Method and apparatus for controlling UE transmission power in wireless communication system
11595911 · 2023-02-28
Assignee
Inventors
- Hyunseok Ryu (Suwon-si, KR)
- Jeongho Yeo (Suwon-si, KR)
- Jinyoung Oh (Suwon-si, KR)
- Sungjin PARK (Suwon-si, KR)
- Jonghyun BANG (Suwon-si, KR)
- Cheolkyu Shin (Suwon-si, KR)
Cpc classification
H04W72/20
ELECTRICITY
H04W52/247
ELECTRICITY
International classification
Abstract
The disclosure relates to a communication method and a system for converging a 5.sup.th-Generation (5G) communication system for supporting higher data rates beyond a 4.sup.th-Generation (4G) system with a technology for Internet of Things (IoT). The disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services.
Claims
1. A method performed by a user equipment (UE) in a wireless communication system, the method comprising: receiving, from a base station, a radio resource control (RRC) message including information related to a sidelink transmission power; determining a first power for sidelink data channel transmission in a symbol where a sidelink control channel and a sidelink data channel are not simultaneously transmitted, based on the information; determining a second power for the sidelink control channel transmission and a third power for the sidelink data channel transmission in a symbol where the sidelink control channel and the sidelink data channel are simultaneously transmitted, based on the determined first power; transmitting the sidelink data channel based on the first power in the symbol where the sidelink control channel and the sidelink data channel are not simultaneously transmitted; and transmitting the sidelink control channel and the sidelink data channel based on the second power and the third power in the symbol where the sidelink control channel and the sidelink data channel are simultaneously transmitted.
2. The method of claim 1, wherein the sidelink control channel and the sidelink data channel are frequency division multiplexed in the symbol where the sidelink control channel and the sidelink data channel are simultaneously transmitted.
3. The method of claim 1, wherein the second power is determined based on a number of resource blocks for the sidelink control channel transmission in the symbol.
4. The method of claim 3, wherein the second power is determined based on a ratio of the number of resource blocks for the sidelink control channel transmission and the sidelink data channel transmission where the sidelink control channel and the sidelink data channel are not simultaneously transmitted.
5. The method of claim 1, wherein the third power is determined based on a number of resource blocks for a sidelink data channel transmission in the symbol where the sidelink control channel and the sidelink data channel are simultaneously transmitted.
6. A method performed by a base station in a wireless communication system, the method comprising: transmitting, to a user equipment (UE), a radio resource control (RRC) message including information related to a sidelink transmission power; receiving a sidelink data channel based on a first power in a symbol where a sidelink control channel and the sidelink data channel are not simultaneously transmitted; and receiving the sidelink control channel and the sidelink data channel based on a second power and a third power in the symbol where the sidelink control channel and the sidelink data channel are simultaneously transmitted, wherein the first power for the sidelink data channel transmission in a symbol where the sidelink control channel and the sidelink data channel are not simultaneously transmitted, is determined based on the information, and wherein the second power for the sidelink control channel transmission and the third power for the sidelink data channel transmission in a symbol where the sidelink control channel and the sidelink data channel are simultaneously transmitted, are determined based on the determined first power.
7. The method of claim 6, wherein the sidelink control channel and the sidelink data channel are frequency division multiplexed in the symbol where the sidelink control channel and the sidelink data channel are simultaneously transmitted.
8. The method of claim 6, wherein the second power is determined based on a number of resource blocks for the sidelink control channel transmission in the symbol.
9. The method of claim 8, wherein the second power is determined based on a ratio of the number of resource blocks for the sidelink control channel transmission and the sidelink data channel transmission where the sidelink control channel and the sidelink data channel are not simultaneously transmitted.
10. The method of claim 6, wherein the third power is determined based on a number of resource blocks for a sidelink data channel transmission in the symbol where the sidelink control channel and the sidelink data channel are simultaneously transmitted.
11. A first user equipment (UE) comprising: a transceiver configured to transmit or receive at least one signal; and at least one processor coupled to the transceiver, wherein the at least one processor is configured to: receive, from a base station, a radio resource control (RRC) message including information related to a sidelink transmission power, determine a first power for sidelink data channel transmission in a symbol where a sidelink control channel and a sidelink data channel are not simultaneously transmitted, based on the information, determine a second power for the sidelink control channel transmission and a third power for the sidelink data channel transmission in a symbol where the sidelink control channel and the sidelink data channel are simultaneously transmitted, based on the determined first power, transmit the sidelink data channel based on the first power in the symbol where the sidelink control channel and the sidelink data channel are not simultaneously transmitted, and transmit the sidelink control channel and the sidelink data channel based on the second power and the third power in the symbol where the sidelink control channel and the sidelink data channel are simultaneously transmitted.
12. The UE of claim 11, wherein the sidelink control channel and the sidelink data channel are frequency division multiplexed in the symbol where the sidelink control channel and the sidelink data channel are simultaneously transmitted.
13. The UE of claim 11, wherein the second power is determined based on a number of resource blocks for the sidelink control channel transmission in the symbol.
14. The UE of claim 13, wherein the second power is determined based on a ratio of the number of resource blocks for the sidelink control channel transmission and the sidelink data channel transmission where the sidelink control channel and the sidelink data channel are not simultaneously transmitted.
15. The UE of claim 11, wherein the third power is determined based on a number of resource blocks for a sidelink data channel transmission in the symbol where the sidelink control channel and the sidelink data channel are simultaneously transmitted.
16. A base station comprising: a transceiver configured to transmit or receive at least one signal; and at least one processor coupled to the transceiver, wherein the at least one processor is configured to: transmit, to a user equipment (UE), a radio resource control (RRC) message including information related to a sidelink transmission power, receive a sidelink data channel based on a first power in a symbol where a sidelink control channel and the sidelink data channel are not simultaneously transmitted, and receive the sidelink control channel and the sidelink data channel based on a second power and a third power in the symbol where the sidelink control channel and the sidelink data channel are simultaneously transmitted, wherein the first power for the sidelink data channel transmission in a symbol where the sidelink control channel and the sidelink data channel are not simultaneously transmitted, is determined based on the information, and wherein the second power for the sidelink control channel transmission and the third power for the sidelink data channel transmission in a symbol where the sidelink control channel and the sidelink data channel are simultaneously transmitted, are determined based on the determined first power.
17. The base station of claim 16, wherein the sidelink control channel and the sidelink data channel are frequency division multiplexed in the symbol where the sidelink control channel and the sidelink data channel are simultaneously transmitted.
18. The base station of claim 16, wherein the second power is determined based on a number of resource blocks for the sidelink control channel transmission in the symbol.
19. The base station of claim 18, wherein the second power is determined based on a ratio of the number of resource blocks for the sidelink control channel transmission and the sidelink data channel transmission where the sidelink control channel and the sidelink data channel are not simultaneously transmitted.
20. The base station of claim 16, wherein the third power is determined based on a number of resource blocks for a sidelink data channel transmission in the symbol where the sidelink control channel and the sidelink data channel are simultaneously transmitted.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
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(22) Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.
DETAILED DESCRIPTION
(23) The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.
(24) The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the disclosure is provided for illustration purpose only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents.
(25) It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces.
(26) In describing the embodiments, descriptions of technologies which are already known in the technical field to which the disclosure belongs and are not directly related to the disclosure are omitted. Such an omission of unnecessary descriptions is intended to prevent obscuring of the main idea of the disclosure and more clearly transfer the main idea.
(27) For the same reason, in the accompanying drawings, some elements are exaggerated, omitted, or schematically illustrated. Further, the size of each element does not entirely reflect the actual size. In the drawings, identical or corresponding elements are provided with identical reference numerals.
(28) The advantages and features of the disclosure and ways to achieve them will be apparent by making reference to embodiments as described below in detail in conjunction with the accompanying drawings. However, the disclosure is not limited to the following embodiments and may be implemented in various different forms, and the embodiments of the disclosure are provided to make the disclosure perfect and completely inform those skilled in the art of the scope of the disclosure and the disclosure is only defined by the scope of the claims. Throughout the specification, the same or like reference numerals designate the same or like elements.
(29) Here, 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. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart block or blocks. These computer program instructions may also be stored in a computer usable or computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer usable or computer-readable memory produce an article of manufacture including instruction means that implement the function specified in the flowchart block or blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operations to be performed on the computer or other programmable data processing apparatus to produce a computer implemented process such that the instructions that execute on the computer or other programmable data processing apparatus provide operations for implementing the functions specified in the flowchart block or blocks.
(30) In addition, each block of the flowchart illustrations may represent a module, segment, or portion of code, which includes 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 the 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.
