CN113170400A

CN113170400A - Method and apparatus for estimating path loss between terminals in wireless communication system

Info

Publication number: CN113170400A
Application number: CN201980076603.0A
Authority: CN
Inventors: 柳贤锡; 吕贞镐; 吴振荣; 朴成珍; 李周镐
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2018-09-27
Filing date: 2019-09-20
Publication date: 2021-07-23
Also published as: KR20200035836A

Abstract

The present disclosure relates to a method and apparatus for estimating inter-terminal bypass path loss for transmission of control information and data information between terminals. The path loss estimation method of a transmitting terminal in a wireless communication system according to an embodiment may include: transmitting a signal for path loss estimation to a receiving terminal; receiving a path loss estimation result report from a receiving terminal in response to a signal for path loss estimation; configuring a transmission power based on the pathloss estimation result report; and performing a bypass transmission with the receiving terminal using the configured transmission power.

Description

Method and apparatus for estimating path loss between terminals in wireless communication system

Technical Field

The present disclosure relates to a method and apparatus for estimating an inter-terminal bypass path loss to transmit control information and data information between terminals, and more particularly, to a method and apparatus for estimating a path loss by using a signal for path loss estimation transmitted via a bypass and controlling a transmission power of the bypass.

Background

After the commercialization of fourth generation (4G) communication systems, efforts have been made to develop an enhanced fifth generation (5G) communication system or pre-5G communication system in order to meet the increasing demand for wireless data services. Accordingly, the 5G communication system or the pre-5G communication system is referred to as an "beyond 4G network communication system" or a "Long Term Evolution (LTE) system". By the third generation partnership project (3)^rdgeneration partnership project, 3GPP) is called a New Radio (NR) system. In order to implement a high data rate, it is considered to implement a 5G communication system in an ultra-high frequency band (mmW) (e.g., 60 GHz). In order to reduce the path loss of radio waves and increase the transmission distance of radio waves in an ultra high frequency band, techniques such as beam forming, massive-input-multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antenna, analog beam forming, and massive antenna have been discussed for a 5G communication system and have been applied to NR systems. In addition, the method can be used for producing a composite materialTo improve system networks, techniques such as evolved small cells, advanced small cells, cloud radio access networks (cloud RANs), ultra-dense networks, device-to-device (D2D) communications, wireless backhaul, mobile networks, cooperative communications, coordinated multi-points (CoMP), and interference cancellation have been developed for 5G communication systems. In addition, Advanced Coding Modulation (ACM) schemes such as hybrid frequency-shift keying (FSK) and Quadrature Amplitude Modulation (QAM) modulation (FQAM) and Sliding Window Superposition Coding (SWSC) and enhanced network access schemes such as filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA) and Sparse Code Multiple Access (SCMA) have been developed for 5G communication systems.

The Internet is evolving from a human-centric connected network through which humans create and consume information, to an Internet of Things (IoT) network through which distributed elements, such as objects, exchange and process information. Internet of Everything (IoE) technology is also emerging, which is a combination of IoT technology and big data processing technology through connection with a cloud server. In order to implement IoT, technical elements such as sensing technology, wired/wireless communication and network infrastructure, service interface technology, and security technology are required, and thus technologies for inter-object connection, such as sensor network, machine to machine (M2M) communication, or machine-type communication (MTC), have recently been studied. In the IoT environment, an intelligent Internet Technology (IT) service that collects and analyzes data generated by connected objects and creates new value in human life may be provided. IoT may be applied to such fields as smart homes, smart buildings, smart cities, smart cars or networked cars, smart grids, healthcare, smart homes, and advanced medical services through the fusion and integration of existing Information Technology (IT) and various industries.

Accordingly, various attempts have been made to apply the 5G communication system to the IoT network. For example, technologies such as sensor networks, M2M communication, and MTC are implemented by 5G communication technologies such as beamforming, MIMO, and array antennas. The application of cloud RAN as a big data processing technology can also be considered as an example of the convergence of 5G technology and IoT technology.

In vehicle communication, vehicle-to-all (V2X) standardization based on LTE systems in 3GPP Rel-14 and Rel-15 has been completed based on a device-to-device (D2D) communication structure. Currently, attempts have been made to develop V2X based on the 5G NR system. V2X based on 5G or NR systems may support unicast communication, multicast (or multicast) communication, broadcast communication, etc. between terminals. Further, unlike the LTE system-based V2X, which is intended to transmit and receive basic safety information required for vehicle road traveling, the 5G or NR system-based V2X is intended to provide more advanced services, such as queuing, advanced driving, extended sensors, and remote driving. Such various services and scenarios require higher reliability and higher data rates than D2D based on the LTE system or V2X based on the LTE system. Therefore, V2X based on 5G or NR systems needs to support link adaptation based on a measure of the quality of the inter-terminal bypass.

Disclosure of Invention

Technical problem

The disclosed embodiments provide a method and apparatus for estimating inter-terminal bypass path loss to support high reliability and high data rates.

Furthermore, the disclosed embodiments provide a method and apparatus for controlling inter-terminal bypass transmission power based on path loss estimates.

Further, the disclosed embodiments provide a method and apparatus for efficiently providing a service in a mobile communication system.

Solution to the problem

The path loss estimation method of a transmitting terminal in a mobile communication system according to an embodiment may include: transmitting a signal for path loss estimation to a receiving terminal; receiving a path loss estimation result report from a receiving terminal in response to a signal for path loss estimation; configuring a transmission power based on the pathloss estimation result report; and performing a bypass transmission with the receiving terminal using the configured transmission power.

A path loss estimation method of a receiving terminal in a wireless communication system according to an embodiment may include receiving a signal for path loss estimation from a transmitting terminal, measuring Reference Signal Received Power (RSRP) based on the signal for path loss estimation, and transmitting a path loss estimation result report including the RSRP to the transmitting terminal.

A transmitting terminal according to an embodiment may include a transceiver, a memory storing a program and data of a path loss estimation method of the transmitting terminal, and a processor configured to execute the program stored in the memory to transmit a signal for path loss estimation to a receiving terminal, receive a path loss estimation result report from the receiving terminal in response to the signal for path loss estimation, configure transmission power based on the path loss estimation result report, and perform bypass transmission with the receiving terminal using the configured transmission power.

A receiving terminal according to an embodiment may include a transceiver, a memory storing a path loss estimation method program and data of the receiving terminal, and a processor configured to execute the program stored in the memory to receive a signal for path loss estimation from a transmitting terminal, measure Reference Signal Received Power (RSRP) based on the signal for path loss estimation, and transmit a path loss estimation result report including the RSRP to the transmitting terminal.

Advantageous effects of the disclosure

According to an embodiment, transmission parameters of bypass control information and data information may be adjusted according to the quality of the bypassed channel. Therefore, in the vehicle communication system, the D2D system, and the like, the reliability and data rate of the bypass control information and the data information may be improved. Further, the amount of interference caused by nearby cells or vehicles may be reduced. Accordingly, more efficient communication between terminals can be supported. In addition, services can be efficiently provided in a mobile communication system.

Drawings

Fig. 1 is a view for describing a vehicle-to-vehicle (V2X) system to which the disclosed embodiments are applied.

Fig. 2 is a view for describing a V2X communication method performed by bypass.

Fig. 3 is a diagram for describing a method of estimating a downlink Path Loss (PL) by a User Equipment (UE) in an existing cellular system.

Fig. 4 is a schematic diagram for describing a method of estimating inter-UE bypass path loss according to the disclosed embodiments.

Fig. 5 is a schematic diagram for describing a method of estimating inter-UE bypass path loss according to another disclosed embodiment.

Fig. 6 is a schematic diagram for describing a method of transmitting and receiving a path loss measurement signal to estimate a bypass path loss according to the disclosed embodiments.

Fig. 7 is a schematic diagram for describing a method of transmitting and receiving a path loss measurement signal to estimate a bypass path loss according to another disclosed embodiment.

Fig. 8A is a schematic diagram for describing a method of transmitting and receiving path loss measurement signals to estimate inter-UE bypass path loss according to another disclosed embodiment.

Fig. 8B is a diagram for describing a method of estimating an inter-UE bypass path loss in more detail according to the embodiment of fig. 8A.

Fig. 8C is another diagram illustrating in more detail the method of estimating inter-UE bypass path loss according to the embodiment of fig. 8A.

Fig. 8D is a diagram for describing a medium access control element (MAC CE) format for reporting inter-UE bypass Reference Signal Received Power (RSRP) values according to the disclosed embodiments.

Fig. 9 is a schematic diagram for describing a method of transmitting and receiving path loss measurement signals to estimate inter-UE bypass path loss according to another disclosed embodiment.

Fig. 10 is a schematic diagram for describing a method of transmitting and receiving path loss measurement signals to estimate inter-UE bypass path loss according to another disclosed embodiment.

Fig. 11 is a flow chart illustrating a path loss estimation operation of a transmitting UE in accordance with the disclosed embodiments.

Fig. 12 is a flow chart illustrating a path loss estimation operation of a receiving UE in accordance with the disclosed embodiments.

Fig. 13 is a flow chart illustrating a path loss estimation operation of a transmitting UE in accordance with another disclosed embodiment.

Fig. 14 is a flow chart illustrating a path loss estimation operation of a receiving UE in accordance with another disclosed embodiment.

Fig. 15 is a block diagram illustrating a structure of a transmitting UE according to an embodiment.

Fig. 16 is a block diagram illustrating a structure of a receiving UE according to an embodiment.

Detailed Description

Best mode

In an embodiment, the path loss estimation result report may include at least one layer 1 reference signal received power (L1-RSRP) measured by the receiving terminal, wherein receiving the path loss estimation result report from the receiving terminal in response to the signal for path loss estimation includes receiving at least one L1-RSRP measured by the receiving terminal via a bypass feedback channel (physical bypass feedback channel (PSFCH)) or receiving a medium access control element (MAC CE) transmitted via a bypass data channel (physical bypass shared channel (PSSCH)).

In an embodiment, the MAC CE may include at least one L1-RSRP, wherein when the MAC CE includes a plurality of L1-RSRPs, the MAC CE includes a User Equipment (UE) ID.

In an embodiment, the path loss estimation result report may include a layer 3RSRP (L3-RSRP) measured by the receiving terminal, wherein receiving the path loss estimation result report from the receiving terminal in response to the signal for path loss estimation includes receiving the L3-RSRP measured by the receiving terminal through a Radio Resource Control (RRC) message transmitted via a bypass data channel (PSSCH).

In an embodiment, receiving the pathloss estimation result report from the receiving terminal in response to the signal for pathloss estimation may include receiving the pathloss estimation result report after the signal for pathloss estimation is transmitted to the receiving terminal, before the preconfigured timer expires, before and after the preconfigured second time, or before and after a point in time when the preconfigured first time has elapsed or a point in time when the preconfigured number of slots is received.

In an embodiment, when the pathloss estimation result report is not received before the preconfigured timer expires, the pathloss estimation method may further comprise sending information to the receiving terminal indicating that the pathloss estimation result report has not been received.

In an embodiment, the signal for path loss estimation may include at least one signal among a bypass synchronization signal including at least one of a primary bypass synchronization signal (PSSS) and a secondary bypass synchronization signal (SSSS), a demodulation reference signal (DMRS) transmitted via at least one of a bypass broadcast channel (physical bypass broadcast channel (PSBCH)), a bypass control channel (physical bypass control channel (PSCCH)), and a bypass data channel (physical bypass shared channel (pscsch)), and a reference signal for supporting a bypass operation.

In an embodiment, transmitting the signal for path loss estimation to the receiving terminal may include transmitting the signal for path loss estimation to the receiving terminal in at least one of a case where a transmission command of the signal for path loss estimation is received from the base station, a case where a Reference Signal Received Power (RSRP) measured by the transmitting terminal for the signal for downlink path loss estimation transmitted by the base station is equal to or greater than a configured threshold or equal to or less than a configured threshold, a case where the transmitting terminal determines that the signal for path loss estimation needs to be transmitted, and a case where a request signal for transmission of the signal for path loss estimation is received from the receiving terminal.

In an embodiment, transmitting the signal for path loss estimation to the receiving terminal may include configuring at least one among a pre-configured transmission power, a maximum transmission power of the transmitting terminal, a transmission power according to a configuration of the base station, a transmission power determined based on an RSRP measured by the transmitting terminal for a signal for downlink path loss estimation transmitted by the base station, and a transmission power determined based on an RSRP measured by the transmitting terminal for a request signal for transmission of the signal for path loss estimation received from the receiving terminal as the transmission power of the signal for path loss estimation.

In an embodiment, receiving a pathloss estimation result report from a receiving terminal in response to a signal for pathloss estimation may include receiving the pathloss estimation result report periodically or aperiodically according to at least one of configuration of a base station and bypass control information.

In an embodiment, the path loss estimation method may further include transmitting information on transmission power of the signal for path loss estimation to the receiving terminal, the information including at least one of offset information between the configured reference signal and the transmission power value of the signal for path loss estimation.

In an embodiment, the signal for path loss estimation and the information on the transmission power of the signal for path loss estimation may be transmitted via the same channel or different channels.

In an embodiment, performing the bypass transmission with the receiving terminal using the configured transmission power may include transmitting at least one of bypass control information and bypass data to the receiving terminal.

In an embodiment, the RSRP may comprise at least one layer 1RSRP (L1-RSRP), wherein sending the path loss estimation result report comprising the RSRP to the sending terminal comprises sending at least one L1-RSRP via a bypass feedback channel (physical bypass feedback channel) or a medium access control element (MAC CE) sent via a bypass data channel (physical bypass shared channel).

In an embodiment, sending a path loss estimation result report including RSRP to the sending terminal may include sending L1-RSRP every preconfigured time or every preconfigured time slot after a signal for path loss estimation is received, until a preconfigured timer expires, or until a report stop command is received from the sending terminal.

In an embodiment, the path loss estimation method may further include reconfiguring the timer when receiving information indicating that the path loss estimation result report has not been received from the transmitting terminal.

In an embodiment, the path loss estimation result report may comprise a layer 3RSRP (L3-RSRP), wherein transmitting the path loss estimation result report comprising the RSRP to the sending terminal comprises sending the L3-RSRP in a Radio Resource Control (RRC) message sent via a bypass data channel (physical bypass shared channel (PSSCH)).

In an embodiment, transmitting the path loss estimation result report including the RSRP to the transmitting terminal may include transmitting the path loss estimation result report periodically or aperiodically according to at least one of configuration of the base station and bypass control information.

In an embodiment, RSRP measurement based on signals used for path loss estimation may include measuring a pre-configured transmit power, a maximum transmit power of a receiving terminal, a configured transmit power according to a base station, and RSRP of signals transmitted by the base station for downlink path loss estimation.

In an embodiment, the path loss estimation method may further include receiving information on transmission power of the signal for path loss estimation, the information including at least one of offset information between the configured reference signal and the transmission power value of the signal for path loss estimation.

In an embodiment, the signal for path loss estimation and the information on the transmission power of the signal for path loss estimation may be received via the same channel or different channels.

A transmitting terminal according to an embodiment may include a transceiver, a memory storing a program and data of a path loss estimation method of the transmitting terminal, and a process configured to execute the program stored in the memory to transmit a signal for path loss estimation to a receiving terminal, receive a path loss estimation result report from the receiving terminal in response to the signal for path loss estimation, configure transmission power based on the path loss estimation result report, and perform bypass transmission with the receiving terminal using the configured transmission power.

A path loss estimation method of a transmitting terminal in a wireless communication system according to another embodiment may include: receiving a signal for path loss estimation from a receiving terminal; estimating a path loss based on the signal for path loss estimation; configuring a transmission power based on a path loss estimation result; and performing a bypass transmission with the receiving terminal using the configured transmission power.

In an embodiment, the signal for path loss estimation may include at least one of a bypass synchronization signal including at least one of a primary bypass synchronization signal (PSSS) and a secondary bypass synchronization signal (SSSS), a demodulation reference signal (DMRS) transmitted via at least one of a bypass broadcast channel (physical bypass broadcast channel (PSBCH)), a bypass control channel (physical bypass control channel (PSCCH)), and a bypass data channel (physical bypass shared channel (pscsch)), and a reference signal for supporting a bypass operation.

In an embodiment, the path loss estimation method may further include transmitting a transmission request signal of the signal for path loss estimation to the receiving terminal in at least one of a case where a command of a transmission request of the signal for path loss estimation is received from the base station, a case where Reference Signal Received Power (RSRP) measured by the transmitting terminal for the signal for bypass path loss estimation transmitted by the base station is equal to or greater than a configured threshold or equal to or less than a configured threshold, and a case where the transmitting terminal determines that the signal for path loss estimation needs to be transmitted.

In an embodiment, transmitting the transmission request signal for the signal for path loss estimation to the receiving terminal may include configuring at least one of a pre-configured transmission power, a maximum transmission power of the transmitting terminal, a transmission power according to a configuration of the base station, and a transmission power determined based on RSRP measured by the transmitting terminal for the signal for downlink path loss estimation transmitted by the base station as the transmission power of the transmission request signal for the signal for path loss estimation.

In an embodiment, the path loss estimation method may further include receiving information on transmission power of the signal for path loss estimation, the information including at least one of offset information between the configured reference signal and a transmission power value of the signal for path loss estimation.

In an embodiment, the information on the transmission power of the signal for path loss estimation and the signal for path loss estimation may be received via the same channel or different channels.

A path loss estimation method of a receiving terminal in a wireless communication system according to another embodiment may include transmitting a signal for path loss estimation to a transmitting terminal, and performing bypass transmission with the transmitting terminal.

In an embodiment, transmitting the signal for path loss estimation to the transmitting terminal may include transmitting the signal for path loss estimation to the transmitting terminal in at least one of a case where a transmission command of the signal for path loss estimation is received from the base station, a case where a Reference Signal Received Power (RSRP) measured by the receiving terminal for the signal for downlink path loss estimation transmitted by the base station is equal to or greater than a pre-configured threshold or equal to or less than a configured threshold, a case where the receiving terminal determines that the signal for path loss estimation needs to be transmitted, and a case where a request signal for transmission of the signal for path loss estimation is received from the transmitting terminal.

In an embodiment, transmitting the signal for path loss estimation to the transmitting terminal may include configuring at least one of a pre-configured transmit power, a maximum transmit power of the receiving terminal, a transmit power according to a configuration of the base station, a transmit power determined based on an RSRP measured by the receiving terminal for a signal transmitted by the base station for downlink path loss estimation, and a transmit power determined based on an RSRP measured by the receiving terminal for a request signal received from the transmitting terminal to transmit the signal for path loss estimation, as a transmit power of the signal for path loss estimation.

In an embodiment, the path loss estimation method may further include transmitting information on transmission power of the signal for path loss estimation to the transmission terminal, the information including at least one of offset information between the configured reference signal and the transmission power value of the signal for path loss estimation.

In an embodiment, performing the bypass transmission with the transmitting terminal may include receiving at least one of bypass control information and bypass data from the transmitting terminal.

A transmitting terminal according to another embodiment may include a transceiver, a memory storing a program and data of a path loss estimation method of the transmitting terminal, and a processor configured to execute the program stored in the memory to receive a signal for path loss estimation from a receiving terminal, estimate a path loss based on the signal for path loss estimation, configure transmission power based on a result of path loss estimation, and perform bypass transmission with the receiving terminal using the configured transmission power.

A receiving terminal according to another embodiment may include a transceiver, a memory storing a path loss estimation method program and data of the receiving terminal, and a processor configured to execute the program stored in the memory to transmit a signal for path loss estimation to a transmitting terminal and to perform bypass transmission with the transmitting terminal.

Disclosure mode

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

In the following description of the embodiments, a description of technologies that are well known in the art and are not directly related to the present disclosure is omitted. This is to clearly convey the gist of the present disclosure by omitting unnecessary descriptions.

For the same reason, some elements in the drawings are enlarged, omitted, or schematically shown. Moreover, the size of each element does not completely reflect the actual size of the element. In the drawings, the same or corresponding elements are denoted by the same reference numerals.

Advantages and features of the present disclosure and methods of accomplishing the same will become apparent with reference to the following detailed description of embodiments of the disclosure taken in conjunction with the accompanying drawings. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments of the disclosure set forth herein; rather, these embodiments of the disclosure are provided so that this disclosure will be thorough and complete and will fully convey the scope of the disclosure to those skilled in the art, and the disclosure will only be defined by the appended claims. In the specification, like reference numerals denote like elements.

In such cases, it will be understood that each block of the flowchart illustrations, and combinations of blocks in the flowchart illustrations, can be implemented by computer program instructions. Because these computer program instructions may be loaded onto a processor of a general purpose computer, special purpose computer, or programmable data processing apparatus, the instructions, which execute via the processor of the computer or another programmable data processing apparatus, create means for implementing the functions specified in the flowchart block(s). Because these computer program instructions may also be stored in a computer usable or computer-readable memory that may direct a computer or another programmable data processing apparatus to function in a particular manner, the instructions stored in the computer usable or computer-readable memory may produce an article of manufacture including instruction means that implement the function specified in the flowchart block or blocks. Because the computer program instructions may also be loaded onto a computer or another programmable data processing apparatus, a series of operational steps may be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block(s).

Further, each block of the flowchart illustrations may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the blocks may occur out of order. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved.

In this case, the term "unit" used in the present embodiment refers to a software or hardware component that performs a specific task, such as a field-programmable gate array (FPGA) or an application-specific integrated circuit (ASIC). However, the term "unit" is not limited to software or hardware. The term "cell" may be configured in an addressable storage medium or configured to operate one or more processors. Thus, a unit may include components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures and subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functionality provided for in the components and the plurality of "cells" may be combined into fewer components and a plurality of "cells" or may be further divided into additional components and a plurality of "cells". Further, the components and "units" may be implemented as one or more Central Processing Units (CPUs) in an operating device or secure multimedia card. Furthermore, the unit in an embodiment may include one or more processors.

Also, for convenience of description, terms used herein to identify an access node, terms representing network entities, terms representing messages, terms representing interfaces between network entities, terms representing various types of identification information, and the like are exemplary. Accordingly, terms used in the present disclosure are not limited, and other terms indicating objects having the same technical meaning may be used.

