TWI896600B - Terminal configured to perform vehicle-to-everything communication - Google Patents

Abstract

An operating method of a terminal configured to perform vehicle-to-everything (V2X) communication in a wireless communication system, including signaling a maximum physical sidelink feedback channel (PSFCH) receiving capability to a base station; and receiving a wireless signal transmitted from the base station based on the maximum PSFCH receiving capability, wherein the maximum PSFCH receiving capability is a maximum number of PSFCHs receivable during one time transmission interval (TTI).

Description

Configured as a terminal for vehicle-to-vehicle communication [Cross reference to related applications]

This application is based upon and claims priority to U.S. Provisional Application No. 62/977,430 filed in the U.S. Patent and Trademark Office on February 17, 2020, and U.S. Provisional Application No. 63/024,098 filed in the U.S. Patent and Trademark Office on May 13, 2020, and Korean Patent Application No. 10-2020-0096942 filed in the Korean Intellectual Property Office on August 3, 2020. The disclosures of each of these applications are incorporated herein by reference in their entirety.

This disclosure relates to an apparatus and method for efficiently transmitting and receiving a physical sidelink feedback channel (PSFCH) to perform vehicle-to-everything (V2X) communications in a wireless communication system.

To meet the increasing demand for wireless data services following the commercialization of the fourth-generation (4G) communication system, efforts have been underway to develop the fifth-generation (5G) communication system.

Consequently, 5G communication systems have recently been commercialized. To achieve high data transmission rates, 5G communication systems can be implemented in ultra-high frequency bands (e.g., millimeter wave (mmWave) bands or 60 gigahertz (GHz) bands). To reduce radio wave path loss and increase the propagation distance of radio waves in ultra-high frequency bands, beamforming technology, massive multiple-input and multiple-output (MIMO) technology, full-dimensional MIMO (FD-MIMO) technology, array antennas, analog beamforming technology, and large antenna technology have been or will be applied to 5G communication systems.

Furthermore, to improve communication networks, the following technologies have been or will be applied to 5G communication systems: evolved small cells, advanced small cells, cloud radio access network (cloud RAN), ultra-dense networks, device-to-device communication (D2D), wireless backhaul, mobile networks, cooperative communications, coordinated multi-point (CoMP), and receive interference cancellation.

In addition, advanced coding modulation (ACM) technologies (such as hybrid frequency shift keying and quadrature amplitude modulation (FQAM) and sliding window superposition coding (SWSC)) and advanced access technologies (such as filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA)) have been or will be applied to 5G communication systems.

Furthermore, unlike long-term evolution (LTE) V2X communications, which only supports broadcast, new-ratio (NR) V2X communications in Release 16 (Rel-16) also support unicast and groupcast. Furthermore, a new physical sidelink feedback channel (PSFCH) has been defined to improve the reliability of both unicast and groupcast. Therefore, a transmitting terminal (e.g., a terminal configured to transmit signals and/or channels) can receive acknowledgment/negative-acknowledgement (ACK/NACK) feedback from a receiving terminal (e.g., a terminal configured to receive signals and/or channels) via the PSFCH, thereby enabling hybrid automatic repeat request (HARQ).

For reference, a low peak-to-average power ratio (PAPR) sequence based on the Zadoff-Chu sequence can be applied to the PSFCH, and the 1-bit HARQ-ACK/NACK included in the PSFCH can have the aforementioned sequence format. Furthermore, the PSFCH can be transmitted in units of one resource block (RB), and code division multiplexing (CDM) can be applied to the PSFCH, allowing multiple users (or terminals) to transmit the PSFCH using a single RB.

However, because a transmitting terminal can simultaneously receive HARQ ACK/NACKs from multiple receiving terminals in multicast mode, the number of PSFCHs to be received by the transmitting terminal can increase as the number of receiving terminals in the group increases. However, since the current 3rd Generation Partnership Project (3GPP) standard does not define a maximum number of PSFCHs that can be transmitted or received by a terminal, the number of received PSFCHs may exceed the PSFCH reception capability of the transmitting terminal. Furthermore, since the transmitting terminal must determine whether all PSFCHs received from the multiple receiving terminals are ACKs or NACKs, the operation of determining whether a PSFCH is an ACK or NACK can increase the workload on the transmitting terminal.

Provided are a device and method for efficiently transmitting and receiving a physical sidelink feedback channel (PSFCH) to perform vehicle-to-everything (V2X) communications in a wireless communication system.

Additional aspects will be set forth in part in the description which follows and will, in part, be apparent from the description or may be learned by practice of the presented embodiments.

According to aspects of the present disclosure, a method of operating a terminal configured to perform vehicle-to-everything (V2X) communication in a wireless communication system includes signaling a maximum physical sidelink feedback channel (PSFCH) reception capability to a base station, wherein the maximum PSFCH reception capability is the maximum number of PSFCHs that can be received during a time transmission interval (TTI).

According to aspects of the present disclosure, a method of a terminal configured to perform vehicle-to-everything (V2X) communication in a wireless communication system includes: signaling a maximum physical sidelink feedback channel (PSFCH) transmission capability to a base station, wherein the maximum PSFCH transmission capability is the maximum number of PSFCHs that can be transmitted during a time transmission interval (TTI).

According to aspects of the present disclosure, a terminal configured to perform vehicle-to-everything (V2X) communications includes: a transceiver configured to transmit and receive one or more wireless signals; and a processor configured to control the transceiver to transmit signals to a base station based on a maximum physical sidelink feedback channel (PSFCH) reception capability, wherein the maximum PSFCH reception capability is the maximum number of PSFCHs that can be received during a time transmission interval (TTI).

According to aspects of the present disclosure, a terminal configured to perform vehicle-to-everything (V2X) communications includes: a transceiver configured to transmit and receive one or more wireless signals; and a processor configured to control the transceiver to transmit signals to a base station based on a maximum physical sidelink feedback channel (PSFCH) transmission capability, wherein the maximum PSFCH transmission capability is the maximum number of PSFCHs that can be transmitted during a time transmission interval (TTI).

According to an aspect of the present disclosure, a terminal configured to perform vehicle-to-everything (V2X) communication includes: a transceiver configured to transmit and receive one or more wireless signals; and a processor configured to: control the transceiver to measure the reference signal received power (RSRP) or signal-to-interference and noise ratio (SINR) of k of a plurality of physical sidelink feedback channels (PSFCHs) received during a time transmission interval (TTI). ratio (SINR), where k is an integer greater than 1; sorting the k PSFCHs in ascending order based on the RSRP or the SINR; controlling the transceiver to sequentially determine whether the k sorted PSFCHs are hybrid automatic repeat request (HARQ) acknowledgments (ACKs) or HARQ negative acknowledgments (NACKs) in the ascending order; and determining whether to retransmit a physical sidelink shared channel (PSSCH) based on the sequential determination.

According to an aspect of the present disclosure, a terminal configured to perform vehicle-to-everything (V2X) communication includes: a transceiver configured to transmit and receive one or more wireless signals; and a processor configured to control the transceiver, wherein the processor is further configured to: control the transceiver to measure a reference signal received power (RSRP) or a signal-to-interference and noise ratio (SINR) of a plurality of physical sidelink feedback channels (PSFCHs) received during a time transmission interval (TTI); and H selects k PSFCHs that meet preset criteria, where k is an integer greater than 1; sorts the selected k PSFCHs in ascending order based on the RSRP or the SINR; controls the transceiver to sequentially determine whether the k sorted PSFCHs are Hybrid Automatic Repeat Request (HARQ) acknowledgments (ACKs) or HARQ Negative Acknowledgments (NACKs); and determines whether to retransmit a physical sidelink shared channel (PSSCH) based on the sequential determination.

21: First Terminal

23: Second Terminal

25: The Third Terminal

27: The Fourth Terminal

29: The Fifth End

31: The Sixth Terminal

33: The Seventh End

35: The Eighth End

51:Base station

53, 55: Terminal

90, 180: Antenna

105: Front End Module (FEM)

110: RF Integrated Circuit (RFIC)

112: Transmitter circuit

114: Receiving circuit

116: Local Oscillator

120: Baseband circuit

122: Controller

124: Storage

125: Signal processing unit

126: Demodulator

128: Receive filter and cell finder

130: Other components

150, 220: Processor

160: Transceiver

170, 230: Memory

200: Network Environment

201: Wireless Communication Devices

202, 204: Electronic devices

206: Server

210: Bus

240: Program

241: Core

243: Middleware

245: Application Programming Interface (API)

247: Applications

249: Network access information

250:I/O interface

260: Display module

262: Internet

264: Wireless Communication

270: Communication Interface

1000: Wireless communication system

CH1: Channel/PSCCH

CH2: Channel/PSSCH

CH3: Channel/PSFCH

S100, S150, S200, S250, S300, S1000, S1100, S1200, S1210, S1220, S1300, S1310, S1320, S1330, S1340, S1350, S2000, S2010, S2020, S2030, S2040, S2100, S2200, S2300: Operation

SIG1, SIG2, SIG3: Signals

The above and other aspects, features, and advantages of certain embodiments of the present disclosure will become more apparent from the following description in conjunction with the accompanying drawings. FIG. 1 is a diagram illustrating unicast, multicast, and physical sidelink feedback channel (PSFCH) transmission processes performed between terminals via a sidelink according to an embodiment.