(31) As used herein, the “unit” refers to a software element or a hardware element, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC), which performs a predetermined function. However, the “unit does not always have a meaning limited to software or hardware. The “unit” may be constructed either to be stored in an addressable storage medium or to execute one or more processors. Therefore, the “unit” includes, for example, software elements, object-oriented software elements, class elements or task elements, processes, functions, properties, procedures, sub-routines, segments of a program code, drivers, firmware, micro-codes, circuits, data, database, data structures, tables, arrays, and parameters. The elements and functions provided by the “unit” may be either combined into a smaller number of elements, “unit” or divided into a larger number of elements, “unit”. Moreover, the elements and “units” may be implemented to reproduce one or more central processing units (CPUs) within a device or a security multimedia card. Also, in an embodiment, the “˜unit” may include one or more processors.
(32) In the embodiments described in detail, main objects are a radio access network (new RAN, NR) and a core network, namely packet core (5G system, 5G core network, or next generation core (NG Core)) in the 5G mobile communication standard specified by a mobile communication standard standardization organization (3GPP). However, the main idea of the disclosure is that the disclosure can be applied to other communication systems having a similar technical background, through a minor modification without deviating far from the range of the disclosure and the application can be conducted by the determination of a person having technical knowledge and skilled in the technical field to which the disclosure belongs.
(33) In a 5G system, in order to support the network automation, a network data collection and analysis function (NWDAF), which is a network function of analyzing data collected in a 5G network and providing the analyzed data, can be defined. The NWDAF can collect/store/analyze information from/in/of the 5G network and provide a result for an unspecified network function (NF), and the analysis result can be independently used in each NF.
(34) Hereinafter, for convenience of description, a part of terms and names, which are defined in the 3rd generation partnership project long term evolution (3GPP LTE) standard such as a standard of 5G, NR, LTE, or a system similar to these systems, can be used. However, the disclosure is not limited by the terms and names, and may be equally applied to a system that is based on another standard.
(35) In addition, terms used below are illustrated for convenience of description, for example, a term used to identify an access node, a term indicating network entities, a term indicating messages, a term indicating an interface between the network entities, a term indicating various pieces of identification information, and the like. Accordingly, the disclosure is not limited to the following terms and other terms having the same technical meaning can be used.
(36) In order to meet wireless data traffic demands that have increased after 4G communication system commercialization, efforts to develop an improved 5G communication system (new radio, NR) have been made. In order to achieve a high data transmission rate, the 5G communication system is designed to support in a mmWave band (for example, 28 GHz frequency band). In the 5G communication system, technologies such as beamforming, massive MIMO, full dimensional MIMO (FD-MIMO), array antenna, analog beam-forming, and large scale antenna are being discussed as a means to mitigate a propagation path loss in the mmWave band and increase a propagation transmission distance. Unlike LTE, the 5G communication system includes 15 kHz to support various subcarrier spacings such as 30 kHz, 60 kHz, and 120 kHz, and a physical control channel uses polar coding and a physical data channel uses low density parity check (LDPC). As well as discrete fourier transform spread orthogonal frequency-division multiplexing (DFT-S-OFDM), cyclic prefix (CP)-OFDM is used as a waveform for uplink transmission. LTE supports hybrid automatic repeat request (ARQ) (HARQ) retransmission based on a transport block (TB), whereas 5G can additionally support HARQ retransmission based on a code block group (CBG) consisting of code blocks (CB).
(37) Further, the 5G communication system has developed technologies such as an evolved small cell, an advanced small cell, a cloud radio access network (cloud RAN), an ultra-dense network, device-to-device (D2D) communication, a wireless backhaul, a vehicle to everything (V2X) network, cooperative communication, coordinated multi-points (CoMP), and received interference cancellation so as to improve the system network.
(38) Meanwhile, the Internet has evolved from a human-oriented connection network in which humans generate and consume information to an internet of things (IoT) network in which distributed elements such as objects exchange and process information. An internet of everything (IoE) technology in which a big data processing technology through a connection with a cloud server or the like is combined with the IoT technology has emerged. In order to implement IoT, technical factors such as sensing technology, wired/wireless communication, network infrastructure, service-interface technology, and security technology are required, and research on technologies such as a sensor network, machine-to-machine (M2M) communication, machine-type communication (MTC), and the like for connection between objects has recently been conducted. In an IoT environment, through collection and analysis of data generated in connected objects, an intelligent internet technology (IT) service to create a new value for peoples' lives can be provided. The IoT can be applied to fields such as those of a smart home, a smart building, a smart city, a smart car, a connected car, a smart grid, health care, a smart home appliance, and high-tech medical services through the convergence of the information technology (IT) of the related art and various industries.
(39) Accordingly, various attempts to apply the 5G communication system to the IoT network have been made. For example, a technology such as a sensor network, machine-to-machine (M2M) communication, and machine-type communication (MTC), has been implemented by the 5G communication technology such as beamforming, MIMO, and array antennas. The application of a cloud RAN as the big data processing technology described above may be an example of convergence of a 3eG technology and the IoT technology. Therefore, a plurality of services can be provided for a user in a communication system, and in order to provide the plurality of services for the user, a method for providing each service according to characteristics within the same time section and an apparatus using this method are required. Research on various services, which are provided in the 5G communication system, has been conducted, and one of the services is a service satisfying requirements such as low latency and high reliability.
(40) In a case of vehicle communication, a standardization operation of LTE-based V2X has been completed at 3GPP Rel-14 and Rel-15, based on a device-to-device (D2D) communication structure, and efforts to develop V2X, based on 5G NR, have been currently made. NR V2X will support unicast communication, groupcast (or multicast) communication, and broadcast communication between UEs. In addition, unlike LTE V2X whose purpose is to transmit or receive basic safety information required for vehicle road driving, NR V2X has a purpose of providing further advanced services such as platooning, advanced driving, extended sensor, and remote driving.
(41) When an NR V2X UE exists within the coverage of a base station, the NR V2X UE may receive, from the base station, parameter values for controlling sidelink transmission power, and control sidelink transmission power, based on the parameter values. In addition, when the NR V2X UE exists out of the coverage of the base station, the NR V2X UE may use preset sidelink transmission power control parameter values to control sidelink transmission power. The sidelink transmission power control parameters may include P.sub.0 and α. In addition, the NR V2X UE may set a transmission power value according to frequency block size of a sidelink control channel and a data channel to be transmitted thereby, as well as the values of P.sub.0 and α mentioned above. That is, when the frequency block size of a sidelink control channel and a data channel to be transmitted increases, the transmission power value may increase, and when the frequency block size decreases, the transmission power value may decrease. A sidelink control channel and a data channel may be time-division-multiplexed (TDMed) on the time axis or frequency-division-multiplexed (FDMed) on the frequency axis, before being transmitted. Therefore, a method and an apparatus for controlling UE transmission power to support sidelink transmission power in these various multiplexing methods are required.
(42) An embodiment of the specification is proposed to support the various multiplexing methods described above, and a purpose is to provide a method and an apparatus for controlling transmission powers of a sidelink control channel and a data channel.
(43) A V2X UE mentioned in the disclosure may indicate an NR V2X UE or an LTE V2X UE. In addition, the V2X UE of the disclosure may indicate a vehicle supporting vehicle-to-vehicle (V2V) communication, a vehicle or a pedestrian's handset (that is, smartphone) supporting vehicle-to-pedestrian (V2P) communication, a vehicle supporting vehicle-to-network (V2N) communication, or a vehicle supporting vehicle-to-infrastructure (V2I) communication. In addition, a UE of the disclosure may indicate a road side unit (RSU) having a UE function, an RSU having a base station function, or an RSU having a part of a base station function and a part of a UE function.
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(46) Referring to
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(48) Referring to
(49) The UE-2 112 may transmit/receive data and control information for V2X communication to/from the UE-1 111 via sidelink.
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(51) Therefore, referring to
(52) The UE-1 121 and the UE-2 122 may transmit or receive data and control information for V2X communication via sidelink.
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(55) Meanwhile, the UE of the disclosure may indicate a vehicle supporting vehicle-to-vehicle (V2V) communication, a vehicle or a pedestrian's handset (that is, smartphone) supporting vehicle-to-pedestrian (V2P) communication, a vehicle supporting vehicle-to-network (V2N) communication, or a vehicle supporting vehicle-to-infrastructure (V2I) communication. In addition, the UE of the disclosure may indicate a road side unit (RSU) having a UE function, an RSU having a base station function, or an RSU having a part of a base station function and a part of a UE function.
(56) In addition, the base station of the disclosure may be previously defined as a base station supporting both V2X communication and general cellular communication or a base station supporting only V2X communication. The base station may indicate a 5G base station (gNB), a 4G base station (eNB), or a road site unit (RSU). Therefore, unless otherwise specified in the disclosure, a base station and an RSU can be mixedly used as the same concept.
