Terminal, wireless communication method, base station, and wireless communication system

Abstract

A wireless communication method is disclosed, the wireless communication method including: receiving configuration information for configuring a Sounding Reference Signal (SRS) via a Downlink Control Information (DCI) or higher layer signaling; and configuring one or more SRS resources for partial frequency sounding or full frequency sounding based on the configuration information. In another aspect, a terminal and a wireless communication system are also disclosed.

Description

[Technical Field]

[0001] One or more embodiments described herein relate to mechanisms for extending the capacity and / or coverage of a Sounding Reference Signal (SRS) by considering Channel State Information Reference Signal (CSI-RS) assisted partial sounding across the frequency spectrum. [Background technology]

[0002] In 5G New Radio (NR) technology, new requirements have been identified for further enhancement of SRS transmission. New items in Rel. 17 relate, for example, to NR Multiple-Input-Multiple-Output (MIMO).

[0003] New research is currently being conducted targeting SRS extensions in both frequency band (FR) 1 and FR 2. In particular, it is being considered to identify and specify extensions for aperiodic SRS triggering to facilitate more flexible triggering and / or reduced downlink control information (DCI) overhead / usage.

[0004] It is also considered to specify SRS switching for up to eight antennas (e.g., xTyR, x={1,2,4}, y={6,8}). Furthermore, it is considered to evaluate and, if necessary, specify mechanisms to extend SRS capacity and / or coverage, including SRS time bundling, increased SRS repetition, and / or partial sounding across frequency. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] 3GPP RP 193133, “New WID: Further enhancements on MIMO for NR,” December 2019 [Non-patent document 2] 3GPP, TS 38.211, “NR; Physical channels and modulation (Release 16)” [Non-patent document 3] 3GPP RAN#1 E-meeting #104e, R1-2009255, “Discussion on SRS enhancement,” November 2020 [Non-patent document 4] 3GPP TS 38.331, “NR; Radio Resource Control; Protocol specification (Release 15)” Summary of the Invention

[0006] In one or more embodiments, a wireless communication method comprises receiving configuration information for Sounding Reference Signal (SRS) configuration via Downlink Control Information (DCI) or higher layer signaling, and configuring one or more SRS resources for partial frequency sounding or full frequency sounding based on the configuration information.

[0007] In one aspect, the wireless communication method further comprises associating one or more Channel State Information-Reference Signal (CSI-RS) resources with the one or more SRS resources.

[0008] In one aspect, the one or more CSI-RS resources and the one or more SRS resources are associated based on the configuration information.

[0009] In one aspect, the configuration information is signaled by Radio Resource Control (RRC) signaling.

[0010] In one aspect, the configuration information is dynamically updated by the DCI.

[0011] In one aspect, the configuration information is dynamically updated by a Medium Access Control Element (MAC CE).

[0012] In one aspect, the wireless communication method further includes activating the one or more SRS resources for transmission, precoding one or more SRS resources for the one or more SRS resources, and transmitting the one or more SRSs.

[0013] In one aspect, the wireless communication method further comprises deactivating the one or more SRS resources for transmission.

[0014] In one or more embodiments, a terminal comprises a receiver that receives configuration information for sounding reference signal (SRS) configuration via downlink control information (DCI) or higher layer signaling, and a controller that configures one or more SRS resources for partial frequency sounding or full frequency sounding based on the configuration information.

[0015] In one or more embodiments, a wireless communication system includes a terminal having a receiver unit configured to receive configuration information for configuring a sounding reference signal (SRS) via downlink control information (DCI) or higher layer signaling, and a controller unit configured to configure one or more SRS resources for partial frequency sounding or full frequency sounding based on the configuration information. The wireless communication system further includes a base station having a transmitter unit configured to transmit the configuration information.

[0016] Other embodiments and advantages of the present invention will be apparent from the following description and drawings. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a diagram illustrating a schematic configuration of a wireless communication system according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating a schematic configuration of a UE according to an embodiment. [Figure 3] 2 is a schematic configuration of a UE 10 according to an embodiment. [Figure 4] An example of partial frequency sounding using SRS is shown. [Figure 5] 1 shows an example of CSI-RS assisted partial frequency sounding using SRS. [Figure 6] 10 shows an example of association between CSI-RS resources and SRS resources. [Figure 7] 10 shows an example of association between CSI-RS resources and SRS resources. [Figure 8] 10 shows an example of association between CSI-RS resources and SRS resources. [Figure 9] 10 shows an example of association between CSI-RS resources and SRS resources. DETAILED DESCRIPTION OF THE INVENTION

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, in which like elements in different drawings are designated with like reference numerals to maintain consistency.