In the present disclosure, for convenience of description, the present disclosure uses terms and names defined in standards regarding fifth generation (5G), new air interface (NR), or Long Term Evolution (LTE) system. However, the present disclosure is not limited by these terms and names, and may be equally applied to systems conforming to other standards.

While the description will focus on the communication standards specified by the third generation partnership project (3GPP) when describing embodiments of the present disclosure in detail, it will be apparent to those of ordinary skill in the art that the main subject matter claimed in the present specification is also applicable to other communication systems and services having a similar technical background without significantly departing from the scope of the present disclosure.

In the present disclosure, a transmitting terminal does not refer to a terminal that transmits a signal for path loss estimation, but refers to a terminal that transmits bypass data and control information. In the present disclosure, the receiving terminal does not refer to a terminal that receives a signal for path loss estimation, but refers to a terminal that receives bypass data and control information.

Fig. 1 is a view for describing a vehicle-to-all (V2X) system to which the disclosed embodiments are applied.

Fig. 1 (a) shows an example in which all V2X User Equipments (UEs) UE-1 and UE-2 are located within the coverage of the base station gNB/eNB/RSU (in-coverage scene). All V2X UEs UE-1 and UE-2 may receive data and control information from the base station gNB/eNB/RSU via Downlink (DL) or may transmit data and control information to the base station via Uplink (UL). In this case, the data and control information may be data and control information for V2X communication or data and control information for general cellular communication other than V2X communication. Further, in fig. 1 (a), V2X UEs UE-1 and UE-2 may transmit and receive data and control information for V2X communications through a bypass (SL).

Fig. 1 (b) shows an example in which V2X UE-1 is located within the coverage of base station gNB/eNB/RSU, while V2X UE-2 is located outside the coverage of base station gNB/eNB/RSU (partial coverage scene). The V2X UE-1 located within the coverage of the base station gNB/eNB/RSU may receive data and control information from the base station gNB/eNB/RSU through a Downlink (DL) or transmit data and control information to the base station gNB/eNB/RSU through an Uplink (UL). The V2X UE UE-2 located outside the coverage of the base station gNB/eNB/RSU is unable to receive data and control information from the base station gNB/eNB/RSU via the Downlink (DL) and unable to transmit data and control information to the base station gNB/eNB/RSU via the Uplink (UL). The V2X UE UE UE-2 may send and receive data and control information for V2X communications through a bypass (SL).

Fig. 1 (c) shows an example where all V2X UEs UE-1 and UE-2 are located outside the coverage of the base station gNB/eNB/RSU (out-of-coverage scene). Therefore, V2X UEs UE-1 and UE-2 cannot receive data and control information from base station gNB/eNB/RSU through Downlink (DL) and cannot transmit data and control information to base station gNB/eNB/RSU through Uplink (UL). V2X UEs UE-1 and UE-2 can send and receive data and control information for V2X communications through a bypass (SL).

Fig. 1 (d) shows an example in which a V2X transmitting UE and a V2X receiving UE are connected to different base stations (radio resource control (RRC) connected state) or camping (RRC disconnected state, i.e., RRC idle state) (inter-cell V2X communication scenario). In this case, the V2X UE UE-1 may be a V2X transmitting UE, while the V2X UE UE-2 may be a V2X receiving UE. Alternatively, V2X UE UE-1 may be a V2X receiving UE, while V2X UE UE UE-2 may be a V2X transmitting UE. V2X UE-1 may receive a V2X dedicated System Information Block (SIB) from a base station to which V2X UE-1 is connected (or a base station to which V2X UE-1 resides), and V2X UE-2 may receive a V2X dedicated SIB from another base station to which V2X UE-2 is connected (or a base station to which V2X UE-2 resides). In this case, the information of the V2X dedicated SIB received by the V2X UE UE-1 and the information of the V2X dedicated SIB received by the V2X UE UE-2 may be different from each other. Therefore, in order to perform V2X communication between UEs located in different cells, unified information is required.

Although the description has been made with reference to fig. 1 by using a V2X system including two UEs UE-1 and UE-2 as an example for convenience, various numbers of UEs may join the V2X system without being limited to the description. The Uplink (UL) and Downlink (DL) with the base stations gNB/eNB/RSU and V2X UEs UE-1 and UE-2 may be referred to as the Uu interface, and the bypass (SL) between V2X UEs UE-1 and UE-2 may be referred to as the PC5 interface. Thus, in the present disclosure, these terms may be used interchangeably.

Meanwhile, in the present disclosure, the UE may refer to a vehicle supporting vehicle-to-vehicle (V2V) communication, a cell phone (e.g., a smart phone) of a vehicle or a pedestrian supporting vehicle-to-pedestrian (V2P) communication, a vehicle supporting vehicle-to-network (V2N) communication, or a vehicle supporting vehicle-to-infrastructure (V2I) communication. Further, in the present disclosure, a UE may refer to a Road Side Unit (RSU) having a UE function, an RSU having a base station function, or an RSU having a part of a UE function and a part of a base station function.

Fig. 2 is a view for describing a V2X communication method performed by a bypass interface.

As shown in fig. 2 (a), the transmitting UE and the receiving UE may perform one-to-one communication, which may be referred to as unicast communication.

As shown in fig. 2 (b), the transmitting UE and the receiving UE may perform one-to-many communication, which may be referred to as multicast or multicast communication. In fig. 2 (B), UE-1, UE-2, UE-3 perform multicast communication by forming one group (group a), and UE-4, UE-5, UE-6, and UE-7 perform multicast communication by forming another group (group B). Each UE performs multicast communication only in a group to which the UE belongs, and does not perform communication between different groups. Although two groups are formed in fig. 2 (b), a greater number of groups may be formed without being limited to the illustration.

Meanwhile, although not shown in fig. 2, the V2X UE may perform broadcast communication. In broadcast communication, all V2X UEs receive data and control information transmitted by V2X transmitting UEs through the bypass. For example, in (b) of FIG. 2, when it is assumed that V2X UE UE UE-1 is a transmitting UE for broadcast communication, all UEs UE-2, UE-3, UE-4, UE-5, UE-6 and UE-7 can receive data and control information transmitted by V2X UE UE-1.

Fig. 3 is a diagram for describing a method for a UE to estimate downlink Path Loss (PL) in an existing cellular system.

The UE TX UE may receive a parameter configuration for estimating downlink path loss and a signal for estimating path loss from the base station eNB/gNB. The UE TX UE may receive a path loss signal for downlink path loss estimation transmitted by the base station eNB/gNB, may measure Reference Signal Received Power (RSRP), and may measure downlink path loss by using [ equation 1 ].

[ equation 1]

Downlink pathloss-transmission power of base station signal-RSRP measured by UE

In this case, the transmission power of the base station signal may be the transmission power of a signal for downlink path loss estimation transmitted by the base station, and the signaling method may vary according to the type of the signal. For example, when the estimated signal is a cell-specific reference signal (CRS), the transmission power of the base station signal may refer to the transmission power of the CRS, and may be transmitted to the UE through a parameter refrencesignalpower of system information. When the estimation signal is a Synchronization Signal Block (SSB), the transmission power of the base station signal may refer to the transmission power of a demodulation reference signal (DMRS) transmitted via a Physical Broadcast Channel (PBCH) and a Secondary Synchronization Signal (SSS), and may be transmitted to the UE through a parameter ss-PBCH-BlockPower of system information. When the estimation signal is a channel state information-reference signal (CSI-RS), the base station may transmit information on the transmission power of the CSI-RS to the UE through a parameter powercontroloffset SS (power control offset SS) of the UE-specific RRC information. In this case, powerControlOffsetSS may refer to a transmission power difference (offset) between the CSI-RS and the SSB.

UE TX UE may configure transmit power values for uplink data and control information based on the estimated downlink path loss value and may perform uplink transmissions.

In fig. 3, the base station eNB/gNB may be considered as a receiver that receives uplink data and control information from the UE. That is, the receiver (base station) may transmit a signal for path loss estimation and a transmission power of the signal for path loss estimation to the transmitter (UE), and the transmitter (UE) may configure a transmission power value for uplink data and control information transmission based on a path loss value estimated by the transmitter (UE) and may perform uplink transmission to the receiver (base station).

Similar operations may be used for bypass path loss estimation between UEs. For example, as shown in (a) of fig. 4, a Receiving (RX) UE may transmit a signal for bypass path loss estimation and information on transmission power to a Transmitting (TX) UE, and the TX UE may estimate a bypass path loss value by using the signal and the information. The RX UE may configure transmit power of the bypass data and control information based on the estimated path loss value and may perform bypass transmission to the TX UE. In more detail, in (a) of fig. 4, the RX UE may transmit a signal for path loss estimation and information on transmission power of the signal to the TX UE. The TX UE may receive a signal for path loss estimation, may measure RSRP, and may estimate path loss by using [ equation 1 ]. The TX UE may configure a bypass transmission power based on the estimated path loss value and may send bypass control information and data information to the RX UE.

As shown in (b) of fig. 4, the RX UE may transmit a signal for path loss estimation in response to a request of the TX UE. In fig. 4 (b), the TX UE may transmit a request for transmission of a signal for path loss estimation to the RX UE, and the RX UE receiving the request may transmit a signal for path loss estimation to the TX UE. In this case, the RX UE may transmit information about the transmission power of the signal for path loss estimation to the TX UE. The TX UE may measure RSRP through a signal for path loss estimation and may estimate path loss by using [ equation 1 ]. The TX UE may configure a bypass transmission power based on the estimated path loss value and may send bypass control information and data information to the RX UE.

In the present disclosure, the TX UE does not refer to a UE that transmits a signal for path loss estimation, but refers to a UE that transmits bypass data and control information. In addition, the RX UE does not refer to a UE that receives a signal for path loss estimation, but refers to a UE that receives bypass data and control information.

Fig. 5 is a schematic diagram illustrating a method of estimating inter-UE bypass path loss according to another disclosed embodiment.

Unlike in fig. 4, in fig. 5, the TX UE transmits a signal for path loss estimation, and the RX UE estimates path loss. As in fig. 4, in fig. 5, the signal for path loss estimation transmitted by the TX UE may be transmitted without a request of the RX UE ((a) of fig. 5), or may be transmitted in response to a request of the TX UE ((b) of fig. 5). In more detail, in fig. 5 (a), the TX UE may transmit a signal for path loss estimation to the RX UE, and may transmit information on transmission power of the signal. The RX UE may measure RSRP by using a signal for path loss estimation, and may estimate path loss by using [ equation 1 ]. The RX UE may report information about the path loss value estimated by the RX UE to the TX UE. The TX UE may configure a bypass transmission power based on information on a path loss value reported from the RX UE, and may transmit bypass control information and data information to the RX UE.

In fig. 5 (b), the RX UE may transmit a request for transmission of a signal for path loss estimation to the TX UE, and the TX UE receiving the request may transmit a signal for path loss estimation to the RX UE. In this case, the TX UE may transmit information about the transmission power of the signal for path loss estimation to the RX UE. The RX UE may measure RSRP through a signal for path loss estimation and may estimate path loss by using [ equation 1 ]. The RX UE may report information of the path loss value estimated by the RX UE to the TX UE. The TX UE may configure a bypass transmission power based on information on a path loss value reported from the RX UE, and may transmit bypass control information and data information to the RX UE.

The signal for path loss estimation described with reference to fig. 4 and 5 may include at least one of the following signals.

A bypass synchronization signal, which refers to a signal for obtaining time/frequency synchronization of a bypass between UEs, and may include a primary bypass synchronization signal (PSSS) and a secondary bypass synchronization signal (SSSS). In path loss estimation, only one of the PSSS and SSSS may be used, or both the PSSS and SSSS may be used. When only one of the two signals is used, the UE may be preconfigured with information about which signal among the PSSS and the SSSS is to be used for estimating the path loss. When both PSSS and SSSS are used, a UE receiving a path loss signal may measure RSRP by using a time/frequency average of PSSS and SSSS.

-demodulation reference signals (DMRSs), transmitted via a bypass broadcast channel similar to the broadcast channel (physical broadcast channel (PBCH)) transmitted by the base station to the UE in general cellular communication, a bypass broadcast channel (physical bypass broadcast channel (PSBCH)) for transmitting primary information for bypass communication that may exist in inter-UE communication. In this case, DMRS may exist in PSBCH used for channel estimation to demodulate and decode the PSBCH. The UE may measure RSRP by using DMRS, and may estimate a path loss value. In this case, the transmission power value of the PSBCH may be a fixed value, and all the bypass UEs may be configured with the transmission power value of the PSBCH from the base station through RRC signaling, or may be pre-identified (pre-configured) without the base station. The same transmission power as the PSSS/SSSS may be used as the transmission power value of the PSBCH, or the transmission power value of the PSBCH may have a fixed offset value and the transmission power value of the PSSS/SSSS. When the base station configures a transmission power value of the PSBCH, the base station may configure a transmission power value of the PSSS/SSSS in the UE, and the UE may calculate the transmission power value of the PSBCH by using a fixed offset value. Alternatively, the base station may configure the transmission power value and offset value of the PSSS/SSSS through system information or UE-specific RRC message.

DMRS, transmitted via a bypass control channel or data channel, a bypass TX UE may transmit a bypass control channel (physical bypass control channel (PSCCH)) or a bypass data channel (physical bypass shared channel (PSCCH)) to a bypass RX UE. In this case, DMRS may exist in each of PSCCH and PSCCH, and the bypass RX UE may measure RSRP by using the DMRS. In this case, the RSRP may be measured using only one of the DMRS of the PSCCH and the DMRS of the PSCCH, or may be measured using both of the DMRS of the PSCCH and the DMRS of the PSCCH. When only one measurement RSRP is used, information on which channel's DMRS among two channels may be predefined. When both the DMRS transmitted via PSCCH and the DMRS transmitted via PSCCH are used, different RSRP measurement operations may be considered according to a multiplexing method of PSCCH and PSCCH. That is, the PSCCH and PSCCH may be time or frequency divided and transmitted. When PSCCH and PSCCH are time-divided and transmitted, the bypass RX UE may measure RSRP by obtaining an average of DMRSs of PSCCH and PSCCH in the time domain. When the PSCCH and PSCCH are frequency-divided and transmitted, the bypass RX UE may measure RSRP by obtaining an average of DMRSs of the PSCCH and DMRSs of the PSCCH in the frequency domain. Alternatively, RSRP may be measured by obtaining an average in both the time and frequency domains. Information on how the bypass RX UE measures RSRP (e.g., an average in the time domain, an average in the frequency domain, or an average in both the time domain/frequency domain) may be predetermined or may be notified to the bypass RX UE by the bypass TX UE via the PSBCH.

New reference signals for supporting a bypass operation, a bypass Sounding Reference Signal (SRS), a bypass channel state information reference signal (CSI-RS) or a bypass Phase Tracking Reference Signal (PTRS) may be defined for purposes similar to existing cellular communication.

Fig. 6 is a detailed schematic diagram illustrating the process of (a) of fig. 4. In the present disclosure, the base station may be a base station supporting both V2X communication and general cellular communication, or a Road Side Unit (RSU) supporting only V2X communication. Thus, unless otherwise stated in this disclosure, a base station and an RSU may be used for the same concept and may be used interchangeably.

Also, in fig. 6, UL synchronization and RRC connection establishment and commands are each marked by dashed lines. In the present disclosure, a process or operation marked by a dotted line may be an optional process or an optional operation. That is, the processes or operations marked by dashed lines may or may not be performed. This is not only the same in fig. 6, but also in other figures below.

V2X UEs within the coverage of the base station may perform downlink synchronization and may obtain system information. In this case, downlink synchronization may be performed by a primary synchronization signal/secondary synchronization signal (PSS/SSS) received from a base station or may be performed by a synchronization signal received from a Global Navigation Satellite System (GNSS). The V2XUE performing downlink synchronization may obtain system information related to V2X through a V2X-dedicated System Information Block (SIB) transmitted by the base station gNB/RSU. In addition, the V2X UE within the coverage can perform uplink synchronization through a random access procedure with the base station and can perform an RRC connection procedure. In this case, the uplink synchronization and RRC connection procedure may be performed by only one of the transmitting UE or the receiving UE, or may be performed by both the transmitting UE and the transmitting UE.

The information on which UE among the transmitting UE and the receiving UE will perform the uplink synchronization and RRC connection procedure may vary according to a transmission mode of the bypass control information/data information, a bypass path loss estimation procedure, a signaling method, and the like. For example, as shown in fig. 6, in a mode in which the base station transmits a command for transmitting a path loss signal to the V2X receiving UE, the receiving UE may have to perform uplink synchronization and RRC connection procedures with the base station. Also, as shown in fig. 7, in a mode in which the base station transmits a command for the UE to transmit a path loss signal to V2X, the transmitting UE may have to perform uplink synchronization and RRC connection procedures with the base station.

Although not shown in fig. 6 and 7, when the base station receives a command for transmitting a path loss signal to the V2X reception UE and transmits a command for receiving a path loss signal to the V2X transmission UE, both the reception UE and the transmission UE may have to perform uplink synchronization and RRC connection procedures with the base station according to a signaling method. For example, when a command of a base station is transmitted to a V2X transmitting UE and a V2X receiving UE through Downlink Control Information (DCI), a medium access control element (MAC CE), or a UE-specific RRC message, the V2X transmitting UE and the V2X receiving UE may perform uplink synchronization and RRC connection procedures with the base station. When a command of a base station is transmitted to the V2X transmitting UE and the V2X receiving UE through the V2X system information, the V2X transmitting UE and the V2X receiving UE may not perform uplink synchronization and RRC connection procedures with the base station.

In fig. 6, the receiving UE may refer to a UE that receives bypass control information and data information, and the transmitting UE may refer to a UE that transmits bypass control information and data information. Thus, the receiving UE and the transmitting UE in fig. 6 may not be related to the transmission and reception of the path loss signal.

The V2X transmitting UE or the V2X receiving UE performing downlink synchronization or uplink synchronization with the base station and RRC connection configuration may perform bypass configuration of unicast communication. The unicast link configuration may be performed at a higher layer (e.g., application layer), and as shown in fig. 6, the unicast link configuration may be performed between a V2X transmitting UE that transmits V2X control information/data information in a unicast manner and a V2X receiving UE that receives V2X control information/data information in a unicast manner. Further, although not shown in fig. 6, the base station may participate in unicast link configuration. For example, V2X sending the UE may send a request for unicast link configuration to the base station, and the base station may send a response to the request to V2X receiving the UE. Further, the base station may send the UE to V2X and V2X receives an acknowledgement that the UE sent the unicast link configuration. However, as described above, since the procedure may be performed in a higher layer, the procedure may not be identified by the physical layer and the MAC layer.

As shown in fig. 6, the base station may receive a command to the V2X for the UE to send a signal for path loss estimation. In this case, the command of the base station may be transmitted to the V2X receiving UE through UE-specific DCI (or group common DCI) for bypass or through MAC CE or UE-specific RRC message. When a command for transmitting a signal for path loss estimation is transmitted through UE-specific DCI or group-common DCI from a base station, the DCI may be distinguished from existing cellular communication using a Radio Network Temporary Identifier (RNTI) different from the UE-specific DCI or the group-common DCI used in the existing cellular communication.

Further, unlike fig. 6, the V2X receiving UE may send a signal to the V2X that the UE sends for path loss estimation after unicast link configuration, without the command of the base station. For example, the V2X receiving UE may start a timer at a time point when the UE receives a request for unicast link configuration from the base station or V2X transmission or a time point when unicast link configuration is successful, and may transmit a signal for path loss estimation to the UE to V2X at a time point when the timer expires. Similarly, the V2X transmitting UE may start a timer from the point in time when the request for unicast link configuration is transmitted or from the point in time when unicast link configuration is successful, and may expect to receive a signal for path loss estimation from the V2X receiving UE at the point in time when the timer expires. In another example, the V2X receiving UE may send a signal for path loss estimation after a certain time period (e.g., [ x ] subframes, [ x ] slots, or [ x ] ms) from the point in time when the unicast link configuration was successful. Similarly, V2X sends a signal that the UE can receive for path loss estimation after a certain period of time (e.g., [ x ] subframes, [ x ] slots, or [ x ] ms) from the point in time when the unicast link configuration was successful.

In another example where V2X receives a signal that a UE sends for path loss estimation without a command of a base station, V2X receiving UE may send the UE signal for path loss estimation to V2X when the RSRP value measured by the UE with the base station received by V2X is equal to or greater than (or greater than) a certain threshold configured by the base station or equal to or less than (or less than) a certain threshold. In this case, the base station may configure the RSRP threshold in the V2X receiving UE through a system transmission block for V2X (V2X SIB) for V2X or a UE-specific RRC/common RRC message for V2X. In another example, the V2X receiving UE may send a signal to the V2X that the UE sends for path loss estimation when the change in RSRP value of the base station is equal to or greater than (or greater than) a certain threshold configured by the base station. Although the V2X receiving UE satisfies the condition of RSRP threshold configured by the base station, when the base station transmits a command for stopping transmission of a signal for path loss estimation, the V2X receiving UE may stop transmission of a signal for path loss estimation.

In another example in which the V2X receives a signal that the UE transmits for path loss estimation without a command of the base station, the V2X receiving UE may transmit a signal for path loss estimation when the modulation order of the V2X data information received by the V2X is equal to or less than a certain order, or less than a certain order. For example, when the modulation order of V2X data information received by the V2X receiving UE is equal to or less than 16 Quadrature Amplitude Modulation (QAM) (or QPSK less than 16-QAM), the V2X receiving UE may transmit a signal for path loss estimation to the V2X transmitting UE. In another example, when the Transport Block Size (TBS) of V2X data information received by a V2X receiving UE is equal to or greater than, a particular bit, the V2X receiving UE may send a signal to the V2X that the UE sends for path loss estimation. For example, when the TBS size of the received V2X data information is equal to or greater than (or greater than) y bits, the V2X receiving UE may send a signal to the V2X that the UE sends for path loss estimation. In another example, when the aggregation level of the V2X control channel received by the V2X receiving UE is equal to or greater than, a certain level (e.g., when the aggregation level is equal to or greater than 8, or equal to 16, i.e., greater than 8), the V2X receiving UE may send signals for path loss estimation.

