Terminal

Abstract

This terminal comprises a reception unit that receives a reference signal in a cell formed by a base station, and a control unit that assumes that the reference signal is set for each group in the cell. The control unit assumes that the groups are set on the basis of information pertaining to an antenna port that receives the reference signal.

Description

Terminal

[0001] The present disclosure relates to a terminal that receives a reference signal.

[0002] The 3rd Generation Partnership Project (3GPP) is developing specifications for the 5th generation mobile communication system (5G, also known as New Radio (NR) or Next Generation (NG)), and is also developing specifications for the next generation of mobile communication systems, known as Beyond 5G, 5G Evolution, or 6G.

[0003] The upcoming 6G wireless communication system is expected to realize ultra-high speed, large capacity communication, and ultra-multiple connections that exceed those of 5G (Non-Patent Document 1). In order to achieve the minimum quality guarantee required for such requirements, it is necessary to secure even more resources.

[0004] NTT Docomo, "Docomo 6G White Paper 5.0 Edition," [online], November 2022, [Retrieved September 28, 2023], Internet <URL: https: / / www.docomo.ne.jp / binary / pdf / corporate / technology / whitepaper_6g / DOCOMO_6G_White_PaperJP_20221116.pdf>

[0005] In 5G, the reference signals (RS) that a terminal (User Equipment, UE) receives from a base station (gNodeB, gNB) for channel demodulation or channel state information (CSI) estimation are specified as UE-specific RSs to enable flexible RS mapping and higher layer transmission using Multiple Input Multiple Output (MIMO).

[0006] Here, in order to make resources for RSs (hereinafter also referred to as RS resources) common resources between UEs, it is conceivable to define the RSs as cell-specific RSs. This makes the RS resources common between UEs, and therefore it is conceivable to secure resources to be used for other channels.

[0007] However, if an RS is defined as a cell-specific RS, the RS will be transmitted to all UEs in the cell. In this case, the RS resource is configured for a UE with a large number of antenna ports (hereinafter also referred to as the number of layers or the number of streams), so that a UE with a small number of antenna ports will have wasted RS resources that cannot be used. For example, if an RS resource is configured for a UE with four antenna ports, the RS resource for two antenna ports will be wasted for a UE with two antenna ports.

[0008] Such problems are thought to arise not only from differences in the number of antenna ports but also from differences in information related to antenna ports (for example, which antenna port to use, whether MIMO is supported, etc.) between UEs within a cell.

[0009] Therefore, the present disclosure has been made in consideration of such circumstances, and aims to provide a terminal that can reduce waste of RS resources even in a cell where terminals with different information related to antenna ports coexist.

[0010] One aspect of the disclosure is a terminal that includes a receiver (radio signal transmitter / receiver 210) that receives a reference signal in a cell formed by a base station, and a controller (controller 270) that assumes that the reference signal is set for each group within the cell, and the controller assumes that the group is set based on information related to the antenna port that receives the reference signal.

[0011] FIG. 1 is a diagram showing an overall schematic configuration of a wireless communication system. FIG. 2 is a diagram showing frequency ranges used in the wireless communication system. FIG. 3 is a diagram showing example configurations of radio frames, subframes, slots, and symbols used in the wireless communication system. FIG. 4 is a functional block diagram of a terminal. FIG. 5 is a functional block diagram of a base station. FIG. 6 is a diagram showing an example of settings for each group in a cell. FIG. 7 is a diagram showing an example of settings for each cell. FIG. 8 is a diagram showing an example of the relationship between the number of antenna ports of a terminal, the number of ports receiving group specific RSs, and the number of ports receiving UE specific RSs. FIG. 9 is a diagram showing an example of the hardware configuration of a base station and a terminal. FIG. 10 is a diagram showing an example configuration of a vehicle.

[0012] Hereinafter, embodiments will be described with reference to the drawings. Note that the same or similar reference numerals are used to designate the same functions or configurations, and descriptions thereof will be omitted as appropriate.

[0013] (1) Configuration of Wireless Communication System (1.1) General Configuration The wireless communication system 10 shown in Fig. 1 is a wireless communication system conforming to a method called 5G. Alternatively, the wireless communication system 10 may be a wireless communication system conforming to a method called Beyond 5G, 5G Evolution, or 6G.

[0014] The wireless communication system 10 can support Massive Multiple-Input Multiple-Output (Massive MIMO), which generates more directional beams by controlling wireless signals transmitted from multiple antenna elements, Carrier Aggregation (CA), which uses multiple component carriers (CCs) as a bundle, and Dual Connectivity (DC), which enables simultaneous communication with two base stations.

[0015] As shown in FIG. 1 , the wireless communication system 10 includes a Next Generation-Radio Access Network (NG-RAN) 20, a base station (next generation NodeB, gNB) 100 connected to the NG-RAN 20, and a terminal (user equipment, UE) 200 that performs wireless communication with the gNB 100. The NG-RAN 20 is connected to a core network (CN) (not shown). The NG-RAN 20 and the CN may be simply referred to as a "network." The gNB 100 may also be considered to be included in the network. Note that the specific configuration of the wireless communication system 10, for example, the number of gNBs 100 and UEs 200, is not limited to the example shown in FIG. 1 .

[0016] The wireless communication system 10 may also support multiple frequency ranges (FR). That is, as shown in Fig. 2, the wireless communication system 10 may support the following FRs: FR1: 410 MHz to 7.125 GHz FR2-1: 24.25 GHz to 52.6 GHz FR2-2: Over 52.6 GHz to 71 GHz

[0017] In FR1, a subcarrier spacing (SCS) of 15, 30, or 60 kHz and a bandwidth (BW) of 5 to 100 MHz may be used, while in FR2-1, an SCS of 60 or 120 kHz (including 240 kHz) and a BW of 50 to 400 MHz may be used.