FIG2 is a diagram illustrating the process of transmitting signals between a terminal and a base station and the process of transmitting and receiving channels between the terminals according to an embodiment.

Figures 3 to 5 are diagrams illustrating a time-frequency range structure applied to a sidelink of a new radio (NR) communication system according to an embodiment.

FIG6 is a block diagram of a radio-frequency (RF) transceiver component included in a terminal or base station according to an embodiment.

FIG7 is a simplified block diagram of the RF transceiver assembly shown in FIG6 according to an embodiment.

FIG8 is a flow chart of the process of transmitting communication between a terminal and a base station according to an embodiment.

Figure 9 is a flowchart of a PSFCH determination method of a terminal according to an embodiment.

FIG10 is a detailed flowchart of operations S1200 and S1300 shown in FIG9 according to an embodiment.

Figure 11 is a flowchart of a PSFCH determination method of a terminal according to an embodiment.

FIG12 is a detailed flowchart of operation S2000 shown in FIG11 according to an embodiment.

FIG13 is a diagram of a wireless communication device according to an embodiment.

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

Various exemplary embodiments will now be described more fully with reference to the accompanying drawings, which illustrate some exemplary embodiments. However, the embodiments may be embodied in different forms and should not be construed as limited to the embodiments described herein. The embodiments may be interchangeable with one another. Rather, these embodiments are provided so that this disclosure will be thorough and complete and fully convey the scope to those skilled in the art. Even when content described in a particular embodiment is not described in other embodiments, that content should be understood to be relevant to those other embodiments unless otherwise stated or such content would conflict with that particular embodiment in those other embodiments. Throughout this specification, like reference numerals generally refer to like elements.

The terms used herein are for describing specific embodiments only and are not intended to limit the scope of other embodiments. Unless the context clearly indicates otherwise, expressions in the singular may include expressions in the plural. Furthermore, it should be understood that the terms "comprises," "comprising," "includes," and/or "including" as used herein specify the presence of stated features, items, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, items, steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms used herein (including technical and scientific terms) should be interpreted according to their customary meanings in the art to which this disclosure pertains. Furthermore, it should be understood that commonly used terms should also be interpreted according to their customary meanings in the relevant art and should not be interpreted in an idealized or overly formal sense unless expressly defined otherwise herein.

Furthermore, the embodiments will be described in detail with a focus on New Radio (NR) systems and Long Term Evolution (LTE)/LTE-Advanced (LTE-A) systems. However, according to the judgment of those skilled in the art, with minor modifications within the scope of this disclosure, the embodiments can be applied not only to other communication systems with similar technical backgrounds but also to other communication systems using both licensed and unlicensed bands.

Before the detailed description below, the definitions of certain words and phrases used throughout this specification are provided. The expression "connected to" and its derivatives may refer to any direct or indirect communication between at least two components, regardless of whether the at least two components are in physical contact with each other. The terms "transmit," "receive," and "communicate," and their derivatives, may include both direct and indirect communication. The terms "comprising" and "including," and their derivatives, may mean including, but not limited to. The term "or" may be inclusive, meaning "and/or." The expression "associated with" and its derivatives may refer to including, included in, interconnected with, containing, contained in, connected to/connected with, combined to/combined with, communicating with, cooperating with, sandwiched between, positioned parallel to, proximate to, bounded by, having, characterized by, having a relationship with, and the like. The term "controller" refers to a device, system, or portion thereof that controls at least one operation. A controller may be implemented in hardware or a combination of hardware with software and/or firmware. The functionality associated with any particular controller may be centralized or distributed, locally or remotely. When the expression "at least one of" precedes a list of items, any and all combinations of one or more of the listed items may be used, or only one of the listed items may be required. For example, the expression "at least one of A, B, and C" may include at least one of A, B, and C, both A and B, both A and C, both B and C, and a combination of A, B, and C.

The various functions described below may be implemented or supported by one or more computer programs, each of which may be comprised of computer-readable code and executed on a computer-readable medium. As used herein, the terms "application" and "program" refer to one or more computer programs, software components, instruction sets, programs, functions, objects, classes, instances, related data, or portions thereof suitable for implementing computer-readable code. The term "computer-readable code" includes all types of computer code, including source code, object code, and execution code. The term "computer-readable media" includes all types of media that can be accessed by a computer, such as read-only memory (ROM), random access memory (RAM), hard disc drives (HDD), compact discs (CD), digital video discs (DVD), or any other type of memory. "Non-transitory" computer-readable media excludes wired, wireless, optical, or other communication links that carry transient electrical or other signals. Non-transitory computer-readable media include media in which data can be stored permanently and media in which data can be stored and later overwritten (such as rewritable optical discs or erasable memory devices).

In the various embodiments described below, hardware access methods will be explained as examples. However, the various embodiments include technologies that use both hardware and software, and therefore, the various embodiments do not exclude software-based access methods.

For the sake of brevity, the following description uses terms referring to control information, items, network entities, messages, and device components as examples. Therefore, the embodiments are not limited to the terms described below, and other terms with equivalent technical meanings may be used instead.

FIG1 is a diagram illustrating unicast, multicast, and physical sidelink feedback channel (PSFCH) transmission procedures performed between terminals via a sidelink according to an exemplary embodiment.

FIG1 illustrates a plurality of terminals configured to perform vehicle-to-everything (V2X) communication according to an embodiment, such as a first terminal 21, a second terminal 23, a third terminal 25, a fourth terminal 27, a fifth terminal 29, a sixth terminal 31, a seventh terminal 33, and an eighth terminal 35.

First, it can be seen that the communication scheme between the first terminal 21 and the second terminal 23 is a one-to-one communication, that is, unicast communication performed via a side link.

Although FIG1 shows an example in which a signal is transmitted from the first terminal 21 to the second terminal 23, the signal may be transmitted in the opposite direction. That is, the signal may be transmitted from the second terminal 23 to the first terminal 21.

Furthermore, the operation of exchanging signals between the first terminal 21 and the second terminal 23 via unicast may include performing a scrambling process, a control information mapping process, a data transmission process, and a unique identification (ID) value verification process using resources or values known between the first terminal 21 and the second terminal 23. Furthermore, the first terminal 21 and the second terminal 23 may be mobile terminals, such as vehicles.

It can be seen that the communication scheme between the third terminal and the fifth terminal 25, 27, and 29 is a multicast communication in which the third terminal 25 transmits common data to other terminals in the group (such as the fourth terminal 27 and the fifth terminal 29) via a sidelink.

During multicast communication, other terminals not included in the group (e.g., the second terminal 23 and the seventh terminal 33) may not receive the multicast signal transmitted by the third terminal 25.

For reference, the terminal configured to transmit signals for multicasting may not be the third terminal 25, but rather another terminal in the group (e.g., the fourth terminal 27 or the fifth terminal 29). Furthermore, the allocation of resources for transmitting signals may be determined by the base station or the terminal serving as the group leader, or may be selected by the terminal configured to transmit signals. Furthermore, the third through fifth terminals 25, 27, and 29 may be mobile terminals, such as vehicles.

Finally, we will now discuss communication between the sixth through eighth terminals 31, 33, and 35. This communication scheme may include one in which the seventh and eighth terminals 33 and 35 receive common data from the sixth terminal 31 in a multicast communication and transmit feedback regarding the success or failure of receiving the common data to the sixth terminal 31. Although not shown in the figure, feedback regarding the success or failure of receiving data can also be transmitted between terminals in unicast communication (e.g., the first terminal 21 and the second terminal 23).

For reference, information related to the success or failure of data reception may be Hybrid Automatic Repeat Request (HARQ)-Acknowledgement/Negative Acknowledgement (ACK/NACK) information included in the PSFCH. Furthermore, the sixth to eighth terminals 31, 33, and 35 may be mobile terminals, such as vehicles.

As described above, various communication schemes can be applied between multiple terminals (e.g., the first through eighth terminals 21, 23, 25, 27, 29, 31, 33, and 35 configured to perform V2X communication according to the exemplary embodiment). Below, FIG. 2 will be described based on a V2X communication scheme.

FIG2 is a diagram illustrating a process of transmitting signals between a terminal and a base station and a process of transmitting and receiving channels between the terminals according to an exemplary embodiment.

2 , a wireless communication system 1000 according to an exemplary embodiment may include a base station 51 and a plurality of terminals (e.g., terminals 53 and 55).

For reference, although FIG2 shows an example in which the wireless communication system 1000 includes only two terminals 53 and 55 and one base station 51 for simplicity, the present disclosure is not limited thereto. That is, the wireless communication system 1000 may include more or fewer terminals and base stations.

Furthermore, each of the terminals 53 and 55 shown in FIG2 may be capable of V2X communications, such as unicast, multicast, and PSFCH transmissions as described with reference to FIG1 . Therefore, while FIG2 illustrates unicast communication between two terminals 53 and 55 , FIG2 may be interpreted as illustrating multicast communication between some terminals in a group.