In another example where V2X receives a signal that the UE sends the UE to V2X for path loss estimation without a command of the base station, the V2X receiving UE may send the UE to V2X for path loss estimation when the RSRP value of the bypass channel previously measured by the UE received by V2X is equal to or greater than (or greater than) a certain threshold configured by the base station, or equal to or less than (or less than) a certain threshold. In this case, the base station may configure the V2X to receive the RSRP threshold of the bypass channel in the UE through a system transport block (V2XSIB) for V2X or a UE-specific RRC/common RRC message for V2X. In this case, when the RSRP value of the bypass channel satisfies a specific threshold condition configured by the base station at least once, the V2X receiving UE may transmit a signal that the UE transmits for path loss estimation to the V2X transmitting UE. Alternatively, when the RSRP value of the bypass channel satisfies a certain threshold condition configured by the base station X times (or more), the V2X receiving UE may send a signal to the V2X that the UE sends for path loss estimation. In this case, X may be predefined or may be configured by the base station. In another example, the V2X receiving UE may send a signal to the V2X that the UE sends for path loss estimation when the change in RSRP value of the bypass channel is equal to or greater than (or greater than) a certain threshold configured by the base station. Even when the V2X receiving UE satisfies the condition of RSRP threshold of the bypass channel configured by the base station, the V2X receiving UE can stop transmitting the signal for path loss estimation when the base station transmits a command for stopping transmitting the signal for path loss estimation. In another example, the threshold of the RSRP value of the bypass channel or the change in the RSRP value of the bypass channel may be pre-configured without signaling from the base station.

In the above example where V2X receives a UE transmitting a signal for path loss estimation, a V2X receiving UE may refer to a UE that has the capability to transmit a signal for V2X path loss estimation. Therefore, in the UE having this capability, V2X that satisfies the above condition receives a signal that the UE can transmit for path loss estimation.

As shown in fig. 6, the base station may transmit a command for transmitting a signal for path loss estimation to the V2X receiving UE, and in this case, whether the V2X receiving UE can transmit a signal for path loss estimation may be the V2X UE capability. That is, the base station may identify a V2X UE having a capability of transmitting a signal for path loss estimation through a capability negotiation procedure with the V2X UE, and may transmit a command for transmitting a signal for V2X path loss estimation only to the UE having the capability of transmitting a signal for V2X path loss estimation. In this case, the command of the base station may be transmitted to the V2X receiving UE through UE-specific DCI (or group common DCI) for bypass or through UE-specific RRC message. The V2X receiving the command to send signals for path loss estimation may send the UEs to the V2X sending signals for path loss estimation. Alternatively, when the above conditions are satisfied without a command of the base station (e.g., timer expiration, RSRP of the base station, or modulation order), the V2X receiving UE having the capability of transmitting a signal for path loss estimation may transmit a signal for path loss estimation to the V2X transmitting UE. In this case, the V2X transmitting UE can obtain information on the transmission power of the signal for path loss estimation by using at least one of the following various methods.

A method of transmitting transmission power information on a signal for path loss estimation according to an embodiment will be described below.

-the base station sending the UE information on the transmit power of the signal for path loss estimation to V2X by RRC signaling

The base station can transmit information on the transmission power of the signal for path loss estimation to the UE to V2X through RRC signaling. Specifically, the base station may transmit information of the transmission power of the signal for path loss estimation to all V2X UEs within the cell coverage through the V2X dedicated system information block V2X SIB. In this case, the V2X transmitting UE can receive information even without RRC connection configuration with the base station. In another example, the base station may transmit, to the V2X, the UE information about the transmission power of the signal for path loss estimation transmitted by the V2X receiving UE through UE-specific RRC or UE-common RRC signaling. In this case, the V2X transmitting UE may have to perform RRC connection configuration with the base station. As described above, when the V2X transmitting UE directly receives information on the transmission power of a signal for path loss estimation from the base station, the V2X receiving UE may not transmit information on the transmission power of a signal for path loss estimation to the V2X transmitting UE.

Depending on whether V2X sends the UE to perform RRC connection configuration, the V2X system may support at least two modes: V2X sends a mode (mode a) in which the UE can operate without RRC connection configuration, and V2X sends a mode (mode B) in which the UE can operate only with RRC connection configuration. In mode a and mode B, the V2X receiving UE may operate even without an RRC connection. A new mode (mode C) may be defined in the V2X system, and in mode C, both the V2X transmitting UE and receiving UE may only operate with RRC connection configuration. Information on which mode among the above modes is to be used may be notified by the base station through system information to all V2X UEs existing within the coverage of the base station. In another example, each pattern may be mapped to a resource pool or resource of the V2X system. That is, a resource or resource pool for mode a, a resource or resource pool for mode B, and a resource or resource pool for mode C may exist, and each UE may derive which mode is to be used for operation from the time/frequency resources or resource pool received from the base station.

-V2X receiving information that the UE transmits to the V2X via a bypass broadcast channel, the UE transmitting information about the transmission power of the signal used for path loss estimation

V2X receives information that the UE can transmit to V2X via the bypass broadcast channel information about the transmit power of the signal used for path loss estimation. In this case, the information on the transmission power transmitted by the UE received by V2X may be information received from the base station. For example, as shown in fig. 1 (b), a case may be considered in which V2X receiving UEs exist within the coverage of the base station and V2X transmitting UEs exist outside the coverage of the base station. In this case, the V2X transmitting UE may not receive system information and RRC information from the base station. Accordingly, V2X existing within the coverage of the base station receives information that the UE can transmit the transmission power of a signal for path loss estimation through the bypass broadcast channel, so that V2X existing outside the coverage of the base station transmits the UE estimation bypass path loss.

In another example, as shown in fig. 1 (d), the V2X receiving UE and the V2X transmitting UE may exist in different cells. That is, V2X receiving UE-1 may exist in the coverage of base station 1, and V2X transmitting UE-2 may exist in the coverage of base station 2. In this case, V2X existing in the coverage of base station 1 receives information that UE-1 can transmit the transmission power of a signal for path loss estimation to UE-2 via a bypass broadcast channel to V2X existing in the coverage of base station 2.

V2X reception UE can transmit the transmission power information determined by the reception UE itself of V2X to V2X outside the cell coverage via a bypass broadcast channel ((b) of fig. 1) or to V2X located in a different cell ((d) of fig. 1), without transmitting the information on the transmission power received from the base station.

-V2X receiving information that the UE transmits to the V2X via the bypass control channel the UE's transmit power on the signal used for path loss estimation

V2X receives information that the UE can transmit to V2X via the bypass control channel information about the transmit power of the signal used for path loss estimation. In this case, the V2X receiving UE may transmit the information about the transmission power that the UE retransmits to the V2X and is received from the base station, or may transmit the transmission power information that the UE determines (or is pre-configured) by the V2X receiving UE itself to the V2X via the bypass control channel without transmitting the information about the transmission power received from the base station. In this case, the V2X transmitting UE may be located at the same base station (or RSU) as the V2X receiving UE, may be located at a different base station from the V2X receiving UE, or may exist outside the coverage of the base station.

-V2X receiving information on transmission power for a UE transmitting signals for path loss estimation to V2X via a bypass data channel

V2X receives information that the UE can transmit the transmission power of a signal for path loss estimation to the V2X by the MAC CE transmitted through the bypass data channel. The V2X receiving UE may retransmit the information on the transmission power received from the base station, or may transmit the transmission power information determined (or pre-configured) by the V2X receiving UE itself to the V2X via a bypass data channel without transmitting the information on the transmission power received from the base station. In this case, the V2X transmitting UE may be located in the same base station as the V2X receiving UE, may be located in a different base station from the V2X receiving UE, or may exist outside the coverage of the base station.

The V2X receives information that the UE can transmit information on the transmission power of a signal for path loss estimation to the V2X through at least one of the above embodiments. In this case, there may be various methods to configure the transmission power information of the signal for path loss estimation. When the V2X receives information that the UE transmits information on the transmission power of a signal for path loss estimation to the V2X transmitting UE, the V2X receives transmission power information that the UE can configure a signal for path loss estimation through at least one of the following embodiments.

A method of configuring information on transmission power of a signal for path loss estimation according to an embodiment will be described below.

-information about the transmission power is transmitted directly

The signal transmit power used for path loss estimation can be transmitted over [ x ] bits. For example, the transmit power of the signal used for path loss estimation may be displayed every 1dBm (by a 1dBm) in the range of-60 dBm to 50 dBm. Therefore, in the above example, the information of the transmission power of the signal for path loss estimation can be transmitted by 7 bits. The method of configuring the transmission power information on the signal for path loss estimation may vary according to the location or environment of the V2X transmitting UE and the V2X receiving UE, as described below.

When V2X transmitting UE and V2X receiving UE exist within the coverage of the same base station, V2X transmitting UE and V2X receiving UE can receive [ x ] bits as the transmission power value of the reference signal through system information or RRC signaling from the same base station. When transmitting the UE transmission power information to V2X through system information or common RRC signaling, V2X receives information that the UE may not transmit the UE transmission power for a signal for path loss estimation to V2X.

Omicron when V2X receiving UE and V2X transmitting UE exist in coverage areas of different base stations, or when V2X receiving UE exists in coverage area of a base station and V2X transmitting UE exists outside coverage area of a base station, V2X receiving UE may transmit to V2X transmission power information of a signal for path loss estimation including [ x ] bits by the UE via at least one of a bypass broadcast channel, a bypass control channel, or a bypass data channel.

The base station may receive, through V2X, an explicit or implicit command for the UE to transmit transmission of transmit power information for the signal for pathloss estimation including [ x ] bits via at least one of a bypass broadcast channel, a bypass control channel, or a bypass data channel. In case of explicit command, the base station may command transmission power information of a signal for path loss estimation through DCI or UE-specific RRC signaling transmitted to the V2X receiving UE through 1-bit indication. In case of implicit command, the base station may command by differently configuring parameters for transmitting path loss signals in the UE at V2X. For example, the base station may configure the signals for path loss estimation for transmission of path loss estimation for transmitting UEs with V2X outside the cell coverage differently from the signals for path loss estimation for transmission of path loss estimation for transmitting UEs with V2X of the same cell coverage (e.g., different sequence indices, different transmission sources, etc.). Further, the base station may differently configure the transmitted signal for pathloss estimation for transmitting pathloss estimation of a UE with V2X located in a different cell from the V2X receiving the UE and the transmitted signal for pathloss estimation for transmitting pathloss estimation of a UE with V2X located in the same cell (e.g., different sequence indices or index sets, different transmission sources, etc.).

-the offset information of the transmission power is transmitted

As in the above-described embodiment, when information on transmission power is directly transmitted, all information on transmission power of a signal used for path loss estimation is notified, resulting in signaling overhead. In particular, when [ x ] bit information is transmitted via a bypass broadcast channel or a bypass control channel, signaling overhead may increase. In order to solve these problems, a method of determining a reference signal and transmitting only offset information with respect to a transmission power value of the reference signal may be considered. In this case, the reference signal may be a synchronization signal of a 5G or NR base station (gNB), a DMRS signal transmitted via a broadcast channel (PBCH) of the gNB, or a CSI-RS of the 5G or NR base station (gNB). In another example, the reference signal may be a synchronization signal of a 4G or LTE base station, a DMRS signal transmitted via a broadcast channel of a 4G or LTE base station, or a CRS of a 4G or LTE base station (eNB). In another example, the reference signal may be a bypass synchronization signal transmitted via a bypass or a DMRS transmitted via a bypass broadcast channel. In another example, the reference signal may be a DMRS transmitted via a bypass control channel.

When the reference signal is a synchronization signal of a 5G or NR base station (gNB), a DMRS transmitted via a broadcast channel (PBCH) of the 5G or NR base station (gNB), or a CSI-RS of the gNB, the operation may vary according to the location and environment of the V2X transmitting UE and the V2X receiving UE, as shown below.

When V2X transmitting UE and V2X receiving UE exist within the coverage of the same base station, V2X transmitting UE and V2X receiving UE can receive the transmission power value of the reference signal through system information or RRC signaling from the same base station. In this case, the system information and common RRC signaling may be signaling for supporting general cellular communication, not for V2X. The offset information may be transmitted through V2X-specific system information or common RRC signaling for supporting V2X. When the offset information is transmitted to the V2X transmitting UE through V2X dedicated system information or RRC signaling for supporting V2X, the V2X receiving UE may not transmit information on transmission power of a signal for path loss estimation by the UE alone to the V2X.

O when V2X receiving UE and V2X transmitting UE exist in coverage areas of different base stations, or when V2X receiving UE exists in coverage area of a base station and V2X transmitting UE exists outside coverage area of a base station, V2X receiving UE may transmit UE transmitting offset value to V2X via at least one of a bypass broadcast channel, a bypass control channel or a bypass data channel.

The base station may send an explicit or implicit command to receive, by V2X, a transmission of offset information for the transmission power of signals used by the UE for pathloss estimation, via at least one of a bypass broadcast channel, a bypass control channel, or a bypass data channel. In case of the explicit command, the base station may instruct to transmit offset information of transmission power of a signal for path loss estimation through DCI or UE-specific signaling transmitted to the V2X receiving UE by 1 bit. In case of implicit command, the base station may command by differently configuring parameters for transmitting path loss signals in the UE at V2X. For example, the base station may differently configure signals for path loss estimation transmitted to V2X transmitting UEs existing outside the cell coverage and signals for path loss estimation transmitted to V2X transmitting UEs in the same cell coverage (e.g., different sequence indices, different transmission sources, etc.). Further, the base station may differently configure signals for path loss estimation transmitted to V2X transmitting UEs located in cells other than the V2X receiving UEs and signals for path loss estimation transmitted to V2X transmitting UEs located in the same cell (e.g., different sequence indices, different transmission sources, etc.). With this configuration, V2X receives information that the UE can determine whether to transmit to V2X the transmission power at which the UE transmits signals for path loss estimation.

Also, when the reference signal is a synchronization signal of the eNB, a DMRS transmitted via a broadcast channel (PBCH) of the eNB, or a CRS of the eNB, the operation may vary according to the location and environment of the V2X transmitting UE and the V2X receiving UE, as described below.

When V2X transmitting UE and V2X receiving UE exist within the coverage of the same base station, V2X transmitting UE and V2X receiving UE can receive the transmission power value of the reference signal through system information or RRC signaling from eNB. In this case, the system information and common RRC signaling may be signaling for supporting general 4G cellular communication (including LTE-NR dual connectivity), rather than signaling for V2X. The offset information may be transmitted through V2X-specific system information or common RRC signaling for supporting V2X. When the offset information is directly transmitted to the V2X transmitting UE through V2X dedicated system information or RRC signaling, V2X receives information that the UE may not transmit the transmission power of the signal for path loss estimation to the V2X transmitting UE.

O when V2X receiving UE and V2X transmitting UE exist in coverage areas of different base stations, or when V2X receiving UE exists in coverage area of a base station and V2X transmitting UE exists outside coverage area of a base station, V2X receiving UE may transmit an offset value of transmission power for path loss estimation signal by UE to V2X via at least one of a bypass broadcast channel, a bypass control channel, or a bypass data channel.

The base station may send explicit or implicit commands for receiving, by V2X, the transmission of the offset value for the transmit power of the signal for path loss estimation by the UE, via at least one of a bypass broadcast channel, a bypass control channel, or a bypass data channel. In case of the explicit command, the base station may transmit offset information of transmission power of a signal for path loss estimation through a 1-bit indication command to receive DCI or UE-specific RRC signaling of the UE through transmission to the V2X. In case of implicit command, the base station may command by differently configuring parameters for transmitting path loss signals in the UE at V2X. For example, the base station may configure the path loss estimation signal transmitted to a V2X transmitting UE outside the cell coverage differently from the path loss estimation signal transmitted to a V2X transmitting UE in the same cell coverage (e.g., different sequence indices, different transmission sources, etc.). Further, the base station may differently configure signals for path loss estimation transmitted to V2X transmitting UEs located in cells other than the V2X receiving UEs and signals for path loss estimation transmitted to V2X transmitting UEs located in the same cell (e.g., different sequence indices, different transmission sources, etc.).

Because there may be various reference signals, information about which reference signal to use (e.g., the type of reference signal to use) may be needed. The information may be transmitted together with a transmission power value of the reference signal or may be transmitted together with offset information.

As described above, the base station or V2X receives transmission power information that the UE can transmit a signal for path loss estimation and a signal for path loss estimation to the V2X. The V2X transmitting the UE receiving the signal for path loss estimation and the transmission power information of the signal for path loss estimation can estimate the bypassed path loss value by using [ equation 1 ]. The V2X transmitting UE may configure a transmit power value for physical channels (e.g., a bypass control channel and a bypass data channel) via which bypass control information and data information are transmitted based on the estimated path loss value. The V2X transmitting UE may receive the UE transmitting bypass control information and data information to the V2X based on the configured transmission power value.

The above embodiments may be similarly or identically applied to the multicast communication method. For example, in the multicast communication method, a group header (group header) serving as a base station for managing communication may exist in a group. Because the group header serves as a base station, the V2X UE may obtain a path loss value and may configure a transmit power value based on the path loss value.

Fig. 7 may correspond to the detailed embodiment of (b) of fig. 4. V2X UEs within the coverage of the base station may perform downlink synchronization and may obtain system information. In this case, downlink synchronization may be performed by a primary synchronization signal/secondary synchronization signal (PSS/SSS) received from a base station or may be performed by a synchronization signal received from a Global Navigation Satellite System (GNSS). The V2X UE performing downlink synchronization can obtain system information related to V2X through a V2X dedicated System Information Block (SIB) transmitted by the base station gNB/RSU. In addition, the V2X UE within the coverage can perform uplink synchronization through a random access procedure with the base station and can perform an RRC connection procedure. In this case, the uplink synchronization and RRC connection procedure may be performed by only one of the transmitting UE or the receiving UE, or may be performed by both the transmitting UE and the receiving UE.

Although not shown in fig. 6 and 7, when the base station receives a command for transmitting a path loss signal to the V2X reception UE and transmits a command for receiving a path loss signal to the V2X transmission UE, both the reception UE and the transmission UE may have to perform uplink synchronization and RRC connection procedures with the base station according to a signaling method. For example, when a command of a base station is transmitted to a V2X transmitting UE and a V2X receiving UE through Downlink Control Information (DCI), MAC CE, or UE-specific RRC message, the V2X transmitting UE and the V2X receiving UE may perform uplink synchronization and RRC connection procedures with the base station. When a command of a base station is transmitted to the V2X transmitting UE and the V2X receiving UE through the V2X system information, the V2X transmitting UE and the V2X receiving UE may not perform uplink synchronization and RRC connection procedures with the base station.

In fig. 7, a receiving UE may refer to a UE that receives bypass control information and data information, and a transmitting UE may refer to a UE that transmits bypass control information and data information. Thus, the receiving UE and the transmitting UE in fig. 7 may not be related to the transmission and reception of the path loss signal.

The V2X transmitting UE or the V2X receiving UE performing downlink synchronization or uplink synchronization with the base station and RRC connection configuration may perform bypass configuration of unicast communication. Such unicast link configuration may be performed at a higher layer (e.g., application layer), and as shown in fig. 7, the unicast link configuration may be performed between a V2X transmitting UE that transmits V2X control information/data information in a unicast manner and a V2X receiving UE that receives V2X control information/data information in a unicast manner. Further, although not shown in fig. 7, the base station may participate in unicast link configuration. For example, V2X sending the UE may send a request for unicast link configuration to the base station, and the base station may receive a response to the unicast link configuration from the UE to V2X. Further, the base station may send the UE to V2X and V2X receives an acknowledgement that the UE sent the unicast link configuration. However, as described above, since the procedure may be performed in a higher layer, the procedure may not be identified in the physical layer and the MAC layer.

As shown in fig. 7, the base station may send a command to V2X that the UE sends a request to send a signal for path loss estimation. In this case, the command of the base station may be transmitted to the V2X transmitting UE through UE-specific DCI (or group common DCI) for bypass or through MAC CE or UE-specific RRC message. When a command is sent to the V2X to send a UE through UE-specific DCI or group-common DCI, the DCI may be distinguished from existing cellular communications using a Radio Network Temporary Identifier (RNTI) that is different from the UE-specific DCI or group-common DCI used in the existing cellular communications.

Further, the command transmitted by the base station to receive the UE to V2X in fig. 6 and the command transmitted by the base station to transmit the UE to V2X in fig. 7 may be transmitted through different UE-specific DCI (or group common DCI), MAC CE, or UE-specific RRC. In this case, different UE-specific DCIs (or group-common DCIs) may be different DCI formats. Further, different MAC CEs may refer to different MAC CE formats. The V2X transmitting UE receiving the command from the base station may receive a request to the V2X transmitting a signal for path loss estimation from the UE. The V2X receiving the request may send a signal to the V2X that the UE sent for path loss estimation. In this case, the request for transmitting the signal for path loss estimation may be explicitly or implicitly performed. In case of explicit request, the V2X sending UE may request to send a signal for path loss estimation using a bit field in the bypass control information (SCI) sent via the bypass control channel. When the V2X receiving UE receives a specific signal from the V2X transmitting UE, an implicit request may be performed. For example, a V2X transmitting UE may send a bypass synchronization signal, and a V2X receiving the bypass synchronization signal may send a signal to the V2X that the UE sends for path loss estimation.

Further, unlike fig. 7, the V2X transmitting UE may transmit a request to transmit a signal for path loss estimation to the V2X receiving UE after unicast link configuration without a command of the base station. For example, the V2X transmitting UE may start a timer from a time point of receiving a request for unicast link configuration or from a time point of success of unicast link configuration, and may receive the UE transmitting a request for a signal for path loss estimation to the V2X at a time point of expiration of the timer. Similarly, the V2X receiving UE may start a timer from the point in time when the request for unicast link configuration is sent or from the point in time when unicast link configuration is successful, and may expect to send a request from the V2X receiving UE to send a signal for path loss estimation at the point in time when the timer expires. In another example, the V2X transmitting UE may receive a request to the V2X that the UE transmit a signal for path loss estimation after a certain time period (e.g., [ x ] subframes, [ x ] slots, or [ x ] ms) from the point in time when the unicast link configuration is successful. Similarly, V2X receives a request that the UE may desire to receive a signal for transmission for path loss estimation after a certain period of time (e.g., [ x ] subframes, [ x ] time slots, or [ x ] ms) from the point in time when the unicast link configuration was successful.