[0018] In FR2-2, to avoid an increase in phase noise, Cyclic Prefix-Orthogonal Frequency Division Multiplexing (CP-OFDM) or Discrete Fourier Transform-Spread-Orthogonal Frequency Division Multiplexing (DFT-S-OFDM) with a larger SCS may be applied.

[0019] 3, one slot in the wireless communication system 10 is composed of 14 symbols. If this configuration is maintained, the larger (wider) the SCS, the shorter the symbol period (and slot period). Note that the SCS is not limited to the frequencies shown in FIG. 3 and may be, for example, 480 kHz, 960 kHz, or other frequencies.

[0020] Furthermore, the number of symbols constituting one slot does not necessarily have to be 14, but may be, for example, 28 or 56. Furthermore, the number of slots per subframe may differ depending on the SCS.

[0021] (2) Functional Block Configuration of Wireless Communication System (2.1) Functional Block Configuration of Terminal As shown in FIG. 4, the UE 200 includes a wireless signal transmitting / receiving unit 210, an amplifier unit 220, a modulation / demodulation unit 230, a control signal / reference signal processing unit 240, an encoding / decoding unit 250, a data transmitting / receiving unit 260, and a control unit 270.

[0022] The radio signal transmitting / receiving unit 210 transmits and receives radio signals to and from the gNB 100. The radio signal transmitting / receiving unit 210 may be configured as a transmitting unit that transmits radio signals to the gNB 100 and a receiving unit that receives radio signals from the gNB 100.

[0023] The radio signal transceiver 210 of the embodiment receives a reference signal (RS) from the gNB 100 in a cell formed by the gNB 100. The RS may include, for example, a demodulation reference signal (DMRS) used for channel demodulation and a CSI-RS used for channel state information (CSI) estimation. The channel may be a control channel or a data channel. The reference signal and channel are not limited to these and may be those described below.

[0024] The radio signal transmitting / receiving unit 210 of the embodiment can receive multiple RSs. For example, it can receive an RS at each of the Xth and Yth symbols among multiple consecutive symbols. Furthermore, if the RS is a DMRS, it can receive a front-loaded RS and an additional RS. The front-loaded RS is an RS that is placed in the first symbol of a data channel, and the additional RS is an RS that is additionally placed in a symbol following the front-loaded RS.

[0025] The amplifier unit 220 is configured by a power amplifier (PA) / low noise amplifier (LNA), etc. The amplifier unit 220 amplifies the radio signal output from the radio signal transmitting / receiving unit 210. The amplifier unit 220 also amplifies the radio signal output from the modulation / demodulation unit 230.

[0026] The modem unit 230 performs data modulation / demodulation, transmission power setting, resource block allocation, etc. for each predetermined communication destination (gNB 100 or another gNB). CP-OFDM / DFT-S-OFDM may be applied in the modem unit 230. Furthermore, DFT-S-OFDM may be used not only for the uplink (UL) but also for the downlink (DL).

[0027] The control signal / reference signal processing unit 240 performs processing related to control signals transmitted and received between the gNB 100, such as radio resource control (RRC) signaling.

[0028] The control signal / reference signal processing unit 240 performs processing related to reference signals transmitted and received between the gNB 100, such as Demodulation Reference Signal (DMRS), Phase Tracking Reference Signal (PTRS), Channel State Information-Reference Signal (CSI-RS), Sounding Reference Signal (SRS), and Positioning Reference Signal (PRS).

[0029] The channels include control channels and data channels. The control channels include a physical uplink control channel (PUCCH), a physical downlink control channel (PDCCH), a physical random access channel (PRACH), a physical broadcast channel (PBCH), etc. The data channels include a physical uplink shared channel (PUSCH), a physical downlink shared channel (PDSCH), etc.

[0030] The encoding / decoding unit 250 performs division / concatenation and coding / decoding of data contained in the radio signal for each predetermined communication destination (gNB100 or another gNB).

[0031] Specifically, the encoding / decoding unit 250 decodes the data output from the modem unit 230 and concatenates the decoded data. In addition, the encoding / decoding unit 250 divides the data output from the data transmitter / receiver 260 into pieces of a predetermined size and performs coding on the divided data.

[0032] The data transmitter / receiver 260 assembles and disassembles data units (Protocol Data Units (PDUs) / Service Data Units (SDUs)) that make up data between each layer. The multiple layers include a Medium Access Control (MAC) layer, a Radio Link Control (RLC) layer, and a Packet Data Convergence Protocol (PDCP) layer. The data transmitter / receiver 260 also performs data error correction and retransmission control based on Hybrid Automatic Repeat Request (HARQ).

[0033] The control unit 270 controls the UE 200. The control unit 270 controls, for example, transmission and reception of radio signals by the radio signal transmission and reception unit 210, amplification by the amplifier unit 220, data modulation / demodulation by the modem unit 230, signal processing by the control signal and reference signal processing unit 240, coding / decoding by the encoding / decoding unit 250, and assembly / disassembly of data units by the data transmission and reception unit 260.

[0034] The control unit 270 of the embodiment assumes that an RS is configured for each group configured in a cell formed by the gNB 100. Such an RS may be called a group-specific RS (see FIG. 6). Note that an RS configured for each cell formed by the gNB 100 may be called a cell-specific RS (see FIGS. 6 and 7), and an RS configured for each UE may be called a UE-specific RS.