The wireless communication system 1000 may be referred to as a radio access technology (RAT). For example, the wireless communication system 1000 may be a wireless communication system using a cellular network, such as a NR communication system, an LTE communication system, an LTE-Advanced (LTE-A) communication system, a Code Division Multiple Access (CDMA) communication system, and a Global System for Mobile Communications (GSM). In an embodiment, the wireless communication system 1000 may be a Wireless Local Area Network (WLAN) communication system or any other wireless communication system.

The wireless communication network used in the wireless communication system 1000 can share available network resources and support communication among multiple wireless communication devices including terminals 53 and 55.

For example, in wireless communication networks, information can be transmitted using various multiple access methods, such as CDMA, frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), orthogonal frequency division multiplexing (OFDM)-FDMA, OFDM-TDMA, and OFDM-CDMA.

In this embodiment, wireless communication system 1000 may be a NR communication system. However, the exemplary embodiments are not limited thereto and may also be applied to both previous and next generation wireless communication systems.

Furthermore, base station 51 may refer to a fixed platform configured to communicate with terminals 53 and 55 and/or another base station. Base station 51 may communicate with terminals 53 and 55 and/or another base station and exchange data and control information with terminals 53 and 55 and/or another base station.

For example, the base station 51 may be referred to as a Node B, an evolved-Node B (eNB), a next-generation Node B (gNB), a sector, a site, a base transceiver system (BTS), an access point (AP), a relay node, a remote radio head (RRH), or a radio unit (RU).

In this embodiment, base station 51 can be interpreted as a portion of the area or functionality covered by a CDMA base station controller (BSC), a wideband CDMA (WCDMA) Node B, an LTE eNB, a NR gNB, or a sector (site). Terminals 53 and 55 can be fixed devices such as user devices or mobile devices such as vehicles, and can refer to any device capable of communicating with base station 51 and transmitting and receiving data and/or control information to and from base station 51.

For example, terminals 53 and 55 may be referred to as a wireless station (STA), a mobile station (MS), a mobile terminal (MT), a user terminal (UT), user equipment (UE), a subscriber station (SS), a wireless device, a handheld device, or a vehicle.

Furthermore, base station 51 can connect to terminals 53 and 55 via wireless channels and provide various communication services to terminals 53 and 55 via the connected wireless channels. Furthermore, all user services of base station 51 can be served via shared channels. Furthermore, base station 51 can schedule terminals 53 and 55 by collecting status information from terminals 53 and 55 (e.g., PSFCH capacity, buffer status, available transmit power, and channel status).

Furthermore, wireless communication system 1000 may utilize an orthogonal frequency division multiplexing (OFDM) scheme to support beamforming technology. Furthermore, wireless communication system 1000 may support an adaptive modulation and coding (AMC) scheme, which determines the modulation scheme and channel coding rate based on the channel status of terminals 53 and 55.

For reference, the wireless communication system 1000 can transmit and receive signals using frequency bands including not only frequency bands less than 6 gigahertz but also frequency bands of 6 gigahertz or greater.

For example, the wireless communication system 1000 can increase the data transmission rate by using a millimeter wave band (e.g., a 28 GHz band or a 60 GHz band).

Signal attenuation per distance can be relatively large in the millimeter wave band. Therefore, the wireless communication system 1000 can support directional beam-based transceiver operations to ensure coverage. Furthermore, the wireless communication system 1000 can perform beam scanning operations to enable directional beam-based transceiver operations.

Here, the term "beam scanning operation" may refer to terminals 53 and 55 and base station 51 sequentially or randomly scanning directional beams having a predetermined pattern to determine a transmit beam and a receive beam whose orientations are aligned with each other. In other words, the pattern of the transmit beam and the receive beam whose orientations are aligned with each other can be defined as a pair of beam patterns. Furthermore, a beam pattern may refer to a beam shape determined based on the beam width and the beam orientation.

Since the terminals 53 and 55 and the base station 51 of the wireless communication system 1000 can be configured and operated as described above, the communication between the terminals 53 and 55 or between the terminals 53 and 55 and the base station 51 will now be described in more detail.

Terminals 53 and 55 can transmit or receive signals SIG1, SIG2, SIG3, and SIG4 to and from base station 51 via uplinks or downlinks, and access the network of wireless communication system 1000. The link (e.g., data transmission and reception interface) between terminals 53 and 55 and base station 51 can be referred to as a Uu link. Furthermore, to exchange various configuration information required for signal transmission and reception operations between terminals 53 and 55 and base station 51, a radio resource control (RRC) connection can be established between the terminal 53 or 55 and base station 51. This RRC connection can be referred to as Uu-RRC.

Specifically, for example, terminals 53 and 55 may transmit signals SIG2 and SIG4 to base station 51 regarding the maximum number of PSFCHs that can be transmitted and received during a time transmission interval (TTI) (e.g., a time slot). In an embodiment, the maximum number of PSFCHs that can be transmitted and received during a TTI may be referred to as the maximum PSFCH transceiving capability (or max PSFCH transceiving capability). Furthermore, information regarding the maximum PSFCH transceiving capability may correspond to RRC information, which may be one of the capabilities information elements of the user equipment (UE). Therefore, terminals 53 and 55 may transmit signals SIG2 and SIG4 regarding the maximum PSFCH transceiving capability to base station 51 via RRC signaling. Therefore, information regarding the maximum PSFCH transceiving capability may be included in the physical uplink shared channel (PUSCH). In addition to being included in the PUSCH, information regarding the maximum PSFCH transceiver capability can also be included in the physical uplink control channel (PUCCH) or the physical random access channel (PRACH). However, the exemplary embodiment relates to an example in which the information is included in the PUSCH.

For reference, in this embodiment, the contents disclosed in Table 1 can be reintroduced and defined in conjunction with the maximum PSFCH transceiver capability of the terminal. Therefore, terminals 53 and 55 can signal their maximum PSFCH transceiver capability to base station 51 based on the items described in Table 1.

For example, the "UE capability signaling" of item (1) of Table 1 can be expressed as shown in Table 2 below.

For example, the "UE capability signaling" of item (2) of Table 1 can be expressed as shown in Table 3 below.

In addition, the contents disclosed in Table 1 can be arranged as shown in Tables 4-1 and 4-2 below.

For reference, Table 4-1 and Table 4-2 are tables that were created by dividing a continuous table into smaller parts due to limited space.

As described above, in the exemplary embodiment, terminal 53 or 55 may signal its maximum PSFCH transceiver capability to base station 51. An example of this scenario is described in more detail with reference to FIG8 . Furthermore, based on the signaling from terminals 53 and 55, base station 51 may perform RRC signaling (e.g., signals SIG1 and SIG3) to terminals 53 and 55, schedule the transmission and reception of signals (e.g., PSSCH, physical sidelink control channel (PSCCH), and PSFCH) between terminals 53 and 55, or perform multicast-related configuration operations (e.g., selecting a group leader and setting the size of the multicast zone).

For reference, terminals 53 and 55 may receive scheduling information for sidelink communications based on RRC signals (e.g., signals SIG1 and SIG3) from base station 51, or receive information (e.g., downlink control information (DCI)) on the physical downlink control channel (PDCCH).

Terminals 53 and 55 can transmit and receive signals between each other via sidelinks, such as channels CH1, CH2, and CH3. The sidelink (e.g., data transceiver interface) between terminals 53 and 55 can be referred to as a PC5 link. Furthermore, to exchange various configuration information required for signal transmission and reception between terminals 53 and 55, an RRC connection can be established between terminals 53 and 55. This RRC connection can be referred to as PC5-RRC.

Herein, channels transmitted and received via the sidelink may include, for example, a sidelink control channel (e.g., the physical sidelink control channel (PSCCH)), a sidelink shared channel or data channel (e.g., the physical sidelink shared channel (PSSCH)), a sidelink broadcast channel broadcast using a synchronization signal (e.g., the physical sidelink broadcast channel (PSBCH)), and a feedback transmission channel (e.g., the physical sidelink feedback channel (PSFCH)).

In this embodiment, terminal 53 configured to perform data transmission operations in the side-link may be referred to as a transmitting terminal, and terminal 55 configured to perform data reception operations in the side-link may be referred to as a receiving terminal. The transmitting terminal and the receiving terminal may perform data transmission operations and data reception operations in the side-link, respectively.

The transmitting terminal 53 may generate sidelink scheduling information, such as sidelink control information (SCI), based on the scheduling information provided by the base station 51. Furthermore, the transmitting terminal 53 may transmit the PSCCH CH1 including the generated sidelink scheduling information to the receiving terminal 55.

Here, the sidelink scheduling information may be transmitted to the receiving terminal 55 as a single SCI, or may be divided into two SCIs and transmitted to the receiving terminal 55. For reference, the method in which the sidelink scheduling information is divided into two SCIs and transmitted to the receiving terminal 55 may be referred to as a 2-phase SCI or a 2-phase PSCCH.

The transmitting terminal 53 can transmit PSSCH CH2 as a data channel to the receiving terminal 55 based on the sidelink scheduling information. Furthermore, the receiving terminal 55 can transmit feedback, namely PSFCH CH3, to the transmitting terminal 53. This feedback includes information related to the success or failure of receiving the PSSCH CH2 transmitted by the transmitting terminal 53, such as HARQ ACK/NACK. Therefore, the transmitting terminal 53 can determine whether the PSFCH CH3 received from the receiving terminal 55 includes a HARQ ACK or a HARQ NACK, and based on the determination result, decide whether to retransmit PSSCH CH2.