In another example where V2X sends a request for a UE to send signals for path loss estimation to a V2X receiving UE without a command of a base station, the V2X sending UE may send a request for a UE to send signals for path loss estimation to a V2X receiving UE when the V2X sends an RSRP value that the UE measures with the base station that is equal to or greater than (or greater than) a certain threshold configured by the base station or equal to or less than (or less than) a certain threshold. In this case, the base station may configure the RSRP threshold in the UE by transmitting the system transport block for V2X (V2X SIB) or the UE-specific RRC/common RRC message for V2X in V2X. In another example, when the change in RSRP value of the base station is equal to or greater than (or greater than) a particular threshold configured by the base station, the V2X sending UE may receive a request to the V2X receiving UE to send a signal for path loss estimation. Although the V2X sends a condition that the UE satisfies the RSRP threshold configured by the base station, when the base station sends a command to stop sending requests to send signals for path loss estimation, the V2X sends a command that the UE may stop sending requests to send signals for path loss estimation.

In another example where V2X transmits a request for a UE to transmit a signal for path loss estimation to V2X reception UE without a command of a base station, when a modulation order of V2X data information to be transmitted by V2X transmission UE is equal to or greater than a certain order, or greater than the certain order, V2X transmission UE may transmit a request for a UE to transmit a signal for path loss estimation to V2X reception UE. For example, when the modulation order of V2X data information to be transmitted by the V2X transmitting UE is equal to or greater than 64-QAM (or 256-QAM greater than 64-QAM), the V2X transmitting UE may transmit a request to transmit a signal for path loss estimation to the V2X receiving UE. In another example, when a Transport Block Size (TBS) of V2X data information to be transmitted by the V2X transmitting UE is equal to or greater than, a particular bit, the V2X transmitting UE may receive a request to the V2X receiving UE to transmit a signal for path loss estimation. For example, when the TBS size of the V2X data information to be transmitted is equal to or greater than (or greater than) y bits, the V2X transmitting UE may receive a request to the V2X that the UE transmit a signal for path loss estimation. In another example, when the aggregation level of the V2X control information to be transmitted by the V2X transmitting UE is equal to or less than, a certain level (e.g., when the aggregation level is equal to or less than 8, or equal to 4 (less than 8)), the V2X transmitting UE may receive a request to transmit a signal for path loss estimation to the V2X receiving UE.

In another example where V2X sends a signal that the UE sends to the V2X reception UE for path loss estimation without a command of the base station, the V2X sending UE may send to the V2X reception UE a signal for path loss estimation when the V2X sends the RSRP value of the bypass channel previously measured by the UE is equal to or greater than (or greater than) a certain threshold configured by the base station, or equal to or less than (or less than) a certain threshold. In this case, the base station may configure the V2X to send the RSRP threshold of the bypass channel in the UE through a system transport block (V2XSIB) for V2X or a UE-specific RRC/common RRC message for V2X. In this case, when the RSRP value of the bypass channel satisfies a specific threshold condition configured by the base station at least once, the V2X transmitting UE may transmit a signal for path loss estimation to the V2X receiving UE. Alternatively, when the RSRP value of the bypass channel satisfies a certain threshold condition configured by the base station X times (or more), the V2X transmitting UE may transmit a signal for path loss estimation to the V2X receiving UE. In this case, X may be predefined or may be configured by the base station. In another example, the V2X sending UE may send a signal for path loss estimation to the V2X receiving UE when the change in RSRP value of the bypass channel is equal to or greater than (or greater than) a certain threshold configured by the base station. Even when the V2X transmitting UE satisfies the condition of RSRP threshold of the bypass channel configured by the base station, the V2X transmitting UE may stop transmitting the signal for path loss estimation when the base station transmits a command for stopping transmitting the signal for path loss estimation. In another example, the threshold of the RSRP value of the bypass channel or the change in the RSRP value of the bypass channel may be pre-configured without signaling from the base station.

As shown in fig. 7, a V2X receiving UE receiving a request from a V2X transmitting UE to transmit a signal for path loss estimation may transmit a signal for path loss estimation to a V2X transmitting UE. In this case, the V2X transmitting UE may receive information about the transmission power of a signal for path loss estimation from the base station or V2X receiving UE. The method of transmitting information on the transmission power of the signal for path loss estimation may be performed in various ways as described with reference to fig. 6. Further, the method of configuring the transmission power information of the signal for path loss estimation may be performed by using one of various examples described with reference to fig. 6. The V2X transmitting UE receiving the UE's transmission power information of the signal for path loss estimation and the signal for path loss estimation from the base station or V2X can estimate the bypassed path loss value by using [ equation 1 ]. The V2X transmitting UE may configure a transmit power value for physical channels (e.g., a bypass control channel and a bypass data channel) via which bypass control information and data information are transmitted based on the estimated path loss value. The V2X transmitting UE may receive the UE transmitting bypass control information and data information to the V2X based on the configured transmission power value.

The above examples may be similarly or identically applied to the multicast communication method. For example, in the multicast communication method, a group header serving as a base station for managing communication may exist in a group. Because the group header serves as a base station, the V2X UE may obtain a path loss value and may configure a transmit power value based on the path loss value.

In fig. 7, there may be a time relationship between a point of time when V2X receives a request for the UE to receive a signal for path loss estimation transmitted by a V2X transmission UE and a point of time when V2X receives a signal for path loss estimation transmitted by the UE to a V2X transmission UE in response to the request. For example, in the request information transmitted by the V2X transmitting UE, the V2X transmitting UE may include timing information on a timing when a signal for path loss estimation will be received by the V2X receiving UE transmission. That is, V2X sends that the UE can transmit the timing-related information in a bit field requesting bypass control information of a signal for path loss estimation by using [ z ] bit. In this case, the unit representing the timing information may be the number of symbols (z symbols), the number of slots (z slots), or the number of subframes (z subframes). Accordingly, the V2X receiving the timing information may transmit a signal for path loss estimation after z symbols (or z slots or z subframes) from the time point of receiving the bit field. In another example, the timing information may be fixed, and the V2X transmitting UE and the V2X receiving UE may use pre-agreed values. In another example, when the V2X transmitting UE and the V2X receiving UE are located in the same base station, the base station may configure the timing information. In another example, the V2X transmitting UE may transmit the timing information configured by the base station to the V2X receiving UE existing outside the coverage of the base station or the V2X receiving UE existing in a different base station via a bypass control channel.

Until the estimated bypass path loss value in fig. 6 and 7 is reflected in transmitting actual bypass control information and data information, there are a plurality of pieces of information to be transmitted and received between the V2X receiving UE and the V2X transmitting UE. In order to transmit such information, it may be necessary to consider how to configure the transmission power value. For example, in fig. 6, the V2X transmitting UE may estimate a bypass path loss value by using a signal for path loss estimation received from the V2X receiving UE, and may configure a transmission power value for bypass control information and data information based on the estimated bypass path loss value. In this case, it may be necessary to consider how to configure the transmission power value for receiving, by V2X, signals for path loss estimation sent by a UE to a V2X sending UE. Also, in fig. 7, the V2X transmitting UE may transmit a request for transmitting a signal for path loss estimation to the V2X receiving UE, and the V2X receiving UE may transmit a signal for bypassing path loss estimation to the V2X transmitting UE based on the request. In this case, it may be necessary to consider how to configure the request for transmitting the signal for path loss estimation transmitted by the V2X transmitting UE to the V2X receiving UE and the transmission power value for V2X receiving the signal for bypassing path loss estimation transmitted by the UE to the V2X transmitting UE. At least one of the following embodiments may be used.

-using a predefined transmit power value

The base station may configure the transmit power value through V2X dedicated SIB or RRC signaling. In this case, the configured transmission power value may be a maximum transmission power value (e.g., Pcmax) of the UE, or an arbitrary value smaller than the maximum transmission power value of the UE. In this case, the base station may perform the configuration by considering the bypassed coverage and the interference of the bypassed communication to the uplink of the base station. The transmit power value may be used for all transmissions until the bypass path loss value is reflected in the transmit power value configuration of the actual bypass control information and data information.

In another example, the transmit power value may be preconfigured without signaling from the base station. The transmit power value may be used for all transmissions until the bypass path loss value is reflected in the transmit power value configuration of the actual bypass control information and data information.

-transmit power value using a bypass path loss value reflecting its own estimate

In fig. 7, the V2X receiving UE may receive a request from the V2X transmitting UE to transmit a signal for path loss estimation. When using this procedure, the V2X receiving UE can measure the bypass RSRP and can estimate the path loss value by using the request signal sent from the V2X sending UE. In this case, the transmission power value for the request for the signal for path loss estimation transmitted by the V2X transmitting UE may be obtained by the V2X receiving UE through the method of Alt 1. The V2X receiving UE may configure the transmit power value of the signal sent to the V2X transmitting UE for path loss estimation based on the path loss value estimated by the V2X receiving UE itself.

Using a value of the transmission power reflecting the downlink path loss value estimated by the base station itself

When the V2X receiving UE is present within the coverage of the base station, the V2X receiving UE can measure the downlink RSRP and can estimate the downlink path loss value by using the SSB or CSI-RS of the base station. The V2X receiving UE may configure the transmit power value of the signal sent to the V2X transmitting UE for bypassing path loss estimation based on the downlink path loss value.

When the V2X transmitting UE exists within the coverage of the base station, the V2X transmitting UE can estimate a downlink path loss value with the base station (or RSU) by using the SSB or CSI-RS of the base station. The V2X transmitting UE may configure a transmission power value of the transmission request information for a signal for bypassing path loss estimation transmitted to the V2X receiving UE based on a downlink path loss value with the base station.

When both the V2X receiving UE and the V2X sending UE are present within the coverage of the base station, the V2X receiving UE can measure the downlink RSRP by using the SSB or CSI-RS of the base station and estimate the path loss value. Further, the V2X transmitting UE can estimate a downlink path loss value with the base station (or RSU) by using the SSB or CSI-RS of the base station. In this case, in fig. 7, the V2X transmitting UE may configure the transmission power value of the transmission request information of the signal for bypass path loss estimation transmitted to the V2X receiving UE based on the downlink path loss value estimated by the V2X transmitting UE itself. The V2X receiving UE may configure a transmit power value of a signal transmitted to the V2X transmitting UE for bypassing path loss estimation based on a downlink path loss value with the base station.

Fig. 8A may correspond to the detailed embodiment of fig. 5 (a). V2X UEs within the coverage of the base station may perform downlink synchronization and may obtain system information. In this case, downlink synchronization may be performed by a primary synchronization signal/secondary synchronization signal (PSS/SSS) received from a base station or may be performed by a synchronization signal received from a Global Navigation Satellite System (GNSS). The V2X UE performing downlink synchronization can obtain system information related to V2X through a V2X dedicated System Information Block (SIB) transmitted by the base station. In addition, the V2X UE within the coverage can perform uplink synchronization with the base station through a random access procedure with the base station and can perform an RRC connection procedure. In this case, the uplink synchronization and RRC connection procedure may be performed by only one of the transmitting UE or the receiving UE, or may be performed by both the transmitting UE and the receiving UE. The information on which UE among the transmitting UE and the receiving UE will perform the uplink synchronization and the RRC connection procedure may vary according to a transmission mode of the bypass control information/data information, a bypass path loss estimation procedure, and a signaling method. For example, as shown in fig. 8A, in a mode in which the base station transmits a command for the UE to transmit a path loss signal to V2X, the transmitting UE may have to perform uplink synchronization and RRC connection procedures with the base station. Also, as shown in fig. 9, in a mode in which the base station transmits a command for transmitting a path loss signal to the V2X receiving UE, the receiving UE may have to perform uplink synchronization and RRC connection procedures with the base station. Although not shown in fig. 8A and 9, when the base station transmits a command for transmitting a path loss signal to the V2X for the UE and transmits a command for receiving a path loss signal to the V2X for the UE, both the receiving UE and the transmitting UE may have to perform uplink synchronization and RRC connection procedures with the base station according to a signaling method. For example, when a command of a base station is transmitted to a V2X transmitting UE and a V2X receiving UE through DCI, MAC CE, or UE-specific RRC, the V2X transmitting UE and the V2X receiving UE may perform uplink synchronization and RRC connection procedures with the base station. When a command of a base station is transmitted to the V2X transmitting UE and the V2X receiving UE through the V2X system information, the V2X transmitting UE and the V2X receiving UE may not perform uplink synchronization and RRC connection procedures with the base station.

The V2X transmitting UE or receiving UE performing uplink synchronization and RRC connection configuration with the base station may perform unicast link configuration. The unicast link configuration may be at a higher layer (e.g., application layer), and as shown in fig. 8A, the unicast link configuration may be performed between a V2X transmitting UE that transmits V2X control information/data information in a unicast manner and a V2X receiving UE that receives V2X control information/data information in a unicast manner. Further, although not shown in fig. 8A, the base station may participate in a unicast link configuration. For example, V2X sending the UE may send a request for unicast link configuration to the base station, and the base station may send a response to the request to V2X receiving the UE. Further, the base station may send the UE to V2X and V2X receives an acknowledgement that the UE sent the unicast link configuration. However, as described above, since the procedure may be performed in a higher layer, the procedure may not be identified in the physical layer and the MAC layer.

As shown in fig. 8A, the base station may send a command to V2X for the UE to send signals for path loss estimation. In this case, the command of the base station may be transmitted to the V2X transmitting UE through UE-specific DCI (or group common DCI) for bypass or through MAC CE or UE-specific RRC. When a command to transmit a signal for path loss estimation is transmitted to a V2X transmitting UE through UE-specific DCI or group-common DCI, the DCI may be distinguished from existing cellular communication using a Radio Network Temporary Identifier (RNTI) different from the UE-specific DCI or the group-common DCI used in the existing cellular communication.

Further, unlike in fig. 8A, the V2X transmitting UE may transmit a signal for path loss estimation after unicast link configuration without a command of the base station. For example, the V2X transmitting UE may start a timer from a point in time when a request for unicast link configuration is received or from a point in time when unicast link configuration is successful, and may transmit a signal for path loss estimation at a point in time when the timer expires. Similarly, the V2X receiving UE may start a timer from the point in time when the request for unicast link configuration is sent or from the point in time when unicast link configuration is successful, and may expect to receive a signal for path loss estimation from the V2X transmitting UE at the point in time when the timer expires. In another example, the V2X transmitting UE may transmit a signal for path loss estimation after a certain period of time (e.g., after [ x ] subframes, [ x ] slots, or [ x ] ms) from the point in time when the unicast link configuration was successful.

In another example where V2X sends a signal that the UE sends for path loss estimation without a command of the base station, when the V2X sends that the RSRP value of the base station that the UE measures is equal to or greater than (or greater than) a certain threshold configured by the base station or equal to or less than (or less than) a certain threshold, the V2X sending UE may send a signal for path loss estimation to the V2X receiving UE. In this case, the base station may transmit the RSRP value in the UE through a system transport block for the V2X SIB (V2X SIB) or a UE-specific RRC/common RRC message for V2X in the V2X. In another example, the V2X sending UE may send a signal for path loss estimation to the V2X receiving UE when the change in RSRP value of the base station is equal to or greater than (or greater than) a certain threshold configured by the base station. Although the V2X transmitting UE satisfies the condition of RSRP value configured by the base station, when the base station transmits a command for stopping transmission of a signal for path loss estimation, the V2X transmitting UE may stop transmission of the signal for path loss estimation.

In another example in which the V2X transmits a signal that the UE transmits for path loss estimation without a command of the base station, the V2X transmits a signal that the UE can transmit for path loss estimation when the modulation order of the V2X data information to be transmitted by the V2X transmission UE is equal to or greater than, a certain order. For example, when the modulation order of V2X data information to be transmitted by the V2X transmitting UE is equal to or greater than 64-QAM (or 256-QAM greater than 64-QAM), the V2X transmitting UE may transmit a signal for path loss estimation to the V2X receiving UE. In another example, the V2X transmission UE may transmit a signal for path loss estimation when an aggregation level of V2X control information to be transmitted by the V2X transmission UE is equal to or less than, a certain level (e.g., when the aggregation level is equal to or less than 8, or equal to 4 (less than 8)). In another example, when the TBS size of V2X data information to be transmitted by a V2X transmitting UE is equal to or greater than (or greater than) a certain number of bits, the V2X transmitting UE may receive a signal that the UE transmits for path loss estimation to the V2X receiving UE. In another example, when there is bypass control information and data information to be transmitted by the V2X transmitting UE to the V2X receiving UE, the V2X transmitting UE may always transmit a signal for path loss estimation to the V2X receiving UE along with the bypass control information and data information.

In another example where V2X sends a signal that the UE sends to the V2X reception UE for path loss estimation without a command of the base station, the V2X sending UE may send to the V2X reception UE a signal for path loss estimation when the V2X sends the RSRP value of the bypass channel previously measured by the UE is equal to or greater than (or greater than) a certain threshold configured by the base station, or equal to or less than (or less than) a certain threshold. In this case, the base station may transmit the RSRP threshold of the configured bypass channel in the UE in V2X through a system transport block (V2XSIB) for V2X, or a UE-specific RRC/common RRC message for V2X. In this case, when the RSRP value of the bypass channel satisfies a specific threshold condition configured by the base station at least once, the V2X transmitting UE may transmit a signal for path loss estimation to the V2X receiving UE. Alternatively, when the RSRP value of the bypass channel satisfies a certain threshold condition configured by the base station X times (or more), the V2X transmitting UE may transmit a signal for path loss estimation to the V2X receiving UE. In this case, X may be predefined or may be configured by the base station. In another example, the V2X sending UE may send a signal for path loss estimation to the V2X receiving UE when the change in RSRP value of the bypass channel is equal to or greater than (or greater than) a certain threshold configured by the base station. Even when the V2X transmitting UE satisfies the condition of the bypass RSRP threshold of the bypass channel configured by the base station, the V2X transmitting UE may stop transmitting the signal for path loss estimation when the base station transmits a command for stopping transmitting the signal for path loss estimation. In another example, a threshold value of the RSRP value of the bypass channel or a change in the RSRP value of the bypass channel may be pre-configured without signaling from the base station.

In the above example where V2X transmits a UE transmitting a signal for path loss estimation, a V2X transmitting UE may refer to a UE that has the capability to transmit a signal for V2X path loss estimation. Therefore, among UEs having this capability, the V2X transmitting UE satisfying the above condition may transmit a signal for path loss estimation.

As shown in fig. 8A, the base station may send a command to the V2X for the UE to send signals for path loss estimation, and whether the V2X sending UE is able to send signals for path loss estimation may be V2X UE capability (i.e., only UEs with the capability to send signals for V2X path loss estimation may send signals for V2X path loss estimation). In this case, the command of the base station may be sent to the UE through UE-specific DCI (or group-common DCI) for bypass or through UE-specific RRC message to V2X having this capability. A V2X transmitting UE receiving a command to transmit a signal for path loss estimation may transmit a signal for path loss estimation to a V2X receiving UE. Alternatively, when the above conditions are satisfied (e.g., timer expiration, RSRP of the base station, or modulation order), the V2X transmitting UE that is to transmit a signal for path loss estimation may transmit a signal for path loss estimation to the V2X receiving UE. In this case, the V2X receiving UE can obtain information on the transmission power of a signal for path loss estimation by using one of the following various methods.

A method of transmitting information on transmission power of a signal for path loss estimation according to an embodiment will be described below.

-the base station receives information about the transmission power of the signal sent by the UE for path loss estimation to V2X through RRC signaling

The base station can receive information on the transmission power of the signal for path loss estimation transmitted by the UE to V2X through RRC signaling. Specifically, the base station may transmit information on the transmission power of a signal for path loss estimation to all V2X UEs within the cell coverage through the V2X dedicated system information block V2X SIB. In this case, the V2X receiving UE can receive information even when there is no RRC connection configuration with the base station. In another example, the base station may transmit information about transmission power of a signal for path loss estimation transmitted by the V2X receiving UE to the V2X through UE-specific RRC or UE-common RRC signaling. In this case, the V2X receiving UE may have to perform RRC connection configuration with the base station. As described above, when the V2X receives the information that the UE directly receives from the base station about the transmission power of the signal for path loss estimation, the V2X receives the information that the UE may not transmit to the V2X about the transmission power of the signal for path loss estimation.

-V2X transmitting UE information about transmission power of signal for path loss estimation to V2X receiving UE via bypass broadcast channel

V2X sends information that the UE can send to V2X information about the transmit power of the signal used for path loss estimation via the bypass broadcast channel. In this case, the information on the transmission power transmitted by the V2X transmitting UE may be information received from the base station. For example, as shown in fig. 1 (b), a scenario in which the V2X transmitting UE exists within the coverage of the base station, and the V2X receiving UE exists outside the coverage of the base station may be considered. In this case, the V2X receiving UE may not be able to receive system information and RRC information from the base station. Accordingly, the V2X transmitting UE existing within the coverage of the base station can transmit information on the transmission power of the signal for path loss estimation via the bypass broadcast channel, so that the V2X existing outside the coverage of the base station receives the UE estimating the bypass path loss.

In another example, as shown in fig. 1 (d), the V2X receiving UE and the V2X transmitting UE may exist in different cells. That is, V2X receiving UE-1 may exist in the coverage of base station 1, while V2X transmitting UE-2 may exist in the coverage of base station 2. In this case, the V2X existing in the coverage of the base station 2 transmits information that the UE-2 can transmit the transmission power of the signal for path loss estimation to the V2X existing in the coverage of the base station 1 via the bypass broadcast channel to the UE-1.

The V2X transmitting UE can transmit transmission power information determined by the V2X transmitting UE itself to the V2X receiving UE outside the cell coverage (fig. 1 (b)) or the V2X receiving UE located in a different cell (fig. 1 (d)) via the bypass broadcast channel without transmitting information on transmission power received from the base station.

-V2X transmitting UE receiving information about transmission power of signal for path loss estimation to V2X receiving UE via bypass control channel

V2X sends information that the UE can send to V2X information about the transmit power of the signal used for path loss estimation via the bypass control channel. In this case, the V2X transmitting UE may retransmit the information on the transmission power received from the base station to the V2X receiving UE, or may transmit the transmission power information determined (or pre-configured) by the V2X transmitting UE itself to the V2X receiving UE via the bypass control channel without transmitting the information on the transmission power received from the base station. In this case, the V2X receiving UE may be located at the same base station (or RSU) as the V2X transmitting UE, may be located at a different base station from the V2X transmitting UE, or may exist outside the coverage of the base station.