[0035] It is assumed that the control unit 270 of the embodiment sets the above-mentioned groups based on information related to antenna ports that receive the RS. The information related to antenna ports that receive the RS may be the number of antenna ports that receive the RS. Furthermore, the information related to antenna ports that receive the RS may be information on which antenna port to use to receive the RS (e.g., transmitted precoding matrix indicator (TPMI)), or information on whether MIMO realized using multiple antenna ports is supported (e.g., whether parameters are set for MIMO).

[0036] In the embodiment, the control unit 270 may assume that the precoder applied to communication with the gNB100 is common (the same) among the UE200 in the above-mentioned group, or may assume that the precoder is different among the UE200 in the above-mentioned group.

[0037] In the embodiment, the control unit 270 may assume that, when the radio signal transmitting and receiving unit 210 receives multiple RSs, some of the multiple RSs are configured for each of the above-mentioned groups, and the remaining multiple RSs are configured for each of the UEs 200. For example, when the radio signal transmitting and receiving unit 210 receives three DMRSs (e.g., a front-loaded RS and two additional RSs), it may assume that the front-loaded RS is configured for each of the above-mentioned groups, and the two additional RSs are configured for each of the UEs 200.

[0038] The control unit 270 of the embodiment may be assumed to determine the number of antenna ports for receiving the RS set for each UE 200 based on the number of antenna ports for receiving the RS set for each group described above and the total number of antenna ports (see Figure 8).

[0039] (2.2) Functional block configuration of base station As shown in Figure 5, the gNB100 includes a radio signal transceiver unit 110 and a control unit 120.

[0040] The radio signal transmitting / receiving unit 110 transmits and receives radio signals to and from the UE 200. The radio signal transmitting / receiving unit 110 may include a transmitting unit that transmits radio signals to the UE 200 and a receiving unit that receives radio signals from the UE 200.

[0041] The radio signal transceiver 110 of the embodiment transmits the above-mentioned reference signal to the UE 200 in the cell formed by the gNB 100.

[0042] The control unit 120 controls the gNB 100. The control unit 120 controls, for example, the transmission and reception of radio signals by the radio signal transmission and reception unit 110. The control unit 120 also performs scheduling for the UE 200.

[0043] In the embodiment, the control unit 120 sets the above-mentioned multiple groups in the cell formed by the gNB 100.

[0044] (3) Operation of Wireless Communication System (3.1) Issues When an RS is defined as a cell-specific RS, this RS is transmitted to all UEs in a cell. In this case, RS resources are configured for UEs with a large number of antenna ports (hereinafter also referred to as the number of layers or the number of streams). Therefore, for UEs with a small number of antenna ports, RS resources are wasted and cannot be used. For example, if RS resources are configured for a UE with four antenna ports, the RS resources for two antenna ports are wasted for a UE with two antenna ports.

[0045] Such problems are thought to arise not only from differences in the number of antenna ports but also from differences in information related to antenna ports (for example, which antenna port to use, whether MIMO is supported, etc.) between UEs within a cell.

[0046] (3.2) Operational Examples (3.2.1) Operational Example 1 UE 200 may assume that a DMRS used to demodulate a data channel is configured for each group. Note that the channel and RS are merely examples, and other channels and RSs may be used. Furthermore, "for each group" may be read as "on a group basis" or "group specific," and "RS configured for each group" may be read as "group specific RS."

[0047] As shown in Fig. 6, the gNB 100 may configure a group ID in addition to a cell ID for the UE 200 in the cell formed by the gNB 100. It is assumed that the group ID is configured, and thereby an RS is configured for each group in the cell to which the UE 200 belongs. Note that in this specification, "an RS is configured" may be interpreted as "an RS resource is configured," and the "resource" may be interpreted as not being limited to a frequency direction but including a time direction, a space direction, etc.

[0048] The group ID may be set based on the number of antenna ports (number of layers) through which the UE 200 receives RSs. For example, the group ID may be set based on the number of antenna ports through which DMRSs used for demodulating a data channel are received. Fig. 6 shows an example in which a UE 200 with one antenna port and a UE 200 with two antenna ports are assigned (grouped) different group IDs.

[0049] This allows RS configuration according to the number of antenna ports of UE 200, and therefore reduces the need for RS resource configuration that would be wasted for a user with a small number of antenna ports.

[0050] If a group ID is not configured, the UE 200 may assume that a DMRS used for demodulating a data channel is not configured. In this case, the UE 200 may assume that not only a group-specific DMRS but also a UE-specific DMRS is not configured.

[0051] (3.2.2) Operation Example 2 UE 200 may assume that a DMRS used to demodulate a data channel is configured for each cell. Note that the channel and RS are merely examples, and other channels and RSs may be used. Furthermore, "for each cell" may be read as "on a cell-by-cell basis" or "cell specific," and "RS configured for each cell" may be read as "cell-specific RS."

[0052] As shown in Fig. 7, the gNB 100 may (re)configure a cell ID for the UE 200 in the cell formed by the gNB 100. It is assumed that the UE 200 is configured with an RS for each cell to which the UE 200 belongs by configuring a cell ID.

[0053] The cell ID may be set based on the number of antenna ports (number of layers) through which the UE 200 receives RSs. For example, the cell ID may be set based on the number of antenna ports through which DMRSs used for demodulating a data channel are received. Fig. 7 shows an example in which different cell IDs are assigned to a UE 200 with one antenna port and a UE 200 with two antenna ports.