(57)
(58) Referring to
(59) Referring to
(60)
(61) Although not shown in
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(63) Referring to
Sidelink transmission power=min{Pc max,P.sub.0+αPL+10 log 10(Number of RBs*2.sup.μ)+Δ}[dBm] Equation 1
(64) In Equation 1, each parameter may indicate the following. Pcmax: Pcmax is a P-max value (when there is no base station, a preset value) indicating the maximum UE transmission output and set by a base station through system information or RRC, and may be determined by a UE by means of UE power class included in the UE. P.sub.0: P.sub.0 may indicate a value (when there is no base station, a preset value) set by a base station through system information or RRC in order to guarantee link quality of a reception UE. α: α is a parameter for compensating a path loss value and has a value between 0 and 1, and may indicate a value (when there is no base station, a preset value) set by a base station through system information or RRC. For example, when α=1, 100% of path loss may be compensated, and when α=0.8, only 80% of path loss may be compensated. Number of resource blocks (RBs): Number of RBs may indicate size of a frequency block allocated for sidelink transmission. 2.sup.μ may be a parameter for compensating a power spectral density (PSD) which varies depending on a subcarrier spacing. For example, a case of using a subcarrier spacing of 15 kHz may indicate that μ=0. Even if the same number of frequency blocks are used, when the subcarrier spacing is doubled to 30 kHz, the PSD may be reduced by half compared with the case of using the subcarrier spacing of 15 kHz. Therefore, in order to compensate the PSD, power is required to be doubled. More specifically, for example, when two frequency blocks are used, 10 log 10(2×2.sup.0)=3 dB is required for the subcarrier spacing of 15 kHz, whereas, in order to maintain the same PSD as that for the subcarrier spacing of 15 kHz, transmission power is required to be increased to 10 log 10(2×2.sup.1)=6 dB for the subcarrier spacing of 30 kHz. PL: PL may indicate an estimated path loss value. The path loss value may be estimated by Equation 2.
The transmission power of a signal used for path loss estimation−The measured reference signal received power (RSRP) value of a signal used for path loss estimation Equation 2
(65) Equation 2 may be differently applied depending on a scenario as follows. When a signal used for path loss estimation is a sidelink signal: the UE1 301, which is a V2X transmission UE, may transmit a sidelink synchronization signal or a sidelink reference signal to the UE2 302 which is a V2X reception UE. The UE2 302 may receive the sidelink synchronization signal or the sidelink reference signal to measure an RSRP value and report the measured RSRP value to the UE1 301. The RSRP value may be transmitted through a physical sidelink feedback channel (PSFCH) or a physical sidelink shared channel (PSSCH). In addition, when the RSRP value is transmitted through the PSSCH, a media access control (MAC) control element (CE) may be used. The UE1 301 may estimate a sidelink path loss value by using Equation 2 through the transmission power of a reference signal that the UE1 transmits to the UE2 302 and the RSRP value reported from the UE2 302. In another example, the UE1 301 may transmit, to the UE2 302, information on the transmission power of the reference signal that the UE1 transmits. Upon receiving the information, the UE2 302 may measure the RSRP value by using the reference signal that the UE1 transmits, and estimate a path loss value through Equation 2. The UE2 302 may transmit an estimated sidelink path loss value to the UE1 301 through the PSFCH or the PSSCH. When the estimated sidelink path loss value is transmitted through the PSSCH, the MAC CE may be used. However, as illustrated in
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(70) Referring to
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(72) Referring to
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(74) Referring to
(75) At the i-th transmission time, the V2X UE using a sidelink resource structure of
P.sub.PSCCH(i)=min{Pc max(i),P.sub.0_PSCCH+α.sub.PSCCH*PL(q)+10 log 10(M*2.sup.μ)+Δ.sub.PSCCH(i)}[dBm]
P.sub.PSSCH(i)=min{Pc max(i),P.sub.0_PSSCH+α.sub.PSSCH*PL(q)+10 log 10(M*2.sup.μ)+Δ.sub.PSSCH(i)}[dBm] Equation 3
(76) In Equation 3, each parameter may indicate the following. Pcmax(i): Pcmax(i) is a P-max value (when there is no base station, a preset value) indicating the maximum UE transmission output at the i-th transmission time and set by a base station through system information or RRC, and may be determined by a UE by means of a communication range and UE power class included in the UE. Since Pcmax(i) is a function of index “i”, different transmission times may result in different Pcmax values. P.sub.0_PSCCH, P.sub.0_PSSCH: P.sub.0_PSCCH and P.sub.0_PSSCH may indicate parameters (when there is no base station, preset values) set by a base station through system information or RRC in order to guarantee link quality of each of the PSCCH and the PSSCH. Values of P.sub.0_PSCCH and P.sub.0_PSSCH may be different from each other according to a sidelink scheduling method. For example, a gNB may schedule a sidelink transmission resource to the V2X transmission UE through downlink control information (DCI). It may be called a mode-1 resource allocation method. In another scheduling method, the gNB may configure resource pool information for sidelink transmission, and may determine a resource required for the V2X transmission UE to transmit sidelink control information and data information by itself. It may be called a mode-2 resource allocation method. Since in a case of mode-1, the gNB may manage a resource in a centralized manner, the gNB may control interference and resource collision problems between different V2X UEs. On the other hand, in a case of mode-2, since UEs manage a resource in a distributed manner, interference and resource collision problems between different V2X UEs may occur as compared to mode-1. Therefore, values of P.sub.0 for sidelink transmission of mode-1 and mode-2 may be different. That is, P.sub.0_PSCCH for mode-1 and P.sub.0_PSCCH for mode-2 have different values. In addition, P.sub.0_PSSCH for mode-1 and P.sub.0_PSSCH for mode-2 have different values. In another example, as illustrated in
(77)
(78) Referring to
(79) At the i-th transmission time, the V2X UE using a sidelink resource structure of
P.sub.PSCCH(i)=min{Pc max(i),P.sub.0_PSCCH+α.sub.PSCCH*PL(q)+10 log 10(N1*2.sup.μ)+Δ.sub.PSCCH(i)}[dBm]
P.sub.PSSCH(i)=min{Pc max(i),P.sub.0_PSSCH+α.sub.PSSCH*PL(q)+10 log 10(M*2.sup.μ)+Δ.sub.PSSCH(i)}[dBm] Equation 4
(80) In Equation 4, each parameter may be interpreted to be the same as Equation 3 illustrated in
(81) A definition and a method of use of parameters including P.sub.0_PSCCH, α.sub.PSCCH, Δ.sub.PSCCH and P.sub.0_PSSCH, α.sub.PSSCH, Δ.sub.PSSCH which are used in Equation 4 may be equal to the definition and the embodiment described in Equation 3 of
(82) In another example, even though UEs exist within the coverage of the base station, exchange of parameters between UEs may not be performed (assuming that exchange of parameters between the UEs is performed in a PC5 RRC layer) when a UE pairing for performing unicast communication is not formed (for example, before PC5 RRC configuration is completed in a PC5 RRC layer of UE A and UE B), or before a UE grouping for performing groupcast communication is formed. A transmission UE for the unicast and groupcast communications may not set a transmission power value based on a sidelink path loss signal. To this end, the preset value with respect to the mentioned parameters may be used, or the value transmitted from the base station through RRC configuration and system information of the base station may be used. The values of the parameters used at this time may be different from the values of the parameters used after PC5 RRC configuration. PL(q) that the transmission UE uses before PC5 RRC configuration in Equation 7, Equation 8, Equation 9, Equation 10, and Equation 11 may indicate a path loss value with respect to Uu link between the base station and the transmission UE, not the sidelink path loss value. In addition, when the UE uses the preset parameters, each of the parameters may include the value of 0, 0 dB, or 0 dBm.
(83) In another example, when in the example above, the PSCCH, the PSSCH, and the PSFCH should be transmitted before PC5 RRC configuration between UEs, which are to perform the unicast or groupcast communication, is completed, the V2X UE may use the preset transmission power value (for example, [X] dBm) or the transmission power value set by the base station. The transmission power values preset for transmitting the PSCCH, the PSSCH, and the PSFCH (or the transmission power values set by the base station) may be different from each other.
(84) In another example, the preset transmission power values or the transmission power values set by the base station, of the PSCCH, the PSSCH, and the PSFCH may be expressed as the transmission power value and the offset value with respect to one channel. For example, when the transmission power values of the PSCCH, the PSSCH, and the PSFCH are preset, the transmission power value of the PSCCH may be set to be [X] dBm, and the offset value for transmission power of the PSSCH and the PSFCH may be set to be +/−[Y] dB (or dBm), based on the transmission power value of the PSCCH. It may be equally applied even when the transmission power values of the PSCCH, the PSSCH, and the PSFCH are set by the base station.
