Base station device, terminal device, and wireless communication system

Abstract

The present invention provides a base station device that transmits a plurality of reference signals to a terminal device and receives measurement results for the plurality of reference signals from the terminal device, the base station device including: a control unit that notifies the terminal device of transmission information pertaining to the transmission of the plurality of reference signals; and a communication unit that receives, from the terminal device, measurement results for some or all of the plurality of reference signals transmitted in accordance with an order of priority determined according to the transmission information by the terminal device.

Description

Base station device, terminal device, and wireless communication system

[0001] The present invention relates to a base station device, a terminal device, and a wireless communication system.

[0002] In recent years, various studies have been conducted at international standardization meetings and other forums on energy conservation technologies for base station equipment in wireless communication systems (see Non-Patent Document 28). Spatial element adaptation and transmission power adaptation have been proposed as energy conservation technologies for base station equipment (see Non-Patent Document 29). Spatial elements include elements related to radio wave transmission and reception, such as wireless transceiver circuits and antennas. A base station equipment is assumed to have multiple wireless transceiver circuits and multiple antennas. The base station equipment can change the number of spatial elements (e.g., wireless transceiver circuits or antennas) or transmission power depending on the communication load. Specifically, when the communication load between the base station equipment and a terminal device decreases, the base station equipment controls one or more wireless transceiver circuits to an off state, reduces the number of antennas in use, and reduces the transmission power of the wireless signal transmitted to the terminal device. In other words, dynamic adaptation of spatial elements or transmission power according to the communication load is realized. As a result, throughput loss is suppressed while power consumption of the base station equipment is reduced. Hereinafter, the adaptation of spatial elements and the adaptation of transmission power may be referred to as adaptation of transmission parameters.

[0003] The base station device, for example, acquires a CSI (Channel State Information) report from the terminal device and determines whether to adapt transmission parameters such as spatial elements and transmission power based on the communication load status. Next, the base station device performs appropriate transmission parameter adaptation and transmits a radio signal to the terminal device with the adapted number of radio transceiver circuits or transmission power. The CSI report is a report transmitted from the terminal device periodically or irregularly, and includes measurement results when receiving a CSI-RS (Reference Signal) transmitted from the base station device.

[0004] In order to realize adaptation of spatial elements without delay, a base station device may transmit multiple types of CSI-RS and acquire multiple types of CSI reports. The base station device, for example, transmits CSI-RS corresponding to different numbers of antenna ports (e.g., 32 antenna ports and 16 antenna ports) and acquires CSI reports corresponding to each of the different numbers of antenna ports. The base station device determines adaptation of spatial elements based on the content of this CSI report. Furthermore, the base station device, for example, transmits CSI-RS corresponding to different transmission powers and acquires CSI reports corresponding to each of the different transmission powers. The base station device determines adaptation of transmission power based on the content of this CSI report.

[0005] When transmitting multiple types of CSI reports, the terminal device can, for example, include multiple types of measurement results in one message and transmit the message to the base station device.

[0006] 3GPP TS 36.133 V17.7.03GPP TS 36.211 V17.2.03GPP TS 36.212 V17.1.03GPP TS 36.213 V17.3.03GPP TS 36.214 V17.0.03GPP TS 36.300 V17.2.03GPP TS 36.321 V17.2.03GPP TS 36.322 V17.0.03GPP TS 36.323 V17.1.03GPP TS 36.331 V17.2.03GPP TS 37.324 V17.0.03GPP TS 37.340 V17.2.03GPP TS 38.133 V17.7.03GPP TS 38.201 V17.0.03GPP TS 38.202 V17.2.03GPP TS 38.211 V17.3.03GPP TS 38.212 V17.3.03GPP TS 38.213 V17.3.03GPP TS 38.214 V17.3.03GPP TS 38.215 V17.2.03GPP TS 38.300 V17.2.03GPP TS 38.321 V17.2.03GPP TS 38.322 V17.1.03GPP TS 38.323 V17.2.03GPP TS 38.331 V17.2.03GPP TS 38.420 V17.2.03GPP TS 38.423 V17.2.0RP-2235403GPP TR 38.864 V18.0.0

[0007] However, when multiple types of measurement results are transmitted in a single message, the size of the CSI report increases. For example, when the terminal device experiences a shortage of radio resources for transmitting the CSI report, the terminal device omits part or all of the CSI report and transmits it to the base station device.

[0008] When the base station device receives an omitted CSI report, it may not be able to acquire information necessary for determining the adaptation of transmission parameters (e.g., spatial elements, transmission power, etc.). In this case, the base station device cannot receive the type of CSI report necessary for the determination, and therefore cannot appropriately adapt the transmission parameters.

[0009] That is, when adapting transmission parameters, there is no appropriate control method for a terminal device to transmit a CSI report corresponding to transmission parameters desired by the base station device.