[0054] The allocation of cell IDs according to the number of antenna ports may be more generalized, so that cell ID #a is assigned to UE 200 with X antenna ports for receiving RS, cell ID #b is assigned to UE 200 with X+1 antenna ports for receiving RS, and so on. Also, cell ID #a may be assigned to UE 200 with X to Y (e.g., X=1, Y=4) antenna ports for receiving RS. X and Y may be uniquely determined by specifications, or may be set / updated / instructed by RRC / MAC CE / DCI from the network.

[0055] This allows RS configuration according to the number of antenna ports of UE 200, and therefore reduces the need for RS resource configuration that would be wasted for a user with a small number of antenna ports.

[0056] (3.2.3) Operation Example 3 UE 200 may assume that the DMRS used for demodulating the data channel is configured by combining the group specific RS of Operation Example 1 and an RS configured for each terminal (UE specific RS). Also, UE 200 may assume that the DMRS used for demodulating the data channel is configured by combining the cell specific RS of Operation Example 2 and a UE specific RS.

[0057] For example, a group-specific RS and a UE-specific RS may be configured in a specific symbol / slot / subframe. Alternatively, they may be uniquely defined by a specification. Example 1: A front-loaded RS may be configured as a group-specific RS, and an additional RS may be configured as a UE-specific RS. In this case, Example 2: An RS in the Xth symbol may be configured as a group-specific RS, and an RS in the Yth symbol may be configured as a UE-specific RS.

[0058] Furthermore, the following options may be considered: Opt. 1: The group-specific RS is always transmitted from one antenna port (one layer transmission). In this case, no RS resources are wasted for a UE 200 with one antenna port. Opt. 2: The number of transmit antenna ports for the group-specific RS is configured by the network (gNB 100). In this case, the RS can be flexibly configured according to the number of antenna ports of the UE 200.

[0059] (3.2.4) Operation Example 4 UE 200 may determine the number of antenna ports for receiving UE-specific RSs based on the number of antenna ports for receiving group-specific RSs and the number of receiving antenna ports, i.e., the total number of antenna ports. For example, the number may be uniquely determined based on a table such as that shown in Fig. 8. The table shown in Fig. 8 may be replaced with the following formula:

[0060] Number of antenna ports receiving UE specific RS = Number of receiving antenna ports - Number of antenna ports receiving group specific RS

[0061] The table and formula shown in FIG. 8 are merely an example, and for example, the following formula may be applied to determine the number of antenna ports for receiving the UE-specific RS.

[0062] Number of antenna ports receiving UE specific RSs = (number of receiving antenna ports - 1) - number of antenna ports receiving group specific RSs

[0063] (3.2.5) Precoder Regarding the precoder within the group in the above-described operation example, the UE 200 may assume that the precoder is common (the same) among the UEs 200 within the group. For example, the UE 200 may assume that a common RS within the group (e.g., a DMRS used to demodulate a data channel) and a downlink channel (e.g., a PDSCH / PDCCH) are in a quasi-co-location (QCL) relationship (the same precoder is applied to both). Note that "being in a QCL relationship" may be interpreted as "having the same Transmission Configuration Indicator (TCI) state" or "having the same spatial relationship."

[0064] This makes it possible to reduce resources for notifying each UE 200 of a precoder.

[0065] In this case, a different precoder may be instructed for each UE 200 by MAC CE / DCI.

[0066] On the other hand, the UE 200 may assume that the precoders within the group in the above-described operation example are different among the UEs 200 within the group. As a premise, the gNB 100 notifies the precoder for each UE 200. Also, it is assumed that a precoder different from the precoder notified for each UE 200 is applied to the common RS within the group.

[0067] For example, the UE 200 may assume that the UE specific RS is received after the precoder notified by the gNB 100 is applied to an antenna port that receives a common RS in the group (e.g., a DMRS used for demodulating a data channel). As a result, the UE 200 may assume that the UE specific RS and the downlink channel (e.g., a PDSCH / PDCCH) are in a quasi-co-located (QCL) relationship.

[0068] Alternatively, UE200 may assume that the antenna port that receives a common RS within the group (e.g., a DMRS used to demodulate a data channel) is precoded by gNB100, and then receives a downlink channel (e.g., a PDSCH / PDCCH).

[0069] This makes it possible to reduce the number of bits of the precoder indication compared to the cell-specific RS of LTE.

[0070] Note that one precoder may be set for each group, or multiple precoders may be set. When multiple precoders are set, UE200 may select one of them and transmit the PMI related to the selected precoder to the network (gNB100). Also, when the network (gNB100) notifies UE200 of multiple groups, UE200 may select one of the groups (or the PMI associated with the group) and report the selected group to the network.

[0071] Note that whether UE 200 assumes that the precoders in a group are the same or different may be switched by RRC.

[0072] (4) Actions and Effects According to the above-described embodiment, in a wireless communication system, by configuring a common RS within a cell, it is possible not only to maximize channel resources but also to reduce RS resources that are wasted for terminals with a small number of antenna ports when configuring the common RS, which can contribute to guaranteeing minimum quality such as throughput.

[0073] (5) Other Embodiments The contents of the present invention have been described above in accordance with the embodiments, but it will be obvious to those skilled in the art that the present invention is not limited to these descriptions and that various modifications and improvements are possible.

[0074] In the above disclosure, the RS has been described as a DMRS mainly used for demodulating a data channel, but is not limited to this. For example, the RS may be a CSI-RS or SRS used for CSI measurement. The RS may also be a CSI-RS or a synchronization signal / broadcast channel block (SSB) used for Radio Resource Management (RRM) measurement. Note that the SSB is used for measurement in NR, so it is assumed that it is replaced with the RS.

