Patent Application
20240292385
The present invention relates to a terminal and a communication method in a wireless communication system.
In LTE (Long Term Evolution) and LTE successor systems (e.g., LTE-A (LTE Advanced), NR (New Radio) (also referred to as 5G)), a D2D (Device to Device) technology in which terminals communicate directly with each other without using base station is being discussed (e.g., Non-Patent Document 1).
The D2D reduces traffic between the terminals and the base stations and enables communication between the terminals even when the base stations are unable to communicate during a disaster, etc. Although the 3GPP (3rd Generation Partnership Project) refers to D2D as a “sidelink.” the more generic term D2D is used herein. However, in the description of embodiments described below, the sidelink is also used as needed.
The D2D communication is broadly classified into: D2D discovery for discovering other terminals capable of communication; and D2D communication (D2D direct communication, direct communication between terminals, etc.,) for direct communication between terminals. Hereinafter, when D2D communication and D2D discovery are not specifically distinguished, it is simply called D2D. A signal sent and received by D2D is called a D2D signal. Various use cases of V2X (Vehicle to Everything) services in NR have been discussed (e.g., Non-Patent Document 2).
Improving delay performance and reliability has been discussed as an enhancement of the NR sidelink. For example, in the resource allocation mode 2 in which terminals autonomously select resources, a terminal 20A shares information indicating a resource set with a terminal 20B, and the terminal 20B improves communication reliability and reduces delay by taking the information into account in the resource selection for transmission.
Here, in a case where the terminal 20B operates in the resource allocation mode 1 (Resource allocation mode 1), a resource used for sidelink transmission is scheduled by the base station 10. With respect to the above, a case is assumed in which information received from the terminal 20A indicating a resource set overlaps with the scheduled resource.
The present invention has been made in view of the above points, and it is an object of the present invention to determine an operation in a case where a resource used for transmission overlaps with transmission of another terminal in the direct communication between terminals.
According to the disclosed technique, a terminal is provided. The terminal includes: a reception unit configured to receive, from a base station, information for scheduling a first resource used for transmission to another terminal in a resource pool; and a transmission unit configured to transmit a signal for reserving the first resource to the another terminal. The reception unit receives information related to resource selection from the another terminal, and the transmission unit does not perform transmission using the first resource in a case where the information related to resource selection indicates that the first resource collides with another signal, indicates that the first resource is not included in a recommended resource set, or indicates that the first resource is included in a non-recommended resource set, and where a position of the first resource in a time domain is a future position.
According to the disclosed technique, an operation can be determined in a case where a resource used for transmission overlaps with transmission of another terminal in the direct communication between terminals.
In the following, referring to the drawings, one or more embodiments of the present invention will be described. It should be noted that the embodiments described below are examples. Embodiments of the present invention are not limited to the following embodiments.
In operations of a wireless communication system according to an embodiment of the present invention, conventional techniques will be used appropriately. With respect to the above, for example, the conventional techniques are related to, but not limited to. the existing LTE. Further, it is assumed that the term “LTE” used in the present specification has, unless otherwise specifically mentioned, a broad meaning including a scheme of LTE-Advanced and a scheme after LTE-Advanced (e.g., NR), or wireless LAN (Local Area Network).
In addition, in an embodiment of the present invention, the duplex method may be a TDD (Time Division Duplex) method, an FDD (Frequency Division Duplex) method, or any other method (e.g., Flexible Duplex, or the like).
Further, in an embodiment of the present invention, the expression, radio (wireless) parameters are “configured (set)” may mean that a predetermined value is pre-configured, or may mean that a radio parameter indicated by the base station 10 or the terminal 20 is configured.
Further, in 3GPP, V2X using LTE/NR's cellular communication and communication between terminals has been discussed. V2X using cellular communication may be referred to as cellular V2X. In NR V2X, discussions have been performed to realize higher system capacity, reduced latency, higher reliability, and QoS (Quality of Service) control.
With respect to LTE V2X or NR V2X, it is assumed that discussions may be not limited to 3GPP specifications in the future. For example, it is assumed to be discussed on: how to secure interoperability; how to reduce cost by implementing higher layers; how to use or how to switch multiple RATs (Radio Access Technologies); how to handle regulations of each country; how to obtain and distribute data of LTE/NR V2X platform; and how to manage and use databases.
In an embodiment of the present invention, a form of embodiment is mainly assumed in which communication apparatuses are mounted on vehicles. However, an embodiment of the present invention is not limited to such a form. For example, communication apparatuses may be terminals held by people, may be apparatuses mounted on drones or aircraft, or may be base stations. RSUs, relay stations (relay nodes), terminal capable of scheduling, etc.
It should be noted that SL (Sidelink) may be distinguished from UL (Uplink) or DL (Downlink) based on any one of, or any combination of the following 1) through 4). Furthermore. SL may be referred to as a different name.
Further, with respect to OFDM (Orthogonal Frequency Division Multiplexing) of SL or UL, any of CP-OFDM (Cyclic-Prefix OFDM), DFT-S-OFDM (Discrete Fourier Transform-Spread-OFDM), OFDM without Transform precoding, and OFDM with Transform precoding may be applied.
In LTE SL, with respect to allocating SL resources to terminal 20. Mode 3 and Mode 4 are defined. In Mode 3, transmission resources are dynamically allocated using a DCI (Downlink Control Information) that is transmitted from a base station 10 to a terminal 20. Further, in Mode 3, SPS (Semi Persistent Scheduling) is enabled (available). In Mode 4. the terminal 20 autonomously selects transmission resources from a resource pool.
40) It should be noted that a slot in an embodiment of the present invention may be read on (replaced with) a symbol, a mini slot, a subframe, a radio frame, or a TTI (Transmission Time Interval). Further, a cell in an embodiment of the present invention may be read on (replaced with) a cell group, a carrier component, a BWP (bandwidth part), a resource pool, a resource, a RAT (Radio Access Technology), a system (including a wireless LAN), etc.
Note that, in an embodiment of the present invention, the terminal 20 is not limited to a V2X terminal, but may be any type of terminal that performs D2D communication. For example, the terminal 20 may be a terminal carried by a user, such as a smart phone, or an IoT (Internet of Things) device, such as a smart meter.
In addition, it is expected that HARQ (Hybrid automatic repeat request) is supported for unicast and groupcast of sidelink in NR-V2X. In addition. SFCI (Sidelink Feedback Control Information) containing a HARQ response is defined in NR-V2X. In addition, it is being discussed that SFCI is transmitted via PSFCH (Physical Sidelink Feedback Channel).
Note that, in the following description, it is assumed that PSFCH is used in the transmission of HARQ-ACK on sidelink. However, this just an example. For example, PSCCH may be used to transmit HARQ-ACK on sidelink, PSSCH may be used to transmit HARQ-ACK on sidelink, or other channels may be used to transmit HARQ-ACK on sidelink.