-V2X transmitting UE information about transmission power of signal for path loss estimation to V2X receiving UE via bypass data channel

V2X transmitting UE can receive information about transmission power of a signal for path loss estimation transmitted by the UE to V2X through MAC CE transmitted through a bypass data channel. The V2X transmission UE may retransmit the information on the transmission power received from the base station, or may transmit the transmission power information determined (or pre-configured) by the V2X transmission UE itself to the V2X via a bypass data channel without transmitting the information on the transmission power received from the base station. In this case, the V2X receiving UE may be located at the same base station (or RSU) as the V2X transmitting UE, may be located at a different base station from the V2X transmitting UE, or may exist outside the coverage of the base station.

The V2X transmitting UE may receive information on transmission power of a signal for path loss estimation transmitted by the UE to the V2X through at least one of the above embodiments. In this case, there may be various methods to configure the transmission power information of the signal for path loss estimation. When the V2X transmitting UE receives information on transmission power of a signal for path loss estimation transmitted by the UE to the V2X, the V2X transmitting UE can configure the transmission power information of the signal for path loss estimation by using at least one of the following embodiments.

A method of configuring information of transmission power of a signal for path loss estimation according to an embodiment will be described below.

-information about the transmission power is transmitted directly

The transmission power of the signal used for path loss estimation can be transmitted by [ x ] bits. For example, the transmit power of a signal used for path loss estimation may be displayed every 1dBm in the range of-60 dBm to 50 dBm. Therefore, in the above example, the information of the transmission power of the signal for path loss estimation can be transmitted by 7 bits. The method of configuring the transmission power information of the signal for path loss estimation may vary according to the location or environment of the V2X transmitting UE and the V2X receiving UE, as described below.

When V2X transmitting UE and V2X receiving UE exist within the coverage of the same base station, V2X transmitting UE and V2X receiving UE can receive [ x ] bits as the transmission power value of the reference signal through system information or RRC signaling from the same base station. When receiving the UE transmission power information to the V2X through system information or common RRC signaling, the V2X transmission UE may not receive information on the transmission power of a signal for path loss estimation to the V2X.

O when V2X transmitting UE and V2X receiving UE exist within the coverage of different base stations, or when V2X transmitting UE may exist within the coverage of a base station and V2X receiving UE exists outside the coverage of a base station, V2X transmitting UE may transmit to V2X receiving UE transmission power information of a signal for path loss estimation including [ x ] bits via at least one of a bypass broadcast channel, a bypass control channel, or a bypass data channel.

The base station may transmit an explicit or implicit command for transmission of information (including [ x ] bits) for transmitting the transmit power of a signal for path loss estimation by the V2X transmitting the UE via at least one of a bypass broadcast channel, a bypass control channel, or a bypass data channel. In case of the explicit command, the base station may command to transmit information on transmission power of a signal for path loss estimation through DCI or UE-specific RRC signaling transmitted to the V2X transmission UE through a 1-bit indication. In case of implicit command, the base station may command by differently configuring parameters for transmitting a path loss signal in the V2X transmitting UE. For example, the base station may configure the signals for path loss estimation transmitted for path loss estimation of a receiving UE for V2X outside of cell coverage differently from the signals for path loss estimation transmitted for path loss estimation of a receiving UE for V2X in the same cell coverage (e.g., different sequence indices, different transmission sources, etc.). Further, the base station may configure the signals for path loss estimation transmitted for path loss estimation of a V2X receiving UE located in a different cell than the V2X transmitting UE and the signals for path loss estimation transmitted for path loss estimation of a V2X receiving UE located in the same cell differently (e.g., different sequence index or set of indices, different transmission sources, etc.).

-the offset information of the transmission power is transmitted

As in the above-described embodiment, when information on transmission power is directly transmitted, all information on transmission power of a signal used for path loss estimation is notified, resulting in signaling overhead. In particular, when [ x ] bit information is transmitted via a bypass broadcast channel or a bypass control channel, signaling overhead may increase. In order to solve these problems, a method of determining a reference signal and transmitting only offset information with respect to a transmission power value of the reference signal may be considered. In this case, the reference signal may be a synchronization signal of a 5G or NR base station (gNB), a DMRS transmitted via a broadcast channel (PBCH) of the gNB, or a CSI-RS of the 5G or NR base station (gNB). In another example, the reference signal may be a synchronization signal of a 4G or LTE base station (eNB), a DMRS transmitted via a broadcast channel of the 4G or LTE base station (eNB), or a CRS of the 4G or LTE base station (eNB). In another example, the reference signal may be a bypass synchronization signal transmitted via a bypass or a DMRS transmitted via a bypass broadcast channel. In another example, the reference signal may be a DMRS transmitted via a bypass control channel.

When the reference signal is a synchronization signal of a 5G or NR base station (gNB), a DMRS transmitted via a broadcast channel (PBCH) of the 5G or NR base station (gNB), or a CSI-RS of the gNB, the operation may vary according to the location and environment of the V2X transmitting UE and the V2X receiving UE as shown below.

When V2X transmitting UE and V2X receiving UE exist within the coverage of the same base station, V2X transmitting UE and V2X receiving UE can receive the transmission power value of the reference signal through system information or RRC signaling from the same base station. In this case, the system information and common RRC signaling may be signaling for supporting general cellular communication, not for V2X. The offset information may be transmitted through V2X-specific system information or common RRC signaling for supporting V2X. When the offset information is transmitted to the V2X receiving UE through V2X dedicated system information or RRC signaling for supporting V2X, the V2X transmitting UE may not transmit information on transmission power of a signal for path loss estimation to the V2X receiving UE.

Omicron when V2X receiving UE and V2X transmitting UE exist within the coverage of different base stations, or when V2X receiving UE exists within the coverage of a base station and V2X transmitting UE exists outside the coverage of a base station, V2X receiving UE can transmit offset value to V2X receiving UE via at least one of bypass broadcast channel, bypass control channel and bypass data channel.

The base station may send an explicit or implicit command to send, by the V2X, offset information for the transmit power of the signal used for pathloss estimation via at least one of the bypass broadcast channel, the bypass control channel, or the bypass data channel. In case of the explicit command, the base station may command to transmit offset information of transmission power of a signal for path loss estimation through DCI or UE-specific signaling transmitted to the V2X transmission UE through 1 bit. In the case of an implicit command, the base station may command by differently configuring the parameters used to send the UE path loss signal to V2X. For example, the base station may differently configure signals for path loss estimation transmitted to V2X receiving UEs existing outside the cell coverage and signals for path loss estimation transmitted to V2X receiving UEs in the same cell coverage (e.g., different sequence indices, different transmission sources, etc.). Further, the base station may differently configure signals for path loss estimation transmitted to V2X receiving UEs located in a cell different from the V2X transmitting UEs and signals for path loss estimation transmitted to V2X receiving UEs located in the same cell (e.g., different sequence indices, different transmission sources, etc.). With this configuration, the V2X transmitting UE can determine whether to transmit information on the transmission power of a signal for path loss estimation to the V2X receiving UE.

Also, when the reference signal is a synchronization signal of the eNB, a DMRS transmitted via a broadcast channel (PBCH) of the eNB, or a CRS of the base station, the operation may vary according to the location and environment of the V2X transmitting UE and the V2X receiving UE, as described below.

When V2X transmitting UE and V2X receiving UE exist within the coverage of the same base station, V2X transmitting UE and V2X receiving UE can receive the transmission power value of the reference signal through system information or RRC signaling from eNB. In this case, the system information and common RRC signaling may be signaling for supporting general 4G cellular communication (including LTE-NR dual connectivity), rather than signaling for V2X. The offset information may be transmitted through V2X-dedicated system information or common RRC signaling supporting V2X. When the offset information is directly transmitted to the V2X transmitting UE through V2X dedicated system information or RRC signaling, V2X transmits information on transmission power that the UE may not transmit a signal for path loss estimation to the V2X receiving UE.

O when V2X receiving UE and V2X transmitting UE exist in coverage areas of different base stations, or when V2X transmitting UE exists in coverage area of a base station and V2X receiving UE exists outside coverage area of a base station, V2X transmitting offset value of transmission power by which UE can receive UE transmission path loss estimation signal to V2X via at least one of bypass broadcast channel, bypass control channel or bypass data channel.

The base station may send an explicit or implicit command to the V2X sending the UE to send the offset value for the transmit power of the signal for pathloss estimation via at least one of a bypass broadcast channel, a bypass control channel, or a bypass data channel. In case of the explicit command, the base station may instruct to transmit the offset information of the transmission power of the signal for path loss estimation through DCI or UE-specific RRC signaling transmitted to the V2X transmission UE by 1 bit. In case of implicit command, the base station may command by differently configuring V2X to send parameters in the UE for sending path loss signals. For example, the base station may differently configure signals for path loss estimation transmitted to V2X receiving UEs existing outside the cell coverage and signals for path loss estimation transmitted to V2X receiving UEs in the same cell coverage (e.g., different sequence indices, different transmission sources, etc.). Further, the base station may differently configure signals for path loss estimation transmitted to V2X receiving UEs located in a cell different from the V2X transmitting UEs and signals for path loss estimation transmitted to V2X receiving UEs located in the same cell (e.g., different sequence indices, different transmission sources, etc.). With this configuration, the V2X transmitting UE can determine whether to transmit information on the transmission power of a signal for path loss estimation to the V2X receiving UE.

As described above, the base station or V2X transmitting UE may receive transmission power information of the signal for path loss estimation and the signal for path loss estimation transmitted by the UE to V2X. The V2X receiving the signal for path loss estimation and the transmission power information of the signal for path loss estimation may receive the path loss value of the bypass by using [ equation 1 ]. The V2X receiving UE may send UE report estimation result to V2X. In this case, the reporting method may be performed by one of the following various methods.

Referring to fig. 8A, the V2X receiving UE may send UE report path loss estimation result to V2X, and in this case, the V2X receiving UE may report RSRP measured by the V2X receiving UE itself, or may directly report path loss value estimated by the V2X receiving UE itself.

A method of configuring report information according to an embodiment will be described below.

-reporting the measured RSRP value

V2X the receiving UE may send a UE report to V2X L1-RSRP or L3-RSRP measured by the receiving UE itself of V2X. In this case, L1-RSRP may refer to layer 1(PHY layer) RSRP, and L3-RSRP may refer to layer 3 RSRP. L1-RSRP may refer to an instantaneous RSRP value measured at the physical layer. In contrast, L3-RSRP may refer to an RSRP value obtained by layer 3 by averaging L1-RSRP over a particular time period (e.g., 100 ms). In this case, a filter coefficient for obtaining the average may be required. When averaging the L1-RSRP, the filter coefficients may be used to determine a weight value between the past measured RSRP value and the now measured RSRP value. The information on the filter coefficient may use a filter coefficient value configured from the base station or predetermined.

-reporting the estimated path loss value

The V2X receiving UE can directly report the path loss value estimated by the V2X receiving UE itself. For this reason, the V2X receiving UE may need to obtain information about the transmission power of the signal for path loss estimation transmitted by the V2X transmitting UE. The information may be transmitted by referring to various embodiments described with respect to a method of transmitting information on transmission power of a signal for path loss estimation or a method of configuring transmission power information of a signal for path loss estimation.

Referring to fig. 8A, the V2X receiving UE may send a UE report to V2X the RSRP measured by the UE itself received by V2X, or may report the pathloss value measured by the UE itself received by V2X. In this case, the reported RSRP value or path loss value may be transmitted through the following channels.

A channel through which report information is transmitted according to an embodiment will be described below.

-transmitting via a bypass feedback channel (physical bypass feedback channel, PSFCH)

V2X the receiving UE can send to V2X via the bypass feedback channel the UE either the RSRP value measured by the receiving UE itself of V2X or the path loss value estimated by the receiving UE itself of V2X. In this case, via the feedback channel, only the RSRP or the path loss value may be transmitted, or the RSRP or the path loss value may be multiplexed with at least one of the other bypass feedback information and may be transmitted. In this case, the bypass feedback information (SFI) may include an automatic repeat request (ARQ) -acknowledgement (HARQ-ACK), Channel State Information (CSI), a Rank Indicator (RI), a Precoder Matrix Indicator (PMI), a Layer Indicator (LI), or a Scheduling Request (SR) for a bypass channel.

-transmission via a bypass data channel (physical bypass shared channel (psch))

RSRP values measured by the UEs received by V2X or path loss values estimated by the UEs received by V2X may be sent via the bypass data channel. In this case, the RSRP value or the estimated path loss value may be multiplexed with at least one of the bypass data information and the other bypass feedback information transmitted via the bypass feedback channel as described above, and may be transmitted. Further, when the V2X receives that the UE does not have data information to send to the V2X sending UE, but a bypass data channel is allocated from the base station/RSU or another V2X UE, only the RSRP value or the estimated path loss value may be sent via the bypass data channel, or may be multiplexed with at least one of the other pieces of bypass feedback information and may be sent.

In another example where RSRP values or estimated path loss values are sent via a bypass data channel, V2X receives MAC Control Elements (CEs) that the UE may use sent via the bypass data channel.

When a specific V2X receiving UE reports an RSRP value or a path loss value by using the above-described channel, other V2X receiving UEs may also perform reporting. Therefore, in order to prevent collision and interference between resources used by different V2X receiving UEs, it may be necessary to allocate and control the resources transmitting the reported information. For this reason, the following methods may exist.

Resources for transmitting the reported information according to the embodiment will be described below.

-base station allocating resources for reporting

When V2X receiving UEs and V2X transmitting UEs are present in the coverage of the base station, the base station may allocate time/frequency resources in which V2X receiving UEs will send reports. Further, the base station may allocate time/frequency resources where V2X sends a report that the UE will receive.

This allocation information may be sent to the V2X receiving UE and the V2X transmitting UE via UE-specific RRC messages or common RRC messages.

In another example, the base station may allocate resources to V2X receiving the UE by using the UE-specific DCI sent for the bypass control information, and may send the UE to V2X sending resource information to be received by V2X sending the UE by using the UE-specific DCI sent for the bypass control information. In this case, the format of DCI transmitted to the V2X transmitting UE and the format of DCI transmitted to the V2X receiving UE may be different from each other. However, in this case, since DCI must be transmitted to each of the transmitting UE and the receiving UE, signaling overhead may increase. To solve this problem, the resource allocation information may be simultaneously transmitted to the transmitting UE and the receiving UE by using the group common DCI.

In another example, there may be a relationship between the resources on which the signals for path loss estimation are received by the V2X and the resources on which V2X receives the signals to be reported by the UE for RSRP or path loss values. In this case, the V2X receiving UE may be preconfigured with resources in which signals for path loss estimation are to be received from the base station. Thus, the V2X receiving UE may derive the time/frequency/code resources available for the V2X receiving UE to report to the V2X sending UE by using the time/frequency/code resources of the signal received by the V2X receiving UE for path loss estimation.

V2X receiving UEs may be present within the coverage of the base station, while V2X transmitting UEs may be present outside the coverage of the base station. In this case, although the base station may allocate time/frequency resources in which the V2X reception UE will transmit the report, the base station may not allocate time/frequency resources in which the V2X transmission UE will receive the report. In this case, there may be separate resources for V2X UEs that are out of coverage of the base station. The resources may be orthogonal in the time/frequency/code domain to the resources that may be used by V2X UEs present within the coverage of the base station. Therefore, in consideration of this, the base station may allocate resources, on which the V2X receiving UE can transmit the report, from among the time/frequency resources on which the V2X transmitting UE can receive the report.

O can receive UE through UE-specific RRC message or common RRC message and send allocation information of UE transmission resource where V2X receiving UE can report to V2X and V2X. In another example, the base station may receive the UE allocation resource to V2X by using the UE-specific DCI sent for the bypass control information.

In another example, there may be a relationship between the resources on which the signals for path loss estimation are received by the V2X and the resources on which V2X receives the signals to be reported by the UE for RSRP or path loss values. In this case, since the V2X transmitting UE exists outside the coverage of the base station, the V2X transmitting UE may be pre-configured with resources for transmitting signals for path loss estimation. V2X receives resources that the UE may be configured with from the base station for receiving signals for path loss estimation. Thus, the V2X receiving UE can derive the time/frequency/code resources available for the V2X receiving UE to send UE reports to the V2X by using the time/frequency/code resources of the signals received by the V2X receiving UE itself for path loss estimation.

V2X receiving UEs may be present outside the base station coverage, while V2X transmitting UEs may be present within the base station coverage. In this case, although the base station may allocate time/frequency resources in which the V2X transmission UE will transmit a signal for path loss estimation, the base station may not allocate time/frequency resources in which the V2X reception UE will transmit a report. In this case, there may be separate resources for V2X UEs that are out of coverage of the base station. The resources may be orthogonal in the time/frequency/code domain to the resources that may be used by V2X UEs that exist within the coverage of the base station. Thus, in view of this, the base station may allocate time/frequency/code resources where the V2X transmitting UE may transmit signals for path loss estimation. In this case, there may be a relationship between the resources on which signals for path loss estimation are sent by the V2X to the UE and the resources on which V2X receives the RSRP or path loss value to be reported by the UE.

The allocation information of resources for which the UE transmits signals for path loss estimation may be transmitted to V2X through a UE-specific RRC message or a common RRC message. In another example, the base station may allocate resources for transmitting signals for path loss estimation to the UE by transmitting the UE to V2X using UE-specific DCI. The V2X receiving UE can derive the time/frequency/code resources available for the V2X receiving UE to send UE reports to the V2X by using the time/frequency/code resources of the signals received by the V2X receiving UE itself for path loss estimation.

Both V2X receiving UEs and V2X transmitting UEs may be present outside the coverage of the base station. In this case, the base station may not allocate time/frequency resources for V2X to receive the report to be transmitted by the UE and time/frequency resources for V2X to transmit the report to be received by the UE. In this case, there may be separate resources for V2X UEs that are out of coverage of the base station. The resources may be orthogonal in the time/frequency/code domain to the resources that may be used by V2X UEs present within the coverage of the base station.

There may be a relationship between the resources used by V2X to receive signals received by the UE for path loss estimation and the resources V2X to receive signals to report RSRP or path loss values. Thus, the V2X receiving UE can derive the time/frequency code resources available for the V2X receiving UE to send UE reports to the V2X by using the time/frequency/code resources of the signals received by the V2X receiving UE itself for path loss estimation.

Another V2X UE allocating resources for reporting

V2X sending reports that the UE can allocate resources for V2X receiving the UE. In this case, the resource allocation information for the report may be explicitly transmitted via the bypass control channel. Further, the resource allocation information may be transmitted together with resource allocation information in which V2X receives a signal that the UE receives for path loss estimation. Further, the V2X transmitting UE may be configured with resource allocation information from the base station for the V2X receiving UE's report, and may transmit the information received from the base station to the V2X receiving UE via the bypass control channel. In this case, the base station may transmit the UE transmission resource candidates for reporting to V2X, and V2X transmits that the UE may select one of the resource candidates configured from the base station and may receive the UE notification of the selected one to V2X via the bypass control channel.

The resource allocation information for the report may be sent implicitly. In this case, there may be a relationship between the resources on which the signals for path loss estimation received by the UE are received by V2X and the resources in which V2X receives the RSRP or path loss value to be reported by the UE. The V2X receiving UE may be configured with resources in which the V2X receives a signal that the UE will receive from the base station for path loss estimation or may send UE reception information from V2X. Thus, the V2X receiving UE may derive the time/frequency/code resources available for the V2X receiving UE to report to the V2X transmitting UE by using the time/frequency/code resources used by the V2X receiving UE's own signals for path loss estimation from the base station or V2X transmitting UE.

When the V2X receiving UE receives a signal for path loss estimation from the V2X transmitting UE and then transmits a UE report result to V2X, the V2X receiving UE may report the result periodically or aperiodically. In an embodiment, the periodic or aperiodic report may be associated with the interval at which V2X receives the UE to perform the reporting. For example, in case of periodic reporting, the receiving UE may continuously perform reporting during the reporting interval, i.e. between the start time and the end time of the reporting. Further, in the case of aperiodic reporting, the receiving UE may perform reporting once at a reporting time instead of configuring an interval at which the reporting is performed. Further, after V2X receives the signal that the UE receives for path loss estimation from the V2X transmitting UE, V2X receives the reporting occasion that the UE needs to determine when to perform reporting.

The report time according to the embodiment will be described below.

-receiving signalling from a base station

The base station may receive the UE through RRC or MAC CE signaling to V2X and transmit a time interval for the UE notification to be performed to V2X. The V2X receiving UE that has received the RRC or MAC CE signal may start reporting after a certain period of time (e.g., [ x1] symbols, [ x2] slots, or [ x3] subframes from a time point when RRC signaling is received from the base station through a downlink and HARQ-ACK is transmitted to the base station through an uplink). Once reporting begins, the V2X receiving UE may perform sending UE reports to V2X during an interval configured by the base station. This operation may be referred to as periodic reporting or semi-continuous reporting.

In another example, the base station may transmit a UE notification to the V2X of a point in time when reporting is to be performed to the UE and the V2X through UE-specific DCI or group-common DCI. The V2X receiving the UE may transmit a report based on the timing information included in the received UE-specific DCI or group-common DCI. The V2X transmitting UE may receive the report based on the timing information included in the received UE-specific DCI or group-common DCI. In another example, a V2X receiving a UE that has received UE-specific DCI or group-common DCI may send a UE transmission report to V2X at a fixed time period (e.g., after [ x ] ms or [ x ] slots). In this case, the fixed time period may be configured from the base station, or may be a value previously agreed between the V2X transmitting UE and the V2X receiving UE. This operation may be referred to as aperiodic reporting.

-receiving signaling from another V2X UE

The base station may receive the UE through RRC or MAC CE signaling to V2X and transmit a time interval for the UE notification to be performed to V2X. The V2X transmitting the UE may indicate a time point at which the UE will perform reporting by bypassing the control information to the V2X. The V2X receiving UE may send a report based on the timing information included in the bypass control information received by the V2X receiving UE. The V2X transmitting UE may receive the UE reception report from V2X based on the timing information included in the bypass control information transmitted by the V2X transmitting UE. The reporting may be performed during a time interval of signaling received from the base station through RRC or MAC. This operation may be referred to as periodic or semi-continuous reporting.