[0010] Therefore, one disclosure provides a base station device, a terminal device, and a wireless communication system that suppresses interference with adaptation of transmission parameters due to omission of part of a CSI report.

[0011] A base station device that transmits multiple reference signals to a terminal device and receives measurement results of the multiple reference signals from the terminal device, and has: a control unit that notifies the terminal device of transmission information regarding the transmission of the multiple reference signals; and a communication unit that receives from the terminal device measurement results of some or all of the multiple reference signals that were transmitted by the terminal device in accordance with a priority determined in accordance with the transmission information.

[0012] One disclosure can suppress the disruption to transmission parameter adaptation caused by the omission of some CSI reports.

[0013] FIG. 1 is a diagram illustrating an example of the configuration of a wireless communication system 10. FIG. 2 is a diagram illustrating an example of the configuration of a base station device 200. FIG. 3 is a diagram illustrating an example of the configuration of a terminal device 100. FIG. 4 is a diagram illustrating an example of a CSI report sequence. FIG. 5 is a diagram illustrating an example of a CSI report sequence in a periodic system. FIG. 6 is a diagram illustrating an example of a CSI report sequence in a quasi-periodic system. FIG. 7 is a diagram illustrating an example of a CSI report sequence in an aperiodic system. FIG. 8 is a diagram illustrating an example of a priority determination method in a first system. FIG. 9 is a diagram illustrating an example of a priority determination method in a second system. FIG. 10 is a diagram illustrating an example of a parameter z other than the number of antenna ports. FIG. 11 is a diagram illustrating an example of another equation. FIG. 12 is a diagram illustrating an example of a table related to the parameter z. FIG. 13 is a diagram illustrating an example of a sequence of a method for specifying a priority determination process. FIG. 14 is a diagram illustrating an example of a sequence of a method for specifying a preset priority determination process. FIG. 15 is a diagram illustrating an example of a definition related to a priority determination process method. FIG. 16 is a diagram illustrating an example of a definition of the parameter z and AlfaList. Fig. 17 is a diagram showing an example of a definition related to the configuration of a CSI report. Fig. 18 is a diagram showing an example of a table related to priority. Fig. 19 is a diagram showing an example of definitions of priority and BetaList. Fig. 20 is a diagram showing an example of a definition related to the configuration of a CSI report. Fig. 21 is a diagram showing an example of a definition of associatedReportConfigInfoList. Fig. 22 is a diagram showing an example of a description of a specification.

[0014] [First Embodiment] A first embodiment will be described.

[0015] <Regarding the Wireless Communication System 10> Fig. 1 is a diagram showing an example of the configuration of a wireless communication system 10. The wireless communication system 10 includes a base station device 200 and terminal devices 100-1 to 100-m. The wireless communication system 10 is, for example, a communication system that supports adaptation of spatial elements.

[0016] The base station device 200 is a device that is wirelessly connected to the terminal devices 100-1 to 100-m and performs wireless communication, and is, for example, an eNodeB or a gNodeB. The base station device 200 may be configured as a single device, or may be configured as multiple devices such as a CU (Central Unit) and a DU (Distributed Unit).

[0017] The terminal devices 100-1 to 100-m (hereinafter sometimes referred to as terminal devices 100) are communication devices that are wirelessly connected to the base station device 200 and transmit and receive data, and are, for example, smartphones or tablet terminals.

[0018] In the wireless communication system 10, the base station device 200 determines adaptation of data transmission parameters (for example, spatial elements, transmission power, etc.) in accordance with the received CSI report. The base station device 200 controls the CSI report transmitted by the terminal device 100. The base station device 200 transmits a CSI-RS to be measured by the terminal device 100. The terminal device 100 receives the CSI-RS, measures the radio signal, includes the measurement result in a CSI report, and transmits the CSI report to the base station device 200.

[0019] Upon receiving the CSI report, the base station apparatus 200 determines whether the transmission parameters are appropriate, for example, by turning on / off the radio transceiver circuitry or changing the transmission output.

[0020] 2 is a diagram showing an example of the configuration of the base station device 200. The base station device 200 includes a CPU (Central Processing Unit) 210, a storage 220, a memory 230, and wireless communication circuits 250-1 to 250-n.

[0021] The storage 220 is an auxiliary storage device such as a flash memory, a hard disk drive (HDD), or a solid state drive (SSD) that stores programs and data. The storage 220 stores a wireless communication control program 221 and a CSI report control program 222.

[0022] The memory 230 is an area into which the programs stored in the storage 220 are loaded. The memory 230 may also be used as an area in which the programs store data.

[0023] The wireless communication circuits 250-1 to 250-n (hereinafter, sometimes referred to as wireless communication circuits 250) are devices that perform wireless communication with the terminal device 100. The base station device 200 transmits and receives signals (messages) to and from the terminal device 100 via the wireless communication circuits 250. The wireless communication circuits 250 are, for example, wireless transceiver circuits and have antenna ports. The base station device 200 controls the number of antenna ports used for communication by turning the wireless communication circuits 250 ON / OFF.