Hereinafter, for the sake of convenience, the overall information reported by the terminal 20 in the HARQ is referred to as HARQ-ACK. This HARQ-ACK may also be referred to as HARQ-ACK information. Further, more specifically, a codebook applied to the HARQ-ACK information reported from the terminal 20 to the base station 10 or the like is called a HARQ-ACK codebook. The HARQ-ACK codebook defines a bit string (sequence) of the HARQ-ACK information. Note that “HARQ-ACK” sends not only ACK but also NACK.
Hereinafter, when the terminals 20A, 20B, or the like are not particularly distinguished, the term “terminal 20” or “user device” will be simply described.
As described above, in an embodiment, the terminal 20 is, for example, a device mounted in a vehicle such as an automobile and has a cellular communication function as a UE in LTE or NR and a sidelink function. Terminal 20 may be a conventional portable terminal (such as a smartphone). Further, the terminal 20 may also be an RSU. The RSU may be a UE-type RSU having the function of a UE or a gNB-type RSU having the function of a base station device.
Note that the terminal 20 need not be a single housing device. For example, even when various sensors are arranged and distributed in a vehicle, a device including the various sensors may be a terminal 20.
Further, processing contents of sidelink transmission data of the terminal 20 are basically the same as those of UL transmission in LTE or NR. For example, the terminal 20 scrambles a codeword of the transmission data, modulates to generate complex-valued symbols, and maps the complex-valued symbols to one or two layers, and performs precoding. Further, the precoded complex-valued symbols are mapped to a resource element to generate a transmission signal (e.g., complex-valued time-domain SC-FDMA signal), and the generated signal is transmitted from each antenna port.
It is noted that the base station 10 has a function of cellular communication as a base station in LTE or NR and a function of enabling communication of the terminal 20 according to an embodiment of the present invention (e.g., resource pool setting, resource allocation, etc.). Further, the base station 10 may also be an RSU (gNB-type RSU).
Further, in the wireless communication system according to an embodiment of the present invention, a signal waveform used by the terminal 20 for SL or UL may be OFDMA, SC-FDMA, or other signal waveforms.
In step S101, the terminal 20A autonomously selects a resource to be used for PSCCH and PSSCH from a resource selection window having a predetermined period. The resource selection window may be configured to the terminal 20 by the base station 10. Here, the predetermined period of the resource selection window may be specified by an implementation condition of the terminal such as a processing time or a maximum allowable packet delay time, or may be specified in advance by technical specifications. and the predetermined period may be referred to as a section in a time domain. In step S102 and Step S103, the terminal 20A transmits, using the resource autonomously selected in step S101, SCI (Sidelink Control Information) via PSCCH and/or PSSCH and transmits SL data via PSSCH. For example, the terminal 20A may transmit the PSCCH using a frequency resource adjacent to the PSSCH frequency resource with the same time resource as at least a portion of the time resource of the PSSCH.
40) The terminal 20B receives the SCI (PSCCH and/or PSSCH) and the SL data (PSSCH) transmitted from the terminal 20A. The received SCI may include information of a PSFCH resource for the terminal 20B to send HARQ-ACK for reception of the data. The terminal 20A may include information of the autonomously selected resource in the SCI and transmit the included information.
In step S104, the terminal 20B transmits a HARQ-ACK for the received data to the terminal 20A using the PSFCH resource specified by the received SCI.
In step S105, when the HARQ-ACK received in step S104 indicates a request for retransmission, that is, when the HARQ-ACK is a NACK (negative response), the terminal 20A retransmits the PSCCH and the PSSCH to the terminal 20B. The terminal 20A may retransmit the PSCCH and the PSSCH using an autonomously selected resource.
Note that in a case where HARQ control with HARQ feedback is not performed, step S104 and step S105 need not be performed.
In step S201, the terminal 20A autonomously selects a resource to be used for PSCCH and PSSCH from a resource selection window having a predetermined period. The resource selection window may be configured to the terminal 20 by the base station 10.
In step S202 and step S203, the terminal 20A transmits, using the resource autonomously selected in step S201, an SCI via PSCCH and/or PSSCH, and transmits SL data via PSSCH. For example, the terminal 20A may transmit the PSCCH using a frequency resource adjacent to the PSSCH frequency resource with the same time resource as at least a portion of the time resource of the PSSCH.
In step S204, the terminal 20A retransmits, using the resource autonomously selected in step S201, the SCI via PSCCH and/or PSSCH and the SL data via PSSCH to the terminal 20B. The retransmission in step S204 may be performed multiple times.
It is noted that, if the blind retransmission is not performed, step S204 may not be performed.
In step S301, the base station 10 performs SL scheduling by sending DCI (Downlink Control Information) to the terminal 20A via PDCCH. Hereafter, for the sake of convenience, the DCI for SL scheduling is called SL scheduling DCI.
Further, in Step S301, it is assumed that the base station 10 also transmits DCI for DL scheduling (which may be referred to as DL assignment) to the terminal 20A via the PDCCH. Hereafter, for the sake of convenience, the DCI for DL scheduling is called a DL scheduling DCI. The terminal 20A, which has received the DL scheduling DCI, receives DL data via PDSCH using a resource specified by the DL scheduling DCI.
In step S302 and step S303, the terminal 20A transmits, using the resource specified by the SL scheduling DCI, SCI (Sidelink Control Information) via PSCCH and/or PSSCH and transmits SL data via PSSCH. Note that, in the SL scheduling DCI, only a PSSCH resource may be specified. In this case, for example, the terminal 20A may transmit the PSCCH using a frequency resource adjacent to the PSSCH frequency resource with the same time resource as at least a portion of the time resource of the PSSCH.
The terminal 20B receives the SCI (PSCCH and/or PSSCH) and the SL data (PSSCH) transmitted from the terminal 20A. The SCI received via the PSCCH and/or PSSCH includes information of a PSFCH resource for the terminal 20B to send a HARQ-ACK for reception of the data.
The information of the resource is included in the DL scheduling DCI or SL scheduling DCI transmitted from the base station 10 in S301, and the terminal 20A acquires the information of the resource from the DL scheduling DCI or the SL scheduling DCI and includes the acquired information in the SCI. Alternatively, the DCI transmitted from the base station 10 may not include the information of the resource, and the terminal 20A may autonomously include the information of the resource in the SCI and transmit the SCI including the information.
In step S304, the terminal 20B transmits a HARQ-ACK for the received data to the terminal 20A using the PSFCH resource specified by the received SCI.