In another example, the operation may be performed without information about the time interval at which the reporting is to be performed from the base station. In this case, the V2X receiving UE receiving bypass control information from the V2X may perform transmission of a report to the V2X based on the timing information and start information of the report (i.e., trigger information of the report) included in the bypass control information. In another example, a V2X receiving UE that has received bypass control information may send a UE send report to V2X after a fixed time period (e.g., after [ x ] ms or [ x ] slots). In this case, the fixed time period may be configured from the base station, or may be a value previously agreed between the V2X transmitting UE and the V2X receiving UE. This operation may be referred to as aperiodic reporting. This operation may be referred to as aperiodic reporting.

When the V2X receiving UE receives a signal for path loss estimation from the V2X transmitting UE and then transmits the UE report result to V2X, the V2X receiving UE needs to determine how to configure a transmission power value of a channel for reporting.

The configuration of the initial transmission power value of the channel transmitting the report information according to the embodiment will be described below.

-using a predefined transmit power value

The base station may receive the transmission power value of the channel configured for reporting in the UE in V2X through a V2X dedicated channel or RRC signaling. In this case, the configured transmission power value may be a maximum transmission power value (e.g., Pcmax) of the UE, or an arbitrary value smaller than the maximum transmission power value of the UE. In this case, the base station may perform the configuration by considering the coverage of the bypass and the interference of the bypass communication to the uplink of the base station.

In the absence of a base station (i.e., when communication between V2X UEs is performed outside the coverage of the base station), the transmit power value of the channel for receiving UE reports by V2X to transmit UE reports to V2X may be preconfigured.

As shown in fig. 8A, V2X receives signals that the UE can measure RSRP by sending signals for path loss estimation received by the UE from V2X, and can estimate the bypass path loss value. In this case, the V2X receiving UE may configure the transmit power value of the channel that sends the UE report to V2X based on the bypass path loss value estimated by the V2X receiving UE itself.

When the V2X receiving UE exists in the coverage of the base station, the V2X receiving UE can configure a transmission power value of a channel that transmits a UE report to the V2X based on RSRP measured by using the SSB or CSI-RS of the base station and a downlink path loss value estimated by using the RSRP.

The V2X sending UE may send bypass control information and data information to the V2X receiving UE based on RSRP value or path loss estimate reported from the V2X receiving UE.

The above-described embodiments may be similarly or identically applied to the multicast communication method. For example, in the multicast communication method, a group header serving as a base station for managing communication may exist in a group. Such a group header may serve as a base station.

In fig. 8A, a transmitting UE may transmit a signal for path loss estimation to a receiving UE, the receiving UE of the received signal may measure RSRP by using the path loss estimation signal and may report the RSRP to the transmitting UE, and the transmitting UE may estimate a bypassed path loss value by using the received RSRP. Further, the RSRP reported by the receiving UE to the sending UE may be L1-RSRP or L3-RSRP. Fig. 8B shows a specific example of a receiving UE reporting L1-RSRP to a sending UE.

In fig. 8B, the same process as in fig. 8A will not be described. For example, although not shown in fig. 8B, downlink synchronization with base station and system parameter acquisition, uplink synchronization and RRC connection configuration, and unicast link configuration (PC-5RRC connection configuration) between the transmitting UE and the receiving UE may be performed in the same manner as in fig. 8. Further, the transmitting UE may receive a command from the base station to transmit the bypass path loss estimate signal.

To estimate the path loss, the L3-RSRP value needs to be filtered at layer 3. In more detail, the physical layer (layer 1) may calculate an L1-RSRP value and may transmit an L1-RSRP value to layer 3, and layer 3 may obtain the L3-RSRP value by obtaining an average in the time domain or the time domain and the space domain using the L1-RSRP value received from the physical layer. In order to estimate the path loss more accurately, it is necessary to obtain the average over a sufficiently long time.

When the receiving UE reports L1-RSRP to the transmitting UE, the above-described L3 filtering operation must be performed for a sufficiently long time for accurate path loss estimation. To do so, the receiving UE may have to report L1-RSRP to the sending UE multiple times. Since L1-RSRP is a value calculated in layer 1, L1-RSRP may be transmitted via a bypass feedback channel (physical bypass feedback channel (PSFCH)) or a bypass data channel (physical bypass shared channel (PSSCH)). Therefore, when the receiving UE has to report L1-RSRP to the transmitting UE multiple times, this means that the receiving UE has to transmit the PSFCH or PSSCH to the transmitting UE multiple times. Because the V2X UE may not be able to perform transmission and reception simultaneously, when the receiving UE transmits the PSFCH or the PSSCH multiple times, the receiving UE may not be able to receive the bypass control information and the data information that may be transmitted from another transmitting UE. Furthermore, a V2X UE may not be able to simultaneously transmit two or more different channels in one carrier (i.e., two or more different channels cannot be frequency divided and transmitted in one carrier). Therefore, when the receiving UE transmits the PSFCH or PSSCH to the transmitting UE multiple times to report L1-RSRP, the receiving UE may not be able to transmit the bypass control information and the data information to another UE. To solve these problems, N L1-RSRP reports may be transmitted once in the time domain by the MAC CE shown in (c) or (D) of fig. 8D.

As another problem of the case where the receiving UE reports L1-RSRP to the transmitting UE, a protocol related to transmission and reception of L1-RSRP may be required between the transmitting UE and the receiving UE, so that the transmitting UE receives L1-RSRP transmitted by the receiving UE and performs L3 filtering. In more detail, as shown in fig. 8B, after the receiving UE receives the bypass path loss estimation signal transmitted from the transmitting UE and measures L1-RSRP, a protocol for when to report L1-RSRP to the transmitting UE may be required. In other words, the sending UE needs to know the point in time at which the L1-RSRP report is sent from the receiving UE after sending the bypass path loss estimation signal.

For example, the transmitting UE may desire to report L1-RSRP from the receiving UE after [ x1] ms or [ x2] slots from the slot in which the bypass path loss estimate signal was transmitted. However, when there is no PSFCH or PSSCH resource for reporting the L1-RSRP at the time point when the receiving UE reports the L1-RSRP, or when severe congestion occurs despite the existence of the PSFCH or PSSCH resource, the receiving UE may not be able to report the L1-RSRP to the transmitting UE. Therefore, in order for the transmitting UE to perform L3 filtering by using L1-RSRP filtering reported from the receiving UE, it is necessary to ensure a sufficiently long reception window time. That is, when the transmitting UE desires to report L1-RSRP from the receiving UE every [ X1] ms or [ X2] slots after transmitting the bypass path loss estimation signal, the transmitting UE may attempt to receive L1-RSRP during + Δ 1ms or- Δ 1ms from [ X1] ms, or may attempt to receive L1-RSRP during + Δ 2ms or- Δ 2ms from [ X2] slots.

In another example, in order for a transmitting UE to perform L3 filtering, the transmitting UE may have to perform filtering during a total of [ x4] ms or a total of [ x3] L1-RSRP values reported from receiving UEs every [ x1] ms or every [ x2] slot. Therefore, the receiving UE may have to continuously perform transmission to the transmitting UE until the total number of L1-RSRP values reported every [ x1] ms or [ x2] slots is [ x3] (in fig. 8B, the total number of L1-RSRP values reported by the receiving UE to the transmitting UE is N). Alternatively, the receiving UE may have to continuously send L1-RSRP reported every [ x1] ms or [ x2] slots to the transmitting UE until a total of [ x4] ms.

In another example, although not shown in fig. 8B, the sending UE may send a command to the receiving UE to stop reporting L1-RSRP. The receiving UE may report L1-RSRP every [ x1] ms or [ x2] slots until the receiving UE receives a command to stop reporting L1-RSRP from the sending UE. The command to stop reporting L1-RSRP may be included in PC-5RRC signaling, MAC CE, or SCI information.

In another example, the operations may be performed based on a timer. In more detail, the transmitting UE may transmit a bypass path loss estimate signal and may start a T1 timer. The sending UE may maintain a receive window for receiving the L1-RSRP values reported from the receiving UE until the T1 timer expires. When the T1 timer expires, the sending UE may derive a layer 3RSRP value by using the L1-RSRP report received until the T1 timer expires. The receiving UE may receive the bypass path loss estimate signal and may start a T2 timer. The receiving UE may send the L1-RSRP value to the sending UE at least once on available resources until the T2 timer expires. When the T2 timer expires, the receiving UE may stop sending L1-RSRP reports. In the above example, T1 and T2 may be the same as or different from each other.

In the above example, when the sending UE does not receive any L1-RSRP report from the receiving UE until the T1 timer of the sending UE expires, the sending UE may send information (e.g., HARQ-NACK) to the receiving UE to inform this. The receiving UE receiving the information may reconfigure the previously running T2 timer (i.e., reset the previously running T2 timer) and may report L1-RSRP to the sending UE. In another example, when the sending UE obtains enough L1-RSRP samples for performing layer 3 filtering before the T1 timer expires (i.e., when N RSRP values are obtained), the sending UE may send information to the receiving UE to inform this (e.g., send HARQ-ACK) and may terminate the T1 timer. The receiving UE may terminate the T2 timer when the receiving UE receives information from the sending UE indicating that sufficient L1-RSRP samples were obtained and the T2 timer of the receiving UE has not expired.

[ x1], [ x2], [ x3], [ x4], Δ 1, Δ 2, T1, T2, and filter coefficients for performing L3 filtering may be configured by the base station through system information or RRC signaling. In another example, the transmitting UE and the receiving UE may perform PC-5RRC connection configuration during unicast link connection configuration, and in this case, through PC-5RRC signaling. In another example, the parameter may be a fixed value that may refer to a value embedded in the transmitting UE and the receiving UE.

Fig. 8C is another diagram for describing in more detail the method of estimating the inter-UE bypass path loss according to the embodiment of fig. 8A.

In fig. 8C, the same process as in fig. 8A will not be described. For example, although not shown in fig. 8C, downlink synchronization and system parameter acquisition with the base station, uplink synchronization and RRC connection configuration, and unicast link configuration (PC-5RRC connection configuration) between the transmitting UE and the receiving UE may be performed in the same manner as in fig. 8. Further, the transmitting UE may receive a command from the base station to transmit the bypass path loss estimate signal.

Unlike in fig. 8B, where the receiving UE reports L1-RSRP to the sending UE, in fig. 8C, the receiving UE may report RSRP to the sending UE only once when the receiving UE reports L3-RSRP to the sending UE. Therefore, the problem occurring when the receiving UE reports L1-RSRP to the transmitting UE can be solved. However, in the case of L3-RSRP reporting, since the final value of reported RSRP is generated in layer 3, L3-RSRP must be reported from and sent to the RRC of the receiving UE, and may be sent via the PSSCH.

A protocol may be required between the sending UE and the receiving UE so that the sending UE receives the L3-RSRP sent by the receiving UE and estimates the bypass path loss value. In more detail, as shown in fig. 8C, after the receiving UE receives the bypass path loss estimation signal transmitted from the transmitting UE and measures L3-RSRP, a protocol for when to report L3-RSRP to the transmitting UE may be required. In other words, the sending UE needs to know the point in time at which the L3-RSRP report is sent from the receiving UE after sending the bypass path loss estimation signal.

For example, the transmitting UE may desire to report L3-RSRP from the receiving UE after [ x1] ms or [ x2] slots from the slot in which the bypass path loss estimate signal was transmitted. However, when there is no PSSCH resource for reporting L3-RSRP at the time point when the receiving UE reports L3-RSRP, or when severe congestion occurs despite the existence of the PSSCH resource for reporting L3-RSRP, the receiving UE may not be able to report L3-RSRP to the transmitting UE. Therefore, in order for the transmitting UE to estimate the bypass path loss value by using the L3-RSRP reported from the receiving UE, it is necessary to ensure a sufficiently long reception window time. That is, when the transmitting UE desires to report L3-RSRP from the receiving UE every [ x1] ms or every [ x2] slots after transmitting the bypass path loss estimation signal transmitted by the transmitting UE itself, the transmitting UE may attempt to receive L3-RSRP during + Δ 1ms or- Δ 1ms from [ x1] ms, or may attempt to receive L3-RSRP during + Δ 2ms or- Δ 2ms from [ x2] slots.

In another example, the operations may be performed based on a timer. In more detail, the transmitting UE may transmit a bypass path loss estimate signal and may start a T1 timer. The sending UE may maintain a receive window for receiving the L3-RSRP values reported from the receiving UE until the T1 timer expires. The receiving UE may receive the bypass path loss estimate signal and may start a T2 timer. The receiving UE may perform operations (e.g., sensing and resource selection operations) to find available resources to report the L3-RSRP value to the sending UE until the T2 timer expires. Receiving UEs that did not find available resources for reporting the L3-RSRP before the T2 timer expired may stop reporting the L3-RSRP. In the above example, T1 and T2 may be the same as or different from each other.

In another example, the sending UE may drop reception of L3-RSRP when the sending UE does not receive any L3-RSRP reports from the receiving UE until the T1 timer expires. Alternatively, when the transmitting UE does not receive the L3-RSRP report from the receiving UE until the T1 timer expires, the transmitting UE may send information (e.g., HARQ-NACK) indicating this to the receiving UE. The receiving UE receiving the information may reconfigure the previously running T2 timer (i.e., reset the previously running T2 timer) and may re-report the L3-RSRP to the sending UE.

[ x1], [ x2] to Δ 1, Δ 2, T1, T2, and filter coefficients for performing L3 filtering may be configured by the base station through system information or RRC signaling. In another example, the transmitting UE and the receiving UE may perform PC-5RRC connection configuration during unicast link connection configuration, and in this case, through PC-5RRC signaling. In another example, the parameter may be a fixed value that may refer to a value embedded in the transmitting UE and the receiving UE.

Fig. 8D is a diagram for describing a MAC CE format for reporting inter-UE bypass RSRP values.

In (a) of fig. 8D, the MAC CE includes 8 bits, and RSRP transmitted through the MAC CE is represented as 7 bits (bit 1 is a reserved bit). In this case, the RSRP may be L1-RSRP. The RSRP may have a range of-140 dBm to-44 dBm (1dB magnitude change).

Fig. 8D (b) is another example of a MAC CE for transmitting RSRP. Unlike (a) in fig. 8D, in (b) of fig. 8D, a UE ID including N bits may be transmitted together with 7-bit RSRP. In this case, the UE ID may include a source ID of the transmitting UE, a destination ID of the receiving UE, or both the source ID and the destination ID. When one of the source ID and the destination ID is transmitted together with RSRP through the MAC CE, the source ID or the destination ID may include 16 bits or 24 bits. When both the source ID and the destination ID are transmitted together with RSRP through the MAC CE, bit sizes of the source ID and the destination ID may be 16 bits or 24 bits each, and may be the same as or different from each other. That is, when it is assumed that the bit size of the source ID is N1, and the bit size of the destination ID is N2, N1 ≠ N2 or N1 ≠ N2, and each of N1 and N2 may be 16 bits or 24 bits.

Fig. 8D (c) is another example of a MAC CE for transmitting RSRP. Unlike (a) in fig. 8D, N RSRP values are transmitted through one MAC CE. That is, assuming that the receiving UE must report N L1-RSRP values to the transmitting UE as in fig. 8B, N MAC CEs may be required to transmit when the MAC CE of (a) of fig. 8D is used. In this case, signaling overhead may increase, and half-duplex may increase. Therefore, it may be preferable that the receiving UE transmits N L1-RSRP values through one MAC CE as shown in (c) or (D) of fig. 8D.

Fig. 8D (D) is another example of a MAC CE for transmitting RSRP. Unlike (c) in fig. 8D, N RSRP values are transmitted through one MAC CE. However, unlike (c) of fig. 8D, the first RSRP value from among the N RSRP values may include 7 bits, and the remaining N-1 RSRP values may each include 4 bits. In more detail, each RSRP value in (c) of fig. 8D may include 7 bits and may be represented in a range of-140 dBm to-44 dBm (1dB magnitude change). Although the first RSRP value includes 7 bits in (D) of fig. 8D, like (c) of fig. 8D, the second to last nth RSRP values may be RSRP values representing differences from previously reported RSRP values. For example, the second RSRP value RSRP-2 included in the MAC CE and transmitted may refer to a difference between the first RSRP value RSRP-1 reported for the first time and the RSRP value measured for the second time. The third RSRP value RSRP-3 included in the MAC CE and transmitted may refer to a difference between the second RSRP value RSRP-2 reported the second time and the RSRP value measured the third time. Such RSRP value difference may include 4 bits as shown in (D) of fig. 8D, and may be represented in a range of-140 dBm to-44 dBm (2dB size variation). When compared with (c) of fig. 8, fig. 8D (D) may reduce the size of bits transmitted through the MAC CE. In more detail, as N increases (as the number of reported L-RSRP values increases), the MAC CE overhead can be significantly reduced, since 3N bits can be reduced.

The receiving UE may be configured with information on whether to report L1-RSRP by using the MAC CE of (a) of fig. 8D or L1-RSRP by using the MAC CE of (c) and/or (D) of fig. 8D. This means that the transmitting UE may be configured with information on whether to receive L1-RSRP by using the MAC CE of (a) of fig. 8D or L1-RSRP by using the MAC CE of (c) and/or (D) of fig. 8D. The configuration may be received through system information or RRC signaling of the base station, or may be received through PC-5RRC signaling. In another example, the configuration may be preconfigured.

Fig. 9 may correspond to the detailed embodiment of (b) of fig. 5. V2X UEs within the coverage of the base station may perform downlink synchronization and may obtain system information. In this case, downlink synchronization may be performed by a primary synchronization signal/secondary synchronization signal (PSS/SSS) received from a base station or may be performed by a synchronization signal received from a Global Navigation Satellite System (GNSS). The V2X UE performing downlink synchronization can obtain system information related to V2X through a V2X dedicated System Information Block (SIB) transmitted by the base station gNB/RSU. In addition, the V2X UE within the coverage can perform uplink synchronization through a random access procedure with the base station and can perform an RRC connection procedure. In this case, the uplink synchronization and RRC connection procedure may be performed by only one of the transmitting UE or the receiving UE, or may be performed by both the transmitting UE and the receiving UE.

The information on which UE among the transmitting UE and the receiving UE will perform the uplink synchronization and RRC connection procedure may vary according to a transmission mode of the bypass control information/data information, a bypass path loss estimation procedure, a signaling method, and the like. For example, as shown in fig. 8A, in a mode in which the base station transmits a command for the UE to transmit a path loss signal to V2X, the transmitting UE may have to perform uplink synchronization and RRC connection procedures with the base station. Further, as shown in fig. 9, in a mode in which the base station transmits a command for transmitting a path loss signal to the V2X receiving UE, the receiving UE may have to perform uplink synchronization and RRC connection procedures with the base station.

Although not shown in fig. 8A and 9, when the base station receives a command for transmitting a path loss signal to the V2X reception UE and transmits a command for receiving a path loss signal to the V2X transmission UE, both the reception UE and the transmission UE may perform uplink synchronization and RRC connection procedures with the base station according to a signaling method. In fig. 9, a receiving UE may refer to a UE that receives bypass control information and data information, and a transmitting UE may refer to a UE that transmits bypass control information and data information. Therefore, the receiving UE and the transmitting UE in fig. 9 may not be related to the transmission and reception of the path loss signal.

The V2X transmitting UE or the V2X receiving UE performing uplink synchronization and RRC connection configuration with the base station may perform unicast link configuration. The unicast link configuration may be performed at a higher layer (e.g., application layer), and as shown in fig. 9, the unicast link configuration may be performed between a V2X transmitting UE that transmits V2X control information/data information in a unicast manner and a V2X receiving UE that receives V2X control information/data information in a unicast manner. Further, although not shown in fig. 8A, the base station may participate in a unicast link configuration. For example, V2X sending the UE may send a request for unicast link configuration to the base station, and the base station may receive a response to the unicast link configuration from the UE to V2X. Further, the base station may send the UE to V2X and V2X receives an acknowledgement that the UE sent the unicast link configuration. However, as described above, since the procedure may be performed in a higher layer, the procedure may not be identified in the physical layer and the MAC layer.

As shown in fig. 9, the base station may receive a command to the V2X that the UE transmits a transmission request for a signal for path loss estimation. In this case, the command of the base station may be transmitted to the V2X receiving UE through UE-specific DCI for bypass (group common DCI) or through MAC CE or UE-specific RRC message. When a command is sent to the V2X to receive a UE through UE-specific DCI or group-common DCI, the DCI may be distinguished from existing cellular communications using a Radio Network Temporary Identifier (RNTI) that is different from the UE-specific DCI or group-common DCI used in the existing cellular communications.

Further, unlike in fig. 9, the V2X receiving the UE may send the UE a request to send a signal for path loss estimation to the V2X without a command of the base station after unicast link configuration. For example, the V2X receiving UE may start a timer from a point in time when the request for unicast link configuration is received or from a point in time when unicast link configuration is successful, and may send a request for transmission of a signal for path loss estimation at a point in time when the timer expires. Similarly, the V2X transmitting UE may start a timer from the point in time when the request for unicast link configuration is transmitted or from the point in time when unicast link configuration is successful, and may expect to receive a request for the UE to transmit a signal for path loss estimation from V2X at the point in time when the timer expires. In another example, the V2X receiving UE may send a request to the V2X that the UE send a signal for path loss estimation after a certain period of time (e.g., after [ x ] subframes, [ x ] slots, or [ x ] ms) from the point in time that the unicast link configuration was successful. Similarly, the V2X transmitting UE may expect to receive a request from the V2X that the UE receive a signal for path loss estimation transmission after a certain period of time (e.g., [ x ] subframes, [ x ] slots, or [ x ] ms) from the point in time when the unicast link configuration was successful.

In another example where V2X receives a request that a UE send a signal for path loss estimation to V2X without a command of a base station, when V2X receives that the RSRP value measured by the UE together with the base station is equal to or greater than (or greater than) a certain threshold configured by the base station or equal to or less than (or less than) a certain threshold, the V2X receiving UE may send a request to V2X that the UE send a signal for path loss estimation. In this case, the base station may configure the RSRP threshold in the V2X receiving UE through a system transport block for V2X (V2X SIB) or UE-specific RRC/common RRC message for V2X. In another example, when the change in RSRP value of the base station is equal to or greater than (or greater than) a particular threshold configured by the base station, V2X receiving the UE may send a request to V2X the UE to send a signal for path loss estimation. Although V2X receives the condition that the UE satisfies the RSRP value configured by the base station, when the base station transmits a command for stopping transmission of a request for transmission of a signal for path loss estimation, V2X receives a request that the UE may stop transmission of a signal for path loss estimation.