[0024] The CPU 210 is a processor that loads programs stored in the storage 220 into the memory 230, executes the loaded programs, configures each unit, and realizes each process.

[0025] The CPU 210 executes the wireless communication control program 221 to establish a communication unit and perform wireless communication control processing. The wireless communication control processing is processing for controlling wireless communication with the terminal device 100, including transmission output. In the wireless communication control processing, the base station device 200 wirelessly connects to the terminal device 100 and transmits and receives signals (messages).

[0026] The CPU 210 executes the CSI report control program 222 to construct a control unit and perform CSI report control processing. The CSI report control processing is processing for instructing the terminal device 100 to transmit a CSI report, transmitting a CSI-RS, and receiving a CSI report. Furthermore, in the CSI report control processing, the base station device 200 instructs a method of priority determination processing and transmits parameters necessary for priority determination when the amount of data in the CSI report exceeds the amount of radio resources.

[0027] 3 is a diagram illustrating an example of the configuration of the terminal device 100. The terminal device 100 includes a CPU 110, a storage 120, a memory 130, and a wireless communication circuit 150.

[0028] The storage 120 is an auxiliary storage device such as a flash memory, HDD, or SSD that stores programs and data. The storage 120 stores a wireless communication program 121 and a CSI report program 122.

[0029] The memory 130 is an area into which the programs stored in the storage 120 are loaded. The memory 130 may also be used as an area in which the programs store data.

[0030] The wireless communication circuit 150 is a device that performs wireless communication with the base station device 200. The terminal device 100 transmits and receives signals (messages) to and from the base station device 200 via the wireless communication circuit 150.

[0031] The CPU 110 is a processor that loads programs stored in the storage 120 into the memory 130, executes the loaded programs, configures each unit, and realizes each process.

[0032] The CPU 110 executes the wireless communication program 121 to configure a terminal communication unit and perform wireless communication processing. The wireless communication processing is processing for performing wireless communication with the base station device 200. In the wireless communication processing, the terminal device 100 wirelessly connects to the base station device 200 and transmits and receives signals (messages).

[0033] The CPU 110 executes the CSI report program 122 to construct a processing unit and perform CSI report processing. The CSI report processing is processing of receiving and measuring CSI-RS and transmitting a CSI report in accordance with instructions from the base station device 200. Furthermore, if the amount of data in the CSI report exceeds the amount of radio resources during the CSI report processing, the terminal device 100 determines a priority order and transmits a CSI report in which some or all of the data is omitted.

[0034] <Overview of CSI Report> A CSI report is a report including measurement results when the terminal device 100 receives a CSI-RS. The base station device 200 requests the terminal device 100 to transmit a CSI report in order to determine optimal parameters for transmitting a radio signal to the terminal device (hereinafter, sometimes referred to as downlink transmission). The CSI report includes, for example, the following measurement results (information elements) related to downlink transmission:

[0035] ・RI (rank indicator) ・PMI (precoding matrix indicator) ・CQI (channel quality indicator) ・LI (Layer indicator) ・CRI (CSI-RS resource indicator) ・L1-RSRP (layer-1 Reference Signal Received Power) ・L1-SINR (layer-1 Signal to Interference & Noise Ratio)

[0036] The measurement results of the CSI report may change if the number of spatial elements or the transmit power changes. For example, if the number of antenna ports changes, the PMI, RI, CQI, CRI, etc. may change. Also, if the transmit power changes, the RI, CQI, LI, LI-RSRP, L1-SINE, etc. may change.

[0037] Fig. 4 is a diagram showing an example of a sequence of a CSI report. The CSI report in Fig. 4 is transmitted, for example, periodically. The base station device 200 transmits a configuration message (for example, RRC for periodic CSI) including a CSI report configuration (Config) to the terminal device 100 (S1). The terminal device 100 receives the configuration message (S1) and stores the CSI report configuration.

[0038] The base station device 200 transmits the CSI-RS to the terminal device 100 (S2). The CSI-RS is transmitted according to the number of types of measurement targets in the CSI report. For example, if 16 antenna ports and 32 antenna ports are to be measured, the base station device 200 transmits two CSI-RSs for each measurement. Note that the base station device 200 may transmit multiple CSI-RSs included in one CSI-RS.

[0039] When the terminal device 100 receives the CSI-RS (S2), it performs measurements associated with the signal reception and transmits a CSI report to the base station device 200 (S3). The CSI report includes multiple types of CSI reports, such as for 16 antenna ports and 32 antenna ports. As shown in FIG. 4 , the terminal device 100 can include multiple types of CSI reports in one message or signal and transmit the same to the base station device 200.

[0040] <CSI Report Transmission / Reception Method> There are three methods for transmitting and receiving CSI reports, for example: Each method will be described below.