(85)
(86) Referring to
(87) At the i-th transmission time, the V2X UE using a sidelink resource structure of
P.sub.PSCCH(i)=γ1+min{Pc max(i),P.sub.0_PSCCH+α.sub.PSCCH*PL(q)+β+Δ.sub.PSCCH(i)}[dBm]
P.sub.PSSCH(i)=γ2+min{Pc max(i),P.sub.0_PSSCH+α.sub.PSSCH*PL(q)+β+Δ.sub.PSSCH(i)}[dBm] Equation 5
(88) In Equation 5, each parameter indicates the following. γ1, γ2: Referring to
γ1=10 log 10{(10{circumflex over ( )}(ε/10)×N1)/[(M−N1)+10{circumflex over ( )}(ε/10)×N1]} [dB]
γ2=10 log 10{[10{circumflex over ( )}(ε/10)×(M−N1)]/[(M−N1)+10{circumflex over ( )}(ε/10)×N1]} [dB] Equation 6
(89) ε indicates a value representing a difference between PSDs of the PSCCH and the PSSCH, and may have a unit of [dB]. For example, when the PSCCH and the PSSCH use the same PSD, ε may be 0. Generally, a control channel is required to guarantee the reliability higher than that of a data channel. In that case, the PSCCH has the higher PSD than that of the PSSCH. For example, when ε=3, it may indicate that the PSCCH has the PSD higher than that of the PSSCH by 3 dB. The fixed value is always used as the value of ε (for example, ε=3) or the base station may transmit the value of ε to the UE through system information or RRC configuration. In that case, as illustrated in
(90) In another example, even though UEs exist within the coverage of the base station, exchange of parameters between the UEs, which are to perform unicast/groupcast communication, may not be performed when an unicast UE pair for performing unicast communication is not formed (for example, a case in which PC5 RRC configuration is not completed), or before a UE grouping for performing groupcast communication is formed. Therefore, the transmission UE for unicast and groupcast communications may not set a sidelink transmission power value based on a sidelink path loss value. To this end, with respect to the mentioned parameters, a preset value may be used, or a value transmitted from the base station through RRC configuration and system information of the base station may be used. The values of the parameters used at this time may be different from the values of the parameters used after PC5 RRC configuration. PL(q) that the transmission UE uses before PC5 RRC configuration in Equation 7, Equation 8, Equation 9, Equation 10, and Equation 11 may indicate a path loss value with respect to Uu link between the base station and the transmission UE, not the sidelink path loss value. In addition, when the UE uses the preset parameters, each of the parameters may include the value of 0, 0 dB, or 0 dBm.
(91) In another example, the preset transmission power values or the transmission power values set by the base station, of the PSCCH, the PSSCH, and the PSFCH may be expressed as the transmission power value and the offset value with respect to one channel. For example, when the transmission power values of the PSCCH, the PSSCH, and the PSFCH are preset, the transmission power value of the PSCCH may be set to be [X] dBm, and the offset value for transmission power of the PSSCH and the PSFCH may be set to be +/−[Y] dB (or dBm), based on the transmission power value of the PSCCH. It may be equally applied even when the transmission power values of the PSCCH, the PSSCH, and the PSFCH are set by the base station.
(92)
(93) Referring to
(94) Although not shown in
(95) At the i-th transmission time, the V2X UE using a sidelink resource structure of
(96) Method 1) Parameters for Determining P.sub.PSCCH and P.sub.PSSCH are Independently Set.
(97) Method 1-1) Scalding Down or Scaling Up of Transmission Power A UE may temporarily calculate values of P.sub.PSCCH and P.sub.PSSCH through Equation 7.
P.sub.PSCCH(i)=P.sub.0_PSCCH+α.sub.PSCCH*PL(q)+10 log 10(N1*2.sup.μ)+Δ.sub.PSCCH(i) [dBm]
P.sub.PSSCH-1(i)=P.sub.0_PSSCH+α.sub.PSSCH*PL(q)+10 log 10(N2*2.sup.μ)+Δ.sub.PSSCH(i) [dBm]
P.sub.PSSCH-2(i)=P.sub.0_PSSCH+α.sub.PSSCH*PL(q)+10 log 10(M*2.sup.μ)+Δ.sub.PSSCH(i) [dBm] Equation 7
(98) In Equation 7, referring to
P.sub.Sidelink(i)=min{Pc max(i),P.sub.PSCCH(i)+P.sub.PSSCH-1(i),P.sub.PSSCH-2(i)} Equation 8
P.sub.Sidelink(i)=min{Pc max(i), max[P.sub.PSCCH(i)+P.sub.PSSCH-1(i),P.sub.PSSCH-2(i)]} Equation 9
(99) In Equation 8 and Equation 9, each parameter may indicate the following. P.sub.Sidelink(i): Sidelink transmission power at the i-th sidelink transmission time Pcmax(i): Pcmax(i) is equal to what described in Equation 1, Equation 3, Equation 4, Equation 5, and Equation 6. P.sub.PSCCH(i): PSCCH transmission power at the i-th sidelink transmission time P.sub.PSSCH-1(i): PSSCH transmission power in symbols during which the PSCCH and the PSSCH are frequency-divided and transmitted at the i-th sidelink transmission time At the i-th sidelink transmission time, a case of P.sub.PSCCH(i)+P.sub.PSSCH-1(i)<P.sub.PSSCH-2(i)<Pcmax(i) may occur. Transmission power used for the i-th sidelink transmission may be P.sub.Sidelink(i)=P.sub.PSCCH(i)+P.sub.PSSCH-1(i) by Equation 8, and may scale down P.sub.PSSCH-2(i) obtained by Equation 7 by w1 such that P.sub.PSCCH(i)+P.sub.PSSCH-1(i)=w1*P.sub.PSSCH-2(i) is satisfied. w1 may have a value which is larger than 0 and equal to 1, or smaller than 1. In a case of using Equation 9, transmission power used for the i-th sidelink transmission may be P.sub.Sidelink(i)=P.sub.PSSCH-2(i), and may scale up P.sub.PSCCH(i)+P.sub.PSSCH-1(i) obtained by Equation 7 by w1 such that P.sub.PSSCH-2(i)=w1[P.sub.PSCCH(i)+P.sub.PSSCH-1(i)] is satisfied. w1 may have a value larger than 1. In another example, at the i-th sidelink transmission time, a case of P.sub.PSSCH-2(i)<P.sub.PSCCH(i)+P.sub.PSSCH-1(i)<Pcmax(i) may occur. Transmission power used for the i-th sidelink transmission may be P.sub.Sidelink(i)=P.sub.PSSCH-2(i) by Equation 8, and may scale down P.sub.PSCCH(i)+P.sub.PSSCH-1(i) obtained by Equation 7 by w1 such that P.sub.PSSCH-2(i)=w1[P.sub.PSCCH(i)+P.sub.PSSCH-1(i)] is satisfied. w1 may have a value which is larger than 0 and equal to 1, or smaller than 1. Transmission power used for the i-th sidelink transmission may be P.sub.Sidelink(i)=P.sub.PSCCH(i)+P.sub.PSSCH-1(i) by Equation 9, and may scale up P.sub.PSSCH-2(i) obtained by Equation 7 by w1 such that P.sub.PSCCH(i)+P.sub.PSSCH-1(i)=w1*P.sub.PSSCH-2(i) is satisfied. w1 may have a value larger than 1.
(100) Method 1-2) Sidelink Transmission Power is Determined by the Transmission Power of the K1 Symbols. Method 1-2 is the same as method 1-1 in that the UE temporarily calculates values of P.sub.PSCCH and P.sub.PSSCH-1 through Equation 7. However, unlike method 1-1, in method 1-2, P.sub.PSSCH-2 mentioned in Equation 7 may not be calculated. Therefore, transmission power at the i-th sidelink transmission time may be determined as shown in Equation 10.
P.sub.Sidelink(i)=min{Pc max(i),P.sub.PSCCH(i)+P.sub.PSSCH-1(i)} Equation 10
(101) When sizes of frequency blocks in the K1 symbols and the K2 symbols are different, or since values of transmission power control parameters are different, transmission power values of the K1 symbols and the K2 symbols are different, as previously illustrated, P.sub.PSSCH-2(i) may be scaled up or scaled down.
(102) Method 1-3) Sidelink Transmission Power is Determined by the Transmission Power of the K2 Symbols. In method 1-3, transmission power at the i-th sidelink transmission time may be determined by Equation 11.
P.sub.Sidelink(i)=min{Pc max(i),P.sub.PSSCH-2(i)} Equation 11
(103) In Equation 11, P.sub.PSSCH-2(i) may be equal to P.sub.PSSCH-2(i) illustrated in Equation 7. The UE may use P.sub.PSSCH-2(i) obtained by Equation 11 to calculate transmission powers of the PSCCH and PSSCH transmitted in the section of K1 symbols. More specifically, through P.sub.PSSCH-2(i) obtained by Equation 11, and P.sub.PSCCH(i) and P.sub.PSSCH-1(i) illustrated in Equation 7, temporary transmission powers of the PSCCH and the PSSCH in the section of K1 symbols may be calculated and values of X1, X2, and Y may be calculated as shown in Equation 12.
X1=10{circumflex over ( )}[P.sub.PSCCH(i)/10],X2=10{circumflex over ( )}[P.sub.PSSCH-1(i)/10],Y=10{circumflex over ( )}[P.sub.Sidelink(i)/10] Equation 12
(104) The UE may determine transmission powers of the PSCCH and the PSSCH transmitted in the section of K1 symbols through Equation 13, by using the values of X1, X2, and Y obtained by Equation 12.