[0019] In the following description of embodiments of the present invention, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known features are not described in detail to avoid obscuring the present invention.

[0020] 1 illustrates a wireless communication system 1 according to one or more embodiments of the present invention. The wireless communication system 1 includes a user equipment (UE) 10, a base station (BS) 20, and a core network 30. The wireless communication system 1 may be an NR system. The wireless communication system 1 is not limited to the specific configuration described herein and may be any type of wireless communication system, such as an LTE / LTE-Advanced (LTE-A) system.

[0021] The BS 20 may communicate uplink (UL) signals and downlink (DL) signals with the UEs 10 within the cell of the BS 20. The DL and UL signals may include control information and user data. The BS 20 may communicate the DL and UL signals with the core network 30 via a backhaul link 31. The BS 20 may be a gNodeB (gNB). The BS 20 may also be referred to as a network (NW).

[0022] The BS 20 includes an antenna, a communication interface (e.g., an X2 interface) for communicating with neighboring BSs 20, a communication interface (e.g., an S1 interface) for communicating with the core network 30, and a central processing unit (CPU) such as a processor or circuit for processing signals transmitted to and received from the UE 10. The operation of the BS 20 may be realized by the processor processing or executing data and programs stored in a memory. However, the BS 20 is not limited to the above hardware configuration and may be realized by any other appropriate hardware configuration, as will be understood by those skilled in the art. Multiple BSs 20 may be deployed to cover a wider service area of ​​the wireless communication system 1.

[0023] The UE 10 may communicate DL signals and UL signals including control information and user data with the BS 20 using a multiple input multiple output (MIMO) technique. The UE 10 may be an information processing device having a wireless communication function, such as a mobile station, a smartphone, a mobile phone, a tablet, a mobile router, or a wearable device. The wireless communication system 1 may include one or more UEs 10.

[0024] The UE 10 includes a CPU, e.g., a processor, RAM (Random Access Memory), flash memory, and a wireless communication device for transmitting and receiving wireless signals between the BS 20 and the UE 10. For example, the operation of the UE 10 described below may be realized by the CPU processing or executing data and programs stored in the memory. However, the UE 10 is not limited to the above hardware configuration, and may be configured, for example, with a circuit for realizing the processing described below.

[0025] 1, the BS 20 may transmit a CSI reference signal (CSI-RS) to the UE 10. In response, the UE 10 may transmit a CSI report to the BS 20. Similarly, the UE 10 may transmit an SRS to the BS 20.

[0026] (BS composition) A BS 20 according to an embodiment of the present invention will be described below with reference to Fig. 2. Fig. 2 is a diagram for explaining a schematic configuration of the BS 20 according to an embodiment of the present invention. The BS 20 may include a plurality of antennas (antenna element group) 201, an amplifier unit 202, a transceiver unit (transmitter / receiver) 203, a baseband signal processor 204, a call processor 205, and a transmission path interface 206.

[0027] User data transmitted in DL from the BS 20 to the UE 10 is input from the core network to the baseband signal processing unit 204 via the transmission path interface 206 .

[0028] The baseband signal processing unit 204 performs, on the signals, Packet Data Convergence Protocol (PDCP) layer processing, user data division and concatenation, RLC (Radio Link Control) layer transmission processing such as RLC retransmission control transmission processing, Medium Access Control (MAC) retransmission control including HARQ transmission processing, scheduling, transmission format selection, channel coding, Inverse Fast Fourier Transform (IFFT) processing, precoding processing, etc. Subsequently, the resulting signals are transferred to each transceiver unit 203. For the DL control channel signals, transmission processing including channel coding and inverse fast Fourier transform is performed, and the resulting signals are transferred to each transceiver unit 203.

[0029] The baseband signal processing unit 204 notifies each UE 10 of control information (system information) for communication within the cell by higher layer signaling (e.g., RRC (Radio Resource Control) signaling and a broadcast channel). The information for communication within the cell includes, for example, the UL system bandwidth or the DL system bandwidth.