[0041] <1. Periodic CSI reporting> Periodic CSI reporting is a method in which the terminal device 100 periodically transmits CSI reports. Hereinafter, this may be referred to as a periodic method.

[0042] 5 is a diagram showing an example of a sequence of CSI reporting in a periodic manner. The base station device 200 (gNB) transmits an RRC setup, an RRC configuration, an RRC reconfiguration, or an RRC resume including a configuration (config) related to the CSI report to the terminal device 100 (UE) (S10). The terminal device 100 receives and stores the configuration related to the CSI report (CSI configuration). The CSI configuration includes, for example, information related to the CSI-RS to be measured and information related to the content of the CSI report to be reported.

[0043] The CSI report in the periodic method does not transmit a trigger that triggers transmission in the MAC layer or PHY layer (No low layer trigger).

[0044] The base station device 200 transmits the CSI-RS to the terminal device 100 (S11). The base station device 200 transmits one or more types of CSI-RS according to information on the CSI-RS included in the CSI configuration.

[0045] The terminal device 100 receives the CSI-RS, performs measurements, and then transmits a CSI report to the base station device 200 (S12). The CSI report is transmitted, for example, using the PUCCH. Furthermore, even if multiple types of measurement results are requested, the CSI report is transmitted in one message.

[0046] Thereafter, the base station device 200 repeats transmitting the CSI-RS and receiving the CSI report at predetermined time intervals (periodic) (S13, S14).

[0047] Semi-persistent CSI reporting is a scheme in which the terminal device 100 periodically transmits CSI reports until it receives an end trigger, triggered by receiving a start trigger from the base station device 200. Hereinafter, this may be referred to as a quasi-periodic scheme.

[0048] 6 is a diagram showing an example of a CSI reporting sequence in the quasi-periodic mode. The base station device 200 transmits an RRC setup, an RRC configuration, an RRC reconfiguration, or an RRC resume including a setting related to the CSI report to the terminal device 100 (S20). The terminal device 100 receives and stores the setting related to the CSI report (CSI setting).

[0049] The base station device 200 transmits, for example, a MAC-CE including an activation indicator to the terminal device 100 as a start trigger for starting transmission of a CSI report (S21). Upon receiving the MAC-CE, the terminal device 100 waits for a CSI-RS and starts processing a CSI report. Note that the base station device 200 may transmit DCI scrambled with the SP_CSI_RNTI instead of the MAC-CE.

[0050] When a DCI is used as a trigger to start the quasi-periodic transmission, one DCI may be able to handle only one CSI report. For example, when triggering transmission of CSI reports for both 16 antenna ports and 32 antenna ports, the base station device 200 may need to transmit two DCIs, one corresponding to the 16 antenna ports and the other corresponding to the 32 antenna ports.

[0051] The base station device 200 transmits the CSI-RS to the terminal device 100 (S22). The base station device 200 transmits one or more types of CSI-RS according to information on the CSI-RS included in the CSI configuration.

[0052] The terminal device 100 receives the CSI-RS, performs measurements, and then transmits a CSI report to the base station device 200 (S23). The CSI report is transmitted using, for example, the PUCCH or the PUSCH.

[0053] Thereafter, the base station device 200 repeats the transmission of the CSI-RS and the reception of the CSI report at predetermined time intervals (S24, S25).

[0054] Then, the base station device 200 transmits a MAC-CE including a deactivation indicator, which is an end trigger for terminating the periodic transmission of the CSI report, to the terminal device 100 (S26). Note that the base station device 200 may transmit DCI scrambled with the SP_CSI_RNTI instead of the MAC-CE. Upon receiving the end trigger, the terminal device 100 ends standby for the CSI-RS and terminates processing of the CSI report.

[0055] Aperiodic CSI reporting is a scheme in which the terminal device 100 transmits a CSI report non-periodically (for example, once) when it receives a CSI report transmission instruction from the base station device 200. Hereinafter, this may be referred to as an aperiodic scheme.

[0056] 7 is a diagram showing an example of a sequence of CSI reporting in the non-periodic scheme. The base station apparatus 200 transmits an RRC setup, an RRC configuration, an RRC reconfiguration, or an RRC resume including a setting related to CSI reporting to the terminal apparatus 100 (S30). The terminal apparatus 100 receives and stores the setting related to CSI reporting (CSI setting).

[0057] The base station device 200 transmits, as a CSI report transmission trigger, for example, DCI including a CSI transmission request (CSI request) to the terminal device 100 (S31). Upon receiving the DCI, the terminal device 100 waits for a CSI-RS and performs CSI report processing.

[0058] The base station device 200 transmits the CSI-RS to the terminal device 100, for example, after X slots (X is an integer) (S32). The base station device 200 transmits one or more types of CSI-RS according to information about the CSI-RS included in the CSI configuration.