P.sub.PSCCH(i)=10 log 10[X1*Y/(X1+X2)]
P.sub.PSSCH-1(i)=10 log 10[X2*Y/(X1+X2)] Equation 13
(105) Method 2) Parameters for Determining P.sub.PSCCH and P.sub.PSSCH are Set to be the Same.
(106) In a case of method 2, since parameters for determining transmission powers of the PSCCH and the PSSCH are set to be the same, the parameters of the PSCCH and the PSSCH, which are illustrated in Equation 3, Equation 4, Equation 5, and Equation 7, may be the same. More specifically, at the i-th sidelink transmission time, it may be indicated that P.sub.0_PSCCH=P.sub.0_PSSCH=P.sub.0, α.sub.PSCCH=α.sub.PSSCH=α, and Δ.sub.PSCCH=Δ.sub.PSSCH=Δ. Another precondition of method 2 is that P.sub.PSCCH and P.sub.PSSCH may have the fixed power density offset or the set power density offset. Under these assumptions, method 2 may have two methods described below.
(107) Method 2-1) Sidelink Transmission Power is Determined by the Transmission Power of the K1 Symbols.
(108) At the section of the K1 symbols during which the PSCCH and the PSSCH are frequency-divided and transmitted at the i-th sidelink transmission time, P.sub.PSCCH and P.sub.PSSCH-1 may be determined by Equation 14.
P.sub.PSCCH(i)=γ1+P.sub.0+αPL(q)+β+Δ(i) [dBm]
P.sub.PSSCH-1(i)=γ2+P.sub.0+αPL(q)+β+Δ(i) [dBm] Equation 14
(109) In Equation 14, γ1 and γ2 may be equal to what defined in Equation 6. In Equation 14, β may indicate 10 log 10[(M−N1)+10{circumflex over ( )}(ε/10)×N1] [dB]. Transmission power at the i-th sidelink transmission time may be calculated as shown in Equation 10, by using Equation 14. In method 2-1, when sizes of frequency blocks in the K1 symbols and the K2 symbols are different, the value of P.sub.PSCCH(i)+P.sub.PSSCH-1(i) may be different from P.sub.PSSCH-2(i). In that case, as illustrated above, P.sub.PSSCH-2(i) may be scaled up or scaled down.
(110) Method 2-2) Sidelink Transmission Power is Determined by the Transmission Power of the K2 Symbols.
(111) Unlike method 2-1, at the section of K2 symbols during which the PSCCH and the PSSCH are not frequency-divided at the i-th sidelink transmission time, sidelink transmission power may be determined by Equation 11. P.sub.Sidelink(i) having been determined by Equation 11 may be distributed by Equation 12 and Equation 13. Meanwhile, with respect to the transmission power parameters used in Equation 7, Equation 8, Equation 9, Equation 10, and Equation 11, the transmission UE may use the value set by the base station or use the value preset to the UE, by means of the methods mentioned in
(112)
(113) Referring to
(114) At the i-th transmission time, the V2X UE using a sidelink resource structure of
P.sub.PSCCH(i)=min{Pc max(i),P.sub.0_PSCCH+α.sub.PSCCH*PL(q)+10 log 10(M*2.sup.μ)+Δ.sub.PSCCH(i)}[dBm]
P.sub.PSSCH(i)=min{Pc max(i),P.sub.0_PSSCH+α.sub.PSSCH*PL(q)+10 log 10(N1*2.sup.μ)+Δ.sub.PSSCH(i)}[dBm] Equation 15
(115) In Equation 15, each parameter may be interpreted to be the same as Equation 4 illustrated in
(116) In addition, with respect to the transmission power parameters used in Equation 15, the transmission UE may use the value set by the base station or use the value preset to the UE, by means of the methods mentioned in
(117) In another example, even though UEs exist within the coverage of the base station, exchange of parameters between UEs, which are to perform unicast/groupcast communication, may not be performed when a UE pairing for performing unicast communication is not formed (for example, before PC5 RRC configuration is completed), or before a UE grouping for performing groupcast communication is formed. A transmission UE for the unicast and groupcast communications may not set a sidelink transmission power value, based on sidelink path loss estimation. To this end, with respect to the mentioned parameters, the UE may use the preset value or the value transmitted from the base station through RRC configuration and system information of the base station. The values of the parameters used at this time may be different from the values of the parameters used after PC5 RRC configuration. PL(q) that the transmission UE uses before PC5 RRC configuration in Equation 7, Equation 8, Equation 9, Equation 10, and Equation 11 may indicate a path loss value with respect to Uu link between the base station and the transmission UE, not the sidelink path loss value. In addition, when the UE uses the preset parameters, each of the parameters may include the value of 0, 0 dB, or 0 dBm.
(118) In another example, the preset transmission power values or the transmission power values set by the base station, of the PSCCH, the PSSCH, and the PSFCH may be expressed as the transmission power value and the offset value with respect to one channel. For example, when the transmission power values of the PSCCH, the PSSCH, and the PSFCH are preset, the transmission power value of the PSCCH may be set to be [X] dBm, and the offset value for transmission power of the PSSCH and the PSFCH may be set to be +/−[Y] dB (or dBm), based on the transmission power value of the PSCCH. It may equally applied even when the transmission power values of the PSCCH, the PSSCH, and the PSFCH are set by the base station.
(119)
(120) Referring to
(121) Referring to
(122) Meanwhile, as shown in
P.sub.PSCCH(i)=X1+min{Pc max(i),10 log 10(X2*2.sup.μ)+P.sub.0_PSCCH+α.sub.PSCCH*PL(q)}[dBm] Equation 16
P.sub.PSCCH(i)=X1+min{Pc max(i),10 log 10(X2*2.sup.μ)+P.sub.0_PSCCH+α.sub.PSCCH*PL(q),P.sub.Congestion}[dBm] Equation 17
P.sub.PSCCH(i)=X1+min{Pc max(i),10 log 10(X2*2.sup.μ)+P.sub.0_PSCCH+α.sub.PSCCH*PL(q),P.sub.Congestion,P.sub.Range}[dBm] Equation 18
(123) Each parameter of Equation 16, Equation 17, and Equation 18 may indicate the following. Pcmax(i): Pcmax(i) indicates the maximum UE transmission output at the i-th sidelink transmission and a P-max value (when there is no base station, a preset value) set by a base station through system information or RRC, and may be determined by a UE by means of UE power class included in the UE. P.sub.0_PSCCH: P.sub.0_PSCCH may indicate a value (when there is no base station, a preset value) set by a base station through system information or RRC in order to guarantee link quality of a reception UE. α.sub.PSCCH: α.sub.PSCCH is a parameter for compensating a path loss value and has a value between 0 and 1, and may indicate a value (when there is no base station, a preset value) set by a base station through system information or RRC. For example, when α.sub.PSCCH=1, 100% of path loss may be compensated, and when α.sub.PSCCH=0.8, only 80% of path loss may be compensated. X1: X1 indicates
(124)
and M.sub.PSCCH and M.sub.PSSCH may indicate the sizes of frequency blocks allocated for transmitting the PSCCH and the PSSCH, respectively. In addition, F is a parameter for power boosting of the PSCCH. For example, when the PSCCH performs power boosting in order to maintain a PSD higher 3 dB than that of the PSSCH, ε may be 3. When the PSCCH and the PSSCH maintain the same PSD (or a case in which power boosting is not performed), ε may be 0. The fixed value may be used as the value of ε (that is, ε is fixed to 3), or the value of ε may be set through RRC and system information of the base station. When there is no base station, the value of ε may be preset. For example, in a case in which the value of ε is set, the V2X transmission UE and reception UE may receive the value of ε which is set through PC-5 RRC, when unicast connection is configured. X2: X2 indicates 10 log.sub.10(M.sub.PSSCH+10.sup.ε/10×M.sub.PSCCH), and M.sub.PSCCH, M.sub.PSSCH, and ε may be the same as the description of X1 above. 2μ: 2μ may be a parameter for compensating a power spectral density (PSD) which varies depending on a subcarrier spacing. For example, a case of using a subcarrier spacing of 15 kHz may indicate that μ=0. Even if the same number of frequency blocks are used, when the subcarrier spacing is doubled to 30 kHz, the PSD may be reduced by half compared with the case of using the subcarrier spacing of 15 kHz. Therefore, in order to compensate the PSD, power is required to be doubled. More specifically, for example, when two frequency blocks are used, 10 log 10(2×20)=3 dB is required for the subcarrier spacing of 15 kHz, whereas, in order to maintain the same PSD as that for the subcarrier spacing of 15 kHz, transmission power is required to be increased to 10 log 10(2×21)=6 dB for the subcarrier spacing of 30 kHz. PL: PL may indicate an estimated path loss value. The path loss value may be estimated by Equation 2. P.sub.Congestion: P.sub.Congestion included in Equation 17 and Equation 18 is a parameter reflecting a congestion level of the V2X transmission UE, and may indicate the maximum transmission power that the V2X transmission UE may use according to the congestion level. More specifically, when the base station determines that the congestion level is high in a resource pool configured thereby, the base station may transmit a value of P.sub.Congestion to the V2X transmission UE through system information and RRC configuration. In another example, the V2X transmission UE may receive a set value of P.sub.Congestion when unicast link connection is configured through PC-5 RRC. In another example, the V2X transmission UE may use a value of P.sub.Congestion included in preconfigured resource pool information. The value of P.sub.Congestion has a unit of [dBm] and may have a range from −41 [dBm] to 31 [dBm] by 1 [dBm]. The value of P.sub.Congestion may be associated with the priority of the PSSCH that the V2X transmission UE transmits. That is, when the priority of the PSSCH that the V2X transmission UE transmits is high, even though the congestion level is high, the set value of P.sub.Congestion may be high (for example, 31 [dBm]) because the transmission of the PSCCH and the PSSCH corresponding thereto should be successfully performed. On the other hand, when the priority of the PSSCH that the V2X transmission UE transmits is low and the congestion level is high, since failure in transmission of the PSCCH and the PSSCH corresponding thereto makes no problem (or the transmission may be given up), the set value of P.sub.Congestion may be low (for example, −41 [dBm]). Meanwhile, the value of P.sub.Congestion may include the value of −∞. Since the value indicates −∞ in a unit of dBm, when the value is converted to a linear domain, the value may 10{circumflex over ( )}(−∞/10)=10{circumflex over ( )}(−∞)=1/(10{circumflex over ( )}∞)≈0 [mW]. In Equation 17, when P.sub.Congestion=−∞, the value may indicate P.sub.PSCCH(i)=X1+P.sub.Congestion=P.sub.Congestion=−∞ [dBm]. As mentioned above, it may indicate that in the linear domain, the transmission power of the PSCCH is 0 [mW] (that is, the PSCCH is not transmitted).