As described above, various signals or channels can be transmitted and received between terminals 53 and 55 and base station 51, as will be explained in more detail below.

The wireless communication system 1000 according to the exemplary embodiment has the characteristics and configuration described above. Therefore, the time-frequency structure of the sidelink application of the NR communication system according to the exemplary embodiment will now be described with reference to Figures 3 to 5.

For reference, the time-frequency range structures shown in Figures 3 through 5 may be examples of time-frequency ranges applicable to this embodiment, and therefore, the present disclosure is not limited thereto. However, for the sake of brevity, the time-frequency range structures shown in Figures 3 through 5 will be described as examples.

First, referring to Figure 3 , the horizontal axis represents the time domain, and the vertical axis represents the frequency range. The smallest transmission unit in the time domain may be an OFDM symbol, and N _symb OFDM symbols may form a time slot. A subframe may be 1.0 milliseconds (ms) long, and a radio frame may be 10 ms long. The smallest transmission unit in the frequency domain may be a subcarrier, and the system transmission bandwidth may include a total of N _BW subcarriers.

In the time-frequency domain, the basic unit of resources can be a resource element (RE), which can be represented by an OFDM symbol index and a subcarrier index. A resource block (RB) or physical resource block (PRB) can be defined by N _symb consecutive OFDM symbols in the time domain and N _RB consecutive subcarriers in the frequency domain. Therefore, an RB can include N _symb × N _RB REs.

For reference, the minimum data transmission unit is typically a RB. In NR communication systems, _Nsymb is typically at least one, _NRB is equal to 12, and _NBW and _NRB are proportional to the system transmission bandwidth. Furthermore, the data rate increases in proportion to the number of RBs scheduled for a terminal.

Additionally, channel bandwidth can indicate the RF bandwidth corresponding to the system's transmission bandwidth. For example, in an NR communication system with a subcarrier bandwidth of 30 kHz and a channel bandwidth of 100 MHz, the transmission bandwidth can include 273 RBs.

Referring to Figures 4 and 5 , based on the above description, the subchannels and resource pools defined in Release 16 (Rel-16) NR V2X communications to improve resource efficiency are shown. For reference, Figure 4 shows the basic frame structure of NR V2X communications and Phase 2 PSCCH, such as the time-frequency domain structure. Furthermore, Figure 5 illustrates the resource pools.

Specifically, in NR V2X communication, a timeslot may include at least one resource pool, each of which may include multiple subchannels. Here, the subchannel size may be, for example, any one of 10 RBs, 15 RBs, 20 RBs, 25 RBs, 50 RBs, 75 RBs, and 100 RBs. However, depending on the situation, the subchannel size may be any one of 4 RBs, 5 RBs, and 6 RBs. As an example, Figure 4 shows an example including subchannel #1 and subchannel #2, each of which includes 15 RBs (shown as RB #0 of subchannel #1 to RB #14 of subchannel #1 and RB #0 of subchannel #2 to RB #14 of subchannel #2).

In addition, the 0th symbol in the time slot (symbol 0) can be used for automatic gain control (AGC) training.

Furthermore, a PSFCH, used to determine whether the PSSCH was received correctly, can be allocated and transmitted in the twelfth symbol (symbol 12) of a time slot. Transmission timing can be two or three time slots after the time slot in which the PSSCH was transmitted. For example, when a PSSCH is transmitted in time slot A, a PSFCH corresponding to the PSSCH can be transmitted in time slot A+2 or time slot A+3 as feedback.

For reference, a PSFCH may include 1 PRB (or 1 RB) and be transmitted in each subchannel. Furthermore, the transmit/receive cycle of each PSFCH may be set, and the minimum value of the transmit/receive cycle may be set to 1, for example, 1 time slot unit. Since multiple PSFCHs may use the same resources, up to six cyclic shifts may be applied to different PSFCHs transmitted in the same RB. Therefore, up to ( *6 cyclic shift pairs/sub-channels) 410 PSFCHs.

The AGC for receiving the PSFCH can be assigned in the symbol immediately preceding the PSFCH (e.g., symbol 11). Because the transmitting entity (e.g., transmitting terminal) for symbols 0 through 9 (symbols 0 through 9) differs from the transmitting terminal (e.g., receiving terminal) for the 11th and 12th symbols (symbols 11 and 12), separate AGCs for the PSFCH may be required.

Additionally, guard symbols can be assigned to the tenth and thirteenth symbols (symbols 10 and 13) to ensure a guard period for timing advance. The transmitting entity for the 0th through ninth symbols (symbols 0 to 9) differs from the transmitting terminal for the eleventh and twelfth symbols (symbols 11 and 12), so the receiver may misalign the symbol timing. Therefore, guard symbols may be required.

In addition to the channels and symbols described above, the demodulation reference signal (DMRS), PSCCH, and PSSCH may be allocated to the first through ninth symbols (symbols 1 through 9). Furthermore, the PSFCH, AGC, and guard symbols may be allocated to the first through ninth symbols (symbols 1 through 9). However, for simplicity, the exemplary embodiment relates to an example in which the PSFCH, AGC, and guard symbols are allocated to the tenth through thirteenth symbols.

For reference, in NR V2X communications, since the PSCCH is transmitted in two phases, the first PSCCH can be assigned to the PSCCH scheduling range, and the second PSCCH can be assigned to the PSSCH range.

More specifically, the first PSCCH may be located in the lowest RB of a subchannel (e.g., RB #0 of subchannel #0) and include the first SCI. Furthermore, the first SCI may include PSSCH allocation information (e.g., frequency domain resource allocation (FDRA) and time domain resource allocation (TDRA)) and allocation information for the second PSCCH. The second PSCCH may include the second SCI and be initially allocated to the lowest RE, e.g., SC #1, excluding the REs for the DMRS in the first DMRS symbol (e.g., DMRS symbol 0), where SC stands for subcarrier. Furthermore, the second SCI may include information necessary for decoding the PSSCH.

As described above, the time-frequency range for sidelink applications in an NR communication system can be configured according to this embodiment. The configuration of a radio frequency (RF) transceiver in a terminal or base station according to this exemplary embodiment will be described below with reference to Figures 6 and 7.

FIG6 is a block diagram of an RF transceiver assembly included in a terminal or base station according to an exemplary embodiment. FIG7 is a simplified block diagram of the RF transceiver assembly shown in FIG6 according to an embodiment.

For reference, the RF transceiver components shown in Figures 6 and 7 may be included in the terminal 53 or 55 shown in Figure 2 or in the base station 51. Furthermore, the RF transceiver components shown in Figures 6 and 7 may include components in the transmission path and components in the reception path.

For the sake of brevity, the following description will focus on an example in which the RF transceiver components shown in Figures 6 and 7 are included in the terminal 53 shown in Figure 2. Furthermore, the description of the baseband circuit 120 shown in Figure 6 will focus on the components in the receive path.

First, referring to FIG6 , a terminal (e.g., terminal 53) may include an antenna 90, a front-end module (FEM) 105, an RF integrated circuit (RFIC) 110, and a baseband circuit 120.

Antenna 90 can be connected to FEM 105 and transmit the signal provided by FEM 105 to another wireless communication device (such as a terminal or base station), or provide the signal received from another wireless communication device to FEM 105. Furthermore, FEM 105 can be connected to antenna 90 and separate the transmit and receive frequencies. In other words, FEM 105 can separate the signal provided by RFIC 110 for each frequency band and provide the separated signal to the corresponding antenna 90. Furthermore, FEM 105 can provide the signal provided by antenna 90 to RFIC 110.

As described above, antenna 90 can transmit the frequency-separated signal to the outside (e.g., outside the terminal (e.g., terminal 53)), or provide the signal received from the outside to FEM 105.

For reference, antenna 90 may include, for example, an array antenna, but is not limited thereto. Furthermore, antenna 90 may be provided singularly or plurally. Thus, in some embodiments, terminal 53 may use multiple antennas to support phased arrays and multiple-input, multiple-output (MIMO). However, for simplicity, FIG6 shows a single antenna 90.

FEM 105 may include an antenna tuner. The antenna tuner may be connected to antenna 90 and adjust the impedance of antenna 90.

RFIC 110 can up-convert the baseband signal received from baseband circuit 120 and generate an RF signal. In addition, RFIC 110 can down-convert the RF signal received from FEM 105 and generate a baseband signal.

Specifically, the RFIC 110 may include a transmit circuit 112 for up-conversion operations, a receive circuit 114 for down-conversion operations, and a local oscillator 116.

For reference, the transmit circuit 112 may include a first analog baseband filter, a first mixer, and a power amplifier. Furthermore, the receive circuit 114 may include a second analog baseband filter, a second mixer, and a low-noise amplifier.

Here, the first analog baseband filter may filter the baseband signal received from the baseband circuit 120 and provide the filtered baseband signal to the first mixer. Furthermore, the first mixer may perform up-conversion (up-conversion) of the baseband signal to a higher frequency band based on the frequency of the signal provided by the local oscillator 116. Due to the up-conversion, the baseband signal may be provided as an RF signal to the power amplifier, which may amplify the power of the RF signal and provide the amplified RF signal to the FEM 105.