[0030] In each transmitting / receiving unit 203, precoding is performed for each antenna, and frequency conversion processing to a radio frequency band is performed on the baseband signal output from the baseband signal processing unit 204. The amplifier unit 202 amplifies the radio frequency signal that has been frequency converted, and the resulting signal is transmitted from the antenna 201.

[0031] With regard to data transmitted on the UL from UE 10 to BS 20, radio frequency signals are received by each antenna 201, amplified by amplifier 202, frequency converted into baseband signals by transceiver 203, and input to baseband signal processor 204.

[0032] The baseband signal processing unit 204 performs FFT processing, IDFT processing, error correction decoding processing, MAC retransmission control reception processing, and RLC layer and PDCP layer reception processing on the user data contained in the received baseband signal. The resulting signal is then transferred to the core network via the transmission path interface 206. The call processing unit 205 performs call processing such as setting up and releasing communication channels, manages the status of the BS 20, and manages radio resources.

[0033] (UE configuration) A UE 10 according to an embodiment of the present invention will be described below with reference to Fig. 3. Fig. 3 shows a schematic configuration of the UE 10 according to the embodiment of the present invention. The UE 10 has a plurality of UE antennas 101, an amplifier unit 102, a circuit 103 including a transceiver unit (transmitter / receiver) 1031, a control unit 104, and an application unit 105.

[0034] In the DL, radio frequency signals received by the UE antenna 101 are amplified by each amplifier unit 102 and frequency converted to baseband signals by the transceiver unit 1031. The control unit 104 performs reception processing such as FFT processing, error correction decoding, and retransmission control on these baseband signals. DL user data is transferred to the application unit 105. The application unit 105 performs processing related to layers higher than the physical layer and MAC layer. In the downlink data, broadcast information is also transferred to the application unit 105.

[0035] On the other hand, UL user data is input from the application unit 105 to the control unit 104. The control unit 104 performs retransmission control (Hybrid ARQ) transmission processing, channel coding, precoding, DFT processing, IFFT processing, etc., and transfers the resulting signals to each transceiver unit 1031. The transceiver unit 1031 converts the baseband signal output from the control unit 104 into a radio frequency band. Thereafter, the frequency-converted radio frequency signal is amplified in the amplifier unit 102 and subsequently transmitted from the antenna 101.

[0036] As mentioned above, SRS enhancements are contemplated, and one or more embodiments described herein may provide mechanisms for extending the capacity and / or coverage of SRS by including time bundling of SRS, increased SRS repetition, and / or partial sounding across frequency.

[0037] In one or more embodiments, with reference to the example shown in Figure 4, fractional frequency sounding using SRS may be performed. One or more potential advantages of fractional frequency sounding include the possibility of:

[0038] Compared to full-band sounding, partial-band sounding (or partial frequency sounding) offers a way to increase the power per subcarrier, since the available transmit power is allocated to a smaller portion of the bandwidth.

[0039] Furthermore, the capacity of the SRS is expanded since it gives the network the opportunity to multiplex more UE ports in the remaining frequency resources.

[0040] One potential drawback is that full-band frequency selective scheduling of DL transmissions cannot be realized because the entire band is not sounded by the SRS transmission within one slot. Furthermore, due to partial frequency sounding, the network may not be able to extract the interference structure of the channel.

[0041] One or more embodiments will now be described with reference to the example shown in Figure 5. As mentioned above, due to partial frequency sounding, the NW may not be able to extract the channel interference structure. As a solution, [3] proposes associating SRS resources with CSI-RS resources so that the UE can use CSI-RS to measure DL interference covariance and precode SRS transmissions accordingly.

[0042] For example, as shown in Figure 5, based on DL interference measurements taking into account the associated CSI-RS resource CSI-RS#1, the UE precodes the SRS resource SRS#1 so that the NW can get an idea about the interference situation at the UE before the SRS resource SRS#1 is transmitted.

[0043] It should be noted that precoded SRS transmission may also be applied to full frequency sounding with SRS.

