eNB may configure NR-SS based RACH resources,

may include NR-SS-related QCL information indicating that an eNB beam in which each RACH

resource will be received has a correlation with which CSI-RS transmission beam in an RACH

resource configuration, and may transmit the RACH resource configuration. A UE for which the

NR-SS based RACH resources including the CSI-RS-related QCL information have been

configured may select some NR-SS based RACH resources that belong to the NR-SS based

RACH resources and may be transmitted by the UE and received by the eNB based on the

downlink measurement results of CSI-RSs having a QCL relation. Furthermore, the UE may

previously select a UE transmission beam in which a RA preamble will be transmitted in the

selected NR-SS based RACH resource based on the downlink measurement results of CSI-RSs

having a QCL relation, and may directly transmit the RA preamble using an optimal beam

without procedures, such as separate NR-SS measurement and UE beam sweeping.

In an embodiment, referring to FIG. 6A, an NR-SS based RACH resource may be

configured orthogonally with respect to a time axis with the same beam sweeping pattern (i.e.,

base station CSI-RS transmission beam sweeping = RACH reception beam sweeping) as a

CSI-RS. In this case, the NR-SS based RACH resource may be configured through mapping for

a CSI-RS orthogonally present with respect to the time and frequency axes.

In another embodiment, referring to FIG. 6B, an NR-SS based RACH resource may be

18057023_1 (GHMatters) P112258.AU configured orthogonally with respect to a time axis with the same beam sweeping pattern (i.e., base station CSI-RS transmission beam sweeping = RACH reception beam sweeping) as a

CSI-RS. In this case, the NR-SS based RACH resource may be configured through mapping for

a CSI-RS orthogonally present with respect to the time and frequency axes.

In this case, the NR-SS based RACH resource may have a QCL relation with one or

more CSI-RSs. In such a case, a UE may classify transmitted preamble sequences and notify an

eNB of the best CSI-RS.

An eNB may notify a UE of the correlation between the preamble sequence and the

CSI-RS using the following method or the eNB and the UE may implicitly be aware of the

correlation. Some or one of the various schemes included in the description of FIG. 4D may be

used as a detailed relation configuration and preamble sequence selection scheme.

. FIG. 7A is an example of a time and frequency segmentation CSI-RS based RACH

configuration method according to an embodiment of the disclosure.

FIG. 7B is an example of a time and sequence segmentation CSI-RS based RACH

configuration method according to an embodiment of the disclosure. A detailed sequence-RS

relation configuration and preamble sequence selection scheme may use some or one of the

various schemes included in the description of FIG. 4D.

FIG. 7C is an example of a time and sequence segmentation NR-SS based RACH

configuration method according to an embodiment of the disclosure.

Referring to FIGS. 7A, 7B and 7C, a UE may identify QCL association information

between different RSs using QCL information included in a CSI-RS (RS2) based RACH

configuration. The UE may identify a QCL association relation between two signals of an

18057023_1 (GHMatters) P112258.AU

NR-SS, a CSI-RS, and an RACH resource and a resource using a QCL association relation

included in an RACH configuration and a QCL association relation included in CSI-RS

configuration or NR-SS configuration, may derive the remaining one QCL association, and may

apply and use them.

For example, a UE may identify that a CSI-RS based RACH resource has a QCL

relation with which CSI-RS, may identify that a corresponding CSI-RS has a QCL relation with

which NR-SS in CSI-RS configuration information, and itself may finally identify that which

NR-SS and which CSI-RS based RACH resource have a QCL relation. A detailed sequence-RS

relation configuration and preamble sequence selection scheme may use at least one of the

various schemes described above with reference to FIG. 4D.

FIG. 8 is a diagram showing a UE according to an embodiment of the disclosure.

Referring to FIG. 8, the UE 800 may include a transceiver 810 configured to transmit

and receive signals and a controller 830. The UE 800 may transmit and/or receive a signal,

information or a message through the transceiver 810. The controller 830 may control an overall

operation of the UE 800. The controller 830 may include at least one processor. The controller

830 may control the operations of the UE described above.

Furthermore, the controller 830 receives RACH configuration information transmitted

by an eNB, specifies a resource in which an RA preamble will be transmitted based on various

types of information, such as an RS having a QCL association included in the configuration

information, and performs a random access operation in the corresponding resource.