(125) The resource pool information of the PSCCH may be configured from the base station or PC-5 RRC, or may be preconfigured. Within the configured (or preconfigured) resource pool, a V2X resource allocation mode, in which the V2X transmission UE selects a resource for transmitting the PSCCH through a sensing process, may exist. The sensing process may indicate a process of decoding sidelink control information (SCI) transmitted through the PSCCH and a process of measuring RSRP of the DMRS of the PSSCH associated with the PSCCH. A mode in which the V2X transmission UE selects a resource through the sensing process may be called mode-2. V2X transmission UEs operating in mode-2 may perform decoding of the PSCCH to select the PSCCH resource which may be occupied thereby within the configured (or preconfigured) PSCCH resource pool or the PSCCH resource region. In addition, the V2X transmission UE may measure the congestion level of the PSCCH transmitted from each slot within the PSCCH resource pool or the PSCCH resource region. Similarly, V2X transmission UEs operating in mode-2 may perform decoding of the PSCCH to select the PSSCH resource which may be occupied thereby within the configured (or preconfigured) PSSCH resource pool or the PSSCH resource region, and may measure RSRP of the DMRS transmitted through the PSSCH. In addition, the V2X transmission UE may measure the congestion level of the PSSCH transmitted from each slot within the PSSCH resource pool or the PSSCH resource region.
(126) In mode-2 mentioned above, the congestion level of the PSCCH or the PSSCH may be measured by means of a ratio (B/A) between the entire number of resources constituting the PSCCH resource pool (or PSCCH resource region) or the PSSCH resource pool (or PSSCH resource region) and the number of resources occupied by other UE. That is, when the congestion level of the PSCCH is measured, A may be the entire number of PSCCH resources constituting the PSCCH resource pool, and when the congestion level of the PSSCH is measured, A may be the entire number of PSSCH resources constituting the PSSCH resource pool. When the congestion level of the PSCCH is measured, B may be calculated by comparing the value of a received signal strength indicator (RSSI) of the PSCCH symbols with the critical value of the RSSI, which is set (or is preset) through the base station or PC-5 RRC. For example, assuming that the PSCCH that each UE transmits within the PSCCH resource pool is constituted by x symbols, the total received power (x total received powers) for each of the symbols is obtained to obtain the average of x symbols. Accordingly, the RSSI of the PSCCH that each UE transmits may be measured. The V2X transmission UE may compare the measured value of the RSSI with the critical value of the RSSI, which is set (or preset) through the base station or PC-5 RRC, and may thus determine that the corresponding PSCCH is occupied by other UE when the measured value of the RSSI is larger than the set critical value of the RSSI. Therefore, the corresponding PSCCH may be included in B. Meanwhile, when the congestion level of the PSSCH is measured, B may be calculated by comparing the value of the RSSI of the PSSCH symbols with the critical value of the RSSI, which is set (or preset) through the base station or PC-5 RRC.
(127) The measurement of the congestion level may be calculated during the specific time section. For example, A and B may be measured with respect to the PSCCH resource (or PSSCH resource) existing within the time section to [n-K, n−1] slot of the configured PSCCH resource pool (or PSSCH resource pool). Therefore, the congestion level measured in n slot may indicate the congestion level measured with respect to the PSCCH resource (or PSSCH resource) existing within the time section to [n-K, n−1] slot. The fixed value (or preset value) may be used as K, or K may be set through the base station or PC-5 RRC.
(128) In Equation 17 and Equation 18, when the i-th PSCCH is transmitted, with respect to the congestion level reflected in the value of P.sub.Congestion which is set from the base station or PC-5 RRC, the congestion measurement time to obtain the congestion level is required to be defined. For example, the base station or PC-5 RRC may use a measured congestion level result before k1 slot or k2 symbol prior to the i-th PSCCH transmission of the UE transmission UE. That is, the congestion level reflected in the value of P.sub.Congestion used for the transmission power calculation of the PSCCH transmitted through the i-th slot may indicate the congestion level measured at i-k1 slot or the congestion level measured before k2 symbol, based on the first symbol of the PSCCH transmitted through the i-th slot. As mentioned above, the congestion level measured at i-k1 slot may indicate the congestion level measured with respect to the PSCCH resource existing within the [i-k1-K, i-k1-1] time section. In addition, the congestion level measured in i-k2 symbol may indicate the congestion level measured with respect to the PSCCH resource existing within the [i-k2-K, i-k2-1] time section.
(129) Equation 16 may be applied in a mode (mode-1) in which the base station schedules a transmission resource of the V2X transmission UE by using downlink control information (DCI) transmitted through a PDCCH. In another example, when the value of P.sub.Congestion of Equation 17 is not set from the base station or PC-5 RRC, Equation 16 may be applied, or when both the values of P.sub.Range and P.sub.Congestion of Equation 18 are not set from the base station or PC-5 RRC, Equation 16 may be applied.
(130) When the value of P.sub.Congestion is set from the base station or PC-5 RRC, Equation 17 may be applied. When both the values of P.sub.Range and P.sub.Congestion are set from the base station or PC-5 RRC, Equation 18 may be applied. The value of P.sub.Congestion may be omitted from Equation 18. In that case, when the value of P.sub.Range is set from the base station or PC-5 RRC, Equation 18 may be applied. P.sub.Range: P.sub.Range of Equation 18 may indicate a transmission power value for meeting a range requirement in the V2X communication. More specifically, the range requirement or range information may indicate the minimum distance which guarantees QoS (for example, delay time, reliability, data transmission rate, etc.) of a sidelink data packet transmitted through the unicast or groupcast communication. In the unicast or groupcast V2X communication, the transmission UE may receive information on a range transferred from the upper layer (for example, application layer) thereof. The range information may be expressed as a distance having a unit of meter (m) or may be expressed as an index. That is, an application layer may provide the range information for an AS layer in units of meter (for example, 100 m). In another example, the application layer may provide a range index for the AS layer. In this case, the minimum distance may be mapped to each range index (that is, index 1=100 m, index 2=200 m, etc.). Upon receiving the range information, the AS layer may generate the value of P.sub.Range mapped to the corresponding range information. For example, the value of P.sub.Range corresponding to the range of 100 m (or range index 1) and the value of P.sub.Range corresponding to the range of 200 m (or range index 2) may be generated. In another example, upon receiving the range information transferred from the application layer, the AS layer may transfer the corresponding information to RRC and generate the value of P.sub.Range in RRC.
(131) Meanwhile, referring to
(132) The sidelink resource pool information may include information on whether to apply the mentioned downlink path loss value to sidelink transmission power, whether to apply an uplink path loss value to sidelink transmission power, or whether to use any path loss estimation signal which may have the same meaning as it. For example, the base station may transmit, to the UE, information on the sidelink resource pool through system information or RRC configuration, and the information on the sidelink resource pool may include set parameters for sidelink transmission power, which may be used in the corresponding resource pool. The parameters for transmission power may include at least one piece of information on P.sub.0_PSCCH, α.sub.PSCCH, and PL(q) mentioned in Equation 16, Equation 17, and Equation 18. More specifically, PL(0) may indicate the application of downlink path loss and may indicate to estimate downlink path loss by using the SSB (q=0). PL(1) may indicate the application of downlink path loss and may indicate to estimate downlink path loss by using the downlink CSI-RS (q=1). In addition, PL(2) may indicate the application of sidelink path loss and may indicate to estimate sidelink path loss by using the sidelink CSI-RS or the sidelink DMRS (q=2). In another example, it may be explicitly written that the SSB, CSI-RS, sidelink CSI-RS, or sidelink DMRS is used for the resource pool information through system information or RRC configuration.