[0044] One or more embodiments relate to switching between full-frequency sounding and partial-frequency sounding using SRS. In particular, higher layer signaling or DCI is used to configure the UE to consider partial-bandwidth SRS transmission or full-bandwidth SRS transmission. For example, DCI or higher layer signaling is used to indicate to the UE whether partial-bandwidth sounding using SRS or full-bandwidth sounding is to be considered. That is, x=0→full band, x=1→half of the available band.

[0045] Regarding dynamic switching, DCI may be used for dynamic switching between full frequency sounding / partial frequency sounding using SRS. In particular, for dynamic switching using DCI, one or more of the following options may be considered:

[0046] As a first option, one bit is added to the DCI to enable switching between partial frequency sounding / full frequency sounding using SRS. As a second option, an SRS request field in the DCI indicates the SRS resource. The indicated SRS resource contains the settings required for partial frequency sounding / full frequency sounding. When dynamic switching between partial frequency sounding and full frequency sounding with SRS transmission is performed, the following may be considered: If partial frequency sounding is indicated, during dynamic switching, the SRS is precoded taking into account interference information derived from the associated CSI-RS. Otherwise, the SRS is not precoded for partial frequency sounding taking into account interference information derived from the associated CSI-RS.

[0047] If full frequency sounding is indicated, the SRS is precoded for full frequency sounding, taking into account interference information derived from the associated CSI-RS. Otherwise, the SRS is not precoded for full frequency sounding.

[0048] One or more embodiments according to Figure 6 relate to associating CSI-RS resource(s) with SRS resource(s), in particular, the UE is configured with the association of CSI-RS resource(s) with SRS resource(s) using higher layer signaling or DCI.

[0049] As a first option according to one or more embodiments, it is contemplated that, using RRC signaling, SRS resources with usage set to "Antenna Switching" are associated with CSI-RS resources for the purpose of DL interference measurements. In particular, the example shown in Figure 6 illustrates a new RRC IE that may be used for such association.

[0050] It should be noted that if a precoded SRS is only applicable to partial frequency sounding, the UE may not consider the associated CSI-RS resource in deriving DL interference information when full frequency sounding is configured.

[0051] As a second option according to one or more embodiments, it is contemplated that the association between a CSI-RS resource and one or more specific SRS resources may be dynamically updated / configured using DCI or MAC-CE. For example, if an UL SRS transmission is requested using DCI, the UE is configured with the required CSI-RS association information. As another example, multiple CSI-RS resources may be associated with one SRS resource. In this case, the UE is updated / configured with the specific CSI-RS resource to be considered from among the CSI-RS resources using DCI or MAC-CE.

[0052] According to one or more examples shown in Figure 7, it is contemplated that a single CSI-RS resource may be associated with multiple SRS resources using higher layer signaling or DCI. For example, as shown in Figure 7, the CSI-RS#1 resource is associated with the SRS#1 resource and the SRS#2 resource, both of which have usage set to "Antenna Switching."

[0053] According to one or more alternative embodiments shown in Figure 8, it is contemplated that multiple CSI-RS resources may be associated with a single SRS resource using higher layer signaling or DCI. For example, as shown in Figure 8, CSI-RS#1 and CSI-RS#2 resources are associated with the SRS#1 resource whose usage is set to "Antenna Switching."

[0054] According to one or more alternative embodiments shown in Figure 9, it is contemplated that a single CSI-RS resource may be associated with SRS resources of different uses using higher layer signaling or DCI. For example, as shown in Figure 9, the CSI-RS#1 resource is associated with an SRS#1 resource whose use is "Antenna Switching" and an SRS#2 resource whose use is "Non codebook."

[0055] One or more embodiments relate to activation of precoded SRS for partial / full frequency sounding, i.e., using higher layer signaling or DCI, the UE is instructed / activated to precode or not precode SRS transmissions for partial / full frequency sounding.

[0056] Regarding dynamic switching, DCI may be used for dynamic switching between precoding and non-precoding of SRS transmission. In particular, for dynamic switching using DCI, one or more of the following options may be considered:

[0057] In a first option, according to one or more embodiments, one bit is added to the DCI to activate / deactivate SRS precoding.

[0058] In a second option according to one or more embodiments, an SRS request field in the DCI indicates an SRS resource. The indicated SRS resource includes the configuration required for precoding / non-precoding of the SRS. For example, if the indicated SRS resource is associated with a CSI-RS resource, the UE precodes the SRS transmission taking into account interference information derived from the associated CSI-RS resource; otherwise, no precoding is performed for the SRS.