The low-noise amplifier may amplify the RF signal provided by FEM 105 and provide the amplified RF signal to the second mixer. The second mixer may down-convert the RF signal from a high-band frequency to a baseband frequency based on the frequency of the signal provided by local oscillator 116. Due to the down-conversion, the RF signal may be provided as a baseband signal to the second analog baseband filter. The second analog baseband filter may filter the baseband signal and provide the filtered baseband signal to baseband circuit 120.

In addition, the baseband circuit 120 can receive a baseband signal from the RFIC 110 and process the baseband signal, or generate a baseband signal and provide the baseband signal to the RFIC 110.

In addition, the baseband circuit 120 may include a controller 122, a memory 124, and a signal processing unit 125.

Specifically, controller 122 controls not only the overall operation of baseband circuit 120 but also the overall operation of RFIC 110. Furthermore, controller 122 can write data to or read data from memory 124. To this end, controller 122 may include at least one processor, at least one microprocessor, or at least one microcontroller, or may be part of a processor. More specifically, controller 122 may include, for example, a central processing unit (CPU) and a digital signal processor (DSP).

The memory 124 can store basic programs, applications, and data (such as configuration information) used for the operation of the terminal 53. For example, the memory 124 can store instructions and/or data associated with the controller 122, the signal processing unit 125, or the RFIC 110.

Furthermore, the memory 124 may include various storage media. Specifically, the memory 124 may include volatile memory, non-volatile memory, or a combination of volatile and non-volatile memory. For example, the memory 124 may include random access memory (RAM) (e.g., dynamic RAM (DRAM), phase-change RAM (PRAM), magnetic RAM (MRAM), and static RAM (SRAM)) and flash memory (e.g., NAND flash memory, NOR flash memory, and OneNAND flash memory).

In addition, the memory 124 can store various processor-executable instructions. The processor-executable instructions can be executed by the controller 122.

The signal processing unit 125 can process the baseband signal received from the RFIC 110.

Specifically, the signal processing unit 125 may include a demodulator 126, a receive filter and cell searcher (RxFilter & cell searcher) 128, and other components 130.

First, the demodulator 126 may include a channel estimator, a data deconfiguration unit, an interference whitener, a symbol detector, a channel state information (CSI) generator, a mobility measurement unit, an automatic gain control unit, an automatic frequency control unit, a symbol timing recovery unit, a delay spread estimation unit, and a time correlator, and performs the functions of each of the above components.

In this context, a mobility measurement unit (MMU) may be a unit configured to measure the signal quality of a serving cell and/or neighboring cells to support mobility. The MMU may measure the cell's received signal strength indicator (RSSI), reference signal received power (RSRP), reference signal received quality (RSRQ), and reference signal (RS)-to-interference and noise ratio (SINR).

For reference, although not shown in the figure, the demodulator 126 may include multiple sub-demodulators configured to independently or jointly perform the above-described operations for de-diffused signals in 2nd generation (2G) communication systems, 3rd generation (3G) communication systems, 4th generation (4G) communication systems, and 5th generation (5G) communication systems, or signals having corresponding frequency bands.

The receive filter and cell searcher 128 may include a receive filter, a cell searcher, a fast Fourier transform (FFT) unit, a time duplex-automatic gain control (TD-AGC) unit, and a time duplex-automatic frequency control (TD-AFC) unit.

The receive filter, also referred to herein as the receiver (Rx) front end, samples, cancels interference, and amplifies the baseband signal received from RFIC 110. Furthermore, the cell detector may include a primary synchronization signal (PSS) detector and a secondary synchronization signal (SSS) detector to measure the magnitude and quality of signals from neighboring cells.

In addition, other components 130 may include a symbol processor, a channel decoder, and an uplink processor.

Here, the symbol processor can perform channel deinterleaving, demultiplexing, and rate matching on each channel to decode the demodulated signal. Furthermore, the channel decoder can decode the demodulated signal in units of code blocks.

For reference, the symbol processor and channel decoder may include a hybrid automatic repeat request (HARQ) processing unit, a turbo decoder, a cyclic redundancy check (CRC) checker, a Viterbi decoder, and a turbo encoder.

An uplink processor configured to generate a baseband signal for transmission may include a signal generator, a signal distributor, an inverse fast Fourier transform (IFFT) unit, a discrete Fourier transform (DFT) unit, and a transmitter (Tx) front end.

In this context, the signal generator generates PUSCH, PUCCH, and PRACH. Furthermore, the Tx front end performs operations such as interference cancellation and digital mixing on the transmitted baseband signal.

For reference, other components 130 may further include a sidelink processor. The sidelink processor may generate a physical sidelink shared channel (PSSCH), a physical sidelink control channel (PSCCH), and a physical sidelink feedback channel (PSFCH). In another embodiment, the sidelink processor may not be provided separately but may be integrated with the uplink processor into a single processor. However, for simplicity, the exemplary embodiment relates to an example in which the sidelink processor is provided separately from the uplink processor.

The signal processing unit 125 may have the configuration and characteristics described above. However, the configurations or functions of the demodulator 126, the receive filter and cell searcher 128, and other components 130 in the signal processing unit 125 may be modified. For example, the channel estimator in the demodulator 126 may be included in the receive filter and cell searcher 128 or another component 130, and the FFT unit in the receive filter and cell searcher 128 may be included in the demodulator 126 or another component 130. Furthermore, the channel decoder in the other components 130 may be included in the demodulator 126 or the receive filter and cell searcher 128. However, for the sake of simplicity, the exemplary embodiment relates to an example in which the configurations or functions of the demodulator 126, the reception filter and the cell searcher 128, and other components 130 in the signal processing unit 125 are implemented as described above.

As described above, FIG6 shows a case where the baseband circuit 120 includes a controller 122, a memory 124, and a signal processing unit 125.

However, at least two of the controller 122, the memory 124, and the signal processing unit 125 may be integrated into a single component in the baseband circuit 120. Furthermore, the baseband circuit 120 may include additional components in addition to the aforementioned components, or may not include some components. Furthermore, the signal processing unit 125 may include additional components in addition to the aforementioned components, or may not include some components.

However, for the sake of simplicity, the exemplary embodiment relates to an example in which the baseband circuit 120 includes the above-mentioned components.

Furthermore, in some embodiments, the controller 122, the memory 124, and the signal processing unit 125 may be included in a single device. In other embodiments, the controller 122, the memory 124, and the signal processing unit 125 may be distributed and included in separate devices, for example, in a distributed architecture.

The RF transceiver assembly shown in FIG6 having the above configuration may be included in one or more of the terminal 53 or 55 or the base station 51 shown in FIG2, for example.

RFIC 110 and baseband circuit 120 may include components known to those skilled in the art, as shown in FIG6 . Furthermore, these components may be implemented in a known manner using hardware, firmware, software logic, or a combination thereof.

However, FIG6 merely illustrates an example of RF transceiver components, and the present invention is not limited thereto. That is, various changes may be made in FIG6 , such as the addition or deletion of components.

FIG7 shows an example in which the configuration of the RF transceiver assembly shown in FIG6 is partially changed (e.g., simplified).

Specifically, the terminal 53 may include a processor 150, a transceiver 160, a memory 170, and an antenna 180.

The processor 150 can control the overall operation of the transceiver 160 and write data to or read data from the memory 170. That is, the processor 150 may be, for example, a component that includes the functionality of the controller 122 shown in FIG. 6 .

Transceiver 160 can transmit and receive wireless signals and is controlled by processor 150. That is, transceiver 160 may be, for example, a component that includes the functions of FEM 105, RFIC 110, and signal processing unit 125 shown in FIG6 .

Memory 170 may include basic programs, applications, and data (e.g., configuration information) used for the operation of terminal 53. Therefore, memory 170 may store instructions and/or data associated with processor 150 and transceiver 160. Specifically, memory 170 may be, for example, a component that includes the functionality of memory 124 shown in FIG. 6 .

Antenna 180 can be connected to transceiver 160 and transmit a signal provided by transceiver 160 to another wireless communication device (e.g., a terminal or a base station), or provide a signal received from another wireless communication device to transceiver 160. In other words, antenna 180 can be, for example, a component that includes the functionality of antenna 90 shown in FIG. 6 .

Since the terminal 53 or 55 or the base station 51 has the characteristics and configurations described above in the exemplary embodiment, an example of a process for performing communication between the terminal 53 or 55 and the base station 51 to enable V2X communication will now be described in detail with reference to FIG. 8 .

FIG8 is a flow chart of a communication process performed between the terminal 53 or 55 and the base station 51 shown in FIG2 according to an embodiment.

For reference, Figure 8 will be described with reference to Figures 2 and 7.

Referring to Figure 8, to enable efficient PSFCH transmission and reception in V2X communications, communication can be transmitted between a terminal 53 (which can be, for example, a transmitting terminal) and a base station 51.

First, in operation S100, to enable efficient PSFCH transmission and reception, the terminal 53 may notify the base station 51 of the maximum number of PSFCHs that can be received during a TTI. In an embodiment, the maximum number of PSFCHs that can be received during a TTI may be referred to as the maximum PSFCH receiving capability F (or max PSFCH receiving capability F).

Specifically, the processor 150 can control the transceiver 160 to signal the maximum PSFCH receiving capability F to the base station 51.