(133) In another example, when there is no base station, the V2X transmission UE may receive set parameters for sidelink transmission power from the preconfigured resource pool information. In that case, the V2X UE may acquire the transmission power parameters mentioned above from the preconfigured resource pool information.
(134) In another example, regardless of whether the base station exists, when unicast connection with the V2X reception UE is configured, the V2X transmission UE may perform PC-5 RRC configuration. As parameters for sidelink transmission power are set from the PC-5 RRC (a case in which the sidelink resource pool information does not include the sidelink transmission power parameters), or as information on the sidelink resource pool is configured from the PC-5 RRC, the parameters for sidelink transmission power may be set (a case in which the sidelink resource pool information includes the sidelink transmission power parameters).
(135) In Equation 16, Equation 17, and Equation 18, when downlink path loss is applied or when sidelink path loss is applied, P.sub.0_PSCCH and α.sub.PSCCH may be set to have different values. That is, when the UE applies downlink path loss, P.sub.0_PSCCH and α.sub.PSCCH may be set to be A1 and B1, respectively, and when the UE applies sidelink path loss, P.sub.0_PSCCH and α.sub.PSCCH may be set to be A2 and B2, respectively. In a scenario where sidelink and Uu link (that is, downlink and uplink) share a frequency, sidelink transmission power control may be performed with the purpose of reducing interference caused by the sidelink transmission in an uplink signal received by the base station, thus a downlink path loss value may be applied. Unlike this, in a scenario where sidelink and Uu link do not share a frequency, as sidelink quality is guaranteed and unnecessarily high transmission power is not used, a sidelink path loss value may be applied in order to reduce power consumption.
(136) Meanwhile, unlike the examples mentioned above, the V2X UE may receive all sidelink transmission power parameters when the downlink path loss value is applied and sidelink transmission power parameters when the sidelink path loss value is applied. That is, the V2X UE may receive, from the base station, through system information or RRC, or through PC-5 RRC of the UE, all of: P.sub.0_PSCCH and α.sub.PSCCH which may be used when the downlink path loss value is applied, and the type of path loss estimation signals for estimating downlink path loss (a SSB or a downlink CSI-RS); and P.sub.0_PSCCH and α.sub.PSCCH which may be used when the sidelink path loss value is applied, and the type of sidelink path loss estimation signals for estimating sidelink path loss (a sidelink CSI-RS or a sidelink DMRS).
(137) As illustrated above, the resource pool information may include sidelink transmission power parameter information including P.sub.0_PSCCH and α.sub.PSCCH, and the type of path loss estimation signals for estimating path loss. More specifically, all of: P.sub.0_PSCCH_DL and α.sub.PSCCH_DL which may be used when the downlink path loss value is applied, and the type of path loss estimation signals used for estimating downlink path loss; and P.sub.0_PSSCH_SL and α.sub.PSSCH_SL which may be used when the sidelink path loss value is applied, and the type of sidelink path loss estimation signals used for estimating sidelink path loss may be configured in the resource pool information (that is, both a SSB or a downlink CSI-RS and a sidelink CSI-RS or a sidelink DMRS are configured).
(138) In another example, a path loss index set in the resource pool information may indicate the type of path loss estimation signals used for estimating path loss (for example, when q=0 indicates a SSB, q=1 indicates a downlink CSI-RS, and q=2 indicates a sidelink CSI-RS or a sidelink DMRS, both q=0 and q=2 or q=1 and q=2 are set).
(139) When the V2X UE receives all of sidelink transmission power parameters when the downlink path loss value is applied and sidelink transmission power parameters when the sidelink path loss value is applied, the V2X UE may calculate the PSCCH transmission power through Equation 19 or Equation 20.
P.sub.PSCCH(i)=X1+min{Pc max(i),10 log 10(X2*2.sup.μ)+min{P1,P2}}[dBm] Equation 19
P.sub.PSCCH(i)=X1+min{Pc max(i), min{P3,P4}}[dBm] Equation 20
(140) Each parameter of Equation 19 and Equation 20 may indicate the following. Pcmax(i), X1, X2, and 2.sup.μ are the same as what described in Equation 16. P1: P1 indicates transmission power when the downlink path loss value is applied, and may be P1=P.sub.0_PSCCH_DL+α.sub.PSCCH_DL*PL(q). The index q expressing path loss may be omitted from P1. P2: P2 indicates transmission power when the sidelink path loss value is applied, and may be P2=P.sub.0_PSCCH_SL+α.sub.PSCCH_SL*PL(q). The index q expressing path loss may be omitted from P2. P3: P3 indicates transmission power when the downlink path loss value is applied, and may be P3=P1+10 log 10(X2*2.sup.μ). The index q expressing path loss may be omitted from P3. P4: P4 indicates transmission power when the sidelink path loss value is applied, and may be P4=P2+10 log 10(X2*2.sup.μ). The index q expressing path loss may be omitted from P4.
(141) Although not shown in Equation 19 and Equation 20, as shown in Equation 17 and Equation 18, P.sub.Congestion and P.sub.Range may be included in Equation 19 and Equation 20. More specifically, Equation 19 may be expressed as Equation 21.
P.sub.PSCCH(i)=X1+min{Pc max(i),P.sub.Congestion,P.sub.Range,10 log 10(X2*2.sup.μ)+min{P1,P2}}[dBm] Equation 21
(142) Equation 21 illustrates a case in which both P.sub.Congestion and P.sub.Range are included, but one of P.sub.Congestion and P.sub.Range may be omitted from Equation 21.
(143) Similarly, Equation 20 may be expressed as Equation 22.
P.sub.PSCCH(i)=X1+min{Pc max(i),P.sub.Congestion,P.sub.Range, min{P3,P4}}[dBm] Equation 22
(144) Equation 22 illustrates a case in which both P.sub.Congestion and P.sub.Range are included, but, as shown in Equation 21, one of P.sub.Congestion and P.sub.Range may be omitted from Equation 22.
(145) Equation 16, Equation 17, Equation 18, Equation 19, Equation 20, Equation 21, and Equation 22 are equations for determining the transmission power value of the PSCCH. Similarly, the transmission power value of the PSSCH may be calculated, but the transmission power of the PSSCH may be calculated while being divided into two parts. The first part is transmission power of the PSSCH, which corresponds to K1 symbols in
P.sub.PSSCH-1(i)=X1−ε+min{Pc max(i),P.sub.Congestion,P.sub.Range,10 log 10(X2*2.sup.μ)+min{P1,P2}}[dBm] Equation 23
(146) Parameters defined in Equation 23 may be the same as what described in Equation 21. When Equation 16, Equation 17, Equation 18, Equation 19, Equation 20, or Equation 22 is used to calculate the PSCCH transmission power value, X1 defined in each of the equations is changed to X1-ε, and an equation for calculating P.sub.PSSCH-1(i) may be thus derived. In addition, in order to calculate P.sub.PSSCH-1(i) by means of the modification of Equation 23, Equation 22 may be used to apply P.sub.PSSCH-1(i)=X1−ε+min{Pcmax(i), P.sub.Congestion, P.sub.Range, min{P3, P4}} [dBm].
(147) The transmission power equation with respect to the first part of the PSCCH and the PSSCH constituting K1 symbols in
(148) As illustrated in
P.sub.PSSCH-2(i)=P.sub.PSCCH(i)+P.sub.PSSCH-1(i) [dBm] Equation 24
(149) The parameters of Equation 24 are the same as what mentioned in Equation 16, Equation 17, Equation 18, Equation 19, Equation 20, Equation 21, Equation 22, and Equation 23. In Equation 24, each of P.sub.PSCCH(i) and P.sub.PSSCH-1(i) may be smaller than the value of Pcmax(i) which is the UE maximum transmission power (that is, P.sub.PSCCH(i)<Pcmax(i) and P.sub.PSSCH-1(i)<Pcmax(i)), but P.sub.PSSCH-2(i) which is the sum of P.sub.PSCCH(i) and P.sub.PSSCH-1(i) may be larger than Pcmax(i). In that case, P.sub.PSSCH-2(i) may be recalculated through Equation 25 and Equation 26.
P′.sub.PSSCH-2(i)=min{Pc max(i),P.sub.PSSCH-2(i)}[dBm] Equation 25
P′.sub.PSSCH-2(i)=δ.Math.P.sub.PSSCH-2(i) [dBm] Equation 26
(150) In Equation 26, δ is a scaling factor and may be larger than 0, and smaller than or equal to 1. In order to satisfy P.sub.PSSCH-2(i)≤Pcmax(i), the value of δ may be set by the transmission UE.