[0059] The terminal device 100 receives the CSI-RS, for example, after Y slots (Y is an integer), performs measurement, and then transmits a CSI report to the base station device 200 (S33). The CSI report is transmitted using, for example, a PUSCH.

[0060] When the base station device 200 and the terminal device 100 complete the transmission and reception of the CSI report, they end the series of non-periodic CSI reports.

[0061] <Priority Determination Process> As described above, regardless of the CSI report method, multiple types of CSI reports may be transmitted in one message. However, depending on the amount of radio resources allocated to the terminal device 100, it may not be possible to transmit all of the CSI reports. Therefore, the terminal device 100 may determine the priority of each CSI report in the priority determination process and omit some or all of the data according to the priority. The priority determination process will be described below.

[0062] 1. First Method The first method is a priority determination method that does not take spatial factors into consideration. Fig. 8 is a diagram showing an example of the first method for determining priority.

[0063] For example, when the terminal device 100 is requested to transmit CSI reports for 16 antenna ports and 32 antenna ports but is unable to transmit both CSI reports due to a lack of radio resources, the terminal device 100 determines the priority order using equation (1).Then, the terminal device 100 omits either the 16 antenna ports or the 32 antenna ports in accordance with the priority order and transmits the CSI report.

[0064] The parameter y indicates the CSI reporting mode: 0 is set for the aperiodic mode using PUSCH, 1 is set for the quasi-periodic mode using PUSCH, 2 is set for the quasi-periodic mode using PUCCH, and 3 is set for the periodic mode using PUSCCH.

[0065] The parameter k is a factor related to the transmission of a CSI report. For a CSI report that transmits L1-RSRP or L1-SINR, 0 is set. For a CSI report that does not transmit L1-RSRP or L1-SINR, 1 is set.

[0066] The parameter c indicates the index of the serving cell.

[0067] Ncells indicates the value of maxNrofServingCells, which is an RRC parameter. Note that the RRC parameter may also be referred to as a parameter of an upper layer.

[0068] The parameter s indicates the reportConfigID.

[0069] The parameter Ms indicates the value of maxNrofCSI-ReportConfigurations, which is an RRC parameter.

[0070] In Equation 1, the priority is calculated by multiplying each parameter by a coefficient and adding them together. For example, the higher the priority, the higher the priority.

[0071] <2. Second Method> The second method is a priority determination method that takes spatial elements into consideration. Fig. 9 is a diagram showing an example of a priority determination method of the second method. In Equation 2 in the second method, a parameter z related to a transmission parameter (e.g., spatial element, transmission output, etc.) is added to the parameters used in Equation 1.

[0072] The parameter z is a parameter related to the number of antenna ports or transmission output of CSI-RS transmitted by the base station apparatus 200. In Equation 2, the parameter z is, for example, the number of antenna ports or a value related to the number of antenna ports (number of CSI-RS antenna ports).

[0073] 10 is a diagram showing examples of a parameter z other than the number of antenna ports. Parameter z may be, for example, a value related to transmission power (CSI-RS Tx power), an offset of CSI-RS transmission power compared to the transmission power of a PDSCH (Physical Downlink Shared Channel), an offset of CSI-RS transmission power compared to the transmission power of a SSS (Secondary Synchronization Signal), or a total value of the number of antenna ports and transmission power (number of CSI-RS antenna ports & CSI-RS Tx power).

[0074] In Equation 2, the priority is calculated by multiplying each parameter by a coefficient and adding the resulting values. As in Equation 1, the priority is higher the larger the value.

[0075] Note that Equation 2 is not limited to the one shown in Fig. 9. Fig. 11 is a diagram showing other examples of equations. Equation 2 may be Equations 3 to 6 shown in Fig. 11. Equations 2 to 6 each use the parameter z in different ways.

[0076] The base station device 200 selects the first method or the second method depending on, for example, the degree of consideration of the transmission parameters (how much consideration the transmission parameters should be given when determining the priority order), and then notifies the terminal device 100 of the selected method.

[0077] For example, when the base station device 200 wants to measure the effect of changing a transmission parameter, the base station device 200 selects the second method that takes the transmission parameter into consideration. Note that the base station device 200 may determine the formula for determining the priority from some or all of Equations 1 to 6, for example.

[0078] FIG. 12 is a diagram showing an example of a table relating to the parameter z.

[0079] 12A is a diagram showing the relationship between the number of antenna ports and the parameter z. For example, the greater the number of antenna ports, the smaller the value of the parameter z.

[0080] 12B shows the relationship between transmission power and parameter z. The transmission power in FIG. 12B is, for example, an offset value of the CSI-RS transmission power compared to SSS. The larger the offset value, the smaller the value of parameter z.

[0081] 12C is a diagram showing the relationship between transmission power and parameter z. The transmission power in FIG. 12C is, for example, an offset value of the CSI-RS transmission power compared to the PDSCH. The larger the offset value, the smaller the value of parameter z.