Here, a TTI may include a time slot, and the maximum PSFCH reception capability F may include the number of PSFCHs received in at least one of multicast and unicast. That is, the maximum PSFCH reception capability F may include the total number of PSFCHs received in each of multicast and unicast, or may include only the number of PSFCHs received in multicast or unicast. Therefore, the maximum PSFCH reception capability F may be, for example, any of 10, 20, 30, 40, 50, 100, 200, 300, and 410.

At operation S150, when the base station 51 receives a signal from the terminal 53 regarding the maximum PSFCH reception capability F, the base station 51 may set the sidelink communication of the terminal 53 to satisfy the following inequality: L×M×N.

For reference, F may refer to the maximum number of PSFCHs that can be received during one time slot, and L may refer to the number of PSSCHs transmitted in a multicast during each time slot. Furthermore, M may refer to the number of receiving terminals included in the same group as the transmitting terminal (e.g., the terminal group used for multicast), and N may refer to the PSFCH reception period.

That is, to enable efficient PSFCH transmission and reception, base station 51 can consider the maximum PSFCH reception capability F to determine the values L, M, and N associated with terminal 53. Furthermore, base station 51 can further consider the following method in multicast mode to satisfy the above inequality.

1) When the inequality F < L × M × N is satisfied for all receiving terminals included in a group, the base station 51 can determine that "NACK-based HARQ," in which only one common PSFCH is received from each receiving terminal corresponding to a NACK among receiving terminals included in the same group as the transmitting terminal, is a HARQ scheme. In this case, the value M can be 1.

2) When the receiving terminals included in the combined group satisfy the inequality F When L×M×N, the base station 51 may determine “ACK/NACK-based HARQ” as the HARQ scheme in which the transmitting terminal receives a PSFCH from each of all receiving terminals included in the same group as the transmitting terminal.

3) To satisfy the inequality F Base station 51 can determine the zone size (L×M×N), i.e., the range of the area within which base station 51 sets multicast. For example, if the terminals included in the group have a high F value, base station 51 can set the zone size to a larger one; if the terminals included in the group have a low F value, base station 51 can set the zone size to a smaller one. For reference, the number of terminals included in the group can be determined based on the zone size.

4) When a group leader configured to perform multicast is determined among the terminals included in the group, the base station 51 may select a value F that satisfies the inequality F L×M×N terminals serve as group leaders. When multiple terminals meet the above conditions, the base station 51 can select the terminal with the best channel status as the group leader.

Furthermore, in operation S200 , to enable efficient PSFCH transmission and reception, the terminal 53 may notify the base station 51 of the maximum number of PSFCHs that can be transmitted during a TTI. In an embodiment, the maximum number of PSFCHs that can be transmitted during a TTI may be referred to as the maximum PSFCH transmission capability R (or max PSFCH transmission capability R).

Specifically, the processor 150 can control the transceiver 160 to signal the maximum PSFCH transmission capability R to the base station 51.

Here, a TTI may include a time slot, and the maximum PSFCH transmission capacity R may include the number of PSFCHs transmitted in at least one of multicast and unicast. That is, the maximum PSFCH transmission capacity R may include the total number of PSFCHs transmitted in each of multicast and unicast, or may include only the number of PSFCHs transmitted in multicast or unicast. Therefore, the maximum PSFCH transmission capacity R may be, for example, any of 1, 2, 3, 4, 5, 10, 20, 30, and 68.

For reference, operation S200 may be performed before operation S100, or operations S100 and S200 may be performed simultaneously. Furthermore, terminal 53 may perform only one of operations S100 and S200, and depending on the operation performed by terminal 53, base station 51 may perform only a specific operation S150 or S250, or only a portion of operation S150 or S250. However, for simplicity, the exemplary embodiment relates to an example in which operation S200 is performed after operation S100, and terminal 53 performs both operations S100 and S200.

When the base station 51 receives the signaling information about the maximum PSFCH transmission capability R from the terminal 53, at operation S250, the base station 51 may set the sidelink communication of the terminal 53 to satisfy the following inequality: U + G R

For reference, U may refer to the number of PSSCHs received in unicast during one time slot, and G may refer to the number of PSSCHs received in multicast during one time slot. In addition, R may refer to the maximum number of PSFCHs that can be transmitted during one time slot.

That is, in order to perform efficient PSFCH transceiver operation, the base station 51 can be based on the inequality U+G R determines whether terminal 53 belongs to unicast and/or multicast by considering the maximum PSFCH transmission capability R. Furthermore, to satisfy the above inequality, base station 51 can prioritize unicast and multicast and determine R receiving channels (e.g., R receiving channels that can be received in unicast and multicast) as receiving channels for terminal 53 based on the order of higher priority.

As described above, due to the above process, at operation S300, base station 51 may perform RRC communication with terminal 53 based on the communication received from terminal 53. Therefore, base station 51 may schedule sidelink communications with terminal 53 or perform multicast-related configuration operations (e.g., selecting a group leader within a group and setting the size of a multicast zone).

As described above, communication can be transmitted between the terminal 53 and the base station 51, enabling efficient PSFCH transmission and reception in V2X communications. Below, an example of a PSFCH determination method for a terminal in V2X communications according to an exemplary embodiment will be described with reference to Figures 9 and 10.

FIG9 is a flowchart of a PSFCH determination method of a terminal according to an exemplary embodiment. FIG10 is a detailed flowchart of operations S1200 and S1300 shown in FIG9 according to an exemplary embodiment.

For reference, Figures 9 and 10 will be described with reference to Figures 2 and 7.

Referring to FIG. 9 , first, at operation S1000 , k PSFCHs (where k is an integer greater than 1) may be selected from all PSFCHs received during one TTI, and the RSRP or SINR of the selected k PSFCHs may be measured.

Specifically, the processor 150 may select k PSFCHs from all PSFCHs based on a pre-defined criterion or randomly. Furthermore, the processor 150 may control the transceiver 160 to sequentially measure the RSRP or SINR of k PSFCHs (where k is an integer greater than 1) among all PSFCHs received during a TTI.

For reference, after selecting all k PSFCHs, the processor 150 may control the transceiver 160 to sequentially measure the RSRP or SINR of the k PSFCHs. In one embodiment, whenever a PSFCH is selected, the processor 150 may control the transceiver 160 to immediately measure the RSRP or SINR of the selected PSFCH.

Here, k may be preset by the manufacturer or user of terminal 53 based on at least one of the channel status of terminal 53, the performance of terminal 53, and the total number of PSFCHs. Furthermore, for example, when a base station (e.g., base station 51 in FIG. 8 ) configures a sidelink, it may instruct terminal 53 to set k to any value within a specific range.

When the RSRP or SINR of the selected k PSFCHs are measured sequentially, at operation S1100, the k PSFCHs may be sorted in ascending order based on the measured RSRP or SINR.

Specifically, processor 150 may sort the k PSFCHs in ascending order based on their RSRP or SINR measured by transceiver 160. Once the k PSFCHs have been sorted in ascending order, at operation S1200 , it may be determined in ascending order whether the k sorted PSFCHs are HARQ ACKs or HARQ NACKs. At operation S1300 , based on the determination result, it may be determined whether the PSSCH will be retransmitted.

Specifically, the processor 150 may control the transceiver 160 to determine, in ascending order, whether the k sorted PSFCHs are HARQ ACKs or HARQ NACKs. Furthermore, the processor 150 may determine whether to retransmit the PSSCH based on the determination result.

For reference, the HARQ ACK/NACK determination operation may be performed by a channel decoder of the transceiver 160 (e.g., the channel decoder included in the other components 130 shown in FIG6 ).

FIG10 specifically illustrates an example of operations S1200 and S1300 according to an embodiment.

Specifically, referring to FIG. 10 , operation S1200 may start with operation S1210 as follows: determining the mth PSFCH (where 1 m (integer) k) Is it HARQ ACK or HARQ NACK?

Therefore, if the mth PSFCH (where 1 m (integer) k) is HARQ ACK, it may be determined whether m is less than k at operation S1320. Based on the determination result of operation S1320, the HARQ ACK/NACK determination operation may continue for the (m+1)th PSFCH to the (k)th PSFCH among the ordered k PSFCHs (returning to operation S1210), or the HARQ ACK/NACK determination operation for the ordered k PSFCHs may be terminated (continuing to operations S1330 to S1350).

For example, when m is less than k, e.g., when at least one of the ordered k PSFCHs has not undergone HARQ ACK/NACK determination, HARQ ACK/NACK determination may be performed sequentially on the (m+1)th PSFCH to the (k)th PSFCH at operation S1210.

Otherwise, when m is equal to k, for example, when the HARQ ACK/NACK determination operation has been performed on all the ordered k PSFCHs, the HARQ ACK/NACK determination operation for the ordered k PSFCHs may be terminated, and the process proceeds to operations S1330 to S1350. Depending on whether at least one PSFCH among all the PSFCHs has not undergone the HARQ ACK/NACK determination operation, it may be determined whether to continue measuring the RSRP or SINR of the next k PSFCHs.