In another example where V2X receives a request that the UE send a signal for path loss estimation to V2X without a command of the base station, the V2X receiving UE may send a request to the V2X to send the UE a signal for path loss estimation when the RSRP value of the bypass channel measured by the V2X receiving UE is equal to or greater than (or greater than) a certain threshold configured by the base station or equal to or less than (or less than) a certain threshold. In this case, the base station may configure the V2X to receive the RSRP value of the bypass channel in the UE through a system transport block for V2X (V2X SIB) or a UE-specific RRC/common RRC message for V2X. In this case, when the RSRP value of the bypass channel satisfies a specific threshold condition configured by the base station at least once, the V2X receiving UE may send a request to the V2X transmitting UE to transmit a signal for path loss estimation. Alternatively, when the RSRP value of the bypass channel satisfies a certain threshold condition configured by the base station X times (or more), V2X receives a request that the UE can send a signal for path loss estimation to V2X. In this case, X may be predefined or may be configured by the base station. In another example, when the change in RSRP value of the bypass channel is equal to or greater than (or greater than) a particular threshold configured by the base station, the V2X receiving UE may send a request to the V2X the UE to send a signal for path loss estimation. Even when the V2X receives a condition that the UE satisfies the RSRP value of the bypass channel configured by the base station, the V2X receiving UE may stop sending a request for sending a signal for path loss estimation when the base station sends a command for stopping sending a request for sending a signal for path loss estimation. In another example, the threshold of the RSRP value of the bypass channel or the change in the RSRP value of the bypass channel may be pre-configured without signaling from the base station.

In the above example where V2X receives a UE request to transmit a signal for path loss estimation, a V2X transmitting UE may refer to a UE that has the capability to transmit a signal for V2X path loss estimation. Therefore, it may be assumed that the V2X receiving UE may know information in advance about the V2X transmitting UE having the capability of transmitting a signal for path loss estimation.

As shown in fig. 9, the base station may receive a command to the V2X that the UE sends a request to send a signal for path loss estimation, and the V2X sends whether the UE is able to send a signal for path loss estimation may be V2X UE capable (i.e., only UEs with the capability to send a signal for V2X path loss estimation may send a signal for V2X path loss estimation). Accordingly, the base station may receive the UE transmission command to the V2X by considering the capability of the V2X transmission UE. In this case, the command of the base station may be transmitted to the V2X receiving UE through UE-specific DCI (or group common DCI) for bypass or through UE-specific RRC. V2X receiving a command to send a request for a signal for path loss estimation may send a request to V2X for the UE to send a signal for path loss estimation. Alternatively, when the above conditions are satisfied (i.e., timer expiration, RSRP of the base station, or modulation order), the V2X receiving UE that will send a request to send a signal for path loss estimation may send the V2X the UE sending a request to send a signal for path loss estimation. The V2X transmitting UE receiving the request may transmit a signal for path loss estimation to the V2X receiving UE. In this case, the V2X receives information that the UE can obtain the transmission power of a signal for path loss estimation from the V2X transmitting UE by using various methods.

The method of transmitting information on the transmission power of the signal for path loss estimation may be performed in various ways as described with reference to fig. 8A. Further, the method of configuring the transmission power information of the signal for path loss estimation may be performed by using one of various examples described with reference to fig. 8A. The V2X receiving the signal for path loss estimation and the transmission power information of the signal for path loss estimation from the base station or the V2X transmitting UE may estimate the bypassed path loss value by using [ equation 1], and may report the estimated path loss value to the V2X transmitting UE. In another example, as described with reference to fig. 8A, instead of reporting a path loss value, the V2X receiving UE may report an RSRP value measured by the V2X receiving UE itself. As for a reporting method, a channel on which the reported information is transmitted, a resource on which the reported information is transmitted, a time point at which the reported information is transmitted, and a method of configuring an initial transmission power value of the channel on which the reported information is transmitted, there may be various methods described with reference to fig. 8A.

Until the estimated bypass path loss value in fig. 8A and 9 is reflected in transmitting actual control information and data information, there are a plurality of pieces of information to be transmitted and received between the V2X transmitting UE and the V2X receiving UE. In order to transmit such information, it may be necessary to consider how to configure the transmission power value. For example, in fig. 8A, the V2X receiving UE may estimate a bypass path loss value by using a signal for path loss estimation received from the V2X transmitting UE, and may configure a transmission power value of bypass control information and data information based on the estimated bypass path loss value. In this case, it may be necessary to determine how to configure the transmit power value of the signal for path loss estimation sent to the UE to be received by V2X. Further, in fig. 9, the V2X transmitting UE may transmit a request for transmitting a signal for path loss estimation to the V2X, and the V2X transmitting UE may transmit a signal for bypassing path loss estimation to the V2X receiving UE based on the request. In this case, it may be necessary to determine how to configure the request for transmitting the signal for path loss estimation transmitted by the V2X receiving UE to the V2X and the transmission power value for transmitting the signal for bypassing path loss estimation transmitted by the UE to the V2X receiving UE by the V2X. In this case, at least one of the following methods may be used.

-using a predefined transmit power value

The base station may configure the transmit power value through V2X dedicated SIB or RRC signaling. In this case, the configured transmission power value may be a maximum transmission power value (e.g., Pcmax) of the UE, or an arbitrary value smaller than the maximum transmission power value of the UE. In this case, the base station may perform the configuration by considering the coverage of the bypass and the interference of the bypass communication to the uplink of the base station. The transmit power value may be used for all transmissions until the bypass path loss value is reflected in the transmit power value configuration of the actual bypass control information and data information.

In fig. 9, the V2X transmitting UE may receive a request from the V2X that the UE receive a signal for path loss estimation. When using this procedure, the V2X sending UE may measure the bypass RSRP and may measure the path loss value by using a request signal sent from the V2X receiving UE. In this case, a transmission power value for receiving a request for a signal for path loss estimation transmitted by a UE from V2X may be obtained by the V2X reception UE through an embodiment using a predefined transmission power value. The V2X transmitting UE may configure the transmit power value of the signal transmitted to the V2X receiving UE for path loss estimation based on the path loss value estimated by the V2X transmitting UE itself.

When the V2X sending UE is present within the coverage of the base station, the V2X sending UE can measure the downlink RSRP and estimate the downlink path loss value by using the SSB or CSI-RS of the base station. The V2X transmitting UE may configure the transmit power value of the signal sent to the V2X receiving UE for bypassing path loss estimation based on the downlink path loss value.

When the V2X receiving UE exists within the coverage of the base station, the V2X receiving UE can estimate a downlink path loss value with the base station (or RSU) by using the SSB or CSI-RS of the base station. The V2X receiving UE may configure a transmission power value of transmission request information for a signal for bypassing path loss estimation transmitted to the V2X transmitting UE based on a downlink path loss value with a base station.

When both the V2X receiving UE and the V2X transmitting UE are present within the coverage of the base station, the V2X transmitting UE can measure the downlink RSRP by using the SSB or CSI-RS of the base station and estimate the path loss value. Further, the V2X receiving UE can estimate the downlink path loss value of the base station (or RSU) by using the SSB or CSI-RS of the base station. In this case, in fig. 9, the V2X receiving UE may configure the transmission power value of the transmission request information transmission of the signal for bypassing path loss estimation transmitted to the V2X transmitting UE based on the downlink path loss value estimated by the V2X receiving UE itself. The V2X transmitting UE may configure a transmit power value of a signal for bypass loss estimation transmitted to the V2X receiving UE based on a downlink path loss value with the base station.

Fig. 10 is a diagram illustrating a method of transmitting and receiving a path loss measurement signal to estimate an inter-UE bypass path loss according to another embodiment of the present disclosure.

Specifically, fig. 10 is a schematic diagram showing a method of estimating path loss in two directions. In this case, the estimation in both directions may refer to a case in which the V2X receiving UE estimates a path loss value by receiving a signal for path loss estimation transmitted by the V2X transmitting UE, and the V2X transmitting UE estimates a path loss value by receiving a signal for path loss estimation transmitted by the V2X receiving UE.

V2X UEs within the coverage of the base station may perform downlink synchronization and may obtain system information. In this case, downlink synchronization may be performed by a primary synchronization signal/secondary synchronization signal (PSS/SSS) received from a base station or may be performed by a synchronization signal received from a Global Navigation Satellite System (GNSS). The V2X UE performing downlink synchronization can obtain system information related to V2X through a V2X dedicated System Information Block (SIB) transmitted by the base station gNB/RSU. In addition, the V2X UE within the coverage can perform uplink synchronization through a random access procedure with the base station and can perform an RRC connection procedure. In this case, the uplink synchronization and RRC connection procedure may be performed by only one of the transmitting UE or the receiving UE, or may be performed by both the transmitting UE and the receiving UE.

The information on which UE among the transmitting UE and the receiving UE will perform the uplink synchronization and RRC connection procedure may vary according to a transmission mode of the bypass control information/data information, a bypass path loss estimation procedure, a signaling method, and the like. For example, as shown in fig. 8A, in a mode in which the base station transmits a command for the UE to transmit a path loss signal to V2X, the transmitting UE may have to perform uplink synchronization and RRC connection procedures with the base station. Also, as shown in fig. 9, in a mode in which the base station transmits a command for transmitting a path loss signal to the V2X receiving UE, the receiving UE may have to perform uplink synchronization and RRC connection procedures with the base station.

As shown in fig. 10, when the base station transmits a command for transmitting a signal for path loss estimation to both the V2X receiving UE and the V2X transmitting UE, both the receiving UE and the transmitting UE can perform uplink synchronization and RRC connection procedures with the base station according to a signaling method in which the base station transmits a command for transmitting a path loss signal. For example, when a command to transmit a path loss signal is transmitted through UE-specific DCI (or group common DCI) or UE-specific RRC signaling, the receiving UE and the transmitting UE may perform uplink synchronization and RRC connection procedures with the base station. When the command to transmit the path loss signal is transmitted through the V2X-dedicated SIB, the receiving UE and the transmitting UE may not perform uplink synchronization and RRC connection procedures with the base station.

In fig. 10, the receiving UE may refer to a UE that receives bypass control information and data information, and the transmitting UE may refer to a UE that transmits bypass control information and data information. Therefore, the receiving UE and the transmitting UE in fig. 10 may not be related to the transmission and reception of the path loss signal.

The V2X transmitting UE or the V2X receiving UE may perform unicast link configuration. The unicast link configuration may be performed in a higher layer (e.g., application layer), and as shown in fig. 10, the unicast link configuration may be performed between a V2X transmitting UE that transmits V2X control information/data information in a unicast manner and a V2X receiving UE that receives V2X control information/data information in a unicast manner. Further, although not shown in fig. 10, the base station may participate in unicast link configuration. For example, V2X sending the UE may send a request for unicast link configuration to the base station, and the base station may receive a response to the unicast link configuration from the UE to V2X. Further, the base station may send the UE to V2X and V2X receives an acknowledgement that the UE sent the unicast link configuration. However, as described above, since the procedure may be performed in a higher layer, the procedure may not be identified in the physical layer and the MAC layer.

As shown in fig. 10, the base station may transmit a UE to V2X and receive a command for the UE to transmit a signal for path loss estimation from V2X. In this case, the command of the base station may be transmitted to the V2X transmission UE through UE-specific DCI (group common DCI) for bypass or through MAC CE or UE-specific RRC. When a command for transmitting a signal for path loss estimation is transmitted through UE-specific DCI or group-common DCI, the DCI may be distinguished from existing cellular communication using a Radio Network Temporary Identifier (RNTI) different from the UE-specific DCI or the group-common DCI used in the existing cellular communication. When the base station transmits the UE to the V2X through SIB, UE-specific RRC, or common RRC signaling and the V2X receives a command that the UE transmits a signal for path loss estimation, the RRC parameters may include at least one of time resources, frequency resources, and code resources for transmitting the signal for path loss estimation. In this case, the time resource may include at least one information among a start point (at least one of a symbol index, a slot index, or a subframe index) and a transmission period at which a signal for path loss estimation is transmitted. The frequency resource may include at least one information from among a start point of a Resource Block (RB) transmitting a signal for path loss estimation, a size of the RB, a resource pool, and a bandwidth index (when a partial bandwidth is used). Further, the code resource may include at least one information among a sequence index of a signal for path loss estimation, a scrambling ID, and a cyclic shift.

In another example of transmitting a signal for path loss estimation in both directions based on a command of a base station, information on transmission resources of the signal for path loss estimation may be configured in V2X transmitting UEs and V2X receiving UEs through UE-specific RRC or common RRC signaling, and transmission time of the signal for path loss estimation is activated through MAC CE, UE-specific DCI, or group-common DCI.

In another example in which signals for path loss estimation are transmitted in both directions based on commands of the base station as shown in fig. 6, when the base station receives a command for transmitting signals for path loss estimation to the V2X for the UE and the V2X receives a signal for path loss estimation for the UE to transmit to the V2X for the UE, the V2X transmitting UE receiving the signal may transmit signals for path loss estimation to the V2X receiving UE in response. The information about when V2X receives a signal that the UE transmits for path loss estimation may be determined using one of the various embodiments described with reference to fig. 6.

As shown in fig. 7, when the base station transmits a command for the UE to transmit a request for signal transmission for path loss estimation to V2X, and V2X transmits a request for the UE to transmit a signal for path loss estimation to V2X, in response, V2X receiving the request may transmit a signal for path loss estimation to V2X by the UE, and V2X transmitting a signal for path loss estimation to V2X by the UE. The information about when the V2X sending UE receives a request to the V2X for the UE to send a signal for path loss estimation may be determined by using one of the various embodiments described with reference to fig. 7.

Also, as shown in fig. 8A, when the base station transmits a command for the UE to transmit a signal for path loss estimation to V2X, and the V2X transmitting UE transmits a signal for path loss estimation to the V2X receiving UE, in response, the V2X receiving UE receiving the signal may transmit a signal for path loss estimation to the V2X transmitting UE. The information about when V2X sends a signal for path loss estimation by the UE may be determined by using one of the various methods described with reference to fig. 8A.

Finally, as shown in fig. 9, when the base station receives a command to V2X for the UE to send a request to send a signal for path loss estimation, and V2X receives a request to V2X for the UE to send a signal for path loss estimation, the V2X sending UE receiving the request may send a signal for path loss estimation to V2X receiving UE, and in response, V2X receiving UE may send a signal for path loss estimation to V2X sending UE. The information about when V2X receives a request for a signal for path loss estimation by a UE may be determined using one of the various embodiments described with reference to fig. 9.

Further, unlike fig. 10, the V2X transmitting UE and the V2X receiving UE can transmit and receive signals for path loss estimation after unicast link configuration without a command of a base station. For example, the V2X transmitting UE may start a timer from a point in time when a request for unicast link configuration is received or from a point in time when unicast link configuration is successful, and may transmit a signal for path loss estimation at a point in time when the timer expires. Similarly, the V2X receiving UE may start a timer from a point in time when the request for unicast link configuration is transmitted or from a point in time when unicast link configuration is successful, and may transmit a signal for path loss estimation to the V2X at a point in time when the timer expires. In another example, the V2X transmitting UE may transmit a signal for path loss estimation after a certain period of time (e.g., after [ x ] subframes, [ x ] slots, or [ x ] ms) from the point in time when the unicast link configuration was successful. Similarly, the V2X receiving UE may transmit a signal for path loss estimation to the V2X after a certain period of time (e.g., [ x ] subframes, [ x ] slots, or [ x ] ms) from the time point when the unicast link configuration is successful.

In another example where V2X transmits a UE and V2X receives a signal that the UE transmits for path loss estimation without a command of a base station, predefined (preconfigured) parameters may be used and may include at least one of time resources, frequency resources, and code resources for transmitting the signal for path loss estimation. In this case, the time resource may include at least one information among a start point (at least one of a symbol index, a slot index, or a subframe index) and a transmission period at which a signal for path loss estimation is transmitted. The frequency resource may include at least one information among a start point of a Resource Block (RB) transmitting a signal for path loss estimation, a size of the RB, a resource pool, and a bandwidth index (when a partial bandwidth is used). Further, the code resource may include at least one information among a sequence index of a signal for path loss estimation, a scrambling ID, and a cyclic shift.

In another example where V2X transmits a UE and V2X receives a signal that the UE transmits for path loss estimation without a command of a base station, as shown in fig. 6, when V2X receives a signal that the UE transmits for path loss estimation to V2X, the V2X transmitting UE receiving the signal may transmit a signal for path loss estimation to V2X receiving UE in response. The information about when V2X receives a signal that the UE transmits for path loss estimation may be determined using one of the various embodiments described with reference to fig. 6.

Further, as shown in fig. 7, when the V2X transmitting UE receives a request for transmitting a signal for path loss estimation to the V2X transmitting UE, V2X receiving the request may transmit a signal for path loss estimation to the V2X transmitting UE, and in response, the V2X transmitting UE may transmit a signal for path loss estimation to the V2X receiving UE. The information about when the V2X sending UE receives a request to the V2X for the UE to send a signal for path loss estimation may be determined by using one of the various embodiments described with reference to fig. 7.

Also, as shown in fig. 8A, when the V2X transmitting UE transmits a signal for path loss estimation to the V2X receiving UE, the V2X receiving UE receiving the signal may transmit a signal for path loss estimation to the V2X transmitting UE in response. The information about when V2X sends a signal for path loss estimation by the UE may be determined using one of the various embodiments described with reference to fig. 8A.

Finally, as shown in fig. 9, when V2X receives a request that the UE transmit a signal for path loss estimation to V2X, the V2X transmitting UE receiving the request may transmit a signal for path loss estimation to the V2X receiving UE, and in response, the V2X receiving UE may transmit a signal for path loss estimation to the V2X transmitting UE. The information about when V2X receives a request for a UE to send a signal for path loss estimation to V2X may be determined using the various embodiments described with reference to fig. 9.

Although in fig. 10, the transmission of the signal for path loss estimation starts with the V2X transmitting the UE, and the V2X receiving UE transmits the signal for path loss estimation to the V2X transmitting the UE in response, the opposite situation may occur. That is, the transmission of signals for path loss estimation may start with the V2X receiving UE, and in response, the V2X transmitting UE may transmit signals for path loss estimation to the V2X receiving UE. The information about which UE will transmit the signal for path loss estimation first may be pre-agreed (e.g., the transmitting UE always transmits first) or may be determined by the base station's command.

When transmission of a signal for path loss estimation starts from the V2X transmitting UE, the V2X receiving UE may include timing information on a timing at which the V2X receives a signal that the UE must transmit for path loss estimation in a bypass broadcast channel or a bypass control channel. That is, V2X sends the UE can send the timing-related information in the bit field of the bypass broadcast channel or the control channel by using [ z ] bit. In this case, the unit representing [ z ] bit may be the number of symbols (z1 symbols), the number of slots (z2 slots), or the number of subframes (z3 subframes). Accordingly, the V2X receiving the information may transmit a signal for path loss estimation after z1 symbols (or z2 slots or z3 subframes) from a time point of receiving the bit field. In another example, the timing information may be fixed, and the V2X transmitting UE and the V2X receiving UE may use pre-agreed values. In another example, when the V2X transmitting UE and the V2X receiving UE are located at the same base station, the base station may configure the timing information. In another example, the V2X transmitting UE may transmit the timing information configured by the base station to the V2X receiving UE existing outside the coverage of the base station or the V2X receiving UE existing in a different base station via a bypass broadcast channel or a bypass control channel.

Similar operations can be performed even when transmission of a signal for path loss estimation starts from the V2X reception UE. That is, the V2X receiving UE may operate as the V2X transmitting UE in the above example, and the V2X transmitting UE may operate as the V2X receiving UE in the above example.

A V2X UE transmitting a signal for path loss estimation (V2X transmitting UE or V2X receiving UE) may transmit information on transmission power of a signal for path loss estimation. The transmission power information may be transmitted through various embodiments described with reference to fig. 6 to 9.

V2X UE (V2X transmitting UE or V2X receiving UE) receiving a signal for path loss estimation may measure RSRP through the received signal for path loss estimation and may estimate a path loss value through information on the obtained transmission power of the signal for path loss estimation. The V2X transmitting UE may configure a transmission power value for bypassing control information and data information transmission based on a path loss value estimated by the V2X transmitting UE itself, and may perform bypass transmission. The V2X receiving this information may configure the transmit power value for the bypass feedback channel transmission based on the path loss value estimated by the V2X receiving UE itself and may send the UE transmit bypass feedback to V2X. Although the type of information transmitted via the bypass feedback channel is HARQ-ACK in fig. 10, the present disclosure is not limited thereto. For example, the bypass feedback information may include hybrid ARQ-acknowledgement (HARQ-ACK) of the bypass channel, Channel State Information (CSI), Rank Indicator (RI), Precoder Matrix Indicator (PMI), Layer Indicator (LI), or Scheduling Request (SR). In addition, various feedback information may be multiplexed and may be transmitted via a bypass feedback channel.

Fig. 11 illustrates an operation of the transmitting UE of fig. 5, 8A, and 9.

First, in operation 1110, a transmitting UE transmits a signal for path loss estimation to a receiving UE. In an embodiment, examples of signals for path loss estimation may include a bypass synchronization signal, such as a primary bypass synchronization signal (PSSS) or a secondary bypass synchronization signal (SSSS), a demodulation reference signal (DMRS) transmitted via a bypass broadcast channel (physical bypass broadcast channel (PSBCH)), a bypass control channel (physical bypass control channel (PSCCH)), or a bypass data channel (physical bypass shared channel (PSCCH)), and a reference signal for supporting a bypass operation, such as a bypass Sounding Reference Signal (SRS), a bypass channel state information reference signal (CSI-RS), or a bypass Phase Tracking Reference Signal (PTRS).

Further, the transmitting UE may transmit a signal for path loss estimation to the receiving UE at a time point when the transmitting UE receives a command for transmitting a path loss estimation signal from the base station, when Reference Signal Received Power (RSRP) measured by the transmitting UE for a signal for downlink path loss estimation transmitted by the base station is equal to or greater than a configured threshold or equal to or less than a configured threshold, when the transmitting UE determines that the signal for path loss estimation needs to be transmitted, or when the transmitting UE receives a transmission request signal for the signal for path loss estimation from the receiving UE.