[0075] In the above disclosure, the "number of layers" may be read as the "number of ranks." Furthermore, "group specific" may be read as terms such as "semi-cell specific," "group-based," or "common." Furthermore, the "data channel" may be understood to include not only the above-mentioned "PDSCH" but also the "PUSCH."

[0076] The above-described operation examples may be combined and applied in a composite manner, as long as no contradiction occurs.

[0077] In the above disclosure, configure, activate, update, indicate, enable, specify, and select may be interchangeable. Similarly, link, associate, correspond, and map may be interchangeable, and allocate, assign, monitor, and map may be interchangeable.

[0078] Furthermore, specific, dedicated, UE-specific, and UE-dedicated may be interchangeable. Similarly, common, shared, group-common, UE-common, and UE-shared may be interchangeable.

[0079] The block diagrams (FIGS. 4 and 5) used to explain the above-described embodiments show functional blocks. These functional blocks (components) are realized by any combination of hardware and / or software. Furthermore, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are directly or indirectly connected (e.g., wired, wireless, etc.) and these multiple devices. The functional block may be realized by combining software with the single device or multiple devices.

[0080] Functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, election, establishment, comparison, assumption, expectation, regard, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission is called a transmitting unit or transmitter. As mentioned above, there are no particular limitations on how each is implemented.

[0081] Furthermore, the above-described gNB100 and UE200 (the devices) may function as a computer that performs processing of the wireless communication method of the present disclosure. Figure 9 is a diagram showing an example of the hardware configuration of the devices. As shown in Figure 9, the devices may be configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0082] In the following description, the term "apparatus" can be interpreted as a circuit, a device, a unit, etc. The hardware configuration of the apparatus may be configured to include one or more of the apparatuses shown in the drawings, or may be configured to exclude some of the apparatuses.

[0083] Each functional block of the device (FIGS. 4 and 5) is realized by any hardware element of the computer device or a combination of the hardware elements.

[0084] In addition, each function of the device is realized by loading specified software (programs) onto hardware such as processor 1001 and memory 1002, causing processor 1001 to perform calculations, control communication via communication device 1004, and control at least one of reading and writing data in memory 1002 and storage 1003.

[0085] The processor 1001 controls the entire computer by running, for example, an operating system, and may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control unit, an arithmetic unit, and registers.

[0086] The processor 1001 also reads programs (program codes), software modules, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002 and executes various processes in accordance with these. The programs used are those that cause a computer to execute at least some of the operations described in the above-described embodiments. Furthermore, the various processes described above may be executed by a single processor 1001, or may be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The programs may be transmitted from a network via a telecommunications line.

[0087] The memory 1002 is a computer-readable recording medium and may be configured by at least one of, for example, a read-only memory (ROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a random access memory (RAM), etc. The memory 1002 may also be called a register, a cache, a main memory (primary storage device), etc. The memory 1002 may store a program (program code), a software module, etc., capable of executing a method according to an embodiment of the present disclosure.

[0088] Storage 1003 is a computer-readable recording medium, and may be, for example, at least one of an optical disk such as a Compact Disc ROM (CD-ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disk, a digital versatile disk, a Blu-ray disc), a smart card, a flash memory (e.g., a card, a stick, a key drive), a floppy disk, a magnetic strip, etc. Storage 1003 may also be referred to as an auxiliary storage device. The above-mentioned recording medium may be, for example, a database, a server, or other suitable medium including at least one of memory 1002 and storage 1003.

[0089] The communication device 1004 is hardware (transmission / reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also called, for example, a network device, a network controller, a network card, or a communication module.

[0090] The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize, for example, at least one of Frequency Division Duplex (FDD) and Time Division Duplex (TDD).

[0091] The input device 1005 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives input from the outside. The output device 1006 is an output device (e.g., a display, a speaker, an LED lamp, etc.) that outputs to the outside. Note that the input device 1005 and the output device 1006 may be integrated into one device (e.g., a touch panel).

[0092] Furthermore, each device such as the processor 1001 and the memory 1002 is connected to a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses between each device.

[0093] Furthermore, the device may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized by the hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0094] Furthermore, the notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, the notification of information may be performed by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), higher layer signaling (e.g., RRC signaling, Medium Access Control (MAC) signaling), broadcast information (Master Information Block (MIB), System Information Block (SIB)), other signals, or a combination thereof. Furthermore, the RRC signaling may be referred to as an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, or the like.

[0095] Each aspect / embodiment described in the present disclosure may be applied to at least one of a system using Long Term Evolution (LTE), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, a 4th generation mobile communication system (4G), a 5th generation mobile communication system (5G), Future Radio Access (FRA), New Radio (NR), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), or other suitable system, and a next-generation system enhanced based on these. Furthermore, a combination of multiple systems (e.g., a combination of at least one of LTE and LTE-A and 5G) may also be applied.

[0096] The order of the procedures, sequences, flowcharts, etc. of each aspect / embodiment described in this disclosure may be changed unless it is consistent. For example, the methods described in this disclosure present elements of various steps using an example order, and are not limited to the particular order presented.

[0097] In the present disclosure, a specific operation described as being performed by a base station may be performed by its upper node in some cases. In a network consisting of one or more network nodes having a base station, it is clear that various operations performed for communication with a terminal may be performed by at least one of the base station and another network node other than the base station (for example, an MME or an S-GW, etc., but are not limited to these). Although the above example illustrates a case where there is one other network node other than the base station, a combination of multiple other network nodes (for example, an MME and an S-GW) may also be used.