In step S305, the terminal 20A transmits the HARQ-ACK using, for example, a PUCCH (Physical uplink control channel) resource specified by the DL scheduling DCI (or SL scheduling DCI) at the timing (e.g., slot-by-slot timing) specified by the DL scheduling DCI (or SL scheduling DCI), and the base station 10 receives the HARQ-ACK. The HARQ-ACK codebook may include HARQ-ACK received from the terminal 20B or HARQ-ACK generated based on PSFCH that is not received, and HARQ-ACK for the DL data. Note, however, the HARQ-ACK for DL data is not included if DL data is not allocated. In NR Rel. 16, the HARQ-ACK codebook does not include HARQ-ACK for DL data. Note that in a case where HARQ control with HARQ feedback is not performed, step S304 and/or step S305 need not be performed.
In
In a case of groupcast option 2 in which an ACK or NACK is transmitted in a HARQ response in the NR V2X groupcast, it is necessary to determine resources used for transmitting and receiving PSFCH. As shown in
Further, as shown in
In addition, as illustrated in
In addition, a resource in the resource selection window that is a candidate of resource reservation information corresponding to a resource that is not monitored in the sensing window due to transmission, such as the slot tmSL shown in
In the resource selection window from slots n+T1 to n+T2, as shown in
The lower layer of the terminal 20 may report the SA to the higher layer. The higher layer of the terminal 20 may perform random selection for the SA to determine a resource to be used. The terminal 20 may perform sidelink transmission using the determined resource.
Although an operation of the transmission-side terminal 20 has been described with reference to
In step S504, at the timing of T(r_0)-T3 shown in
In step S505, in a case where the preemption is determined in step S504, the terminal 20 indicates, to the higher layer, the preemption, reselects resources at the higher layer, and ends the preemption check. Note that the resource reselection is not required to be performed in the higher layer.
Note that, when reevaluation (Re-evaluation) is performed instead of the preemption check, in step S504, in a case where resources of the resource set (r_0, r_1, . . . ) have not been reserved and where, after determining the set SA of resource candidates, the resources of the resource set (r_0, r_1, . . . ) are not included in SA, the resources are not used and the resource reselection is performed at the upper layer.
The terminal 20 can detect, for example, that another terminal 20 is performing transmission in one or more sensing targets from subframe ty1−k×PstepSL to subframe tyY−k×PstepSL, the length of which being Y subframes. The k may be determined by a 10-bit bitmap, for example.
Note that k may be configured in a 10-bit bitmap or defined in advance, and Pstep may be 100 ms. However, in a case where SL communication is performed using DL and UL carriers, Pstep may be (U/(D+S+U))*100 ms. U corresponds to the number of UL subframes, D corresponds to the number of DL subframes, and S corresponds to the number of special subframes.
In a case where an SCI is detected in the above sensing target and the RSRP exceeds the threshold value, resources in the resource selection window corresponding to the resource reservation field of the SCI are excluded. Also, in a case where an SCI is detected in the sensing target and the RSRP is less than the threshold value, the resource in the resource selection window corresponding to the resource reservation field of the SCI is not excluded. The threshold value may be, for example, a threshold value ThpTX,pRX configured or defined for each resource in the sensing target, based on the transmission-side priority pTX and the reception-side priority pRX.
As shown in
That is, resources that are not excluded because the RSRP is less than the threshold value may be increased by raising the threshold value ThpTX,pRX and by performing the resource identification again. In addition, the RSSI of each resource in the SA may be measured and the resource with the lowest RSSI may be added to the set SB. The operation of adding the resource with the lowest RSSI included in the SA to the SB may be repeated until the set SB of resource candidates becomes equal to or greater than 20% of the resource selection window.
The lower layer of the terminal 20 may report the SB to the higher layer. The higher layer of the terminal 20 may perform random selection for the SB to determine a resource to be used. The terminal 20 may perform sidelink transmission using the determined resource. Note that the terminal 20 may use the resource periodically without performing the sensing for a predetermined number of times (e.g., Cresel times) after the resource is once secured.
Here, power saving based on random resource selection and partial sensing is being discussed in NR Release 17 Sidelink. For example, for the sake of power savings, random resource selection and partial sensing of sidelink in LTE release 14 may be applied to resource allocation mode 2 of NR release 16 sidelink. The terminal 20 to which partial sensing is applied performs reception and sensing only in specific slots in the sensing window.
In addition, in NR Release 17 Sidelink, improvement of delay performance and reliability using inter-terminal coordination (inter-UE coordination) as a baseline is being discussed. For example, the terminal 20A may share information indicating a resource set with the terminal 20B, and terminal 20B may take into account this information in selecting resources for transmission.
For example, regarding the power saving, the terminal 20 may perform full sensing as shown in
Note that the method of: performing random selection at the time of resource selection: and using sensing information at the time of reevaluation or preemption checking, may be treated as partial sensing or as random selection.
The following 1) and 2) may be applied as operations in sensing.
In Release 17, operations may be specified assuming 3 types of terminals 20. One type is Type A, where a Type A terminal 20 does not have capability of receiving any sidelink signals and channels. However, exceptions may be made for receiving PSFCH and S-SSB.
Another type is Type B, where a Type B terminal 20 does not have capability of receiving any sidelink signals and channels except for PSFCH and S-SSB reception.
Yet another type is Type D, where a Type D terminal 20 has capability of receiving all sidelink signals and channels as defined in Release 16. However, reception of some sidelink signals and channels is not excluded.
It should be noted that UE types other than Type A, Type B and Type D mentioned above may be assumed, and the UE type and UE capability may or need not be associated with each other.
In addition, in release 17, multiple resource allocation methods may be configured for a resource pool. In addition. SL-DRX (Discontinuous reception) is supported as one of the power saving functions. That is, the reception operation is performed only for a predetermined section.
In the resource allocation mode 2, in which terminal 20 autonomously selects resources, the terminal 20 receives resource reservation information of another terminal 20 by sensing, and terminal 20 selects resources to be used for transmission, based on the resource reservation information. However, even in a case where each transmission-side terminal 20 performs resource selection based on sensing, collision of resources may occur. There are communication situations that have to be considered as shown below in order to improve communication reliability and to reduce delay.
In addition, for example, with respect to the improvement of latency performance and reliability.
In addition, because the sidelink is a half-duplex communication, collision of resources may occur when terminals 20 both perform transmission.
As a method of improving the reliability and the delay performance, inter-terminal coordination is being discussed. For example, the inter-terminal coordination method 1 and the inter-terminal coordination method 2 as shown below have been discussed. Hereinafter, the terminal 20 that transmits coordination information is described as UE-A, and the terminal 20 that receives the coordination information is described as UE-B.
Inter-terminal coordination method 1) A preferred resource set and/or a non-preferred resource set for transmission of the UE-B is transmitted from the UE-A to the UE-B.