Specifically, at operation S1330, if at least one PSFCH among all PSFCHs has not been subjected to HARQ ACK/NACK determination, the RSRP or SINR measurement of the next k PSFCHs may continue at operation S1340. In this case, operations S1100 to S1300 may be sequentially performed for the next k PSFCHs. Otherwise, at operation S1330, if no PSFCH among all PSFCHs has been subjected to HARQ ACK/NACK determination, the HARQ ACK/NACK determination for all PSFCHs may be terminated at operation S1350.

In addition, at operation S1220, when determining the mth (where 1 m (integer) k) When the PSFCH is HARQ NACK, the HARQ ACK/NACK determination operation on the (m+1)th to (k)th PSFCHs among the sorted k PSFCHs may be interrupted at operation S1310 and it may be determined that the PSSCH will be retransmitted.

For reference, if it is determined that the PSSCH will be retransmitted, all PSSCHs, for example, all PSSCHs corresponding to all PSFCHs, may be retransmitted. Furthermore, operations S1210 to S1350 described above may be performed by processor 150 and transceiver 160.

Specifically, in the PSFCH determination method of the terminal 53, according to an exemplary embodiment, after measuring the RSRP or SINR of the selected k PSFCHs (see operation S1000), it is not necessary to select k new PSFCHs from the remaining PSFCHs again. Instead, prior to selecting the new k PSFCHs, subsequent processing operations (e.g., ACK/NACK determination operations) may be performed on the k PSFCHs selected in operation S1000. Consequently, the complexity of the ACK/NACK determination operation can be reduced compared to a case where all PSFCHs are determined to be ACKs or NACKs at once, and the processing time and memory required for the ACK/NACK determination operation can be reduced. Furthermore, since the PSFCH with a low RSRP or SINR among the selected k PSFCHs is first determined to be ACK or NACK, a NACK can be quickly determined.

As described above, a PSFCH determination method of a terminal according to an exemplary embodiment can be performed. Hereinafter, an example of a PSFCH determination method of a terminal according to another exemplary embodiment will be described with reference to FIG11 and FIG12 .

FIG11 is a flowchart of a PSFCH determination method of a terminal according to an exemplary embodiment. FIG12 is a detailed flowchart of operation S2000 shown in FIG11 .

For reference, Figures 11 and 12 will be described with reference to Figures 2 and 7.

Referring to Figure 11 , first, at operation S2000 , the RSRP or SINR of all PSFCHs received during a TTI may be measured, and k PSFCHs that meet a preset criterion may be selected from the PSFCHs for which RSRP or SINR was measured. Here, k may be an integer greater than 1.

Specifically, the processor 150 may control the transceiver 160 to sequentially measure the RSRP or SINR of all PSFCHs received during a TTI. When the number of PSFCHs with measured RSRP or SINR that meet a preset criterion reaches k, the selection operation, such as operation S2000, may be terminated.

FIG12 specifically illustrates an example of operation S2000.

Specifically, referring to FIG. 12 , operation S2000 may begin with the following operation S2010: measuring the RSRP or SINR of the nth PSFCH (where n is a positive integer less than the total number of PSFCHs).

Therefore, at operation S2010, when the RSRP or SINR of the nth PSFCH (where n is a positive integer less than the total number of PSFCHs) is measured, it can be determined at operation S2020 whether the nth PSFCH meets the preset criteria.

If it is determined that the nth PSFCH meets the preset criteria, then at operation S2030, the cumulative count of PSFCHs meeting the preset criteria may be incremented by 1. At operation S2040, when the cumulative count incremented by 1 (e.g., the number of PSFCHs meeting the preset criteria) equals k, operation S2100 shown in FIG. 11 may be performed. When the cumulative count incremented by 1 (e.g., the number of PSFCHs meeting the preset criteria) is less than k, operation S2010 of measuring the RSRP or SINR of the next PSFCH (e.g., the n+1th PSFCH) may be performed.

Even when it is determined that the nth PSFCH does not meet the preset criteria, operation S2010 of measuring the RSRP or SINR of the next PSFCH (e.g., the n+1th PSFCH) may be performed.

For reference, various criteria may exist, and the method for selecting k PSFCHs based on each criterion may be as follows.

1) When k PSFCHs with RSRP or SINR less than a preset reference value have been accumulated from all PSFCHs, the selection operation can be terminated. Specifically, HARQ ACK/NACK determination can be performed for PSFCHs with RSRP or SINR less than the preset reference value, while HARQ ACK/NACK determination can be omitted for PSFCHs with RSRP or SINR greater than or equal to the preset reference value. The results of the determination operation for some PSFCHs can be considered to represent the determination operation for all PSFCHs. This method can improve data rates by utilizing the fact that when the receiving terminal has channel conditions that are better than a certain threshold, the PSFCH feedback is less likely to be a NACK.

2) When k PSFCHs with RSRP or SINR greater than a preset reference value have been accumulated from all PSFCHs, the selection operation can be terminated. Specifically, HARQ ACK/NACK determination can be performed for PSFCHs with RSRP or SINR greater than the preset reference value, while HARQ ACK/NACK determination can be omitted for PSFCHs with RSRP or SINR less than or equal to the preset reference value. The results of the determination operation for some PSFCHs can be considered to represent the determination operation for all PSFCHs. This method can improve data rates by utilizing the fact that when the receiving terminal has channel conditions worse than a certain threshold, the PSFCH feedback is likely to be a NACK.

3) When k PSFCHs have been accumulated from all PSFCHs whose RSRP or SINR is greater than a first reference value and less than a second reference value, the selection operation may be terminated. Here, the second reference value may be different from the first reference value. Specifically, the HARQ ACK/NACK determination operation may be performed only for PSFCHs whose RSRP or SINR is greater than the first reference value and less than the second reference value. The results of the determination operation for some PSFCHs may be considered to represent the determination operation for all PSFCHs. According to this method, the data rate can be improved by using the two methods described above.

Here, each of k and the reference value may be preset by the manufacturer or user of terminal 53 based on at least one of the channel status of terminal 53, the performance of terminal 53, and the total number of PSFCHs. Furthermore, for example, when a base station (e.g., base station 51 in FIG. 8 ) configures a sidelink, it may instruct terminal 53 to set k to any value within a specific range.

Referring back to FIG. 11 , when k PSFCHs are selected at operation S2000 , the selected k PSFCHs may be sorted in ascending order based on the measured RSRP or SINR at operation S2100 .

Specifically, the processor 150 may sort the k PSFCHs in ascending order based on the RSRP or SINR of the corresponding PSFCHs measured by the transceiver 160.

When the k PSFCHs are sorted in ascending order, it can be determined in ascending order at operation S2200 whether the k sorted PSFCHs are HARQ ACKs or HARQ NACKs, and it can be determined whether the PSSCH will be retransmitted based on the determination result at operation S2300.

For reference, since operations S2100 to S2300 may correspond to operations S1100 to S1300 described above with reference to FIG9 and FIG10 , they will not be described in detail.

As described above, the PSFCH determination method of a terminal according to an exemplary embodiment can be performed. Below, a wireless communication device implemented according to the embodiment will be described with reference to FIG13 .

FIG13 is a block diagram of a wireless communication device 201 according to an embodiment.

For reference, the wireless communication device 201 shown in FIG13 can be applied to a base station (e.g., base station 51 in FIG2 ); an eNB, gNB, and AP or a terminal (e.g., terminal 53 or 55 in FIG2 ); a STA, a MS, and a UE according to embodiments. Furthermore, in some embodiments, the wireless communication device 201 shown in FIG13 can operate in either standalone (SA) mode or non-standalone (NSA) mode.

Specifically, FIG13 shows a wireless communication device 201 implemented in a network environment 200.

Wireless communication device 201 may include a bus 210, a processor 220, a memory 230, an input/output (I/O) interface 250, a display module 260, and a communication interface 270. In other cases, wireless communication device 201 may omit at least one of the aforementioned components, or may further include at least one other component. However, for simplicity, the exemplary embodiment relates to an example in which wireless communication device 201 includes the aforementioned components.

The bus 210 can connect the processor 220, the memory 230, the I/O interface 250, the display module 260, and the communication interface 270. Therefore, signals, such as control information and/or data, can be exchanged and transmitted between the processor 220, the memory 230, the I/O interface 250, the display module 260, and the communication interface 270 via the bus 210.

Processor 220 may include at least one of a central processing unit (CPU), an application processor (AP), and a communication processor (CP). Furthermore, processor 220 may perform operations related to control and/or communication with other components of wireless communication device 201 or data processing operations. In one embodiment, processor 220 may include the functionality of processor 150 shown in FIG. 7 .

The memory 230 may include volatile memory and/or non-volatile memory. Furthermore, the memory 230 may store commands, instructions, or data associated with other components in the wireless communication device 201.

In addition, the memory 230 can store software and/or programs 240. Programs 240 may include, for example, a kernel 241, middleware 243, an application programming interface (API) 245, applications 247 (also referred to as "applications"), and network access information 249.

For reference, at least some of the kernel 241, middleware 243, and API 245 may be referred to as an operating system (OS). Furthermore, in an embodiment, the memory 230 may be a component that includes the functionality of the memory 170 shown in FIG. 7 .

For example, the I/O interface 250 can transmit commands or data received from a user or another external device to other components of the wireless communication device 201. Furthermore, the I/O interface 250 can output commands or data received from other components of the wireless communication device 201 to the user or another external device.

The display module 260 may include, for example, a liquid crystal display (LCD), a light-emitting diode (LED) display, an organic LED (OLED) display, a micro electromechanical system (MEMS) display, or an electronic paper display.

Additionally, the display module 260 can display various content to the user, such as text, images, videos, icons, or codes. The display module 260 may include a touch screen and receive touch, gesture, proximity, or hover input, for example, using an electronic pen or a user's body.

Communication interface 270 can configure communication between wireless communication device 201 and external devices (e.g., electronic devices 202 and 204 or server 206). For example, communication interface 270 can connect to network 262 via wireless or wired communication and communicate with external devices (e.g., electronic device 204 or server 206). Furthermore, communication interface 270 can communicate with external devices (e.g., electronic device 202) via wireless communication 264. Furthermore, communication interface 270 can be a component that includes the functionality of transceiver 160 shown in FIG. 7 .

For reference, wireless communication 264 may be a cellular communication protocol, and may utilize, for example, at least one of NR, LTE, LTE-A, CDMA, WCDMA, universal mobile telecommunication system (UMTS), wireless broadband (WiBro), and GSM. Furthermore, wired communication may include, for example, at least one of universal serial bus (USB), high-definition multimedia interface (HDMI), recommended standard 232 (RS-232), and plain old telephone service (POTS).

Furthermore, the network 262 as a telecommunications network may include, for example, at least one of a computer network (such as a local area network (LAN) or a wide-area network (WAN)), the Internet, and a telephone network.

Furthermore, each of the electronic devices 202 and 204 as external devices may be of the same type as or a different type than the wireless communication device 201. Furthermore, the server 206 may include a group consisting of at least one server.

For reference, all or some of the operations performed by the wireless communication device 201 may be performed by other external devices (e.g., electronic devices 202 and 204 or server 206).

In addition, when the wireless communication device 201 needs to perform a function or service automatically or on request, the wireless communication device 201 can perform the function or service alone, or request other external devices (such as electronic devices 202 and 204 or the server 206) to perform part of the function or service. Additionally, the other external devices (eg, electronic devices 202 and 204 or server 206 ) may perform the requested function or service and transmit the results to wireless communication device 201 . In this case, the wireless communication device 201 may perform the function or service based on the received results or by otherwise processing the received results.

For the above mechanism, for example, cloud computing technology, distributed computing technology, or client-server computing technology can be applied to the wireless communication device 201.

According to the above embodiment, by transmitting signals based on the maximum PSFCH transceiver capacity and utilizing an efficient PSFCH ACK/NACK determination method, the following issues can be addressed: exceeding the PSFCH reception capacity and the operational overload of determining whether a PSFCH is an ACK or NACK. Consequently, terminal performance and operational efficiency can be improved.

While the embodiments have been particularly shown and described, it will be understood that various changes in form and details may be made therein without departing from the spirit and scope of the following claims.

51:Base station

53:Terminal

S100, S150, S200, S250, S300: Operation

Claims (20)

A terminal configured to perform vehicle-to-vehicle communication includes: a transceiver configured to transmit and receive one or more wireless signals; and a processor configured to control the transceiver to signal a maximum physical sidelink feedback channel (PSFCH) reception capability to a base station, wherein the maximum physical sidelink feedback channel reception capability is the maximum number of physical sidelink feedback channels that can be received during a time transmission interval (TTI). The terminal of claim 1, wherein the maximum physical sidelink feedback channel receiving capability is any one of 10, 20, 30, 40, 50, 100, 200, 300, and 410. The terminal of claim 1, wherein the maximum physical sidelink feedback channel reception capability includes the number of the physical sidelink feedback channels received in at least one of multicast and unicast. The terminal of claim 1, wherein the time transmission interval includes a time slot. A terminal configured to perform vehicle-to-vehicle network communications includes: a transceiver configured to transmit and receive one or more wireless signals; and a processor configured to control the transceiver to measure the reference signal received power (RSRP) or signal-to-interference and noise ratio (SINR) of k physical sidelink feedback channels (PSFCHs) received during a time transmission interval, where k is an integer greater than 1. , sorting the k physical sidelink feedback channels in ascending order based on the reference signal received power or the signal to interference and noise ratio, controlling the transceiver to sequentially determine whether the k sorted physical sidelink feedback channels are hybrid automatic repeat request (HARQ) acknowledgments (ACKs) or HARQ negative acknowledgments (NACKs), and determining whether to retransmit a physical sidelink shared channel (PSSCH) based on the sequential determination. The terminal of claim 5, wherein when the sequential determination indicates that the mth physical side-link feedback channel among the k physical side-link feedback channels is the HARQ reply, the processor is further configured to: determine whether m is less than k; and control the transceiver to continue performing the sequential determination on the remaining physical side-link feedback channels among the k physical side-link feedback channels, or control the transceiver to terminate the sequential determination on the k physical side-link feedback channels, wherein m is a positive integer less than or equal to k. The terminal of claim 6, wherein when m is less than k, the processor is further configured to control the transceiver to continue to perform the sequential determination on the remaining physical side-link feedback channels among the k sorted physical side-link feedback channels. The terminal of claim 6, wherein when m is equal to k, the processor is further configured to control the transceiver to terminate the sequential determination and determine whether to continue measuring the reference signal received power or signal-to-interference and noise ratio of additional physical sidelink feedback channels based on whether at least one physical sidelink feedback channel among the multiple physical sidelink feedback channels for which the sequential determination has not been performed exists. The terminal of claim 8, wherein when at least one physical sidelink feedback channel among the plurality of physical sidelink feedback channels has not been subjected to the sequential determination, the processor is further configured to control the transceiver to continue measuring the reference signal received power or the signal-to-interference and noise ratio of the additional physical sidelink feedback channel, and when the sequential determination has been performed on all of the plurality of physical sidelink feedback channels, the processor is further configured to control the transceiver to terminate the sequential determination. The terminal of claim 5, wherein when it is determined that the mth physical side-link feedback channel among the k sorted physical side-link feedback channels is the HARQ negative response, the processor is further configured to: control the transceiver to interrupt the sequential determination of the remaining physical side-link feedback channels among the k sorted physical side-link feedback channels and retransmit the physical side-link common channel, where m is a positive integer less than or equal to k. The terminal of claim 5, wherein k is set based on at least one of: a channel status of the terminal, a performance of the terminal, and a total number of the plurality of physical sidelink feedback channels. A terminal configured to perform vehicle-to-everything (V2X) communication, the terminal comprising: a transceiver configured to transmit and receive one or more wireless signals; and a processor configured to: control the transceiver to measure the reference signal received power (RSRP) or signal-to-interference and noise ratio (SINR) of multiple physical sidelink feedback channels (PSFCHs) received during a time transmission interval (TTI), and select k physical sidelink feedback channels that meet preset criteria from the multiple physical sidelink feedback channels. , where k is an integer greater than 1, and the selected k physical sidelink feedback channels are sorted in ascending order based on the reference signal received power or the signal to interference and noise ratio, and the transceiver is controlled to sequentially determine whether the sorted k physical sidelink feedback channels are hybrid automatic repeat request (HARQ) acknowledgments (ACKs) or HARQ negative acknowledgments (NACKs), and whether a physical sidelink shared channel (PSSCH) is to be retransmitted based on the sequential determination. The terminal as claimed in claim 12, wherein the preset criterion is satisfied when the reference signal received power or the signal to interference and noise ratio is less than a preset reference value. The terminal as claimed in claim 12, wherein the preset criterion is satisfied when the reference signal received power or the signal to interference and noise ratio is greater than a preset reference value. The terminal of claim 12, wherein the preset criterion is satisfied when the reference signal received power or signal-to-interference and noise ratio is greater than a first reference value and less than a second reference value, wherein the second reference value is different from the first reference value. The terminal of claim 12, wherein when it is determined that the mth physical side-link feedback channel among the k sorted physical side-link feedback channels is the HARQ reply, the processor is further configured to: determine whether m is less than k; and control the transceiver to continue the sequential determination on the remaining physical side-link feedback channels among the k sorted physical side-link feedback channels, or control the transceiver to terminate the sequential determination, wherein m is a positive integer less than or equal to k. The terminal of claim 16, wherein when m is less than k, the processor is further configured to control the transceiver to continue to perform the sequential determination on the remaining physical sidelink feedback channels. The terminal of claim 16, wherein when m is equal to k, the processor is further configured to control the transceiver to terminate the sequential determination and determine whether to continue selecting an additional physical side-link feedback channel based on whether at least one physical side-link feedback channel for which the sequential determination has not been performed exists among the plurality of physical side-link feedback channels. The terminal of claim 18, wherein when at least one of the plurality of physical side-link feedback channels is not subjected to the sequential determination, the processor is further configured to select the additional physical side-link feedback channel, and when the sequential determination is performed on all of the plurality of physical side-link feedback channels, the processor is further configured to control the transceiver to terminate the sequential determination. The terminal of claim 12, wherein when it is determined that the mth physical side-link feedback channel among the k sorted physical side-link feedback channels is the HARQ negative response, the processor is further configured to: control the transceiver to interrupt the sequential determination of the remaining physical side-link feedback channels among the k sorted physical side-link feedback channels; and retransmit the physical side-link common channel, wherein m is a positive integer less than or equal to k.