[0059] It should be noted that for the determination of the SRS precoder, interference measurements from the associated CSI-RS resource(s) may be configured.

[0060] Furthermore, it should be noted that the precoder generation for the SRS may be based on any other mechanism / criterion that does not rely on CSI-RS-based interference measurements. For example, referring to the first option according to one or more embodiments, it may be considered that the CSI-RS resources are not associated with the SRS resources. As another example referring to the second option according to one or more embodiments, it may be considered that the association between the CSI-RS resources and the SRS resources is configured. Subsequently, higher layer signaling or DCI is used to instruct the UE whether to consider the associated CSI-RS resources in determining the SRS precoder.

[0061] Variations 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.

[0062] Furthermore, information, signals, etc. may be output from a higher layer to a lower layer and / or from a lower layer to a higher layer. Information, signals, etc. may be input / output via multiple network nodes.

[0063] Input and output information, signals, etc. may be stored in a specific location (for example, memory) or may be managed using a management table. Input and output information, signals, etc. may be overwritten, updated, or added. Output information, signals, etc. may be deleted. Input information, signals, etc. may be transmitted to another device.

[0064] 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) and uplink control information (UCI)), higher layer signaling (e.g., radio resource control (RRC) signaling, broadcast information (master information block (MIB), system information block (SIB), medium access control (MAC) signaling, etc.), other signals, or a combination thereof.

[0065] 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.

[0066] Software, instructions, information, etc. may also be transmitted or received over a transmission medium. For example, if the software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair cable, or Digital Subscriber Line (DSL)) and / or wireless technologies (such as infrared, microwave, etc.), these wired and / or wireless technologies are included within the definition of transmission media.

[0067] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0068] In this disclosure, the terms "base station (BS)," "radio base station," "eNB," "gNB," "cell," "sector," "cell group," "carrier," "component," and "component carrier" may be used interchangeably. A base station may also be called a "fixed station," "NodeB," "eNodeB (eNB)," "access point," "Transmission Point (TP)," "Reception Point (RP)," "femtocell," "small cell," etc.

[0069] 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 service by a base station subsystem (e.g., a small indoor base station (RRH (Remote Radio Head))). The term "cell" or "sector" refers to a part or the entire coverage area of ​​a base station and / or a base station subsystem that provides communication service within this coverage.

[0070] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably.

[0071] A mobile station may also be referred to 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.

[0072] Furthermore, a radio base station in the present disclosure may be interpreted as a user terminal. For example, the aspects / embodiments of the present disclosure may be applied to a configuration in which communication between a radio base station and a user terminal is replaced with communication between multiple user terminals (e.g., D2D (Device-to-Device)). In this case, the user terminal 20 may have the functions of the radio base station 10 described above. Furthermore, terms such as "uplink" and "downlink" may be interpreted as "side." For example, an uplink channel may be interpreted as a side channel.

[0073] Similarly, a user terminal in the present disclosure may be interpreted as a radio base station, in which case the radio base station may have the functions of the user terminal described above.

[0074] In the present disclosure, an operation described as being performed by a base station may be performed by its upper node in some cases. It is apparent that in a network including one or more network nodes having base stations, various operations performed for communication with a terminal may be performed by the base station, one or more network nodes other than the base station (such as, but not limited to, a Mobility Management Entity (MME) and a Serving-Gateway (S-GW)), or a combination thereof.

[0075] One or more embodiments described in this disclosure may be used alone, in combination, or interchangeably implemented. Furthermore, the order of procedures, sequences, flowcharts, and the like used to describe aspects / embodiments in this disclosure may be rearranged unless inconsistent. For example, the various methods described in this disclosure present elements of various steps using an exemplary order, but are not limited to the specific order presented therein.

[0076] One or more embodiments described in this disclosure may be applied to systems using LTE (Long Term Evolution), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), New-RAT (Radio Access Technology), NR (New Radio), NX (New radio access), FX (Future generation radio access), GSM (Global System for Mobile communications), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, UWB (Ultra-Wideband), Bluetooth, or other suitable wireless communication methods, and / or next generation systems enhanced thereon.

[0077] 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."

[0078] 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 or that the first element must in some way precede the second element.