Furthermore, the controller 830 may obtain random access resource configuration

information and QCL information from an eNB, may measure a CSI-RS, may identify an

18057023_1 (GHMatters) P112258.AU random access resource based on the CSI-RS, the QCL information and the random access resource configuration information, and may transmit a random access preamble based on the random access resource. The QCL information may indicate an SS having a QCL relation with the CSI-RS. The random access resource corresponds to the SS. The RACH resource configuration information may include an random access resource. The QCL information may include a CSI-RS identifier and an SS identifier.

FIG. 9 is a diagram showing a UE operation according to an embodiment of the

disclosure.

Referring to FIG. 9, at operation 910, the UE may receive RACH configuration

information in the form of system information (SystemInfo) or a message

(PHY/MAC/RLC/RRC) through a physical broadcast channel (PBCH), a physical downlink

control channel (PDCCH) or a physical downlink shared data channel (PDSCH). At operation

920, the UE that has received the RACH information may itself identify an RACH reception

resource using various types of information, such as resource information included in the

received information, periodicity, a measurement gap, a window, and other RS IDs having a

QCL association relation.

At operation 930, the UE that has identified the existing RSs having a QCL association

relation using the various types of information may select an optimal eNB transmission beam

and UE reception beam capable of maximizing performance based on the existing measurement

results of an RS, and may select a related RS and a resource that belongs to related RACH

resources and in which an RA preamble will be transmitted based on such information.

Furthermore, the UE may select a preamble sequence.

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The UE that has selected the RA resource and the preamble transmits the RA preamble

based on the selected resource at operation 940, and waits to receive a random access response

(RAR) at operation 950.

FIG. 10 is a diagram showing an eNB according to an embodiment of the disclosure.

Referring to FIG. 10, the eNB 1000 may include a transceiver 1010 configured to

transmit and receive signals and a controller 1030. The eNB 1000 may transmit and/or receive a

signal, information or a message through the transceiver 1010. The controller 1030 may control

an overall operation of the eNB 1000. The controller 1030 may include at least one processor.

The controller 1030 may control the operation of a UE above.

Furthermore, the controller 1030 transmits RACH configuration information to a UE

and receives an RA preamble in a corresponding resource. Furthermore, after receiving an RA

preamble in a given RACH resource, the controller may transmit an RAR to the UE using a

beam associated with the corresponding RACH resource.

Furthermore, the controller 1030 may transmit random access resource configuration

information and QCL information to a UE, may transmit a CSI-RS to the UE, may receive a

random access preamble from the UE based on an random access resource, and may control to

transmit a random access response to the UE. The random access resource may be determined

based on a measurement result of the CSI-RS, the QCL information and the random access

resource configuration information. The QCL information may indicate an SS having a QCL

relation with the CSI-RS. The random access resource corresponds to to the SS. The RACH

resource configuration information may include the random access resource. The QCL

information may include a CSI-RS identifier and a SS identifier.

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If the eNB 1000 receives RACH configuration information for a given UE (or an

unspecified UE) from an adjacent eNB, it may transmit such configuration information to UEs

within a network.

The embodiments of the disclosure may provide a method of performing efficient

random access.

Furthermore, in accordance with one embodiment of the disclosure, there are advantages

in that in a beamforming-based system including one or more eNBs and one or more UEs, the

eNB can allocate random access-related information based on different RSs to the UE and the

UE can perform mobility management operations, such as neighbor cell access and handover,

using the random access-related information.

Furthermore, in accordance with one embodiment of the disclosure, a UE recognizes

resources in which random access is used and common information, such as the time, frequency,

and direction between different RSs, and minimizes operations unnecessary to select

transmission and reception beams between an eNB and a UE, for example, an operation of

repeating a process of taking turns transmitting/receiving a beam and selecting a beam through

reception signal measurement. Accordingly, there is an advantages in that power of a UE and

time delay can be reduced.

While the disclosure has been shown and described with reference to various

embodiments thereof, it will be understood by those skilled in the art that various changes in

form and details may be made therein without departing from the spirit and scope of the

disclosure as defined by the appended claims and their equivalents.

In the claims which follow and in the preceding description of the invention, except

18057023_1 (GHMatters) P112258.AU where the context requires otherwise due to express language or necessary implication, the word

"comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e.

to specify the presence of the stated features but not to preclude the presence or addition of

further features in various embodiments of the invention. It is to be understood that, if any

prior art publication is referred to herein, such reference does not constitute an admission that the

publication forms a part of the common general knowledge in the art, in Australia or any other

country.