[0098] Information, signals (information, etc.) may be output from a higher layer (or a lower layer) to a lower layer (or a higher layer), or may be input / output via multiple network nodes.

[0099] The input and output information may be stored in a specific location (for example, a memory) or may be managed using a management table. The input and output information may be overwritten, updated, or added. The output information may be deleted. The input information may be transmitted to another device.

[0100] The determination may be made based on a value represented by one bit (0 or 1), a Boolean value (true or false), or a numerical comparison (e.g., comparison with a predetermined value).

[0101] The aspects / embodiments described in this disclosure may be used alone, in combination, or switched depending on the implementation. Notification of predetermined information (e.g., notification that "X is true") is not limited to explicit notification, but may be implicit (e.g., not notifying the predetermined information).

[0102] Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0103] Software, instructions, information, etc. may also be transmitted or received over a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave), then these wired and / or wireless technologies are included within the definition of transmission media.

[0104] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0105] Note that terms described in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may be a signal (signaling). Furthermore, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, a cell, a frequency carrier, etc.

[0106] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0107] Furthermore, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, may be expressed using relative values ​​from a predetermined value, or may be expressed using other corresponding information. For example, a radio resource may be indicated by an index.

[0108] The names used for the above-described parameters are not intended to be limiting in any way. Furthermore, the mathematical expressions using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (e.g., PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not intended to be limiting in any way.

[0109] In this disclosure, terms such as "base station (BS)," "radio base station," "fixed station," "NodeB," "eNodeB (eNB)," "gNodeB (gNB)," "access point," "transmission point," "reception point," "transmission / reception point," "cell," "sector," "cell group," "carrier," and "component carrier" may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

[0110] A base station can accommodate one or more (e.g., three) cells (also called sectors). When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be divided into multiple smaller areas, and each smaller area can be provided with communication services by a base station subsystem (e.g., a small indoor base station (Remote Radio Head: RRH)).

[0111] The terms "cell" or "sector" refer to part or all of the coverage area of ​​a base station and / or base station subsystem that provides communication services within that coverage area.

[0112] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0113] A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable terminology.

[0114] At least one of the base station and the mobile station may be referred to as a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may be a device mounted on a mobile object, the mobile object itself, etc. The mobile object may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile object (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). At least one of the base station and the mobile station may also include devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an Internet of Things (IoT) device such as a sensor.

[0115] Furthermore, a base station in the present disclosure may be read as a mobile station (user terminal, the same applies hereinafter). For example, the aspects / embodiments of the present disclosure may be applied to a configuration in which communication between a base station and a mobile station is replaced with communication between multiple mobile stations (which may be called, for example, Device-to-Device (D2D) or Vehicle-to-Everything (V2X)). In this case, the mobile station may be configured to have the functions of a base station. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to terminal-to-terminal communication (for example, "side"). For example, terms such as an uplink channel and a downlink channel may be read as a side channel.

[0116] Similarly, a mobile station in the present disclosure may be interpreted as a base station, in which case the base station may have the functions of a mobile station.

[0117] A radio frame may be made up of one or more frames in the time domain, each of which may be called a subframe.

[0118] A subframe may further be composed of one or more slots in the time domain, and may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0119] Numerology may be communication parameters that apply to the transmission and / or reception of a signal or channel, such as subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame structure, specific filtering operations performed by the transceiver in the frequency domain, and specific windowing operations performed by the transceiver in the time domain.

[0120] A slot may consist of one or more symbols in the time domain (such as Orthogonal Frequency Division Multiplexing (OFDM) symbols, Single Carrier Frequency Division Multiple Access (SC-FDMA) symbols, etc.) A slot may be a time unit based on numerology.

[0121] A slot may include multiple minislots. Each minislot may consist of one or multiple symbols in the time domain. A minislot may also be called a subslot. A minislot may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (or PUSCH) mapping type B.

[0122] The radio frame, subframe, slot, minislot, and symbol all represent time units for transmitting signals, and may be referred to by other names corresponding to the radio frame, subframe, slot, minislot, and symbol.

[0123] For example, one subframe may be referred to as a transmission time interval (TTI), multiple consecutive subframes may be referred to as a TTI, or one slot or one minislot may be referred to as a TTI. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (e.g., 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be referred to as a slot, minislot, etc. instead of a subframe.

[0124] Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station schedules each user terminal to allocate radio resources (such as frequency bandwidth and transmission power that can be used by each user terminal) in TTI units. Note that the definition of TTI is not limited to this.

[0125] The TTI may be a transmission time unit for a channel-encoded data packet (transport block), a code block, a code word, etc., or may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) to which a transport block, a code block, a code word, etc. is actually mapped may be shorter than the TTI.

[0126] In addition, when one slot or one minislot is called a TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit for scheduling. Furthermore, the number of slots (minislots) constituting the minimum time unit for scheduling may be controlled.

[0127] A TTI having a time length of 1 ms may be called a regular TTI (TTI in LTE Rel. 8-12), normal TTI, long TTI, regular subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a regular TTI may be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, etc.

[0128] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and equal to or greater than 1 ms.

[0129] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, 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 numerology, for example, 12. The number of subcarriers included in an RB may be determined based on numerology.

[0130] The time domain of an RB may include one or more symbols and may have a length of one slot, one minislot, one subframe, or one TTI. One TTI, one subframe, etc. may each be composed of one or more resource blocks.