[0079] The term "determining" as used in this disclosure may encompass a wide variety of actions. For example, "determining" may be considered to be judging, calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, database, or another data structure), ascertaining, etc. Also, "determining" may be considered to be receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), etc. Additionally, the term "determining" as used in this disclosure may be interpreted as "deciding" to resolve, select, choose, assume, establish, compare, etc. In other words, "determining" may be interpreted as "deciding" to take some action.

[0080] As used in this disclosure, the terms "connected," "coupled," or any variation thereof, mean 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 interpreted as "access."

[0081] In this disclosure, when two elements are connected, they may be considered to be "connected" or "coupled" to one another using one or more wires, cables and / or printed electrical connections, as well as using electromagnetic energy having wavelengths in the radio frequency range, microwave range, light (both visible and invisible) range, as some non-limiting and non-exhaustive examples.

[0082] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." Terms such as "separate" and "coupled" may also be interpreted in the same way as "different."

[0083] Furthermore, the term "or" as used in the specification or claims is not intended to be an exclusive or.

[0084] Although the present invention has been described in detail above, it is clear to those skilled in the art that the present invention is not limited to the embodiments described in this disclosure. The present invention can be implemented in various modifications and alterations without departing from the spirit and scope of the invention as defined by the claims. Therefore, the description of the present disclosure is intended to be illustrative and explanatory and does not impose any limiting meaning on the invention disclosed herein.

[0085] The above-described embodiments and modified embodiments may be combined with each other, and various features of the embodiments may be combined with each other in various combinations. The present invention is not limited to the specific combinations disclosed herein.

[0086] While the present disclosure has been described with respect to only a limited number of embodiments, it will be apparent to those skilled in the art, having the benefit of this disclosure, that various other embodiments may be devised without departing from the scope of the invention, which scope should therefore be limited only by the appended claims.

Claims

1. A receiving unit that receives configuration information for setting a sounding reference signal (SRS) via higher layer signaling; a control unit that determines one or more SRS resources for partial frequency sounding or full frequency sounding based on the configuration information; The control unit precodes the SRS in the SRS transmission using the SRS resource for partial frequency sounding based on an SRS request field of downlink control information (DCI), and does not precode the SRS in the SRS transmission using the SRS resource for full frequency sounding, The control unit switches between the full-frequency sounding and the partial-frequency sounding based on the SRS request field of the DCI.

2. The terminal of claim 1 , wherein the SRS resource for partial frequency sounding is associated with a Channel State Information-Reference Signal (CSI-RS) resource.

3. receiving configuration information for Sounding Reference Signal (SRS) configuration via higher layer signaling; determining one or more SRS resources for partial frequency sounding or full frequency sounding based on the configuration information; precoding an SRS in an SRS transmission using the SRS resource for partial frequency sounding based on an SRS request field of downlink control information (DCI), and not precoding an SRS in an SRS transmission using the SRS resource for full frequency sounding; and switching between the full-frequency sounding and the partial-frequency sounding based on the SRS request field of the DCI.

4. a transmitter configured to transmit, via higher layer signaling, configuration information for configuring one or more Sounding Reference Signal (SRS) resources for partial frequency sounding or full frequency sounding, and downlink control information (DCI) including an SRS request field used for switching between the full frequency sounding and the partial frequency sounding by the terminal; a control unit that controls reception of the precoded SRS based on the SRS request field of the DCI when the terminal transmits SRS using SRS resources for partial frequency sounding, and controls reception of the non-precoded SRS based on the SRS request field of the DCI when the terminal transmits SRS using SRS resources for full frequency sounding.

5. A system including a terminal and a base station, The terminal A receiving unit that receives configuration information for setting a sounding reference signal (SRS) via higher layer signaling; a control unit that determines one or more SRS resources for partial frequency sounding or full frequency sounding based on the configuration information; The control unit precodes the SRS in the SRS transmission using the SRS resource for partial frequency sounding based on an SRS request field of downlink control information (DCI), and does not precode the SRS in the SRS transmission using the SRS resource for full frequency sounding, The controller switches between the full frequency sounding and the partial frequency sounding based on the SRS request field of the DCI; The base station a transmitter that transmits the configuration information and the DCI; a control unit that controls reception of the SRS.

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