Inter-terminal coordination method 2) The UE-A transmits, to the UE-B, information indicating that there is an expected collision, a possibility of a collision, or a fact of a detected collision, for a resource received from the UE-B or a resource indicated by SCI received from the UE-B, with another transmission or reception. Note that the “resource set” may be replaced with the fact.
Further, for example, with respect to the inter-terminal coordination, methods related to the following 1) to 6) may be determined.
In the above-described inter-terminal coordination method 1), the UE-B may perform an operation as described in 1) to 4) below.
In the above-described inter-terminal coordination method 2), the UE-B may perform an operation as described in 1) to 2) below.
In addition, in the above-described inter-terminal coordination method 2), transmitting an indication related to coordination information such as the above-described PSFCH is being discussed. For example, in a case where the UE-A receives information related to transmission or reservation of the UE-B and detects a collision with a kind of signal, based on the information, the UE-A may transmit information indicating that the collision is detected and/or information indicating that resource reselection or retransmission is to be performed to the UE-B via PSFCH or via a channel similar to PSFCH. Hereinafter, the channel similar to PSFCH used for transmitting the information is described as PSCICH (Physical Sidelink Collision Indication Channel), but may be described as PSFCH, and the name is not limited to these names.
Note that the indication via PSCICH may be used as an indication of collision for the future resource, or may be used as an indication of collision for the past resource.
Here, in a case where a transmission resource of the UE-B is scheduled by the gNB in the above-described inter terminal coordination method 2), an operation of the UE-A or the UE-B related to the collision of the transmission resource of the UE-B is required to be determined.
Note that the resource allocation mode 1 UE performs SL transmission in an SL resource scheduled by the gNB. The resource allocation mode 2 UE performs SL transmission in an SL resource selected by the resource allocation mode 2 UE itself. The method of selecting an SL resource may be any one of a method of selection after the resource identification based on full sensing, a method of selection after the resource identification based on partial sensing, or a method of random selection.
Therefore, the resource allocation mode 1 UE may perform an operation described in 1) to 5) below with respect to the collision indication for the SL resource configured or specified by the gNB.
In addition, in a case where a UE receives a signal from another UE (referred to as UE-Y) and the signal is transmission or reservation from the resource allocation mode 1 UE, the UE is not required to transmit a collision indication to the UE-Y even if a collision related to the transmission or reservation is detected. In other words, an operation as the UE-A in the above-described inter-terminal coordination method 2) is not required to be performed.
For example, the resource allocation mode 1 UE may transmit an indication of being the resource allocation mode 1 UE to the reception-side UE via SCI. The SCI may have a dedicated field for an indication of being the resource allocation mode 1 UE. The SCI may be the 1st stage SCI, or may be the 2nd stage SCI.
For example, with respect to each resource pool, the configuration or pre-configuration of resource pools may indicate which of the resource allocation mode 1 UE or the resource allocation mode 2 UE can use each resource pool for transmission. For example, which of the resource allocation mode 1 UE or the resource allocation mode 2 UE can use each resource pool for transmission may be associated with a parameter related to configuration of resource pools viewed from an aspect of reception (for example, SL-RxPool). In addition, which of the resource allocation mode 1 UE or the resource allocation mode 2 UE can use each resource pool for transmission may be associated with a parameter related to the resource pool configuration (for example, SL-ResourcePool. The determination may be performed based on whether a predetermined parameter (for example, sl-UE-SelectedConfigRP) is included in a parameter related to the resource pool configuration (for example, SL-ResourcePool). For example, a case where sl-UE-Selected ConfigRP is included in SL-ResourcePool may indicate that the resource pool is for the resource allocation mode 2 UE, and a case where sl-UE-SelectedConfigRP is not included in SL-ResourcePool may indicate that the resource pool is for the resource allocation mode 1 UE.
For example, in a case where the UE detects a collision between a signal received from the UE-Y that is the resource allocation mode 1 UE and a signal related to transmission or reservation of another UE (referred to as UE-Z), an operation described in 1) to 4) below may be performed.
By performing the above-described operation, unnecessary transmission is prevented and power savings can be achieved, and, the reliability can be improved by transmitting the collision indication to the resource allocation mode 2 UE.
The operation related to the collision indication may be applied to a case in which the preferred resource set and/or non-preferred resource set in the above-described inter-terminal coordination method 1 is transmitted from the UE-A to the UE-B. In a case where the transmission resource of the UE-B is scheduled by the gNB, the UE-B that is the resource allocation mode 1 UE may operate as described below with respect to the preferred resource set and/or non-preferred resource set.
The resource allocation mode 1 UE may perform an operation described in 1) to 4) below with respect to the preferred resource set and/or the non-preferred resource set corresponding to the SL resource configured or indicated by the gNB.
In addition, the resource allocation mode 2 UE is not required to transmit, to the resource allocation mode 1 UE, an indication related to the preferred resource set and/or the non-preferred resource set.
For example, the resource allocation mode 1 UE may transmit an indication of being the resource allocation mode 1 UE to the reception-side UE via SCI. The SCI may have a dedicated field for an indication of being the resource allocation mode 1 UE. The SCI may be the 1st stage SCI, or may be the 2nd stage SCI.
For example, with respect to each resource pool, the configuration or pre-configuration of resource pools may indicate which of the resource allocation mode 1 UE or the resource allocation mode 2 UE can use each resource pool for transmission. For example, which of the resource allocation mode 1 UE or the resource allocation mode 2 UE can use each resource pool for transmission may be associated with a parameter related to configuration of resource pools viewed from an aspect of reception (for example, SL-RxPool). In addition, which of the resource allocation mode 1 UE or the resource allocation mode 2 UE can use each resource pool for transmission may be associated with a parameter related to the resource pool configuration (for example, SL-ResourcePool). The determination may be performed based on whether a predetermined parameter (for example, sl-UE-SelectedConfigRP) is included in a parameter related to the resource pool configuration. For example, a case where sl-UE-SelectedConfigRP is included in SL-ResourcePool may indicate that the resource pool is for the resource allocation mode 2 UE, and a case where sl-UE-Selected ConfigRP is not included in SL-Resource Pool may indicate that the resource pool is for the resource allocation mode 1 UE.
For example, SCI may indicate whether the SL transmission information, which is an indication related to the preferred resource set and/or the non-preferred resource set, is for the resource allocation mode 1 UE or is for the resource allocation mode 2 UE. For example, the destination UE-ID may be associated with a resource allocation mode 2 UE. For example, a UE-ID may be defined that is used for broadcast and/or groupcast for the resource allocation mode 2 UE. For example, the indication related to the preferred resource set and/or the non-preferred resource set may be associated with the above-described UE-ID to be transmitted.