(151) In a case of P′.sub.PSSCH-2(i)=Pcmax(i) by Equation 25, as mentioned above, it occurs that P.sub.PSCCH(i)+P.sub.PSSCH-1(i)=P.sub.PSSCH-2(i)>Pcmax(i). That is, since P.sub.PSSCH-2(i) is limited by Pcmax(i) and the transmission power is thus changed, the transmission power of P.sub.PSCCH(i)+P.sub.PSSCH-1(i) should be changed in order to enable the K1 symbols and the K2 symbols to use the same transmission power. To this end, β.Math.[P.sub.PSCCH(i)+P.sub.PSSCH-1(i)] is used to scale down the sum of the transmission power such that P.sub.PSCCH(i)+P.sub.PSSCH-1(i)≤Pcmax(i) is satisfied. β is a scaling factor and may be larger than 0, and smaller than or equal to 1. In another example, as described in Equation 12 and Equation 13, the transmission power of P.sub.PSSCH-2(i) is redistributed at a rate between the transmission powers of P.sub.PSCCH(i) and P.sub.PSSCH-1(i) and may update each of the transmission power values of P.sub.PSCCH(i) and P.sub.PSSCH-1(i). That is, when the updated transmission power values of P.sub.PSCCH(i) and P.sub.PSSCH-1(i) are defined as P′.sub.PSCCH(i) and P′.sub.PSSCH-1(i), respectively, they may be calculated through P′.sub.PSCCH(i)=10 log 10[X1*Y/(X1+X2)] and P′.sub.PSSCH-1(i)=10 log 10[X2*Y/(X1+X2)] (Equation 13). X1 and X2 are the same as what defined in Equation 12 and Y may indicate Y=10{circumflex over ( )}[P.sub.PSSCH-2(i)/10].
(152) Similarly, when the transmission power of P.sub.PSSCH-2(i) is changed to that of P′.sub.PSSCH-2(i) by Equation 26, the transmission power of P.sub.PSCCH(i)+P.sub.PSSCH-1(i) should be changed in order to enable the K1 symbols and the K2 symbols to use the same transmission power. To this end, as illustrated above, β.Math.[P.sub.PSCCH(i)+P.sub.PSSCH-1(i)] is used to scale down the sum of the transmission power of P.sub.PSCCH(i)+P.sub.PSSCH-1(i), or the changed transmission power value of P.sub.PSSCH-2(i) is redistributed at a ratio between the transmission powers of P.sub.PSCCH(i) and P.sub.PSSCH-1(i), and each of the transmission power values of P.sub.PSCCH(i) and P.sub.PSSCH-1(i) may thus be updated.
(153) The transmission power parameters used in Equation 16, Equation 17, Equation 18, Equation 19, Equation 20, Equation 21, Equation 22, Equation 23, Equation 24, and Equation 26 may use the value set to the transmission UE by the base station or may use the value preset in the UE by means of the methods mentioned in
(154) In another example, even though UEs exist within the coverage of the base station, exchange of parameters between UEs, which are to perform unicast/groupcast communication, may not be performed when a UE pairing for performing unicast communication is not formed (for example, before PC5 RRC configuration is completed), or before a UE grouping for performing groupcast communication is formed. A transmission UE for the unicast and groupcast communications may not set a sidelink transmission power value, based on sidelink path loss estimation. To this end, with respect to the mentioned parameters, the UE may use the preset value or the value transmitted from the base station through RRC configuration and system information of the base station. The values of the parameters used at this time may be different from the values of the parameters used after PC5 RRC configuration. PL(q) that the transmission UE uses before PC5 RRC configuration may indicate a path loss value with respect to Uu link between the base station and the transmission UE, not the sidelink path loss value. In addition, when the UE uses the preset parameters, each of the parameters may include the value of 0, 0 dB, or 0 dBm.
(155) In another example, the preset transmission power values or the transmission power values set by the base station, of the PSCCH, the PSSCH, and the PSFCH may be expressed as the transmission power value and the offset value with respect to one channel. For example, when the transmission power values of the PSCCH, the PSSCH, and the PSFCH are preset, the transmission power value of the PSCCH may be set to be [X] dBm, and the offset value for transmission power of the PSSCH and the PSFCH may be set to be +/−[Y] dB (or dBm), based on the transmission power value of the PSCCH. It may equally applied even when the transmission power values of the PSCCH, the PSSCH, and the PSFCH are set by the base station.
(156)
(157) Referring to
(158) Upon obtaining information on a resource pool from the base station or obtaining information on a preconfigured resource pool, the UE may obtain information on sidelink transmission power parameters included in sidelink resource pool information at operation 1402. The sidelink transmission power parameters included in the sidelink resource pool information may include at least one of the following parameters. P.sub.0: A parameter for guaranteeing link quality of a reception UE α: α is a parameter for guaranteeing a path loss value and has a value between 0 and 1. Number of RBs: A parameter on the size of frequency blocks that the UE may use for transmitting sidelink control information and data information Subcarrier spacing: A parameter on a subcarrier spacing used for transmitting sidelink control information and data information A reference signal used for path loss estimation. That is, a reference signal may indicate a synchronization signal transmitted through downlink of the base station or a DMRS of a physical broadcast channel (PBCH), which is transmitted through downlink of the base station, or may indicate a parameter indicating which signal the UE uses to estimate path loss, among sidelink reference signals transmitted through sidelink between UEs. A parameter on multiplexing methods of a sidelink control channel and a sidelink data channel (for example, information on whether a channel is time-divided and transmitted as shown in
(159) The V2X transmission UE uses information on the parameters to set transmission powers of the sidelink control channel and the sidelink data channel at operation 1403. The V2X transmission UE uses the set transmission power value to transmit the sidelink control channel and the sidelink data channel at operation 1404.
(160)
(161) Referring to
(162) The transceiver 1520 may transmit/receive a signal to/from other network entities.
(163) The controller 1510 may control the UE to perform one action of the embodiments mentioned above. Meanwhile, the controller 1510 and the transceiver 1520 are not necessarily implemented as separate modules, and may be implemented as a single element in the form of a single chip. In addition, the controller 1510 and the transceiver 1520 may be electrically connected to each other. For example, the controller 1510 may be a circuit, an application-specific circuit, or at least one processor. In addition, operations of the UE may be realized by providing a memory device storing corresponding program codes to any element in the UE.
(164)
(165) Referring to
(166) The transceiver 1620 may transmit/receive a signal to/from other network entities.
(167) The controller 1610 may control the base station to perform one action of the embodiments mentioned above. Meanwhile, the controller 1610 and the transceiver 1620 are not necessarily implemented as separate modules, and may be implemented as a single element in the form of a single chip. In addition, the controller 1610 and the transceiver 1620 may be electrically connected to each other. For example, the controller 1610 may be a circuit, an application-specific circuit, or at least one processor. In addition, operations of the base station may be realized by providing a memory device storing corresponding program codes to any element in the base station.
(168) It should be noted that a configuration diagram, an exemplar diagram of a control/data signal transmission method, an operational procedure exemplar diagram, and configuration diagrams, which are illustrated in
(169) The above described operations of the base station or UE may be implemented by providing a memory device storing corresponding program codes to any element in the base station or UE. That is, the controller of the base station or UE may perform the above described operations by reading and executing the program code stored in the memory device by means of a processor or a central processing unit (CPU). Methods according to embodiments of the disclosure as defined by the appended claims or disclosed herein may be implemented in hardware, software, or a combination of hardware and software.
(170) When the methods are implemented by software, a computer-readable storage medium for storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium may be configured for execution by one or more processors within the electronic device. The at least one program may include instructions that cause the electronic device to perform the methods according to various embodiments of the disclosure as defined by the appended claims or disclosed herein.
(171) The programs (software modules or software) may be stored in non-volatile memories including a random access memory and a flash memory, a read only memory (ROM), an electrically erasable programmable read only memory (EEPROM), a magnetic disc storage device, a compact disc-ROM (CD-ROM), digital versatile discs (DVDs), or other type optical storage devices, or a magnetic cassette. Alternatively, any combination of some or all of them may form a memory in which the program is stored. Further, a plurality of such memories may be included in the electronic device.
(172) In addition, the programs may be stored in an attachable storage device which may access the electronic device through communication networks such as the Internet, Intranet, local area network (LAN), wide LAN (WLAN), and storage area network (SAN) or a combination thereof. Such a storage device may access an electronic device which performs embodiments of the disclosure, via an external port. Further, a separate storage device on the communication network may access an electronic device which performs embodiments of the disclosure.
(173) In the above-described detailed embodiments of the disclosure, an element included in the disclosure is expressed in the singular or the plural according to a presented detailed embodiment. However, the singular or plural expressions are selected to be suitable for proposed situations for convenience of description, and the disclosure is not limited to the singular or plural elements. An element expressed in a plural form may be configured in singular, or an element expressed in a singular form may be configured in plural.
(174) While the disclosure has been shown and described with reference to various embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims and their equivalents.