[0131] Note that one or more RBs may also be called a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

[0132] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0133] A Bandwidth Part (BWP) (which may also be referred to as a fractional bandwidth) may represent a subset of contiguous common resource blocks (RBs) for a given numerology on a given carrier, where the common RBs may be identified by their index relative to a common reference point of the carrier. PRBs may be defined in a given BWP and numbered within that BWP.

[0134] The BWP may include a BWP for UL (UL BWP) and a BWP for DL ​​(DL BWP). One or more BWPs may be configured for a UE within one carrier.

[0135] At least one of the configured BWPs may be active, and the UE may not expect to transmit or receive a given signal / channel outside the active BWP. Note that the terms "cell," "carrier," etc. in this disclosure may be read as "BWP."

[0136] The above-described structures of radio frames, subframes, slots, minislots, symbols, etc. are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc. may be variously changed.

[0137] The terms "connected," "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access." As used in this disclosure, two elements may be considered to be "connected" or "coupled" to each other using one or more wires, cables, and / or printed electrical connections, as well as electromagnetic energy having wavelengths in the radio frequency range, microwave range, and optical (both visible and invisible) range, as some non-limiting and non-exhaustive examples.

[0138] The reference signal may also be abbreviated as Reference Signal (RS) and may be called a pilot depending on the applicable standard.

[0139] As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

[0140] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0141] As used in this disclosure, any reference to an element using a designation such as "first," "second," etc. does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed therein or that the first element must precede the second element in some way.

[0142] When the terms "include," "including," and variations thereof are used in this disclosure, these terms are intended to be inclusive, similar to the term "comprising." Furthermore, when the term "or" is used in this disclosure, it is not intended to be an exclusive or.

[0143] In this disclosure, where articles are added by translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0144] As used in this disclosure, the terms "determining" and "determining" may encompass a wide variety of actions. "Determining" and "determining" may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiring (e.g., searching a table, database, or other data structure), ascertaining, and the like. "Determining" and "determining" may also include receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), and the like, all of which are considered to be "determining." "Determining" and "determining" may also include resolving, selecting, choosing, establishing, comparing, and the like, all of which are considered to be "determining." In other words, "judgment" and "decision" can include regarding some action as having been "judged" or "decided." Also, "judgment (decision)" can be interpreted as "assuming," "expecting," "considering," etc.

[0145] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "coupled" may also be interpreted in the same way as "different."

[0146] 10 shows an example of the configuration of a vehicle 2001. As shown in Fig. 10, the vehicle 2001 includes a drive unit 2002, a steering unit 2003, an accelerator pedal 2004, a brake pedal 2005, a shift lever 2006, left and right front wheels 2007, left and right rear wheels 2008, an axle 2009, an electronic control unit 2010, various sensors 2021 to 2029, an information service unit 2012, and a communication module 2013.

[0147] The drive unit 2002 is composed of, for example, an engine, a motor, or a hybrid of an engine and a motor.

[0148] The steering unit 2003 includes at least a steering wheel (also called a handle) and is configured to steer at least one of the front wheels and the rear wheels based on the operation of the steering wheel operated by the user.

[0149] The electronic control unit 2010 is composed of a microprocessor 2031, a memory (ROM, RAM) 2032, and a communication port (IO port) 2033. Signals are input to the electronic control unit 2010 from various sensors 2021 to 2027 provided in the vehicle. The electronic control unit 2010 may also be called an ECU (Electronic Control Unit).

[0150] The signals from the various sensors 2021 to 2028 include a current signal from a current sensor 2021 that senses the current of the motor, a rotation speed signal of the front and rear wheels obtained by a rotation speed sensor 2022, an air pressure signal of the front and rear wheels obtained by an air pressure sensor 2023, a vehicle speed signal obtained by a vehicle speed sensor 2024, an acceleration signal obtained by an acceleration sensor 2025, an accelerator pedal depression amount signal obtained by an accelerator pedal sensor 2029, a brake pedal depression amount signal obtained by a brake pedal sensor 2026, a shift lever operation signal obtained by a shift lever sensor 2027, and a detection signal for detecting obstacles, vehicles, pedestrians, etc. obtained by an object detection sensor 2028.

[0151] The information service unit 2012 is composed of various devices, such as a car navigation system, an audio system, speakers, a television, and a radio, for providing various types of information such as driving information, traffic information, and entertainment information, and one or more ECUs for controlling these devices. The information service unit 2012 uses information obtained from external devices via the communication module 2013, etc., to provide various types of multimedia information and multimedia services to the occupants of the vehicle 1.

[0152] The driving assistance system unit 2030 is composed of various devices that provide functions for preventing accidents and reducing the driver's driving burden, such as millimeter-wave radar, LiDAR (Light Detection and Ranging), cameras, positioning locators (e.g., GNSS, etc.), map information (e.g., high-definition (HD) maps, autonomous vehicle (AV) maps, etc.), gyro systems (e.g., IMU (Inertial Measurement Unit), INS (Inertial Navigation System), etc.), AI (Artificial Intelligence) chips, and AI processors, as well as one or more ECUs that control these devices. The driving assistance system unit 2030 also transmits and receives various information via the communication module 2013 to realize driving assistance functions or autonomous driving functions.

[0153] The communication module 2013 can communicate with the microprocessor 2031 and components of the vehicle 1 via the communication port. For example, the communication module 2013 transmits and receives data via the communication port 2033 to and from a driving unit 2002, a steering unit 2003, an accelerator pedal 2004, a brake pedal 2005, a shift lever 2006, left and right front wheels 2007, left and right rear wheels 2008, an axle 2009, a microprocessor 2031 and memory (ROM, RAM) 2032 in the electronic control unit 2010, and sensors 2021 to 2028, which are provided in the vehicle 2001.

[0154] The communication module 2013 is a communication device that can be controlled by the microprocessor 2031 of the electronic control unit 2010 and can communicate with an external device. For example, it transmits and receives various information to and from the external device via wireless communication. The communication module 2013 may be located either inside or outside the electronic control unit 2010. The external device may be, for example, a base station, a mobile station, or the like.

[0155] The communication module 2013 transmits, via wireless communication to an external device, a current signal from the current sensor that is input to the electronic control unit 2010. The communication module 2013 also transmits, via wireless communication to an external device, the rotation speed signals of the front and rear wheels acquired by a rotation speed sensor 2022, the air pressure signals of the front and rear wheels acquired by an air pressure sensor 2023, the vehicle speed signal acquired by a vehicle speed sensor 2024, the acceleration signal acquired by an acceleration sensor 2025, the accelerator pedal depression amount signal acquired by an accelerator pedal sensor 2029, the brake pedal depression amount signal acquired by a brake pedal sensor 2026, the shift lever operation signal acquired by a shift lever sensor 2027, and the detection signals for detecting obstacles, vehicles, pedestrians, etc. acquired by an object detection sensor 2028, all of which are input to the electronic control unit 2010.

[0156] The communication module 2013 receives various information (traffic information, traffic signal information, vehicle distance information, etc.) transmitted from external devices and displays it on an information service unit 2012 provided in the vehicle. The communication module 2013 also stores the various information received from the external devices in a memory 2032 that can be used by the microprocessor 2031. Based on the information stored in the memory 2032, the microprocessor 2031 may control the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, left and right front wheels 2007, left and right rear wheels 2008, axle 2009, sensors 2021 to 2028, and the like provided in the vehicle 2001.

[0157] Although the present disclosure has been described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is intended to be illustrative and does not have any limiting meaning on the present disclosure.

[0158] (Additional Note) The above disclosure may be expressed as follows.

[0159] A first feature is a terminal comprising: a receiving unit that receives a reference signal in a cell formed by a base station; and a control unit that assumes that the reference signal is set for each group within the cell, wherein the control unit assumes that the group is set based on information related to an antenna port that receives the reference signal.

[0160] A second feature is the terminal based on the first feature, wherein the control unit assumes that the group is set based on the number of antenna ports that receive the reference signal.

[0161] A third feature is the terminal according to the first or second feature, wherein the control unit assumes that a precoder applied to communication with the base station is common among terminals in the group.

[0162] A fourth feature is the terminal according to the first or second feature, wherein the control unit assumes that a precoder applied to communication with the base station differs among terminals in the group.

[0163] A fifth feature is a terminal according to any one of the first to fourth features, wherein the receiving unit receives a plurality of the reference signals, and the control unit assumes that a portion of the plurality of reference signals is set for each group, and the remainder of the plurality of reference signals is set for each terminal.

[0164] A sixth feature is the terminal according to the fifth feature, wherein the control unit determines the number of antenna ports that receive a reference signal set for each of the terminals, based on the number of antenna ports that receive a reference signal set for each of the groups and the number of all antenna ports.

[0165] 10 Wireless communication system 20 NG-RAN 100 gNB 110 Wireless signal transceiver 120 Control unit 200 UE 210 Wireless signal transceiver 220 Amplifier 230 Modulation / demodulation unit 240 Control signal / reference signal processing unit 250 Encoding / decoding unit 260 Data transceiver 270 Control unit 1001 Processor 1002 Memory 1003 Storage 1004 Communication device 1005 Input device 1006 Output device 1007 Bus 2001 Vehicle 2002 Drive unit 2003 Steering unit 2004 Accelerator pedal 2005 Brake pedal 2006 Shift lever 2007 Left and right front wheels 2008 Left and right rear wheels 2009 Axle 2010 Electronic control unit 2012 Information service unit 2013 Communication module 2021 Current sensor 2022 RPM sensor 2023 Air pressure sensor 2024 Vehicle speed sensor 2025 Acceleration sensor 2026 Brake pedal sensor 2027 Shift lever sensor 2028 Object detection sensor 2029 Accelerator pedal sensor 2030 Driving assistance system section 2031 Microprocessor 2032 Memory (ROM, RAM) 2033 Communication port

Claims

1. A terminal comprising: a receiving unit that receives a reference signal in a cell formed by a base station; and a control unit that assumes that the reference signal is set for each group within the cell, wherein the control unit assumes that the group is set based on information related to the antenna port that receives the reference signal.

2. The terminal according to claim 1, wherein the control unit assumes that the group is set based on the number of antenna ports that receive the reference signal.

3. The terminal according to claim 1, wherein the control unit assumes that a precoder applied to communication with the base station is common among terminals in the group.

4. The terminal according to claim 1, wherein the control unit assumes that precoders applied to communication with the base station are different among terminals in the group.

5. The terminal according to claim 1, wherein the receiving unit receives a plurality of the reference signals, and the control unit assumes that a portion of the plurality of reference signals is set for each of the groups, and the remainder of the plurality of reference signals is set for each of the terminals.

6. The terminal according to claim 5, wherein the control unit determines the number of antenna ports for receiving a reference signal set for each of the terminals based on the number of antenna ports for receiving a reference signal set for each of the groups and the total number of antenna ports.

Images