According to the above-described operation, the increase of power consumption can be prevented by avoiding unnecessary transmission.
The above embodiments may be applied to an operation in which one terminal 20 configures or allocates transmission resources of another terminal 20.
The above embodiments need not be limited to V2X terminals, but may be applied to terminals performing D2D communication.
The operation in the above embodiments may be performed only in a specific resource pool. For example, the operation may be performed only in the resource pool that is available for a terminal 20 of release 17 or later.
According to an embodiment of the present invention, the terminal 20 can determine an appropriate sidelink transmission operation in a case where the inter-terminal coordination information is received. In addition, the terminal 20 can determine an appropriate destination of transmission of the inter-terminal coordination information.
In other words, an operation can be determined in a case where a resource used for transmission overlaps with transmission of another terminal in the direct communication between terminals.
Next, a functional configuration example of the base station 10 and the terminal 20 for performing the processes and operations described above will be described. The base station 10 and terminal 20 include functions for implementing the embodiments described above. It should be noted, however, that each of the base stations 10 and the terminal 20 may include only some of the functions in an embodiment.
The transmission unit 110 includes a function for generating a signal to be transmitted to the terminal 20 side and transmitting the signal wirelessly. The reception unit 120 includes a function for receiving various signals transmitted from the terminal 20 and acquiring, for example, information of a higher layer from the received signals. Further, the transmission unit 110 has a function to transmit NR-PSS, NR-SSS, NR-PBCH, DL/UL control signals, DL reference signals, and the like to the terminal 20.
The configuration unit 130 stores preset configuration information and various configuration information items to be transmitted to the terminal 20 in a storage apparatus and reads the preset configuration information from the storage apparatus if necessary. Contents of the configuration information are, for example, information related to configuration of D2D communication, etc.
As described in an embodiment, the control unit 140 performs processing related to the configuration in which the terminal 20 performs D2D communication. Further, the control unit 140 transmits scheduling of D2D communication and DL communication to the terminal 20 through the transmission unit 110. Further, the control unit 140 receives information related to the HARQ response of the D2D communication and the DL communication from the terminal 20 via the reception unit 120. The functional units related to signal transmission in the control unit 140 may be included in the transmission unit 110, and the functional units related to signal reception in the control unit 140 may be included in the reception unit 120.
The transmission unit 210 generates a transmission signal from transmission data and transmits the transmission signal wirelessly. The reception unit 220 receives various signals wirelessly and obtains upper layer signals from the received physical layer signals. Further, the reception unit 220 has a function for receiving NR-PSS, NR-SSS, NR-PBCH, DL/UL/SL control signals, or reference signals transmitted from the base station 10. Further, for example, with respect to the D2D communications, the transmission unit 210 transmits, to another terminal 20, PSCCH (Physical Sidelink Control Channel), PSSCH (Physical Sidelink Shared Channel), PSDCH (Physical Sidelink Discovery Channel), PSBCH (Physical Sidelink Broadcast Channel), etc., and the reception unit 220 receives, from the another terminal 20, PSCCH, PSSCH, PSDCH, or PSBCH.
The configuration unit 230 stores various configuration information received from the base station 10 or the terminal 20 by the receiving unit 220 in the storage apparatus and reads them from the storage apparatus as necessary. In addition, the configuration unit 230 also stores pre-configured configuration information. Contents of the configuration information are, for example, information related to configuration of D2D communication, etc.
The control unit 240 controls D2D communication for establishing RRC connection with another terminal 20 as described in an embodiment of the present invention. Further, the control unit 240 performs processing related to the power-saving operation. Further, the control unit 240 performs HARQ related processing of the D2D communication and DL communication. Further, the control unit 240 transmits, to the base station 10, information related to the HARQ response of the D2D communication to the other terminal 20 and the DL communication scheduled by the base station 10. Further, the control unit 240 may perform scheduling of D2D communication for another terminal 20. In addition, the control unit 240 may autonomously select a resource to be used for D2D communication from the resource selection window, based on the sensing result, or may perform reevaluation or preemption. Further, the control unit 240 performs processing related to power saving in transmission and reception of D2D communications. In addition, the control unit 240 performs processing related to inter-terminal coordination in D2D communication. The functional units related to signal transmission in the control unit 240 may be included in the transmission unit 210, and the functional units related to signal reception in the control unit 240 may be included in the reception unit 220.
In the above functional structure diagrams used for describing an embodiment of the present invention (
Functions include, but are not limited to, judging, determining, calculating, processing, deriving, investigating, searching, checking, receiving, transmitting, outputting, accessing, resolving, selecting, establishing, comparing, assuming, expecting, and deeming; broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assigning, etc. For example, a functional block (component) that functions to transmit is called a transmitting unit or a transmitter. In either case, as described above, the implementation method is not particularly limited.
For example, the base station 10, terminal 20, etc., according to an embodiment of the present disclosure may function as a computer for processing the radio communication method of the present disclosure.
It should be noted that, in the descriptions below, the term “apparatus” can be read as a circuit, a device, a unit, etc. The hardware structures of the base station 10 and terminal 20 may include one or more of each of the devices illustrated in the figure, or may not include some devices.
Each function in the base station 10 and terminal 20 is realized by having the processor 1001 perform an operation by reading predetermined software (programs) onto hardware such as the processor 1001 and the storage device 1002, and by controlling communication by the communication device 1004 and controlling at least one of reading and writing of data in the storage device 1002 and the auxiliary storage device 1003.
The processor 1001 controls the entire computer by, for example, controlling the operating system. The processor 1001 may include a central processing unit (CPU) including an interface with a peripheral apparatus, a control apparatus, a calculation apparatus, a register, etc. For example, the above-described control unit 140, control unit 240, and the like, may be implemented by the processor 1001.
Further, the processor 1001 reads out onto the storage device 1002 a program (program code), a software module, or data from the auxiliary storage device 1003 and/or the communication device 1004, and performs various processes according to the program, the software module, or the data. As the program, a program is used that causes the computer to perform at least a part of operations according to an embodiment of the present invention described above. For example, the control unit 140 of the base station 10 illustrated in
The storage device 1002 is a computer-readable recording medium, and may include at least one of a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM (Electrically Erasable Programmable ROM), a RAM (Random Access Memory), etc. The storage device 1002 may be referred to as a register, a cache, a main memory, etc. The storage device 1002 is capable of storing programs (program codes), software modules, or the like, that are executable for performing communication processes according to an embodiment of the present invention.
The auxiliary storage device 1003 is a computer-readable recording medium, and may include at least one of, for example, an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto optical disk (e.g., compact disc, digital versatile disc, Blu-ray (registered trademark) disk), a smart card, a flash memory (e.g., card, stick, key drive, a floppy (registered trademark) disk, a magnetic strip, etc. The above recording medium may be a database including the storage device 1002 and/or the auxiliary storage device 1003, a server, or any other appropriate medium.