[0082] 12(D) is a diagram showing the relationship between a CSI report identifier and a parameter z. The CSI report identifier is an ID assigned to each type of CSI report. The parameter z is set to a value according to the type of CSI report.

[0083] <Method of Specifying Priority Determination Process> The base station device 200 instructs the terminal device 100 on the priority determination process. The instruction includes, for example, information on which priority determination process to use and information on parameters in the priority determination process (hereinafter, may be referred to as priority information).

[0084] FIG. 13 is a diagram showing an example of a sequence of a method for specifying a priority determination process.

[0085] Step I is a step of setting a rule (priority rule) for determining the priority of CSI reports in the terminal device 100. The priority rule includes, for example, part or all of the priority information. The base station device 200 transmits the priority rule to the terminal device 100 using, for example, RRC, DCI, MAC-CE, etc. (S101).

[0086] Step II is a step of instructing the terminal device 100 on the rule to be applied (application rule). The application rule includes information on which of a plurality of priority rules is to be enabled, such as which method of the priority rules is to be used to determine the priority. The base station device 200 transmits the application rule to the terminal device 100 using, for example, RRC, DCI, MAC-CE, etc. (S102). Note that when the application rule is specified in step I (when the priority determination process is uniquely determined by the priority rule), step II may be omitted.

[0087] Step III is a step in which the terminal device 100 measures the CSI-RS (S103), performs a priority determination process in accordance with the priority rule and the application rule (S104), and transmits a CSI report (S105).

[0088] Fig. 14 is a diagram showing an example of a sequence of a method for specifying a preset priority determination process. In the sequence of Fig. 14, the priority rule for step I is set in advance in the terminal device 100 (S201). Steps II and III, and each message (S202 to S205) are the same as those in Fig. 13.

[0089] <Definition of Information Elements> Fig. 15 is a diagram showing an example of a definition of a priority determination processing method. Priority-rule-r18 indicates whether the first method or the second method should be selected. Furthermore, Priority-rule-r18 may indicate which of three or more priority determination processing methods should be selected, for example.

[0090] 16 shows an example of the definition of the parameters z and AlfaList, where Alfa may be, for example, the number of antenna ports for CSI-RS, the offset of the transmit power of CSI-RS compared to SSS, the offset of the transmit power of CSI-RS compared to PDSCH, or the ID of the CSI report.

[0091] 17 is a diagram illustrating an example of a definition related to the configuration of a CSI report. A definition of a parameter z is added to CSI-ReportConfig.

[0092] <Example of Sequence of Designation Method of Priority Determination Process> Below, a description will be given of the case where there is a pre-setting and the case where there is no pre-setting.

[0093] <1. Case with Pre-setting> The case with pre-setting will be described using, for example, the sequence of the periodic method shown in FIG.

[0094] The terminal device 100 has a priority rule set in advance (step I in FIG. 14).

[0095] The base station device 200 transmits an RRC setup, an RRC configuration, an RRC reconfiguration, or an RRC resume including the applicable rule to the terminal device 100 (S10, step II in FIG. 14).

[0096] The applicable rules include, for example, a method for determining priority and a parameter z. The base station device 200 notifies the priority determination method using, for example, the definition in Fig. 15. The base station device 200 also notifies the parameter z using, for example, the definition in Fig. 16 or 17.

[0097] The terminal device 100 receives and stores the application rule (S10). The base station device 200 transmits CSI-RS to the terminal device 100 (S11, step III in FIG. 14). The base station device 200 transmits CSI-RS for, for example, 16 antenna ports and 32 antenna ports. The base station device 200 also transmits CSI-RS with, for example, a -6 dB output offset and a 0 dB output offset compared to the PDSCH.

[0098] The terminal device 100 receives the CSI-RS, performs measurements, and then creates a CSI report. If the terminal device 100 cannot transmit all of the created CSI reports due to, for example, a lack of radio resources, the terminal device 100 performs a priority determination process. The priority determination process to be performed follows an applicable rule.

[0099] The terminal device 100 transmits the CSI report to the base station device 200 (S12). For example, the terminal device 100 omits the CSI report for 16 antenna ports, which has a low priority, and transmits only the CSI report for 32 antenna ports to the base station device 200. Furthermore, the terminal device 100 omits the CSI report for −3 dB output offset, which has a low priority, and transmits only the CSI report for 0 dB output offset to the base station device 200.

[0100] Thereafter, the base station device 200 repeats transmitting the CSI-RS and receiving the CSI report at predetermined time intervals (S13, S14). When the terminal device 100 is unable to transmit all of the CSI reports during the periodic CSI report transmission, the terminal device 100 performs a priority determination process and omits some or all of the CSI reports before transmitting them.