18057023_1 (GHMatters) P112258.AU

Claims (15)

1. A method of terminal, the method comprising:

obtaining, by the terminal, random access resource configuration information and quasi

co-location (QCL) information from a base station, the random access resource configuration

information including information on a synchronization signal (SS) and information on a channel

state information-reference signal (CSI-RS);

measuring, by the terminal, a CSI-RS;

identifying, by the terminal, a random access resource based on a measurement result of

the CSI-RS, the QCL information and the random access resource configuration information;

and

transmitting, by the terminal, a random access preamble based on the random access

resource,

wherein the QCL information indicates an SS having a QCL relation with the CSI-RS.

2. The method of claim 1, wherein the QCL information includes a CSI-RS

identifier and an SS identifier.

3. The method of claim 1, wherein the random access resource configuration

information includes the random access resource associated with the SS.

4. The method of claim 1, wherein a SS identified based on the measurement result

18057023_1 (GHMatters) P112258.AU of the CSI-RS and the QCL information, and wherein the random access resource is identified based on the identified SS and the random access resource configuration information.

5. A terminal, comprising:

a transceiver configured to transmit and receive signals; and

at least one processor configured to control the terminal to:

obtain random access resource configuration information and quasi co-location

(QCL) information from a base station, , the random access resource configuration information

including information on a synchronization signal (SS) and information on a channel state

information-reference signal (CSI-RS),

measure a CSI-RS,

identify a random access resource based on a measurement result of the CSI-RS,

the QCL information and the random access resource configuration information, and

transmit a random access preamble based on the random access resource,

wherein the QCL information indicates an SS having a QCL relation with the CSI-RS.

6. The terminal of claim 5, wherein the QCL information includes a CSI-RS

identifier and an SS identifier.

7. The terminal of claim 5, wherein the random access resource configuration

includes the random access resource associated with the SS.

18057023_1 (GHMatters) P112258.AU

8. The terminal of claim 5, wherein a SS identified based on the measurement result

of the CSI-RS and the QCL information, and

wherein the random access resource is identified based on the identified SS and the

random access resource configuration information.

9. A method of a base station, the method comprising:

transmitting, by the base station, random access resource configuration information and

quasi co-location (QCL) information to a terminal, the random access resource configuration

information including information on a synchronization signal (SS) and information on a channel

state information-reference signal (CSI-RS);

transmitting, by the base station, a CSI-RS to the terminal;

receiving, by the base station, a random access preamble based on a random access

resource from the terminal; and

transmitting, by the base station, a random access response to the terminal,

wherein the random access resource is determined by the terminal based on a

measurement result of the CSI-RS, the QCL information and the random access resource

configuration information, and

wherein the QCL information indicates an SS having a QCL relation with the CSI-RS.

10. The method of claim 9, wherein the QCL information includes a CSI-RS

identifier and an SS identifier.

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11. The method of claim 9, wherein the random access resource configuration

information includes the random access resource associated with the SS.

12. The method of claim 9, wherein a SS identified based on the measurement result

of the CSI-RS and the QCL information, and

wherein the random access resource is identified based on the identified SS and the

random access resource configuration.

13. A base station, comprising:

a transceiver configured to transmit and receive signals; and

at least one processor configured to control the base station to:

transmit random access resource configuration information and quasi co-location

(QCL) information to a terminal, the random access resource configuration information

including information on a synchronization signal (SS) and information on a channel state

information-reference signal (CSI-RS),

transmit a CSI-RS to the terminal,

receive a random access preamble based on a random access resource from the

terminal, and

transmit a random access response to the terminal,

wherein the random access resource is determined by the terminal based on a

measurement result of the CSI-RS, the QCL information and the random access resource

configuration information, and

18057023_1 (GHMatters) P112258.AU wherein the QCL information indicates an SS having a QCL relation with the CSI-RS.

14. The base station of claim 13, wherein the random access resource configuration

information includes the random access resource associated with the SS, and

wherein the QCL information includes a CSI-RS identifier and an SS identifier.

15. The base station of claim 13, wherein a SS identified based on the measurement

result of the CSI-RS and the QCL information, and

wherein the random access resource is identified based on the identified SS and the

random access resource configuration.

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