The communication device 1004 is hardware (transmission and reception device) for communicating with computers via at least one of a wired network and a wireless network, and may be referred to as a network device, a network controller, a network card, a communication module, etc. The communication device 1004 may comprise a high frequency switch, duplexer, filter, frequency synthesizer, or the like, for example, to implement at least one of a frequency division duplex (FDD) and a time division duplex (TDD). For example, the transmitting/receiving antenna, the amplifier unit, the transmitting/receiving unit, the transmission line interface, and the like, may be implemented by the communication device 1004. The transmitting/receiving unit may be physically or logically divided into a transmitting unit and a receiving unit.
The input device 1005 is an input device that receives an external input (e.g., keyboard, mouse, microphone, switch, button, sensor). The output device 1006 is an output device that outputs something to the outside (e.g., display, speaker, LED lamp). It should be noted that the input device 1005 and the output device 1006 may be integrated into a single device (e.g., touch panel).
Further, the apparatuses including the processor 1001, the storage device 1002, etc., are connected to each other via the bus 1007 used for communicating information. The bus 1007 may include a single bus, or may include different buses between the apparatuses.
Further, each of the base station 10 and terminal 20 may include hardware such as a microprocessor, a digital signal processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), a FPGA (Field Programmable Gate Array), etc., and a part or all of each functional block may be realized by the hardware. For example, the processor 1001 may be implemented by at least one of the above hardware elements.
As described above, according to an embodiment of the present invention, a terminal is provided. The terminal includes: a reception unit configured to receive, from a base station, information for scheduling a first resource used for transmission to another terminal in a resource pool; and a transmission unit configured to transmit a signal for reserving the first resource to the another terminal. The reception unit receives information related to resource selection from the another terminal, and the transmission unit does not perform transmission using the first resource in a case where the information related to resource selection indicates that the first resource collides with another signal, indicates that the first resource is not included in a preferred resource set, or indicates that the first resource is included in a non-preferred resource set, and where a position of the first resource in a time domain is a future position.
According to the above configuration, the terminal 20 can determine an appropriate sidelink transmission operation in a case where the inter-terminal coordination information is received. In other words, an operation can be determined in a case where a resource used for transmission overlaps with transmission of another terminal in the direct communication between terminals.
The transmission unit may transmit a negative response to the base station in a case where the information related to resource selection indicates that the first resource collides with another signal, indicates that the first resource is not included in a preferred resource set, or indicates that the first resource is included in a non-preferred resource set, and where a position of the first resource in a time domain is a future position. According to the above configuration, the terminal 20 can determine an appropriate sidelink transmission operation in a case where the inter-terminal coordination information is received.
The transmission unit may perform retransmission to the another terminal in a case where the information related to resource selection indicates that the first resource collides with another signal, where a position of the first resource in a time domain is a past position, and where there is a resource to be transmitted to the another terminal. According to the above configuration, the terminal 20 can determine an appropriate sidelink transmission operation in a case where the inter-terminal coordination information is received.
The transmission unit may transmit, to the another terminal, information indicating that scheduling is performed by the base station in the resource pool by including the information in a control signal. According to the configuration, the terminal 20 can determine an appropriate destination of transmission of the inter-terminal coordination information.
The resource pool may be configured to be available for a terminal that is scheduled by the base station in the resource pool, or available for a terminal that autonomously selects a resource in the resource pool. According to the configuration, the terminal 20 can determine an appropriate destination of transmission of the inter-terminal coordination information.
In addition, according to an embodiment of the present invention, a communication method performed by a terminal is provided. The communication method includes: receiving, from a base station, information for scheduling a first resource used for transmission to another terminal in a resource pool; transmitting a signal for reserving the first resource to the another terminal; receiving information related to resource selection from the another terminal; and not performing transmission using the first resource in a case where the information related to resource selection indicates that the first resource collides with another signal, indicates that the first resource is not included in a preferred resource set, or indicates that the first resource is included in a non preferred resource set, and where a position of the first resource in a time domain is a future position.
According to the above configuration, the terminal 20 can determine an appropriate sidelink transmission operation in a case where the inter-terminal coordination information is received. In other words, an operation can be determined in a case where a resource used for transmission overlaps with transmission of another terminal in the direct communication between terminals.
As described above, one or more embodiments have been described. The present invention is not limited to the above embodiments. A person skilled in the art should understand that there are various modifications, variations, alternatives, replacements, etc., of the embodiments. In order to facilitate understanding of the present invention, specific values have been used in the description. However, unless otherwise specified, those values are merely examples and other appropriate values may be used. The division of the described items may not be essential to the present invention. The things that have been described in two or more items may be used in a combination if necessary, and the thing that has been described in one item may be appropriately applied to another item (as long as there is no contradiction). Boundaries of functional units or processing units in the functional block diagrams do not necessarily correspond to the boundaries of physical parts. Operations of multiple functional units may be physically performed by a single part, or an operation of a single functional unit may be physically performed by multiple parts. The order of sequences and flowcharts described in an embodiment of the present invention may be changed as long as there is no contradiction. For the sake of description convenience, the base station 10 and the terminal 20 have been described by using functional block diagrams. However, the apparatuses may be realized by hardware, software, or a combination of hardware and software. The software executed by a processor included in the base station 10 according to an embodiment of the present invention and the software executed by a processor included in the terminal 20 according to an embodiment of the present invention may be stored in a random access memory (RAM), a flash memory, a read only memory (ROM), an EPROM, an EEPROM, a register, a hard disk (HDD), a removable disk, a CD-ROM, a database, a server, or any other appropriate recording medium.
Further information indication may be performed not only by methods described in an aspect/embodiment of the present specification but also a method other than those described in an aspect/embodiment of the present specification. For example, the information indication may be performed by physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), upper layer signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, broadcast information (MIB (Master Information Block), SIB (System Information Block))), other signals, or combinations thereof. Further, RRC signaling may be referred to as an RRC message. The RRC signaling may be, for example, an RRC connection setup message, an RRC connection reconfiguration message, or the like.
Each aspect/embodiment described in the present disclosure may be applied to at least one of a system using LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), NR (new Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-WideBand), 50 Bluetooth (registered trademark), and other appropriate systems, and a next generation system enhanced therefrom. Further, multiple systems may also be applied in combination (e.g., at least one of LTE and LTE-A combined with 5G, etc.).
The order of processing steps, sequences, flowcharts or the like of an aspect/embodiment described in the present specification may be changed as long as there is no contradiction. For example, in a method described in the present specification, elements of various steps are presented in an exemplary order. The order is not limited to the presented specific order.
The particular operations, that are supposed to be performed by the base station 10 in the present specification, may be performed by an upper node in some cases. In a network including one or more network nodes including the base station 10, it is apparent that various operations performed for communicating with the terminal 20 may be performed by the base station 10 and/or another network node other than the base station 10 (for example, but not limited to, MME or S-GW). According to the above, a case is described in which there is a single network node other than the base station 10. However, a combination of multiple other network nodes may be considered (e.g., MME and S-GW).
The information or signals described in this disclosure may be output from a higher layer (or lower layer) to a lower layer (or higher layer). The information or signals may be input or output through multiple network nodes.
The input or output information may be stored in a specific location (e.g., memory) or managed using management tables. The input or output information may be overwritten, updated, or added. The information that has been output may be deleted. The information that has been input may be transmitted to another apparatus.
A decision or a determination in an embodiment of the present invention may be realized by a value (0 or 1) represented by one bit, by a boolean value (true or false), or by comparison of numerical values (e.g., comparison with a predetermined value).
Software should be broadly interpreted to mean, whether referred to as software. firmware, middle-ware, microcode, hardware description language, or any other name, instructions, instruction sets, codes, code segments, program codes, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, executable threads, procedures, functions, and the like.
Further, software, instructions, information, and the like may be transmitted and received via a transmission medium, For example, in the case where software is transmitted from a website, server, or other remote source using at least one of wired line technologies (such as coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) and wireless technologies (infrared, microwave, etc.), at least one of these wired line technologies and wireless technologies is included within the definition of the transmission medium.
Information, a signal, or the like, described in the present specification may be represented by using any one of various different technologies. For example, data, an instruction, a command, information, a signal, a bit, a symbol, a chip, or the like, described throughout the present application, may be represented by a voltage, an electric current, electromagnetic waves, magnetic fields, a magnetic particle, optical fields, a photon, or a combination thereof.
It should be noted that a term used in the present specification and/or a term required for understanding of the present specification may be replaced by a term having the same or similar meaning. For example, a channel and/or a symbol may be a signal (signaling). Further, a signal may be a message. Further, the component carrier (CC) may be referred to as a carrier frequency, cell, frequency carrier, or the like.
As used in the present disclosure, the terms “system” and “network” are used interchangeably.
Further, the information, parameters, and the like, described in the present disclosure may be expressed using absolute values, relative values from predetermined values, or they may be expressed using corresponding different information. For example, a radio resource may be what is indicated by an index.
The names used for the parameters described above are not used as limitations. Further, the mathematical equations using these parameters may differ from those explicitly disclosed in the present disclosure. Because the various channels (e.g., PUCCH, PDCCH) and information elements may be identified by any suitable names, the various names assigned to these various channels and information elements are not used as limitations.
In the present disclosure, the terms “BS: Base Station”, “Radio Base Station”, “Base Station”, “Fixed Station”, “NodeB”, “eNodeB (eNB)”, “gNodeB (gNB)”, “Access Point”, “Transmission Point”, “Reception Point”, “Transmission/Reception Point”, “Cell”, “Sector”, “Cell Group”, “Carrier”, “Component Carrier”, and the like, may be used interchangeably. The base station may be referred to as a macro-cell, a small cell, a femtocell, a picocell and the like.
The base station may accommodate (provide) one or more (e.g., three) cells. In the case where the base station accommodates a plurality of cells, the entire coverage area of the base station may be divided into a plurality of smaller areas, each smaller area may provide communication services by means of a base station subsystem (e.g., an indoor small base station or a remote Radio Head (RRH)). The term “cell” or “sector” refers to a part or all of the coverage area of at least one of the base station and base station subsystem that provides communication services at the coverage.
In the present disclosure, terms such as “mobile station (MS)”, “user terminal”, “user equipment (UE)”, “terminal”, and the like, may be used interchangeably.
There is a case in which the mobile station may be referred to, by a person skilled in the art, as a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other appropriate terms.
At least one of the base station and the mobile station may be referred to as a transmission apparatus, reception apparatus, communication apparatus, or the like. The at least one of the base station and the mobile station may be a device mounted on the mobile station, the mobile station itself, or the like. The mobile station may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile body (e.g., a drone, an automated vehicle, etc.), or a robot (manned or unmanned). At least one of the base station and the mobile station may include an apparatus that does not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.
Further, the base station in the present disclosure may be read as the user terminal. For example, each aspect/embodiment of the present disclosure may be applied to a configuration in which communications between the base station and the user terminal are replaced by communications between multiple terminals 20 (e.g., may be referred to as D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.). In this case, the function of the base station 10 described above may be provided by the terminal 20. Further, the phrases “up” and “down” may also be replaced by the phrases corresponding to terminal-to-terminal communication (e.g., “side”). For example, an uplink channel, a downlink channel, or the like, may be read as a sidelink channel.
Further, the user terminal in the present disclosure may be read as the base station. In this case, the function of the user terminal described above may be provided by the base station.
The term “determining” used in the present specification may include various actions or operations. The “determining” may include, for example, a case in which “judging”, “calculating”, “computing”, “processing”, “deriving”, “investigating”, “looking up, search, inquiry” (e.g., looking up a table, database, or other data structures), or “ascertaining” is deemed as “determining”. Further, the “determining” may include a case in which “receiving” (e.g., receiving information), “transmitting” (e.g., transmitting information), “inputting”, “outputting”, or “accessing” (e.g., accessing data in a memory) is deemed as “determining”. Further, the “determining” may include a case in which “resolving”, “selecting”, “choosing”, “establishing”, “comparing”, or the like is deemed as “determining”. In other words, the “determining” may include a case in which a certain action or operation is deemed as “determining”. Further, “decision” may be read as “assuming”, “expecting”, or “considering”, etc.
The term “connected” or “coupled” or any variation thereof means any direct or indirect connection or connection between two or more elements and may include the presence of one or more intermediate elements between the two elements “connected” or “coupled” with each other. The coupling or connection between the elements may be physical, logical, or a combination thereof. For example, “connection” may be read as “access”. As used in the present disclosure, the two elements may be thought of as being “connected” or “coupled” to each other using at least one of the one or more wires. cables, and printed electrical connections and, as a number of non-limiting and non-inclusive examples, electromagnetic energy having wavelengths in the radio frequency region, the microwave region, and the light (both visible and invisible) region.
The reference signal may be abbreviated as RS or may be referred to as a pilot, depending on the applied standards.
The description “based on” used in the present specification does not mean “based on only” unless otherwise specifically noted. In other words, the phrase “based on” means both “based on only” and “based on at least”.
Any reference to an element using terms such as “first” or “second” as used in the present disclosure does not generally limit the amount or the order of those elements. These terms may be used in the present disclosure as a convenient way to distinguish between two or more elements. Therefore, references to the first and second elements do not imply that only two elements may be employed or that the first element must in some way precede the second element.
“Means” included in the configuration of each of the above apparatuses may be replaced by “parts”, “circuits”, “devices”, etc.
In the case where the terms “include”, “including” and variations thereof are used in the present disclosure, these terms are intended to be comprehensive in the same way as the term “comprising”. Further, the term “or” used in the present specification is not intended to be an “exclusive or”.
A radio frame may include one or more frames in the time domain. Each of the one or more frames in the time domain may be referred to as a subframe. The subframe may further include one or more slots in the time domain. The subframe may be a fixed length of time (e.g., 1 ms) independent from the numerology.
The numerology may be a communication parameter that is applied to at least one of the transmission and reception of a signal or channel. The numerology may indicate at least one of, for example, SubCarrier Spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame configuration, specific filtering processing performed by the transceiver in the frequency domain, and specific windowing processing performed by the transceiver in the time domain.
The slot may include one or more symbols in the time domain, such as OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, and the like. The slot may be a time unit based on the numerology.
The slot may include a plurality of mini slots. Each mini slot may include one or more symbols in the time domain. Further, the mini slot may be referred to as a sub-slot. The mini slot may include fewer symbols than the slot. PDSCH (or PUSCH) transmitted in time units greater than a mini slot may be referred to as PDSCH (or PUSCH) mapping type A, PDSCH (or PUSCH) transmitted using a mini slot may be referred to as PDSCH (or PUSCH) mapping type B.
A radio frame, a subframe, a slot, a mini slot and a symbol all represent time units for transmitting signals. Different terms may be used for referring to a radio frame, a subframe, a slot, a mini slot and a symbol, respectively.
For example, one subframe may be referred to as a transmission time interval (TTI), multiple consecutive subframes may be referred to as a TTI, and one slot or one mini slot may be referred to as a TTI. In other words, at least one of the subframe and the TTI may be a subframe (1 ms) in an existing LTE, a period shorter than 1 ms (e.g., 1-13 symbols), or a period longer than 1 ms. It should be noted that the unit representing the TTI may be referred to as a slot, a mini slot, or the like, rather than a subframe.
The TTI refers to, for example, the minimum time unit for scheduling in wireless communications. For example, in an LTE system, a base station schedules each terminal 20 to allocate radio resources (such as frequency bandwidth, transmission power, etc. that can be used in each terminal 20) in TTI units. The definition of TTI is not limited to the above.
The TTI may be a transmission time unit, such as a channel-encoded data packet (transport block), code block, codeword, or the like, or may be a processing unit, such as scheduling or link adaptation. It should be noted that, when a TTI is provided, the time interval (e.g., the number of symbols) during which the transport block, code block, codeword, or the like, is actually mapped may be shorter than the TTI.
It should be noted that, when one slot or one mini slot is referred to as a TTI, one or more TTIs (i.e., one or more slots or one or more mini slots) may be the minimum time unit for scheduling. Further, the number of slots (the number of mini slots) constituting the minimum time unit of the scheduling may be controlled.
A TTI having a time length of 1 ms may be referred to as a normal TTI (a TTI in LTE Rel. 8-12), a long TTI, a normal subframe, a long subframe, a slot, and the like. A TTI that is shorter than the normal TTI may be referred to as a shortened TTI, a short TTI, a partial TTI (or fractional TTI), a shortened subframe, a short subframe, a mini slot, a subslot, a slot, or the like.
It should be noted that the long TTI (e.g., normal TTI, subframe, etc.) may be replaced with a TTI having a time length exceeding 1 ms, and the short TTI (e.g., shortened TTI, etc.,) may be replaced with a TTI having a TTI length less than the TTI length of the long TTI and a TTI length greater than 1 ms.
A resource block (RB) is a time domain and frequency domain resource allocation unit and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same, regardless of the numerology, and may be 12, for example. The number of subcarriers included in an RB may be determined on the basis of numerology.
Further, the time domain of an RB may include one or more symbols, which may be 1 slot, 1 mini slot, 1 subframe, or 1 TTI in length. One TTI, one subframe, etc., may each include one or more resource blocks.
It should be noted that one or more RBs may be referred to as physical resource blocks (PRBs, Physical RBs), sub-carrier groups (SCGs), resource element groups (REGs), PRB pairs, RB pairs, and the like.
Further, a resource block may include one or more resource elements (RE). For example 1 RE may be a radio resource area of one sub-carrier and one symbol.
The bandwidth part (BWP) (which may also be referred to as a partial bandwidth, etc.) may represent a subset of consecutive common RBs (common resource blocks) for a given numerology in a carrier. Here, a common RB may be identified by an index of RB relative to the common reference point of the carrier. A PRB may be defined in a BWP and may be numbered within the BWP.
BWP may include BWP for UL (UL BWP) and BWP for DL (DL BWP). For a terminal 20, one or more BWPs may be configured in one carrier.
At least one of the configured BWPs may be activated, and the terminal 20 may assume that the terminal 20 will not transmit and receive signals/channels outside the activated BWP. It should be noted that the terms “cell” and “carrier” in this disclosure may be replaced by “BWP.”
Structures of a radio frame, a subframe, a slot, a mini slot, and a symbol described above are exemplary only. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of mini slots included in a slot, the number of symbols and RBs included in a slot or mini slot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, and the like, may be changed in various ways.
In the present disclosure, where an article is added by translation, for example “a”, “an”, and “the”, the disclosure may include that the noun following these articles is plural.
In this disclosure, the term “A and B are different” may mean “A and B are different from each other.” It should be noted that the term “A and B are different” may mean “A and B are different from C.” Terms such as “separated” or “combined” may be interpreted in the same way as the above-described “different”.
Each aspect/embodiment described in the present specification may be used independently, may be used in combination, or may be used by switching according to operations, Further, notification (transmission/reporting) of predetermined information (e.g., notification (transmission/reporting) of “X”) is not limited to an explicit notification (transmission/reporting), and may be performed by an implicit notification (transmission/reporting) (e.g., by not performing notification (transmission/reporting) of the predetermined information).
Note that, in the present disclosure, the inter-terminal coordination information is an example of information related to resource selection,
As described above, the present invention has been described in detail. It is apparent to a person skilled in the art that the present invention is not limited to one or more embodiments of the present invention described in the present specification. Modifications, alternatives, replacements, etc., of the present invention may be possible without departing from the subject matter and the scope of the present invention defined by the descriptions of claims. Therefore, the descriptions of the present specification are for illustrative purposes only, and are not intended to be limitations to the present invention.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2021/024256 | 6/25/2021 | WO |