[0101] The same designation method is used for the semi-periodic and non-periodic methods. In the semi-periodic method, for example, step S20 in Fig. 6 corresponds to step S10 in Fig. 5. In the non-periodic method, for example, step S30 in Fig. 7 corresponds to step S10 in Fig. 5.

[0102] 2. Case where no pre-setting is performed The case where no pre-setting is performed will be described using, for example, the sequence of the periodic method shown in FIG.

[0103] The base station device 200 transmits an RRC setup, an RRC configuration, an RRC reconfiguration, or an RRC resume including a priority rule to the terminal device 100 (S10, step I in FIG. 13).

[0104] The priority rule includes, for example, one priority determination process method to be used and a parameter z. Note that if the terminal device 100 supports only one priority determination process method, the priority determination process method may be omitted. The base station device 200 notifies the priority determination process method using, for example, the definition in FIG. 15. Furthermore, the base station device 200 notifies the parameter z using, for example, the definition in FIG. 16 or FIG. 17.

[0105] The terminal device 100 receives the priority rule (S10) and stores it. Note that step II in Fig. 13 is omitted because the application rule is specified in step I.

[0106] The base station device 200 transmits CSI-RS to the terminal device 100 (S11, step III in FIG. 13). The base station device 200 transmits CSI-RS for, for example, 16 antenna ports and 32 antenna ports. The terminal device 100 also transmits CSI-RS with, for example, a -6 dB output offset and a 0 dB output offset compared to the PDSCH. The following process is the same as that in the case with pre-settings.

[0107] The same designation method is used for the semi-periodic and non-periodic methods. In the semi-periodic method, for example, step S20 in Fig. 6 corresponds to step S10 in Fig. 5. In the non-periodic method, for example, step S30 in Fig. 7 corresponds to step S10 in Fig. 5. In this case, step II is omitted, as in the periodic method.

[0108] In the quasi-periodic and non-periodic methods, settings equivalent to the pre-settings may be sent to the terminal device 100, for example, in step S20 of Fig. 6 and step S30 of Fig. 7. In this case, step II is performed in step S21 of Fig. 6 in the quasi-periodic method, and in step S31 in the non-periodic method. The rules to be applied are the same as those in the case of pre-settings, for example.

[0109] When the rules and parameters are notified by DCI or MAC_CE, a new DCI or MAC_CE format may be defined. Also, a field may be added to the DCI or MAC_CE format. Also, a new RNTI may be defined and notified by the new RNTI. The DCI or MAC_CE may be a DCI or MAC_CE that triggers a semi-periodic or aperiodic CSI report, or a DCI or MAC_CE that indicates that the base station device 200 is in a power saving state (i.e., a state in which spatial element adaptation or transmission power adaptation is applied).

[0110] Second Embodiment A second embodiment will be described below. In the second embodiment, the base station device 200 directly specifies the priority instead of the parameter z.

[0111] In the second embodiment, the terminal device 100 does not calculate the priority through the priority determination process. The terminal device 100 uses the priority acquired from the base station device 200 as is, and omits the CSI report.

[0112] FIG. 18 is a diagram showing an example of a table relating to priority orders.

[0113] 18A is a diagram showing the relationship between the number of antenna ports and priority. For example, the greater the number of antenna ports, the smaller the priority value (the higher the priority).

[0114] Fig. 18(B) is a diagram showing the relationship between transmission power and priority. The transmission power in Fig. 12(B) is, for example, an offset value of the transmission power compared to SSS. The larger the offset value, the smaller the priority value (higher the priority).

[0115] 18C is a diagram showing the relationship between transmission power and priority. The transmission power in FIG. 12C is, for example, an offset value of the transmission power compared to the PDSCH. The larger the offset value, the smaller the priority value (the higher the priority).

[0116] 18(D) is a diagram showing the relationship between CSI report identifiers and priorities. The CSI report identifiers are IDs assigned to each type of CSI report. The priorities are set to values ​​according to the type of CSI report.

[0117] 19 is a diagram showing an example of the definition of the priority and BetaList. Beta may be, for example, the number of antenna ports for CSI-RS, the offset of the transmit power of CSI-RS compared to SSS, the offset of the transmit power of CSI-RS compared to PDSCH, or the ID of the CSI report.

[0118] The base station device 200 uses the definition shown in FIG. 19 instead of the definition shown in FIG.

[0119] 20 is a diagram showing an example of a definition related to the configuration of a CSI report. A definition of priority is added to CSI-ReportConfig.

[0120] The base station device 200 uses the definition shown in FIG. 20 instead of the definition shown in FIG.

[0121] [Third Embodiment] For example, in the quasi-periodic scheme, one DCI0_1 may not be sufficient to trigger multiple CSI reports. In this case, it may be necessary to transmit multiple DCI0_1s, which may cause a delay in the transmission of the trigger, resulting in the base station apparatus 200 being unable to receive the CSI report at the appropriate timing. Therefore, information elements that can trigger the start of multiple CSI reports with one DCI0_1 in the quasi-periodic scheme are defined below.