Further, in an embodiment, the transmitting UE may configure a pre-configured transmission power, a maximum transmission power of the transmitting UE, a transmission power according to a configuration of the base station, a transmission power determined based on an RSRP of the transmitting UE for signal measurement for downlink path loss estimation transmitted by the base station, or a transmission power determined based on an RSRP of the transmitting UE for transmission request signal measurement for a signal for path loss estimation received from the receiving UE, as a transmission power of the signal for path loss estimation.

Next, in operation 1120, the transmitting UE receives a pathloss estimation result report from the receiving UE in response to the signal for pathloss estimation. In an embodiment, the path loss estimation result report may include a layer 1RSRP (L1-RSRP), a layer 3RSRP (L3-RSRP) measured by the receiving UE, and a path loss value estimated by the receiving UE. Further, the transmitting UE may receive the pathloss estimation result report via a bypass feedback channel, a bypass control channel, a bypass data channel, or a MAC Control Element (CE). Furthermore, when the transmitting UE receives the pathloss estimation result report via the above-described channel, the transmitting UE may allocate and control resources transmitting the reported information to prevent collision and interference between resources of different V2X UEs.

Further, in embodiments, the transmitting UE may receive the pathloss estimation result report periodically or aperiodically according to the configuration of the base station and the bypass control information.

In operation 1130, the transmitting UE configures a transmission power based on the pathloss estimation result report.

Next, in operation 1140, the transmitting UE may perform a bypass transmission with the receiving UE with the configured transmit power. In an embodiment, the transmitting UE may transmit the bypass control information and the bypass data with the configured transmit power.

Further, in an embodiment, the transmitting UE may transmit information on the transmission power of the signal for path loss estimation to the receiving UE. In an embodiment, the transmitting UE may transmit a transmission power value of a signal for path loss estimation to the receiving UE, and offset information between the configured reference signal and the transmission power value of the signal for path loss estimation. In this case, the information of the transmission power of the signal for path loss estimation and the signal for path loss estimation may be transmitted via the same channel or different channels.

Fig. 12 illustrates the operation of the receiving UE of fig. 5, 8A and 9.

First, in operation 1210, a receiving UE receives a signal for path loss estimation from a transmitting UE. In an embodiment, examples of signals for path loss estimation may include a bypass synchronization signal, such as a primary bypass synchronization signal (PSSS) or a secondary bypass synchronization signal (SSSS), a demodulation reference signal (DMRS) transmitted via a bypass broadcast channel (physical bypass broadcast channel (PSBCH)), a bypass control channel (physical bypass control channel (PSCCH)), or a bypass data channel (physical bypass shared channel (PSCCH)), and a reference signal for supporting a bypass operation, such as a bypass Sounding Reference Signal (SRS), a bypass channel state information reference signal (CSI-RS), or a bypass Phase Tracking Reference Signal (PTRS).

Next, in operation 1220, the receiving UE estimates a path loss based on the signal for path loss estimation.

In operation 1230, the receiving UE transmits a pathloss estimation result report to the transmitting UE. In an embodiment, the path loss estimation result report may include a layer 1RSRP (L1-RSRP), a layer 3RSRP (L3-RSRP) measured by the receiving UE, and a path loss value estimated by the receiving UE. Further, the receiving UE may transmit the pathloss estimation result report via a bypass feedback channel, a bypass control channel, a bypass data channel, or a MAC Control Element (CE). Further, when the receiving UE receives the pathloss estimation result report via the above-described channel, the receiving UE may allocate and control resources in which the report information is transmitted to prevent collision and interference between resources of different V2X UEs.

Further, in embodiments, the receiving UE may periodically or aperiodically send path loss estimation result reports according to the configuration of the base station and the bypass control information.

In an embodiment, the receiving UE may configure a pre-configured transmit power, a maximum transmit power of the receiving UE, a transmit power according to a configuration of the base station, or a transmit power determined based on RSRP measured by the receiving UE for a downlink path loss estimation signal transmitted by the base station as a transmit power of the path loss estimation report signal.

In an embodiment, the receiving UE may transmit a transmission request signal for a signal for path loss estimation to the transmitting UE at a time point when the receiving UE receives a command for a transmission request for the signal for path loss estimation from the base station, when RSRP measured by the receiving UE for a signal for downlink path loss estimation transmitted by the base station is equal to or greater than a configured threshold or equal to or less than a configured threshold, or when the receiving UE determines that the signal for path loss estimation needs to be transmitted. In this case, the receiving UE may configure a pre-configured transmission power, a maximum transmission power of the receiving UE, a transmission power according to the configuration of the base station, or a transmission power determined based on RSRP measured by the receiving UE for a downlink path loss estimation signal transmitted by the base station as a transmission power of a transmission request signal for a signal for path loss estimation.

Further, in an embodiment, the receiving UE may receive information on the transmit power of the signal used for path loss estimation. In an embodiment, the receiving UE may receive a transmission power value of a signal for path loss estimation and offset information between the configured reference signal and the transmission power value of the signal for path loss estimation. In this case, the signal for path loss estimation and the information on the transmission power of the signal for path loss estimation may be received via the same channel or different channels.

Fig. 13 illustrates the operation of the transmitting UE of fig. 4, 6 and 7.

First, in operation 1310, a transmitting UE receives a signal for path loss estimation from a receiving UE. In an embodiment, examples of signals for path loss estimation may include a bypass synchronization signal, such as a primary bypass synchronization signal (PSSS) or a secondary bypass synchronization signal (SSSS), a demodulation reference signal (DMRS) transmitted via a bypass broadcast channel (physical bypass broadcast channel (PSBCH)), a bypass control channel (physical bypass control channel (PSCCH)), or a bypass data channel (physical bypass shared channel (PSCCH)), and a reference signal for supporting a bypass operation, such as a bypass Sounding Reference Signal (SRS), a bypass channel state information reference signal (CSI-RS), or a bypass Phase Tracking Reference Signal (PTRS).

Next, in operation 1320, the transmitting UE estimates a path loss based on the signal for path loss estimation.

In operation 1330, the transmitting UE configures transmission power based on the path loss estimation result.

Next, in operation 1340, the transmitting UE performs a bypass transmission with the receiving UE with the configured transmit power. In an embodiment, the transmitting UE may transmit the bypass control information and the bypass data with the configured transmit power.

In an embodiment, the transmitting UE may transmit a transmission request signal for a signal for path loss estimation to the transmitting UE when the transmitting UE receives a command for a transmission request for the signal for path loss estimation from the base station, when RSRP measured by the transmitting UE for a downlink path loss estimation signal transmitted by the base station is equal to or greater than a configured threshold or equal to or less than a configured threshold, or when the transmitting UE determines that the signal for path loss estimation needs to be transmitted at a point in time. In this case, the transmitting UE may configure, as the transmission power of the transmission request signal for the signal for path loss estimation, a transmission power configured in advance, a maximum transmission power of the transmitting UE, a transmission power according to the configuration of the base station, or a transmission power determined based on RSRP measured by the transmitting UE for a downlink path loss estimation signal transmitted by the base station.

Further, in an embodiment, the transmitting UE may receive information about the transmit power of the signal used for path loss estimation. In an embodiment, a transmitting UE may receive a transmit power value of a signal for path loss estimation and offset information between a configured reference signal and the transmit power value of the signal for path loss estimation. In this case, the signal for path loss estimation and the information on the transmission power of the signal for path loss estimation may be received via the same channel or different channels.

Fig. 14 illustrates the operation of the transmitting UE of fig. 4, 6 and 7.

First, in operation 1410, a receiving UE transmits a signal for path loss estimation to a transmitting UE. In an embodiment, examples of signals for path loss estimation may include a bypass synchronization signal, such as a primary bypass synchronization signal (PSSS) or a secondary bypass synchronization signal (SSSS), a demodulation reference signal (DMRS) transmitted via a bypass broadcast channel (physical bypass broadcast channel (PSBCH)), a bypass control channel (physical bypass control channel (PSCCH)), or a bypass data channel (physical bypass shared channel (PSCCH)), and a reference signal for supporting a bypass operation, such as a bypass Sounding Reference Signal (SRS), a bypass channel state information reference signal (CSI-RS), or a bypass Phase Tracking Reference Signal (PTRS).

Next, in operation 1420, the receiving UE performs bypass transmission with the transmitting UE.

In an embodiment, the receiving UE may transmit a transmission request signal for a signal for path loss estimation to the transmitting UE at a time point when the receiving UE receives a command to transmit the signal for path loss estimation from the base station, when RSRP measured by the receiving UE for a downlink path loss estimation signal transmitted by the base station is equal to or greater than a configured threshold or equal to or less than a configured threshold, when the receiving UE determines that the path loss estimation signal needs to be transmitted, or when the receiving UE receives a transmission request signal for the path loss estimation signal from the transmitting UE. In this case, the receiving UE may configure, as the transmission power of the signal for path loss estimation, a transmission power configured in advance, a maximum transmission power of the receiving UE, a transmission power according to the configuration of the base station, a transmission power determined based on RSRP measured by the receiving UE for a downlink path loss estimation signal transmitted by the base station, or a transmission power determined based on RSRP measured by the receiving UE for a transmission request signal of a path loss estimation signal received from the transmitting UE.

Further, in an embodiment, the receiving UE may transmit information on the transmission power of the signal for path loss estimation. In an embodiment, the receiving UE may transmit a transmission power value of a signal for path loss estimation and offset information between the configured reference signal and the transmission power value of the signal for path loss estimation. In this case, the signal for path loss estimation and the information on the transmission power of the signal for path loss estimation may be transmitted via the same channel or different channels.

Next, in operation 1420, the receiving UE performs bypass transmission with the transmitting UE. In an embodiment, a receiving UE may receive bypass control information and bypass data from a transmitting UE.

Although not shown, the operations of the transmitting UE and the receiving UE of fig. 10 may be similar to those described with reference to fig. 11 to 14. In an embodiment, some operations of the transmitting UE and the receiving UE described with reference to fig. 11 to 14 may be applied to the operations in fig. 10 such as transmission and reception of signals for path loss estimation by the transmitting UE and the receiving UE, path loss estimation based on the signals for path loss estimation, transmission and reception of a path loss estimation result report corresponding to the signals for path loss estimation, transmission power configuration based on the path loss estimation result report, and bypass transmission with the configured transmission power.

Further, although description has been made assuming that there are one transmitting UE and one receiving UE, the present disclosure is not limited thereto, and may be applied even when there are one or more transmitting UEs and receiving UEs. For example, when there are a plurality of transmitting UEs and/or a plurality of receiving UEs, each of the transmitting UEs and/or the receiving UEs may transmit and receive a signal for path loss estimation.

As shown in fig. 15, a transmitting UE of the present disclosure may include a transceiver 1510, a memory 1520, and a processor 1530. The processor 1530, the transceiver 1510, and the memory 1520 may operate according to the above-described communication method of the transmitting UE. However, the element of the transmitting UE is not limited thereto. For example, the transmitting UE may include more or fewer elements than shown in fig. 15. Further, the processor 1530, the transceiver 1510, and the memory 1520 may be implemented as one chip. Further, the processor 1530 may include at least one processor.

The transceiver 1510 may be collectively referred to as a receiver and a transmitter of a transmitting UE, and may transmit and receive signals to and from a base station. The signals transmitted to and received from the base station may include control information and data. To this end, the transceiver 1510 may include a Radio Frequency (RF) transmitter that up-converts and amplifies a frequency of a transmission signal, and an RF receiver that performs low-noise amplification on a reception signal and down-converts the frequency. However, this is merely an example, and the elements of the transceiver 1510 are not limited to RF transmitters and RF receivers.

Further, the transceiver 1510 may receive a signal via a wireless channel and may output a signal to the processor 1530, and may transmit a signal output from the processor 1530 via a wireless channel.

The memory 1520 may store programs and data required for operating the transmitting UE. Further, the memory 1520 may store control information or data included in a signal obtained by the transmitting UE. The memory 1520 may include storage media such as read-only memory (ROM), random-access memory (RAM), a hard disk, a Compact Disc (CD) -ROM, or a Digital Versatile Disc (DVD), or a combination thereof.

Processor 1530 may control a series of processes such that a transmitting UE operates in accordance with the above-described embodiments of the present disclosure. For example, the transceiver 1510 may receive a data signal including a control signal, and the processor 1530 may determine a reception result of the data signal.

In an embodiment, processor 1530 may transmit a signal for path loss estimation to a receiving UE, may receive a path loss estimation result report from the receiving UE in response to the signal for path loss estimation, may configure transmit power based on the path loss estimation result report, and may perform bypass transmission with the receiving UE with the configured transmit power.

Further, in an embodiment, processor 1530 may receive a signal for path loss estimation from a receiving UE, may estimate path loss based on the signal for path loss estimation, may configure transmit power based on the path loss estimation result, and may perform bypass transmission with the receiving UE with the configured transmit power.

As shown in fig. 16, a receiving UE of the present disclosure may include a transceiver 1610, a memory 1620, and a processor 1630. The processor 1630, the transceiver 1610, and the memory 1620 may operate according to the above-described communication method of the receiving UE. However, the element of the receiving UE is not limited thereto. For example, the receiving UE may include more or fewer elements than shown in fig. 16. Further, the processor 1630, the transceiver 1610, and the memory 1620 may be implemented as one chip. Further, the processor 1630 may include at least one processor.

The transceiver 1610 may be collectively referred to as a receiver and a transmitter of a receiving UE, and may transmit and receive signals to and from a base station. The signals transmitted to and received from the base station may include control information and data. To this end, the transceiver 1610 may include an RF transmitter that up-converts and amplifies the frequency of a transmission signal, and an RF receiver that performs low-noise amplification on a reception signal and down-converts the frequency. However, this is only an example, and the elements of the transceiver 1610 are not limited to the RF transmitter and the RF receiver.

In addition, transceiver 1610 may receive signals via a wireless channel and may output signals to processor 1630 and may transmit signals output from processor 1630 via a wireless channel.

The memory 1620 may store programs and data required for operating the reception UE. Further, the memory 1620 may store control information or data included in a signal obtained by a receiving UE. The memory 1620 may include a storage medium such as a ROM, a RAM, a hard disk, a CD-ROM, or a DVD, or a combination thereof.

The processor 1630 may control a series of processes such that the receiving UE operates in accordance with the above-described embodiments of the disclosure. For example, the transceiver 1610 may receive a data signal including a control signal, and the processor 1630 may determine a reception result of the data signal.

In an embodiment, the processor 1630 may control receiving a signal for path loss estimation from a transmitting UE, estimating a path loss based on the signal for path loss estimation, and transmitting a path loss estimation result report to the transmitting UE.

Further, in an embodiment, processor 1630 may send a signal to the sending UE for path loss estimation and may perform bypass transmission with the sending UE.

The methods described herein in accordance with the claims or embodiments of the present disclosure may be implemented by hardware, software, or a combination of hardware and software.

When the methods are implemented by software, a computer-readable storage medium or computer program product storing one or more programs (software modules) may be provided. One or more programs stored in a computer readable storage medium or computer program product are configured to be executable by one or more processors in an electronic device. The one or more programs include instructions for allowing the electronic device to perform methods in accordance with claims or embodiments of the disclosure described herein.

These programs (software modules or software) may be stored in Random Access Memory (RAM), non-volatile memory including flash memory, Read Only Memory (ROM), electrically erasable programmable read-only memory (EEPROM), a magnetic disk storage device, a Compact Disk (CD) -ROM, a Digital Versatile Disk (DVD), another optical storage device, or a magnetic disk. Alternatively, the program may be stored in a memory configured by combining some or all of the storage devices. Further, each of the memories may include a plurality of memories.

Further, the program may be stored in an attachable storage device that is accessible over a communication network such as the internet, an intranet, a Local Area Network (LAN), a wide area network (WLAN), or a Storage Area Network (SAN), or a combination thereof. Such a storage device may be accessible through an external port to a device performing an embodiment of the present disclosure. Furthermore, a separate storage device in a communication network may access a device that performs embodiments of the present disclosure.

In detailed embodiments of the present disclosure, components included in the present disclosure have been expressed as singular or plural according to detailed embodiments of the present disclosure. However, the conditions provided for convenience of description have been appropriately selected for singular or plural expressions, and the present disclosure is not limited to singular or plural components. A component expressed in the plural number may be configured as a single component, or a component expressed in the singular number may be configured as a plurality of components.

The embodiments of the present disclosure disclosed in the present specification and the drawings are provided to easily describe and assist understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. That is, it is apparent to those skilled in the art that various modifications can be made based on the technical spirit of the present disclosure. Further, when necessary, the embodiments of the present disclosure may be used in combination. For example, portions of one embodiment and another embodiment of the present disclosure may be combined with each other. Further, other modifications based on the technical spirit of the embodiments may be made in other systems such as an LTE system, a 5G or NR system, and the like.

Claims

1. A path loss estimation method of a transmitting terminal in a wireless communication system, the path loss estimation method comprising:

transmitting a signal for path loss estimation to a receiving terminal;

receiving a path loss estimation result report from a receiving terminal in response to a signal for path loss estimation;

configuring a transmission power based on the pathloss estimation result report; and

performing a bypass transmission with the receiving terminal using the configured transmission power.

2. The path loss estimation method of claim 1, wherein the path loss estimation result report comprises at least one layer 1 reference signal received power (L1-RSRP) measured by a receiving terminal,

wherein receiving, from the receiving terminal, the path loss estimation result report in response to the signal for path loss estimation comprises receiving the at least one L1-RSRP measured by the receiving terminal via a bypass feedback channel (physical bypass feedback channel (PSFCH)) or receiving a medium access control element (MAC CE) transmitted via a bypass data channel (physical bypass shared channel (PSSCH)).

3. The path loss estimation method of claim 2, wherein the MAC CE comprises the at least one L1-RSRP,

wherein, when the MAC CE comprises a plurality of L1-RSRPs, the MAC CE comprises a User Equipment (UE) ID.

4. The path loss estimation method of claim 1, wherein the path loss estimation result report comprises a layer 3RSRP (L3-RSRP) measured by a receiving terminal,

wherein receiving the path loss estimation result report from the receiving terminal in response to the signal for path loss estimation comprises receiving L3-RSRP measured by the receiving terminal through a Radio Resource Control (RRC) message transmitted via a bypass data channel (PSSCH).

5. The path loss estimation method of claim 1, wherein receiving a path loss estimation result report from a receiving terminal in response to a signal for path loss estimation comprises: receiving a pathloss estimation result report before a preconfigured timer expires, or before and after a preconfigured second time, or before and after a preconfigured first time has elapsed or a preconfigured number of time slots has been received, after a signal for pathloss estimation is transmitted to the receiving terminal.

6. The path loss estimation method according to claim 5, further comprising, when the path loss estimation result report is not received before the pre-configured timer expires, transmitting information indicating that the path loss estimation result report has not been received to the receiving terminal.

7. The path loss estimation method of claim 1, wherein the signal for path loss estimation comprises at least one of a shunt synchronization signal comprising at least one of a Primary Shunt Synchronization Signal (PSSS) and a Secondary Shunt Synchronization Signal (SSSS), a demodulation reference signal (DMRS) transmitted via at least one of a shunt broadcast channel (physical shunt broadcast channel (PSBCH)), a shunt control channel (physical shunt control channel (PSCCH)), and a shunt data channel (physical shunt shared channel (PSCCH)), and a reference signal for supporting a shunt operation.

8. A path loss estimation method of a receiving terminal in a wireless communication system, the path loss estimation method comprising:

receiving a signal for path loss estimation from a transmitting terminal;

estimating a Reference Signal Received Power (RSRP) based on the signal for path loss estimation; and

and sending a path loss estimation result report comprising the RSRP to the sending terminal.

9. The path loss estimation method of claim 8, wherein the RSRP comprises at least one layer 1RSRP (L1-RSRP),

wherein transmitting the path loss estimation result report including the RSRP to the transmitting terminal comprises transmitting at least one of L1-RSRP via a bypass feedback channel (physical bypass feedback channel (PSFCH)) or a medium access control element (MAC CE) via a bypass data channel (physical bypass shared channel (PSSCH)).

10. The path loss estimation method of claim 9, wherein the MAC CE comprises the at least one L1-RSRP,

11. The path loss estimation method of claim 9 wherein sending a path loss estimation result report including the RSRP to the sending terminal comprises sending the L1-RSRP every preconfigured time or every preconfigured time slot until a preconfigured timer expires or until a report stop command is received from the sending terminal after the signal for path loss estimation is received.

12. The path loss estimation method of claim 8 wherein the path loss estimation result report comprises a layer 3RSRP (L3-RSRP),

wherein transmitting a path loss estimation result report including the RSRP to the transmitting terminal comprises transmitting the L3-RSRP by a Radio Resource Control (RRC) message transmitted via a bypass data channel (PSSCH).

13. The path loss estimation method of claim 8, wherein the signal for path loss estimation comprises at least one of a shunt synchronization signal comprising at least one of a Primary Shunt Synchronization Signal (PSSS) and a Secondary Shunt Synchronization Signal (SSSS), a demodulation reference signal (DMRS) transmitted via at least one of a shunt broadcast channel (physical shunt broadcast channel (PSBCH)), a shunt control channel (physical shunt control channel (PSCCH)), and a shunt data channel (physical shunt shared channel (PSCCH)), and a reference signal for supporting a shunt operation.

14. A transmitting terminal, comprising:

a transceiver;

a memory storing a path loss estimation method program and data of a transmission terminal; and

a processor configured to execute a program stored in the memory to transmit a signal for path loss estimation to a receiving terminal, receive a path loss estimation result report from the receiving terminal in response to the signal for path loss estimation, configure transmission power based on the path loss estimation result report, and perform bypass transmission with the receiving terminal using the configured transmission power.

15. A receiving terminal, comprising:

a transceiver;

a memory storing a path loss estimation method program and data of a reception terminal; and

a processor configured to execute a program stored in the memory to receive a signal for path loss estimation from a transmitting terminal, measure Reference Signal Received Power (RSRP) based on the signal for path loss estimation, and transmit a path loss estimation result report including the RSRP to the transmitting terminal.