[0122] 21 is a diagram showing an example of a definition of associatedReportConfigInfoList. For example, instead of the configuration of a single associatedReportConfigInfo in the semi-periodic method shown at the top, associatedReportConfigInfoList is defined, which lists associatedReportConfigInfo.

[0123] Fig. 22 is a diagram showing an example of the specification. Fig. 22 shows that the restrictions in the specification exclude NZP-CSI-RS-Resource-r18. That is, different numbers of antenna ports can be configured for CSI-RS resources belonging to one set defined by NZP-CSI-RS-Resource-r18.

[0124] [Other Embodiments] The above-described embodiments may be used in combination. For example, the base station device 200 and the terminal device 100 may have a common table, and the parameter z and the priority may be notified using a table index or the like.

[0125] Furthermore, the priority rule settings and the application rule settings may partially overlap, or part of one rule may be set in the other rule. For example, the contents set in the priority rule and the contents set in the application rule may all be set in one of the messages or pre-settings, and all of the information required for calculating the priority by the priority processing method or formula may all be set in one of the rules or pre-settings.

[0126] Furthermore, with regard to a method of instructing a priority processing method without pre-setting, for example, content equivalent to pre-setting may be notified by a message other than an RRC message. Furthermore, an application rule may be set by a message other than an RRC message, a DCI, and a MAC CE. The message names in this embodiment are merely examples, and the message names and characteristics (such as managed layers) are not limited to the messages described in the embodiment.

[0127] 10: Wireless communication system 100: Terminal device 110: CPU 120: Storage 121: Wireless communication program 122: CSI report program 130: Memory 150: Wireless communication circuit 200: Base station device 210: CPU 220: Storage 221: Wireless communication control program 222: CSI report control program 230: Memory 250: Wireless communication circuit

Claims

1. A base station device that transmits one or more reference signals to a terminal device, a transmitter that transmits configuration information regarding reporting of the measurement results of the one or more reference signals to the terminal device; a receiving unit that receives, from the terminal device, measurement results of part or all of the one or more reference signals transmitted in accordance with the priority determined by the terminal device in accordance with the setting information; A base station device having the above configuration.

2. The setting information includes information corresponding to the number of antenna ports at the time of transmission of each of the one or more reference signals. The base station apparatus according to claim 1.

3. The setting information includes information on a power offset of each of the one or more reference signals. The base station apparatus according to claim 1.

4. The priority is determined according to identification information corresponding to each of a plurality of pieces of measurement information obtained by measuring the one or more reference signals. The base station apparatus according to claim 1.

5. The transmitter includes request information requesting transmission of the measurement results transmitted in a quasi-periodic manner in physical layer control information and transmits the request information. The base station apparatus according to claim 1.

6. The physical layer control information is scrambled with an SP CSI RNTI (Semi-Persistent Channel State Information Radio Network Temporary Identifier). The base station apparatus according to claim 5.

7. Identification information of the plurality of pieces of measurement information obtained by measuring the one or more reference signals is associated with the request information. The base station apparatus according to claim 5.

8. Each of the plurality of pieces of measurement information corresponds to each of a plurality of types of CSI reports. The base station apparatus according to claim 7.

9. The one or more reference signals are one or more CSI (Channel State Information)-RS (Reference Signal), The transmitter transmits a signal of an RRC (Radio Resource Control) layer including the setting information. The base station apparatus according to claim 1.

10. A receiving unit that receives configuration information regarding reporting of measurement results of one or more reference signals; a transmitter that transmits measurement results of some or all of the one or more reference signals in accordance with a priority order according to the setting information; A terminal device having the above configuration.

11. The setting information includes information corresponding to the number of antenna ports at the time of transmission of each of the one or more reference signals, and information on the power offset of each of the one or more reference signals. The terminal device according to claim 10.

12. The method further includes a control unit that determines the priority according to identification information corresponding to each of a plurality of pieces of measurement information obtained by measuring the one or more reference signals. The terminal device according to claim 10.

13. The receiving unit receives request information requesting transmission of the measurement results transmitted in a quasi-periodic manner, the request information being included in physical layer control information; The physical layer control information is scrambled with an SP CSI RNTI (Semi-Persistent Channel State Information Radio Network Temporary Identifier). The terminal device according to claim 10.

14. The one or more reference signals are one or more CSI (Channel State Information)-RS (Reference Signal), The receiving unit transmits a signal of an RRC (Radio Resource Control) layer including the setting information. The terminal device according to claim 10.

15. A base station device that transmits configuration information regarding reporting of measurement results of one or more reference signals; a terminal device that receives the setting information and transmits measurement results of some or all of the one or more reference signals transmitted from the base station device in accordance with a priority order according to the setting information; A wireless communication system having: