Electronic device and method for setting uplink reference signal

Abstract

According to one embodiment, a method performed by a device of a base station may comprise an operation of determining a first frequency domain for reference signals in an extended frequency domain of frequency domain spectrum shaping (FDSS) on the basis of communication quality for a channel between the base station and a terminal. The method may comprise the operations of: transmitting, to the terminal, resource allocation information about a second frequency domain for data signals in the extended frequency domain; receiving, through the extended frequency domain, uplink signals that are configured on the basis of the FDSS and include the reference signals and data signals; performing channel estimation for the second frequency domain through the reference signal received through the first frequency domain; and acquiring the data signals on the basis of the results of the channel estimation for the second frequency domain.

Description

Electronic device and method for setting uplink reference signals

[0001] The present disclosure relates to an electronic device and method for setting an uplink reference signal.

[0002] To achieve higher output power through waveforms with a low peak-to-average power ratio (PAPR), discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) is used for uplink signals. Even when DFT-S-OFDM is used, PAPR may increase depending on the modulation method.

[0003] The above information may be provided as background art to aid in understanding the present disclosure. No claim or determination is made as to whether any of the above-described matters constitute prior art related to the present disclosure.

[0004] According to one embodiment, a device of a base station may include a transceiver, a memory storing instructions, and a processor. The instructions, when executed by the processor, may cause the device to determine a first frequency region for reference signals among an extended frequency region of frequency domain spectrum shaping (FDSS) based on a communication quality of a channel between the base station and a terminal. The instructions, when executed by the processor, may cause the device to transmit resource allocation information for a second frequency region for data signals among the extended frequency region to the terminal. The instructions, when executed by the processor, may cause the device to receive uplink signals including the reference signals and data signals, configured based on the FDSS, through the extended frequency region. The instructions, when executed by the processor, may cause the device to perform channel estimation for the second frequency domain using the reference signal received through the first frequency domain. The instructions, when executed by the processor, may cause the device to obtain the data signals based on the results of the channel estimation for the second frequency domain.

[0005] According to one embodiment, a method performed in a device of a base station may include an operation of determining a first frequency region for reference signals among an extended frequency region of frequency domain spectrum shaping (FDSS) based on a communication quality for a channel between the base station and a terminal. The method may include an operation of transmitting resource allocation information for a second frequency region for data signals among the extended frequency region to the terminal. The method may include an operation of receiving uplink signals including the reference signals and data signals, configured based on the FDSS, through the extended frequency region. The method may include an operation of performing channel estimation for the second frequency region through the reference signal received through the first frequency region. The method may include an operation of acquiring the data signals based on a result of the channel estimation for the second frequency region.

[0006] According to one embodiment, a non-transitory computer-readable storage medium may store one or more programs. The one or more programs may include instructions that, when executed by a processor of a device of a base station, cause the device to determine a first frequency region for reference signals among an extended frequency region of frequency domain spectrum shaping (FDSS) based on a communication quality of a channel between the base station and a terminal. The one or more programs may include instructions that, when executed by the processor, cause the device to transmit resource allocation information for a second frequency region for data signals among the extended frequency region to the terminal. The one or more programs may include instructions that, when executed by the processor, cause the device to receive uplink signals including the reference signals and data signals, the uplink signals being configured based on the FDSS, through the extended frequency region. The one or more programs may include instructions that, when executed by the processor, cause the device to perform channel estimation for the second frequency domain using the reference signal received through the first frequency domain. The one or more programs may include instructions that, when executed by the processor, cause the device to obtain the data signals based on the results of the channel estimation for the second frequency domain.

[0007] Figure 1 illustrates a wireless communication system.

[0008] Figure 2a illustrates a front-hole interface.

[0009] Figure 2b illustrates the fronthaul interface of an O(open)-RAN(radio access network).

[0010] Figure 3a illustrates the functional configuration of a distributed unit (DU).

[0011] Figure 3b illustrates the functional configuration of a RU (radio unit).

[0012] Figure 4 illustrates an example of function split between DU and RU.

[0013] Figure 5 illustrates an example of a time-frequency domain resource structure supported by a wireless communication system.

[0014] Figure 6 illustrates examples of channels in a communication standard.

[0015] Figure 7 illustrates an example of the operation of a transmitter for performing discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) based on frequency-domain spectral shaping (FDSS).

[0016] Figures 8a and 8b illustrate graphs for showing the PAPR reduction performance according to the use of DFT-S-OFDM based on FDSS.

[0017] Fig. 9 illustrates an example of the operation of a receiving device for receiving a signal configured via DFT-S-OFDM based on FDSS.

[0018] Figure 10 illustrates an example of the operation of a base station and a terminal for determining the frequency range in which a reference signal is transmitted and the power of the reference signal.

[0019] Figure 11 illustrates an example of the operation of a base station and a terminal for transmitting an uplink signal including a reference signal and a data signal.

[0020] Figures 12a, 12b, and 12c illustrate examples of the size of the first frequency domain.

[0021] Figure 13 illustrates an example of the operation of a base station for determining a first frequency range for reference signals.

[0022] The terms used in this disclosure are used only to describe specific embodiments and may not be intended to limit the scope of other embodiments. The singular expression may include plural expressions unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by those of ordinary skill in the art described in this disclosure. Terms defined in general dictionaries among the terms used in this disclosure may be interpreted as having the same or similar meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined in this disclosure. In some cases, even if a term is defined in this disclosure, it cannot be interpreted to exclude embodiments of the present disclosure.

[0023] The various embodiments of the present disclosure described below illustrate a hardware-based approach as an example. However, since the various embodiments of the present disclosure include techniques utilizing both hardware and software, the various embodiments of the present disclosure do not exclude a software-based approach.

[0024] In the following description, terms referring to signals (e.g., signal, information, message, signaling), terms referring to resources (e.g., symbol, slot, subframe, radio frame, subcarrier, resource element (RE), resource block (RB), bandwidth part (BWP), occasion), terms for operational states (e.g., step, operation, procedure), terms referring to data (e.g., packet, user stream, information, bit, symbol, codeword), terms referring to channels, terms referring to network entities, terms referring to components of devices, etc. are examples for convenience of description. Therefore, the present disclosure is not limited to the terms described below, and other terms having equivalent technical meanings may be used.

[0025] In addition, in the present disclosure, expressions such as "more than" or "less than" may be used to determine whether a specific condition is satisfied or fulfilled, but this is merely a description for expressing an example and does not exclude descriptions such as "more than" or "less than." A condition described as "more than" may be replaced with "more than," a condition described as "less than" may be replaced with "less than," and a condition described as "more than and less than" may be replaced with "more than and less than." In addition, hereinafter, "A" to "B" mean at least one of elements from A (including A) to B (including B). hereinafter, "C" and / or "D" mean at least one of "C" or "D," that is, including {"C", "D", "C" and "D"}.

[0026] Although the present disclosure describes various embodiments using terms used in some communication standards (e.g., 3rd Generation Partnership Project (3GPP), extensible radio access network (xRAN), open-radio access network (O-RAN), etc.), these are merely examples for explanation. The various embodiments of the present disclosure can be easily modified and applied to other communication systems.

[0027] Figure 1 illustrates a wireless communication system.

[0028] Referring to FIG. 1, FIG. 1 illustrates a base station (110) and a terminal (120) as some of the nodes utilizing a wireless channel in a wireless communication system. Although FIG. 1 illustrates only one base station, the wireless communication system may further include other base stations identical or similar to the base station (110).

[0029] The base station (110) is a network infrastructure that provides wireless access to the terminal (120). The base station (110) has coverage defined based on the distance at which a signal can be transmitted. In addition to the base station, the base station (110) may be referred to as an 'access point (AP)', 'eNodeB (eNB)', '5th generation node', 'next generation nodeB (gNB)', 'wireless point', 'transmission / reception point (TRP)', or other terms having equivalent technical meanings.

[0030] The terminal (120) is a device used by a user and communicates with the base station (110) via a wireless channel. The link from the base station (110) to the terminal (120) is referred to as a downlink (DL), and the link from the terminal (120) to the base station (110) is referred to as an uplink (UL). In addition, although not shown in FIG. 1, the terminal (120) and another terminal may communicate with each other via a wireless channel. In this case, the link between the terminal (120) and another terminal (device-to-device link, D2D) is referred to as a sidelink, and the sidelink may be used interchangeably with the PC5 interface. In some other embodiments, the terminal (120) may be operated without the involvement of a user. According to one embodiment, the terminal (120) is a device that performs machine type communication (MTC) and may not be carried by the user. Additionally, according to one embodiment, the terminal (120) may be an NB (narrowband)-IoT (internet of things) device.

[0031] The terminal (120) may be referred to as a terminal, or other terms such as 'user equipment (UE),' 'customer premises equipment (CPE),' 'mobile station,' 'subscriber station,' 'remote terminal,' 'wireless terminal,' 'electronic device,' or 'user device,' or other terms having equivalent technical meanings.

[0032] The base station (110) and the terminal (120) can perform beamforming. The base station (110) and the terminal (120) can transmit and receive wireless signals in a relatively low frequency band (e.g., FR 1 (frequency range 1) of NR). In addition, the base station (110) and the terminal (120) can transmit and receive wireless signals in a relatively high frequency band (e.g., FR 2 (or, FR 2-1, FR 2-2, FR 2-3), FR 3 of NR), millimeter wave (mmWave) band (e.g., 28 GHz, 30 GHz, 38 GHz, 60 GHz)). To improve channel gain, the base station (110) and the terminal (120) can perform beamforming. Here, the beamforming can include transmission beamforming and reception beamforming. The base station (110) and the terminal (120) can impart directionality to the transmitted or received signal. To this end, the base station (110) and the terminal (120) can select serving beams through a beam search or beam management procedure. After the serving beams are selected, subsequent communication can be performed through resources that have a QCL relationship with the resource that transmitted the serving beams.

[0033] If large-scale characteristics of a channel carrying a symbol on a first antenna port can be inferred from a channel carrying a symbol on a second antenna port, the first antenna port and the second antenna port can be evaluated to have a QCL relationship. For example, the large-scale characteristics may include at least one of delay spread, Doppler spread, Doppler shift, average gain, average delay, and a spatial receiver parameter.

[0034] Although both the base station (110) and the terminal (120) are described as performing beamforming in FIG. 1, the embodiments of the present disclosure are not necessarily limited thereto. In some embodiments, the terminal may or may not perform beamforming. Furthermore, the base station may or may not perform beamforming. That is, either only one of the base station and the terminal may perform beamforming, or neither the base station nor the terminal may perform beamforming.

[0035] In the present disclosure, a beam refers to a spatial flow of a signal in a wireless channel, and is formed by one or more antennas (or antenna elements), and this forming process may be referred to as beamforming. Beamforming may include at least one of analog beamforming and digital beamforming (e.g., precoding). Reference signals transmitted based on beamforming may include, for example, a demodulation-reference signal (DM-RS), a channel state information-reference signal (CSI-RS), a synchronization signal / physical broadcast channel (SS / PBCH), and a sounding reference signal (SRS). In addition, as a configuration for each reference signal, an IE such as a CSI-RS resource or an SRS-resource may be used, and this configuration may include information associated with the beam. Information associated with a beam may mean whether the configuration (e.g., a CSI-RS resource) uses the same spatial domain filter as another configuration (e.g., another CSI-RS resource within the same CSI-RS resource set) or a different spatial domain filter, or whether it is quasi-co-located (QCL) with a reference signal, and if so, what type it is (e.g., QCL type A, B, C, D).

[0036] In the past, in communication systems with relatively large cell radius of base stations, each base station was installed to include the functions of a digital processing unit (or distributed unit (DU)) and a radio frequency (RF) processing unit (or radio unit (RU)). However, as higher frequency bands are used in 4G (4th generation) and / or subsequent communication systems (e.g., 5G) and the cell coverage of base stations decreases, the number of base stations to cover a specific area has increased. The installation costs for operators to install base stations have also increased. In order to minimize the installation costs of base stations, a structure has been proposed in which the DU and RU of a base station are separated, one or more RUs are connected to one DU via a wired network, and one or more RUs are geographically distributed to cover a specific area. Hereinafter, the deployment structure and expanded examples of base stations according to various embodiments of the present disclosure are described through FIGS. 2A and 2B.

[0037] FIG. 2A illustrates a fronthaul interface. Unlike the backhaul between a base station and a core network, fronthaul refers to the connection between entities between a wireless LAN and a base station. FIG. 2A illustrates an example of a fronthaul structure between a DU (210) and one RU (220), but this is merely for convenience of explanation and the present disclosure is not limited thereto. In other words, embodiments of the present disclosure can also be applied to a fronthaul structure between one DU and multiple RUs. For example, embodiments of the present disclosure can be applied to a fronthaul structure between one DU and two RUs. Furthermore, embodiments of the present disclosure can also be applied to a fronthaul structure between one DU and three RUs.

[0038] Referring to FIG. 2A, a base station (110) may include a DU (210) and an RU (220). A fronthaul (215) between the DU (210) and the RU (220) may be operated via an FX interface. For operation of the fronthaul (215), an interface such as an enhanced common public radio interface (eCPRI) or radio over ethernet (ROE) may be used, for example.

[0039] As communications technology advances, mobile data traffic increases, significantly increasing the bandwidth requirements for the fronthaul between the digital unit and the radio unit. In deployments such as C-RAN (centralized / cloud radio access network), the DU performs functions for the packet data convergence protocol (PDCP), radio link control (RLC), media access control (MAC), and physical layer (PHY), while the RU can be implemented to perform additional functions for the PHY layer in addition to its radio frequency (RF) functions.

[0040] DU (210) may be responsible for upper layer functions of a wireless network. For example, DU (210) may perform functions of the MAC layer and a part of the PHY layer. Here, a part of the PHY layer refers to functions performed at a higher level among the functions of the PHY layer, and may include, for example, channel encoding (or channel decoding), scrambling (or descrambling), modulation (or demodulation), and layer mapping (or layer demapping). According to an embodiment, if DU (210) complies with the O-RAN standard, it may be referred to as O-DU (O-RAN DU). DU (210) may be replaced with a first network entity for a base station (e.g., gNB) in embodiments of the present disclosure, if necessary.

[0041] The RU (220) may be responsible for lower layer functions of a wireless network. For example, the RU (220) may perform a part of the PHY layer, an RF function. Here, a part of the PHY layer refers to functions of the PHY layer that are performed at a relatively lower level than the DU (210), and may include, for example, inverse fast Fourier transform (iFFT) transformation (or fast Fourier transform (FFT) transformation), cyclic prefix (CP) insertion (CP removal), and digital beamforming. An example of such specific functional separation is described in detail in FIG. 4. The RU (220) may be referred to as an 'access unit (AU)', an 'access point (AP)', a 'transmission / reception point (TRP)', a 'remote radio head (RRH)', a 'radio unit (RU)', or other terms having an equivalent technical meaning thereto. In one embodiment, if RU (220) complies with the O-RAN standard, it may be referred to as O-RU (O-RAN RU). RU (220) may be represented as a second network entity for a base station (e.g., gNB) in embodiments of the present disclosure, if necessary.

[0042] Although FIG. 2A illustrates that the base station (110) includes a DU (210) and a RU (220), the embodiments of the present disclosure are not limited thereto. The base station according to the embodiments may be implemented in a distributed deployment according to a centralized unit (CU) configured to perform functions of upper layers of an access network (e.g., packet data convergence protocol (PDCP), radio resource control (RRC)) and a distributed unit (DU) configured to perform functions of lower layers. In this case, the distributed unit (DU) may include the digital unit (DU) and radio unit (RU) of FIG. 1. Between a core (e.g., 5GC (5G core) or NGC (next generation core)) network and a radio network (RAN), the base station may be implemented in a structure in which CU, DU, and RU are arranged in that order. The interface between CU and DU (distributed unit) can be referred to as the F1 interface.

[0043] A centralized unit (CU) can be connected to one or more DUs and can be responsible for functions at a higher layer than the DU. For example, the CU can be responsible for functions at the RRC (radio resource control) and PDCP (packet data convergence protocol) layers, while the DU and RU can be responsible for functions at lower layers. The DU can perform some functions (high PHY) of the RLC (radio link control), MAC (media access control), and PHY (physical) layers, while the RU can be responsible for the remaining functions (low PHY) of the PHY layer. In addition, for example, a digital unit (DU) can be included in a distributed unit (DU) depending on the implementation of a distributed deployment of the base station. Hereinafter, unless otherwise defined, the operations of DU (digital unit) and RU are described, but various embodiments of the present disclosure can be applied to both a base station deployment including CU and a deployment in which DU is directly connected to the core network (i.e., a base station in which CU and DU are integrated as a single entity (e.g., NG-RAN node)).

[0044] Figure 2b illustrates the fronthaul interface of an open RAN (radio access network). A base station (110) according to a distributed deployment is exemplified as an eNB or gNB.

[0045] Referring to FIG. 2b, the base station (110) may include an O-DU (251) and O-RUs (253-1, ..., 253-n). Hereinafter, for convenience of explanation, the operation and function of the O-RU (253-1) may be understood as a description of each of the other O-RUs (e.g., O-RU (253-n)).

[0046] The O-DU (251) is a logical node that includes functions, excluding functions exclusively assigned to the O-RU (253-1), among the functions of a base station (e.g., eNB, gNB) according to FIG. 4 described below. The O-DU (251) can control the operation of the O-RUs (253-1, ..., 253-n). The O-DU (251) may be referred to as an LLS (lower layer split) CU (central unit). The O-RU (253-1) is a logical node that includes a subset of the functions of a base station (e.g., eNB, gNB) according to FIG. 4 described below. Real-time aspects of control plane (C-plane) communication and user plane (U-plane) communication with the O-RU (253-1) can be controlled by the O-DU (251).

[0047] The O-DU (251) can communicate with the O-RU (253-1) through an LLS interface. The LLS interface corresponds to a fronthaul interface. The LLS interface refers to a logical interface between the O-DU (251) and the O-RU (253-1) that utilizes lower layer functional split (i.e., intra-PHY based functional split). The LLS-C between the O-DU (251) and the O-RU (253-1) provides the C-plane through the LLS interface. The LLS-U between the O-DU (251) and the O-RU (253-1) provides the U-plane through the LLS interface.

[0048] In FIG. 2B, to explain the O-RAN, entities of the base station (110) are described as O-DU and O-RU. However, these names are not to be construed as limiting the embodiments of the present disclosure. In the embodiments described below, it is obvious that the operations of the DU (210) can be performed by the O-DU (251). The description of the DU (210) can be applied to the O-DU (251). Similarly, in the embodiments described below, it is obvious that the operations of the RU (220) can be performed by the O-RU (253-1). The description of the RU (220) can be applied to the O-DU (253-1).

[0049] Fig. 3a illustrates the functional configuration of a DU (distributed unit). The configuration illustrated in Fig. 3a can be understood as the configuration of the DU (210) of Fig. 2a (or the O-DU (250) of Fig. 2b) as part of a base station. Terms such as "...unit" and "...unit" used hereinafter mean a unit that processes at least one function or operation, and this can be implemented by hardware, software, or a combination of hardware and software.

[0050] Referring to FIG. 3a, DU (210) includes a transceiver (310), memory (320), and processor (330).

[0051] The transceiver (310) can perform functions for transmitting and receiving signals in a wired communication environment. The transceiver (310) can include a wired interface for controlling direct connections between devices via a transmission medium (e.g., copper wire, optical fiber). For example, the transceiver (310) can transmit electrical signals to other devices via copper wire, or perform conversion between electrical signals and optical signals. The DU (210) can communicate with a radio unit (RU) via the transceiver (310). The DU (210) can be connected to a core network or a CU in a distributed arrangement via the transceiver (310).

[0052] The transceiver (310) may perform functions for transmitting and receiving signals in a wireless communication environment. For example, the transceiver (310) may perform a conversion function between a baseband signal and a bit stream according to the physical layer specifications of the system. For example, when transmitting data, the transceiver (310) generates complex symbols by encoding and modulating the transmitted bit stream. In addition, when receiving data, the transceiver (310) restores the received bit stream by demodulating and decoding the baseband signal. In addition, the transceiver (310) may include multiple transmission and reception paths. Furthermore, according to one embodiment, the transceiver (310) may be connected to the core network or other nodes (e.g., an integrated access backhaul (IAB).

[0053] The transceiver (310) can transmit and receive signals. For example, the transceiver (310) can transmit a management plane (M-plane) message. For example, the transceiver (310) can transmit a management plane (S-plane) message. For example, the transceiver (310) can transmit a control plane (C-plane) message. For example, the transceiver (310) can transmit a user plane (U-plane) message. For example, the transceiver (310) can receive a user plane message. Although only the transceiver (310) is illustrated in FIG. 3A, in other implementations, the DU (210) may include two or more transceivers.

[0054] The transceiver (310) transmits and receives signals as described above. Accordingly, all or part of the transceiver (310) may be referred to as a "communication unit," a "transmitter," a "receiver," or a "transmitter-receiver unit." Furthermore, in the following description, transmission and reception performed via a wireless channel are used to mean that the transceiver (310) performs the processing described above.

[0055] Although not illustrated in FIG. 3A, the transceiver (310) may further include a backhaul transceiver for connection to the core network or other base stations. The backhaul transceiver provides an interface for communicating with other nodes within the network. That is, the backhaul transceiver converts a bit stream transmitted from the base station to other nodes, such as other access nodes, other base stations, upper nodes, the core network, etc., into a physical signal, and converts a physical signal received from other nodes into a bit stream.

[0056] The memory (320) stores data such as basic programs, application programs, and setting information for the operation of the DU (210). The memory (320) may be referred to as a storage unit. The memory (320) may be composed of volatile memory, nonvolatile memory, or a combination of volatile memory and nonvolatile memory. In addition, the memory (320) provides stored data upon request from the processor (330).

[0057] The processor (330) controls the overall operations of the DU (210). The processor (380) may be referred to as a control unit. For example, the processor (330) transmits and receives signals through the transceiver (310) (or through the backhaul communication unit). In addition, the processor (330) records and reads data from the memory (320). In addition, the processor (330) may perform the functions of the protocol stack required by the communication standard. Although only the processor (330) is illustrated in FIG. 3A, the DU (210) may include two or more processors according to other implementation examples.

[0058] The configuration of DU (210) illustrated in FIG. 3A is merely an example, and examples of DUs performing embodiments of the present disclosure are not limited to the configuration illustrated in FIG. 3A. In some embodiments, some configurations may be added, deleted, or changed.

[0059] Fig. 3b illustrates the functional configuration of a radio unit (RU). The configuration illustrated in Fig. 3b can be understood as a configuration of the RU (220) of Fig. 2b or the O-RU (253-1) of Fig. 2b as part of a base station. Terms such as "...unit" and "...unit" used hereinafter mean a unit that processes at least one function or operation, and this can be implemented by hardware, software, or a combination of hardware and software.

[0060] Referring to FIG. 3b, the RU (220) includes an RF transceiver (360), a fronthaul transceiver (365), a memory (370), and a processor (380).

[0061] The RF transceiver (360) performs functions for transmitting and receiving signals via a wireless channel. For example, the RF transceiver (360) upconverts a baseband signal into an RF band signal and transmits it via an antenna, and downconverts an RF band signal received via the antenna into a baseband signal. For example, the RF transceiver (360) may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like.

[0062] The RF transceiver (360) may include multiple transmission and reception paths. Furthermore, the RF transceiver (360) may include an antenna unit. The RF transceiver (360) may include at least one antenna array composed of multiple antenna elements. In terms of hardware, the RF transceiver (360) may be composed of digital circuits and analog circuits (e.g., a radio frequency integrated circuit (RFIC)). Here, the digital circuits and analog circuits may be implemented in a single package. In addition, the RF transceiver (360) may include multiple RF chains. The RF transceiver (360) may perform beamforming. The RF transceiver (360) may apply beamforming weights to a signal to be transmitted and received in order to impart directionality according to the settings of the processor (380). According to one embodiment, the RF transceiver (360) may include a radio frequency (RF) block (or RF section).

[0063] According to one embodiment, the RF transceiver (360) can transmit and receive signals on a radio access network. For example, the RF transceiver (360) can transmit a downlink signal. The downlink signal can include a synchronization signal (SS), a reference signal (RS) (e.g., a cell-specific reference signal (CRS), a demodulation (DM)-RS), system information (e.g., a MIB, a SIB, remaining system information (RMSI), other system information (OSI)), a configuration message, control information, or downlink data. In addition, for example, the RF transceiver (360) can receive an uplink signal. The uplink signal may include a random access related signal (e.g., a random access preamble (RAP) (or Msg1 (message 1)), Msg3 (message 3)), a reference signal (e.g., a sounding reference signal (SRS), DM-RS), or a power headroom report (PHR). Although only the RF transceiver (360) is illustrated in FIG. 3b, in other implementation examples, the RU (220) may include two or more RF transceivers.

[0064] According to embodiments, the RF transceiver (460) may transmit a RIM-RS. The RF transceiver (460) may transmit a first type of RIM-RS (e.g., RIM-RS type 1 of 3GPP) to indicate the detection of far-field interference. The RF transceiver (460) may transmit a second type of RIM-RS (e.g., RIM-RS type 2 of 3GPP) to indicate the presence or absence of far-field interference.

[0065] The fronthaul transceiver (365) can transmit and receive signals. According to one embodiment, the fronthaul transceiver (365) can transmit and receive signals on the fronthaul interface. For example, the fronthaul transceiver (365) can receive a management plane (M-plane) message. For example, the fronthaul transceiver (365) can receive a management plane (S-plane) message. For example, the fronthaul transceiver (365) can receive a control plane (C-plane) message. For example, the fronthaul transceiver (365) can transmit a user plane (U-plane) message. For example, the fronthaul transceiver (365) can receive a user plane message. Although only the fronthaul transceiver (365) is shown in FIG. 3b, according to other implementation examples, the RU (220) may include two or more fronthaul transceivers.

[0066] The RF transceiver (360) and the fronthaul transceiver (365) transmit and receive signals as described above. Accordingly, all or part of the RF transceiver (360) and the fronthaul transceiver (365) may be referred to as a 'communication unit', a 'transmitter unit', a 'receiver unit', or a 'transmitter-receiver unit'. In addition, in the following description, transmission and reception performed through a wireless channel are used to mean that the processing as described above is performed by the RF transceiver (360). In the following description, transmission and reception performed through a wireless channel are used to mean that the processing as described above is performed by the RF transceiver (360).

[0067] The memory (370) stores data such as basic programs, application programs, and setting information for the operation of the RU (220). The memory (370) may be referred to as a storage unit. The memory (370) may be configured as volatile memory, non-volatile memory, or a combination of volatile memory and non-volatile memory. In addition, the memory (370) provides the stored data according to a request from the processor (380). According to one embodiment, the memory (370) may include a memory for conditions, commands, or setting values ​​related to the SRS transmission method.

[0068] The processor (380) controls the overall operations of the RU (220). The processor (380) may be referred to as a control unit. For example, the processor (380) transmits and receives signals through the RF transceiver (360) or the fronthaul transceiver (365). In addition, the processor (380) records and reads data in the memory (370). In addition, the processor (380) may perform functions of a protocol stack required by a communication standard. Although only the processor (380) is illustrated in FIG. 3B, the RU (220) may include two or more processors according to other implementation examples. The processor (380) may be a set of instructions or codes stored in the memory (370), or may be a storage space that stores instructions / codes or instructions / codes that are at least temporarily residing in the processor (380), or may be a part of the circuitry that constitutes the processor (380). Additionally, the processor (380) may include various modules for performing communication. The processor (380) may control the RU (220) to perform operations according to the embodiments described below.

[0069] The configuration of RU (220) illustrated in FIG. 3b is merely an example, and examples of RUs performing embodiments of the present disclosure are not limited to the configuration illustrated in FIG. 3b. In some embodiments, some configurations may be added, deleted, or changed.

[0070] Figure 4 illustrates an example of function split between DUs and RUs. As wireless communication technologies advance (e.g., the introduction of 5G (5th generation) communication systems (or NR (new radio) communication systems), the frequency bands used have increased further. As the cell radius of a base station has become significantly smaller, the number of RUs required for installation has also increased further. Furthermore, in 5G communication systems, the amount of data transmitted has increased by a factor of up to ten, significantly increasing the transmission capacity of the wired network transmitted to the fronthaul. Due to the factors described above, the installation cost of the wired network in the 5G communication system may increase significantly. Therefore, in order to lower the transmission capacity of the wired network and reduce the installation cost of the wired network, 'function split' can be utilized, which transfers some of the functions of the modem of the DU to the RU to lower the transmission capacity of the fronthaul.

[0071] To reduce the burden on the DU, the role of the RU, which is traditionally solely responsible for RF functions, can be expanded to include some physical layer functions. As the RU performs higher-layer functions, its throughput increases, which can increase transmission bandwidth in the fronthaul while reducing latency requirements due to response processing. However, as the RU performs higher-layer functions, virtualization gains decrease, and the RU's size, weight, and cost increase. Considering the trade-offs between the advantages and disadvantages described above, implementing an optimal functional separation is required.

[0072] Referring to Figure 4, the functional separation in the physical layer below the MAC layer is illustrated. For the downlink (DL) that transmits a signal to a terminal through a wireless network, the base station can sequentially perform channel encoding / scrambling, modulation, layer mapping, antenna mapping, RE mapping, digital beamforming (e.g., precoding), iFFT transform / CP insertion, and RF transform. For the uplink (UL) that receives a signal from a terminal through a wireless network, the base station can sequentially perform RF transform, FFT transform / CP removal, digital beamforming (pre-combining), RE demapping, channel estimation, layer demapping, demodulation, and decoding / descrambling. The separation of uplink and downlink functions can be defined in various types depending on the needs of vendors, discussions in standards, etc., according to the above-mentioned trade-offs.

[0073] In the first functional separation (405), the RU performs the RF function, and the DU performs the PHY function. The first functional separation is one in which the PHY function is not substantially implemented in the RU, and may be referred to as Option 8, for example. In the second functional separation (410), the RU performs iFFT conversion / CP insertion in the DL and FFT conversion / CP removal in the UL of the PHY function, and the DU performs the remaining PHY functions. As an example, the second functional separation (410) may be referred to as Option 7-1. In the third functional separation (420a), the RU performs iFFT conversion / CP insertion in the DL and FFT conversion / CP removal and digital beamforming in the UL of the PHY function, and the DU performs the remaining PHY functions. As an example, the third functional separation (420a) may be referred to as Option 7-2x Category A. In the fourth functional separation (420b), the RU performs up to digital beamforming in both the DL and UL, and the DU performs upper PHY functions after the digital beamforming. For example, the fourth functional separation (420b) may be referred to as Option 7-2x Category B. In the fifth functional separation (425), the RU performs up to RE mapping (or RE demapping) in both the DL and UL, and the DU performs upper PHY functions after RE mapping (or RE demapping). For example, the fifth functional separation (425) may be referred to as Option 7-2. In the sixth functional separation (430), the RU performs up to modulation (or demodulation) in both the DL and UL, and the DU performs upper PHY functions after modulation (or demodulation). For example, the sixth functional separation (430) may be referred to as Option 7-3. In the seventh functional separation (440), the RU performs encoding / scrambling (or decoding / descrambling) in both the DL and UL, and the DU performs subsequent upper PHY functions up to modulation (or demodulation). For example, the seventh functional separation (440) may be referred to as Option 6.

[0074] In one embodiment, when a large amount of signal processing is expected, such as in the FR 1 MMU, functional separation at a relatively high layer (e.g., the fourth functional separation (420b)) may be required to reduce fronthaul capacity. In addition, functional separation at too high a layer (e.g., the sixth functional separation (430)) may complicate the control interface and cause a burden on the implementation of the RU due to the inclusion of a large number of PHY processing blocks within the RU. Therefore, appropriate functional separation may be required depending on the arrangement and implementation method of the DU and the RU.

[0075] In one embodiment, if the precoding of data received from the DU cannot be processed (i.e., if the precoding capability of the RU is limited), the third functional separation (420a) or a lower functional separation (e.g., the second functional separation (410)) may be applied. Conversely, if the DU has the capability to process the precoding of data received from the DU, the fourth functional separation (420b) or a higher functional separation (e.g., the sixth functional separation (430)) may be applied.

[0076] Hereinafter, embodiments in the present disclosure are described based on the third functional separation (420a) (which may be referred to as category A (CAT-A)) or the fourth functional separation (420b) (which may be referred to as category B (CAT-B)) for performing beamforming processing in an RU unless otherwise specified. The O-RAN standard distinguishes the types of O-RUs depending on whether the precoding function is located at the interface of the O-DU or the O-RU interface. An O-RU that does not perform precoding (i.e., has low complexity) may be referred to as a CAT-A O-RU. An O-RU that performs precoding may be referred to as a CAT-B O-RU.

[0077] Hereinafter, the term "upper-PHY" refers to physical layer processing handled in the DU of the fronthaul interface. For example, the upper-PHY may include FEC encoding / decoding, scrambling, and modulation / demodulation. Hereinafter, the term "lower-PHY" refers to physical layer processing handled in the RU of the fronthaul interface. For example, the lower-PHY may include FFT / iFFT, digital beamforming, PRACH (physical random access channel) extraction, and filtering. However, the above-described criteria do not exclude embodiments through other functional separations. The functional configuration, signaling, or operation of the embodiments described below may be applied not only to the third functional separation (420a) or the fourth functional separation (420b), but also to other functional separations.

[0078] Embodiments of the present disclosure exemplarily describe the standards of eCPRI and O-RAN as fronthaul interfaces when transmitting messages between a DU (e.g., DU (210) of FIG. 2a) and an RU (e.g., RU (220) of FIG. 2a). The Ethernet payload of the message may include an eCPRI header, an O-RAN header, and additional fields. Hereinafter, various embodiments of the present disclosure are described using standard terms of eCPRI or O-RAN, but other expressions having equivalent meanings to each term may be used instead in various embodiments of the present disclosure. Hereinafter, various embodiments of the present disclosure are described using standard terms of eCPRI or O-RAN, but are not limited thereto. For example, in various embodiments of the present disclosure, the CPRI standard may be used as the fronthaul interface.

[0079] The fronthaul transport protocol can use Ethernet and eCPRI, which are easy to share with networks. The Ethernet payload can include an eCPRI header and an O-RAN header. The eCPRI header can be located at the beginning of the Ethernet payload. The contents of the eCPRI header are as follows.

[0080] 1) ecpriVersion (4 bits): This parameter indicates the eCPRI protocol version.

[0081] 2) ecpriReserved (3 bits): This parameter is reserved for further use by eCPRI.

[0082] 3) ecpriConcatenation (1 bit): This parameter indicates when eCPRI concatenation is in use.

[0083] 4) ecpriMessage (1 byte): This parameter indicates the type of service carried by the message type. For example, the parameter indicates an IQ data message, a real-time control data message, or a transmission network delay measurement message.

[0084] 5) ecpriPayload (2 bytes): This parameter indicates the byte size of the payload portion of the eCPRI message.

[0085] 6) ecpriRtcid / ecpriPcid (2 bytes): This parameter is the eAxC (extended antenna-carrier) identifier (eAxC ID) and identifies a specific data flow associated with each C-plane (ecpriRtcid) or U-plane (ecpriPcid) message.

[0086] 7) ecpriSeqid (2 bytes): This parameter provides unique message identification and ordering at both levels. The first octet of this parameter is a sequence ID used to identify the order of messages within the eAxC message stream. The sequence ID is used to ensure that all messages are received and to reorder out-of-order messages. The second octet of this parameter is a subsequence ID. The subsequence ID is used to ensure ordering and implement reordering when radio-transport-level (eCPRI or IEEE-1914.3) fragmentation occurs.

[0087] The eAxC identifier (ID) includes a band and sector identifier ('BandSector_ID'), a component carrier identifier ('CC_ID'), a spatial stream identifier ('RU_Port_ID'), and a distributed unit identifier ('DU_Port_ID'). The bit allocation of the eAxC ID can be distinguished as follows.

[0088] 1) DU_port ID: The DU_port ID is used to distinguish processing units (e.g., different baseband cards) in the O-DU. The O-DU is expected to allocate bits for the DU_port ID, and the O-RU is expected to append the same value to the UL U-plane message carrying the same sectionId data.

[0089] 2) BandSector_ID: Aggregated cell identifier (band and sector distinction supported by O-RU).

[0090] 3) CC_ID: CC_ID identifies the carrier component supported by the O-RU.

[0091] 4) RU_port ID: The RU_port ID specifies logical flows such as data layer or spatial streams, and signaling channels that require separate numerologies (e.g. PRACH) or special antenna allocation such as SRS.

[0092] The application protocol of the fronthaul may include a control plane (C-plane), a user plane (U-plane), a synchronization plane (S-plane), and a management plane (M-plane).

[0093] The control plane may be configured to provide scheduling information and beamforming information via control messages. The control plane refers to real-time control between DUs and RUs. The user plane may include IQ sample data transmitted between DUs and RUs. The user plane may include user downlink data (IQ data or SSB / RS), uplink data (IQ data or SRS / RS), or PRACH data. A weight vector of the beamforming information described above may be multiplied by the user's data. The synchronization plane generally refers to traffic between DUs and RUs for a synchronization controller (e.g., IEEE grand master). The synchronization plane may be related to timing and synchronization. The management plane refers to non-real-time control between DUs and RUs. The management plane may be related to initial setup, non-realtime reset or reset, and non-realtime report.

[0094] Control plane messages, or C-plane messages, can be encapsulated based on a two-layer header approach. The first layer can consist of the eCPRI common header or the IEEE 1914.3 common header, which contains fields used to indicate the message type. The second layer is the application layer, which contains fields necessary for control and synchronization. Within the application layer, sections define the characteristics of U-plane data transmitted or received on a beam with a single pattern ID. The following section types are supported within the C-plane:

[0095] Section Type can indicate the purpose of control messages transmitted on the control plane. For example, the purposes of each Section Type are as follows.

[0096] 1) sectionType=0: Used to indicate resource blocks or symbols not used in DL or UL.

[0097] 2) sectionType=1: Used for most DL / UL wireless channels. Here, "most" refers to channels that do not require time or frequency offsets, such as those required for mixed numerology channels.

[0098] 3) sectionType=2: reserved for further use

[0099] 4) sectionType=3: PRACH and mixed-numerology channels. Channels that require a time or frequency offset or differ from the nominal SCS value(s).

[0100] 5) sectionType=4: reserved for further use

[0101] 6) sectionType=5: UE scheduling information. Transmits UE scheduling information so that the RU can perform real-time BF weight calculations (O-RAN optional BF method).

[0102] 7) sectionType=6: Transmits UE-specific channel information. Periodically transmits UE channel information to enable the RU to perform real-time BF weight calculations (O-RAN optional BF method).

[0103] 8) sectionType=7: Used for LAA support

[0104] Figure 5 illustrates an example of a time-frequency domain resource structure supported by a wireless communication system. Figure 5 illustrates the basic structure of the time-frequency domain, which is a wireless resource region in which data or control channels are transmitted in the downlink or uplink in a 5G NR system to which the present embodiment can be applied.

[0105] Referring to Figure 5, the horizontal axis represents the time domain and the vertical axis represents the frequency domain. The minimum transmission unit in the time domain is an OFDM symbol, N symbOFDM symbols (502) are grouped to form one slot (506). Referring to FIG. 4, in a wireless communication system to which the present invention is applied, one radio frame (514) can be defined as having a length of 10 ms, which is composed of 10 subframes having the same length of 1 ms. In addition, one radio frame (514) can be divided into half-frames of 5 ms, and each half-frame includes 5 subframes. In FIG. 5, a slot (506) is composed of 14 OFDM symbols, but the length of a slot may vary depending on the subcarrier spacing. For example, in the case of numerologies having a 15 kHz subcarrier spacing, a slot is composed of a length of 1 ms, which is the same length as a subframe. In contrast, for numerators with a 30 kHz subcarrier spacing, a slot consists of 14 OFDM symbols, but two slots can be included in one subframe with a length of 0.5 ms.

[0106] That is, subframes and frames are defined with fixed time lengths, and slots are defined with the number of symbols, so that the time length can vary depending on the subcarrier spacing. Referring again to FIG. 5, the radio resources supported in the wireless communication system to which the invention proposed in this specification can be applied are composed of a plurality of time resources, which are symbols, and a plurality of frequency resources, which are subcarriers, and each time resource and frequency resource can be expressed as a two-dimensional resource grid. In FIG. 5, a square, which is the smallest physical resource composed of one subcarrier and one symbol within the resource grid, is called a Resource Element (RE) (512).

[0107] In a wireless communication system to which the invention proposed in this specification can be applied, the minimum transmission unit in the frequency domain is a subcarrier, and the carrier bandwidth constituting the resource grid is N BW It consists of a number of subcarriers (504).

[0108] The basic unit of resources in the time-frequency domain is a resource element (hereinafter referred to as 'RE') (512), which can be represented by an OFDM symbol index and a subcarrier index. A resource block (508) can include a plurality of resource elements (512). In a wireless communication system to which the invention proposed in this specification can be applied, a resource block (508) (or physical resource block (hereinafter referred to as 'PRB')) is N in the time domain. symb N consecutive OFDM symbols and frequency domain SC RB can be defined as N consecutive subcarriers. In an NR system, a resource block (RB) (508) is defined as N in the frequency domain. SC RB can be defined as a series of consecutive subcarriers (510). One RB (508) is N in the frequency axis. SC RB Contains RE(512) of the dog.

[0109] In general, the minimum transmission unit of data is RB and the number of subcarriers is N. SC RB=12. The frequency domain may include common resource blocks (CRBs). Physical resource blocks (PRBs) may be defined in the bandwidth part (BWP) of the frequency domain. The CRB and PRB numbers may be determined based on the subcarrier spacing. The data rate may increase in proportion to the number of RBs scheduled to the terminal.

[0110] In NR systems, in the case of frequency division duplex (FDD) systems that operate downlink and uplink by frequency division, the downlink transmission bandwidth and uplink transmission bandwidth may be different. The channel bandwidth represents the radio frequency (RF) bandwidth corresponding to the system transmission bandwidth. [Table 1] shows part of the correspondence between the system transmission bandwidth, subcarrier spacing (SCS), and channel bandwidth defined in the NR system in a frequency band (e.g., frequency range (FR) 1 (510 MHz to 7125 MHz)) lower than the upper limit defined in the standard (e.g., 7.125) GHz. And [Table 2] shows some of the correspondences between transmission bandwidth, subcarrier spacing, and channel bandwidth defined in NR system in frequency bands higher than the lower limit defined in the specification (e.g., 24.25 GHz) (e.g., FR2 (24250 MHz - 52600 MHz) or FR2-2 (52600 MHz ~ 71000 MHz)). For example, an NR system with 100 MHz channel bandwidth with 30 kHz subcarrier spacing has a transmission bandwidth composed of 273 RBs. In [Table 1] and [Table 2], N / A may be a bandwidth-subcarrier combination not supported by the NR system.

[0111] Channel bandwidth [MHz] SCS 5 10 20 50 80 100 Transmission bandwidth configuration NRB 15kHz2552106207N / AN / A30kHz11245113321727360kHzN / A112465107135

[0112] Channel bandwidth [MHz] SCS50100200400 Transmission bandwidth configuration N RB 60kHz66132264N / A120kHz3266132264

[0113] Figure 6 illustrates examples of channels in a communication standard.

[0114] Figure 6 illustrates examples of channels in a communication standard. The channels may include a physical channel (610), a transport channel (620), and a logical channel (630), depending on the layers defined in the communication standard.

[0115] Referring to FIG. 6, a physical channel (610) may provide functions (e.g., channel coding, HARQ processing, modulation, multi-antenna processing, resource mapping) necessary for generating physical signals at the physical layer. At the physical layer, physical signals are modulated using OFDM and may be transmitted in a wireless environment via time-frequency resources (e.g., resources of the resource grid of FIG. 5).

[0116] In downlink transmission, a physical channel (610) may include at least one of a physical broadcast channel (PBCH), a physical downlink shared channel (PDSCH), or a physical downlink control channel (PDCCH). The PDCCH may be used to carry downlink control information (DCI). Generally, downlink data refers to symbols transmitted through the PDSCH, and a downlink control signal may include symbols transmitted through the PDCCH. In addition, in the downlink, in addition to the channels illustrated in FIG. 6, a synchronization signal (e.g., a primary synchronization signal (PSS), a secondary synchronization signal (SSS)) and an SS / PBCH block including a broadcast signal (e.g., a PBCH)) may be transmitted for synchronization. In addition, in the downlink, a channel state information-reference signal (CSI-RS) for obtaining measurement or channel information, a demodulation reference signal (DMRS) for channel estimation and demodulation, and a phase tracking reference signal (PTRS) may be transmitted in the downlink.

[0117] In uplink transmission, the physical channel (610) may include at least one of a physical uplink shared channel (PUSCH), a physical uplink control channel (PUCCH), or a physical random access channel (PRACH). The PUSCH or PUCCH may be used to carry uplink control information (UCI). Generally, uplink data refers to symbols transmitted through the PUSCH, and the uplink control signal may include symbols corresponding to the UCI. For example, the UCI may include at least one of a scheduling request (SR), a hybrid automatic request (HARQ)-acknowledge (ACK) bit(s), or channel state information (CSI). In addition, in the uplink, in addition to the channels illustrated in FIG. 6, a DMRS and a PTRS for channel estimation and demodulation may be transmitted in the downlink for channel estimation.

[0118] The transmission channel (620) connects the physical layer and the medium access channel (MAC) layer located at an upper level of the physical layer, and can be classified according to how data is transmitted through the wireless interface. In the downlink, the transmission channel (620) may include at least one of a paging channel (PCH) for paging, a broadcast channel (BCH) for broadcasting system information, or a downlink shared channel (DL-SCH) for transmitting downlink data. In the uplink, the transmission channel (620) may include at least one of a random access channel (RACH) for transmitting a random access preamble or an uplink shared channel (UL-SCH) for transmitting downlink data.

[0119] The logical channel (630) is located above the transport channel and is mapped to the transport channel (620). The logical channel (630) can be divided into a control channel for transmitting control region information and a traffic channel for transmitting user region information. The control channel of the logical channel (630) can include at least one of a paging control channel (PCCH), a broadcast control channel (BCCH), a common control channel (CCCH), or a dedicated control channel (DCCH). The traffic channel of the logical channel (630) can include a dedicated traffic channel (DTCH).

[0120] In describing embodiments of the present disclosure, a random access signal may include sequences transmitted via a physical random access channel (PRACH). 'Data' may include signals other than a reference signal. For example, 'data' obtained by a receiver in uplink communication may include signals transmitted via a physical random access channel (PUSCH). However, the PUSCH is exemplary, and it is understood that embodiments of the present disclosure may also be applied to other channels requiring channel estimation (e.g., PDSCH, PBCH, PDCCH, PUCCH).

[0121] In the following specification, a transmitter and a receiver for performing discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) based on frequency-domain spectral shaping (FDSS) will be described. A signal (or waveform) based on DFT-S-OFDM can provide a lower peak-to-average power ratio (PAPR) and higher output power compared to a signal (or waveform) based on OFDM. As the output power increases, the cell radius increases, and the signal to noise ratio (SNR) of a receiving device can increase, so DFT-S-OFDM can be used for uplink. However, the present invention is not limited thereto. When a transmitting device transmits a signal based on DFT-S-OFDM, a receiving device can receive the signal using a simple decoder such as OFDM. Even when DFT-S-OFDM is used, PAPR may increase depending on the modulation method. For example, even when DFT-S-OFDM is used, PAPR may increase as the QAM size increases. Therefore, when DFT-S-OFDM is performed based on FDSS, PAPR may be reduced. In the following Fig. 7, a transmission device for performing DFT-S-OFDM based on FDSS will be described.

[0122] Figure 7 illustrates an example of the operation of a transmitter for performing discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) based on frequency-domain spectral shaping (FDSS).

[0123] Referring to FIG. 7, a transmitting device (e.g., terminal (120)) can configure (or generate) a signal (e.g., an uplink signal) using DFT-S-OFDM. For example, the transmitting device can modulate a waveform using DFT-S. The operation of modulating a waveform based on the DFT-S method can be referred to as transform precoding.

[0124] According to one embodiment, a transmitting device may include a plurality of blocks for performing DFT-S-OFDM based on FDSS. For example, a transmission path of the transmitting device may include an encoding block (701), a symbol mapping block (702), a serial-to-parallel conversion block (703), an M-point DFT block (704), a spectral extension block (705), a spectral shaping block (706), a frequency resource allocation block (707), an N-point IFFT block (708), a parallel-to-serial conversion block (709), and a CP (cyclic prefix) addition block (710). According to an embodiment, at least some of the plurality of blocks included in the transmission path may be omitted.

[0125] For example, the encoding block (701) may be used to encode a transmission bit stream. The symbol mapping block (702) may be used to modulate a codeword generated according to the encoding into a symbol based on at least one of binary phase-shift keying (BPSK), quadrature phase shift keying (QPSK), 16 quadrature amplitude modulation (QAM), 64QAM, 128QAM, or 256QAM. The serial-to-parallel conversion block (703) may be used to change the transmission path from serial to parallel. The M-point DFT block (704) may be used to perform an M-sized DFT operation. M may be set to an integer. According to an embodiment, the M-point DFT block (704) may also perform DFT (discrete frequency transform) spreading.

[0126] For example, the spectral extension block (705) and the spectral shaping block (706) can be configured for frequency-domain spectral shaping (FDSS). For example, the spectral extension block (705) can be used to construct data (730) by copying at least a portion of the data (720). Each of the data (721) and the data (722) can be a portion of the data (720). The data (721) and the data (722) can constitute opposite ends of the data (720) in the frequency domain. The spectral extension block (705) can add the data (721) to the end of the data (720). The spectral extension block (705) can add the data (722) to the beginning of the data (720). The spectral expansion block (705) can expand the data (720) into the data (730) by adding data (721) and data (722) to the data (720). The processor (311) can configure the data (730) to have a circular characteristic in the frequency domain. The spectral shaping block (706) can be used to multiply the data (730) in the frequency domain (or the extended frequency domain) by the shaping filter (740). The spectral shaping block (706) can multiply the data (730) in the frequency domain by the shaping filter (740) tone-by-tone. PAPR can be reduced through frequency extension operation and spectral shaping operation performed based on the above-described spectral extension block (705) and spectral shaping block (706).

[0127] For example, the frequency resource allocation block (707) can be used to allocate data acquired through the spectral shaping block (706) to PRB (or RE). The N-point IFFT block (708) can be used to perform an IFFT of size N. Data (or signal) in the frequency domain can be changed into data (or signal) in the time domain through the IFFT block (708). The parallel-to-serial conversion block (709) can be used to change the transmission path from parallel to serial. The CP addition block (710) can be used to add (or insert) a CP to a signal. Based on the plurality of blocks described above, the transmitting device can transmit a transmission signal (e.g., an uplink signal).

[0128] Figures 8a and 8b illustrate graphs for showing the PAPR reduction performance according to the use of DFT-S-OFDM based on FDSS.

[0129] Referring to Fig. 8a, the x-axis of graphs (801) to (804) represents PAPR. The y-axis of graphs (801) to (804) represents the probability that the PAPR of a signal is greater than the PAPR of the x-axis. The unit of the x-axis is [dB].

[0130] Graphs (801) to (804) represent PAPR performance when the modulation scheme is QPSK, the data size is 52 RB, and the spectral extension is applied to 10 RB, which is about 20% of the data size. Graph (801) represents the PAPR performance of DFT-S-OFDM based on FDSS (or DFT-S-OFDM with FDSS applied). Graph (802) represents the PAPR performance of DFT-S-OFDM. Graph (803) represents the PAPR performance of OFDM. Graph (804) represents the theoretical PAPR performance of OFDM.

[0131] Referring to graph (801) and graph (803) (or graph (804)), the probability that the PAPR of the signal is greater than the PAPR of the x-axis is 10 -4 (or 0.0001), DFT-S-OFDM based on FDSS can provide improved performance of more than 4 [dB] compared to OFDM. Referring to graph (801) and graph (802), the probability that the PAPR of the signal is greater than the PAPR of the x-axis is 10 -4 (or 0.0001), DFT-S-OFDM based on FDSS can provide improved performance of about 1.5 [dB] compared to DFT-S-OFDM.

[0132] Referring to Fig. 8b, the x-axis of graphs (811) to (814) represents PAPR. The y-axis of graphs (811) to (814) represents the probability that the PAPR of a signal is greater than the PAPR of the x-axis. The unit of the x-axis is [dB].

[0133] Graphs (811) to (814) represent PAPR performance when the modulation method is 256 QAM, the data size is 52 RB, and the spectral extension is applied to 10 RB, which is about 20% of the data size. Graph (811) represents the PAPR performance of DFT-S-OFDM based on FDSS (or DFT-S-OFDM with FDSS applied). Graph (812) represents the PAPR performance of DFT-S-OFDM. Graph (813) represents the PAPR performance of OFDM. Graph (814) represents the theoretical PAPR performance of OFDM.

[0134] Referring to graph (811) and graph (813) (or graph (804)), the probability that the PAPR of the signal is greater than the PAPR of the x-axis is 10 -4(or 0.0001), DFT-S-OFDM based on FDSS can provide improved performance of about 3 [dB] compared to OFDM. Referring to graphs (811) and (812), the probability that the PAPR of the signal is greater than the PAPR of the x-axis is 10 -4 (or 0.0001), DFT-S-OFDM based on FDSS can provide improved performance of about 1 [dB] compared to DFT-S-OFDM.

[0135] Referring to FIGS. 8A and 8B, the transmitting device can lower the PAPR of the transmission signal through the spectral expansion block (705) and the spectral shaping block (706) of FIG. 7, and can secure better linearity through a designated power amplifier. Accordingly, the transmitting device can obtain signal quality gains through FDSS.

[0136] By applying FDSS to the transmission path, PAPR can be lowered, but more resources and power can be used than DFT-S-OFDM. Therefore, if the signal generated (or composed) through DFT-S-OFDM based on FDSS is not properly processed at the receiving device, performance degradation may occur. In addition, since spectral stretching is applied to the data signal at the transmitting device and a shaping filter is applied to the spectral stretched data signal, the receiving device must perform channel estimation and inverse compensation of the shaping filter. The reference signal can also be subjected to spectral stretching and a shaping filter in the same manner as the data signal. If the reference signal is subjected to spectral stretching and a shaping filter, loss may occur in the reference signal. Therefore, in the following specification, the design of the reference signal and the operation of the receiving device when DFT-S-OFDM based on FDSS is used will be described.

[0137] Fig. 9 illustrates an example of the operation of a receiving device for receiving a signal configured via DFT-S-OFDM based on FDSS.

[0138] Referring to FIG. 9, a receiving device (e.g., a base station (110)) can receive a signal (e.g., an uplink signal) generated using DFT-S-OFDM. For example, the receiving device can include a plurality of blocks for receiving a signal (e.g., an uplink signal) generated using DFT-S-OFDM based on FDSS. The plurality of blocks can be configured to perform operations opposite to those performed in the transmitting device of FIG. 7.

[0139] For example, the receiving path of the receiving device may include a CP removal block (901), a serial-to-parallel conversion block (902), an N-point FFT block (903), a frequency resource extraction block (904), a channel estimation block (905), an FDSS detection block (906), an M-point IDFT block (907), a parallel-to-serial conversion block (908), a symbol demapping block (909), and a decoding block (910). According to an embodiment, at least some of the plurality of blocks included in the receiving path may be omitted.

[0140] For example, the CP removal block (901) can be used to remove the CP of the received signal. The CP removal block (901) can be used to perform the opposite operation of the CP addition block (710) of FIG. 7. The serial-to-parallel conversion block (902) can be used to change the receiving path from serial to parallel. The serial-to-parallel conversion block (902) can correspond to the serial-to-parallel conversion block (703) of FIG. 7. The N-point FFT block (903) can be used to perform an FFT of size N. The N-point FFT block (903) can be used to perform the opposite operation of the N-point IFFT block (708) of FIG. 7. Through the N-point FFT block (903), data (or signal) in the time domain can be changed into data (or signal) in the frequency domain. The frequency resource extraction block (904) can be used to extract data from an allocated frequency resource (e.g., PRB or RE). As an example, the frequency resource extraction block (904) can be used to extract the RB signal of a specific user.

[0141] For example, the channel estimation block (905) and the FDSS detection block (906) can be configured for FDSS. The channel estimation block (905) can be used to perform channel estimation using a reference signal. The FDSS detection block (906) can be used to perform a combining operation as compensation for the shaping filter (740) of the spectral shaping block (706) of FIG. 7. The specific operations of the channel estimation block (905) and the FDSS detection block (906) will be described below through mathematical equations.

[0142] For example, the M-point IDFT block (907) can be used to perform an M-sized IDFT operation. M can be set to an integer. The M-point IDFT block (907) can be used to perform the opposite operation of the M-point DFT block (704) of FIG. 7. The parallel-to-serial conversion block (908) can be used to change the receiving path from parallel to serial. The symbol demapping block (909) can be used to demodulate into symbols based on at least one of binary phase-shift keying (BPSK), quadrature phase shift keying (QPSK), 16 quadrature amplitude modulation (QAM), 64QAM, 128QAM, or 256QAM. The decoding block (910) can be used to decode the codeword demodulated through the symbol demapping block (909).

[0143] Referring to the multiple blocks of the above-described receiving path, the receiving signal (e.g., data signal or reference signal) can be configured as in mathematical expression 1.

[0144]

[0145]

[0146]

[0147] Referring to Equation 2, K is the length of the data signal and the extension signal according to the spectral extension. M is the length of the data signal. M represents the number of QAM symbols. L is the length of the extension signal.

[0148]

[0149]

[0150]

[0151]

[0152]

[0153]

[0154]

[0155]

[0156]

[0157]

[0158]

[0159] According to one embodiment, the same shaping filter (740) as that of the data signal may be applied to the reference signal. Since the same shaping filter (740) as that of the data signal is applied to the reference signal, the receiving device may not receive information about the shaping filter (740) of FIG. 7. Therefore, the receiving device may perform correction so that the shaping filter (740) is included in the channel during channel estimation. However, when a ZC (zadoff-chu) sequence is used for the reference signal in the uplink, the spectral extension and shaping filter may not need to be applied. For example, since the ZC sequence has a constant size in both the time domain and the frequency domain, it may already have a low PAPR. Therefore, when a ZC (zadoff-chu) sequence is used for the reference signal in the uplink, the spectral extension and shaping filter may not need to be applied. If a reference signal is transmitted through an extended frequency range (or subcarriers) according to spectral expansion without using a shaping filter, resources and power may be used excessively. Therefore, examples of a transmitting device (e.g., a terminal (120)) and a receiving device (e.g., a base station (110)) for variably changing the frequency range (or length of the reference signal) through which the reference signal is transmitted will be described below.

[0160] Figure 10 illustrates an example of the operation of a base station and a terminal for determining the frequency range in which a reference signal is transmitted and the power of the reference signal.

[0161] Referring to FIG. 10, in operation 1001, the terminal (120) can transmit CSI (channel state information) or SRS (sounding reference signal) to the base station (110).

[0162] According to one embodiment, the terminal (120) may transmit CSI to the base station (110). For example, the base station (110) may transmit a cell-specific reference signal (CRS) or a channel state information-reference signal (CSI-RS) to the terminal (120). The terminal (120) may transmit CSI to the base station (110) based on the CRS or CSI-RS.

[0163] For example, the base station (110) may transmit a CRS or CSI-RS to the terminal (120) to identify the state of a channel (or downlink channel). For example, the CRS or CSI-RS may be generated by applying a weight that is identified based on a pseudo random sequence. The base station (110) may transmit the generated CRS or CSI-RS to the terminal (120). Depending on the embodiment, the CRS or CSI-RS may be transmitted periodically or aperiodically. The terminal (120) may identify a CQI indicating the channel state of the downlink identified based on the CRS or CSI-RS. The terminal (120) may determine a CQI index that satisfies a specified condition from among a plurality of CQI indices. When the terminal (120) receives data (e.g., a single PDSCH block), the terminal may determine a CQI index to indicate a modulation scheme and code rate that does not exceed a specified ratio (e.g., 10% for enhanced mobile broadband (eMBB) and 0.001% for ultra-reliable and low latency communications (URLLC)) of BLER.

[0164] The terminal (120) can identify the state of a channel (downlink channel) based on the CRS or CSI-RS. The terminal (120) can determine signal quality to identify the state of the channel. In the present disclosure, the signal quality may be, for example, at least one of RSRP (reference signal received power), BRSRP (beam reference signal received power), RSRQ (reference signal received quality), RSSI (received signal strength indicator), SINR (signal to interference and noise ratio), CINR (carrier to interference and noise ratio), SNR (signal to noise ratio), EVM (error vector magnitude), BER (bit error rate), and BLER (block error rate). In addition to the examples described above, it goes without saying that other terms having equivalent technical meanings or other metrics indicating channel quality may be used. Hereinafter, in the present disclosure, high signal quality means a case where a signal quality value related to a signal magnitude is large or a signal quality value related to an error rate is small. A higher signal quality may indicate a smoother wireless communication environment. Hereinafter, in the present disclosure, SINR is exemplified as an indicator of signal quality for determining CQI. The terminal (120) can identify a downlink channel condition based on a change (or modification) of the CRS or CSI-RS. The terminal (120) can identify (or measure) the SINR for the CRS or CSI-RS. The terminal (120) can transmit information indicating the SINR for the CRS or CSI-RS. Information indicating the SINR for a reference signal can be referred to as the CQI.For example, a higher SINR may result in a higher CQI value. A lower SINR may result in a lower CQI value.

[0165] The base station (110) can receive channel state information (CSI) including CQI. The base station (110) can receive the CQI based on the CSI. The base station (110) can obtain information on a preferred modulation scheme (e.g., QPSK, 16QAM, 64 QAM) or code rate of the terminal (520) based on the CQI. The base station (110) can identify a modulation and coding scheme (MCS) based on a CQI index included in the CQI. For example, the base station (110) can identify an MCS based on a predefined CQI table and an MCS table. The CQI table can indicate a modulation scheme with a higher modulation order or a higher code rate as the CQI index value is higher. The base station (110) can set a higher MCS index as the CQI index is higher. The base station (110) can set the MCS index lower as the CQI index decreases. The MCS index set according to the CQI value can be used for modulation and encoding of downlink data.

[0166] According to one embodiment, the terminal (120) may transmit an SRS to the base station (110). For example, the terminal (120) may transmit the SRS in at least one direction. The base station (110) may identify a channel condition based on the received SRS.

[0167] In operation 1002, the base station (110) may acquire the quality of a channel. For example, the base station (110) may acquire (or identify) the quality of a channel between the base station (110) and a terminal (120). The quality of the channel may include channel selectivity.

[0168] In operation 1003, the base station (110) can determine a first frequency domain for a reference signal (e.g., a demodulate reference signal (DMRS)) and a power of the reference signal. For example, the base station (110) can determine the first frequency domain for the reference signal and the power of the reference signal based on the quality of the channel. For example, the base station (110) can determine the first frequency domain for the reference signal and the power of the reference signal based on at least one of a spectral extension length for FDSS and / or a performance of a shaping filter, as well as the quality of the channel.

[0169] In operation 1004, the base station (110) may transmit information for indicating a first frequency range and / or information for indicating the power of reference signals to the terminal (120). For example, the base station (110) may transmit the information for indicating the first frequency range and / or information for indicating the power of reference signals to the terminal (120) via at least one of a radio resource control (RRC) message, a medium access control (MAC) control element (CE), or a downlink control indicator (DCI). For example, the information for indicating the first frequency range may indicate a ratio of the first frequency range to an extended frequency range extended based on spectral extension. For example, the information for indicating the power of reference signals may be configured based on an energy per resource element (EPRE).

[0170] Figure 11 illustrates an example of the operation of a base station and a terminal for transmitting an uplink signal including a reference signal and a data signal.

[0171] Referring to FIG. 11, in operation 1101, the base station (110) may transmit an RRC message to the terminal (120). For example, the RRC message may include at least one of information indicating a first frequency range for reference signals (e.g., DMRS) and / or information indicating the power of the reference signals.

[0172] In operation 1102, the base station (110) may transmit downlink control information (DCI) to the terminal (120). For example, the DCI may be transmitted via a physical downlink control channel (PDCCH). The DCI may include resource allocation information for a second frequency domain for data signals (e.g., PDSCH). The first frequency domain may include the second frequency domain. The DCI may include information necessary for decoding the data signals. For example, the DCI may have a DCI format 1_x (x=0, 1, 2, ...) of the NR standard.

[0173] In operation 1103, the terminal (120) can identify the first frequency range and the power of the reference signals. For example, the terminal (120) can identify the first frequency range and / or the power of the reference signals for the reference signals based on at least one of an RRC message and / or DCI.

[0174] For example, the terminal (120) can identify a first frequency range for reference signals among the extended frequency range of the FDSS. The terminal (120) can identify the power of the reference signals to be transmitted through the first frequency range.

[0175] In operation 1104, the terminal (120) may transmit an uplink signal to the base station (110). The uplink signal may be transmitted through the extended frequency range of the FDSS. The base station (110) may receive the uplink signal from the terminal (120) through the extended frequency range of the FDSS.

[0176] For example, an uplink signal may include at least one of reference signals, data signals, and / or extension signals. The extension signals may be configured based on at least a portion of the data signals. The extension signals may correspond to at least a portion of the data signals.

[0177] The reference signals may be transmitted via a first frequency region of the extended frequency region. The data signals may be transmitted via a second frequency region of the extended frequency region. The extended signals may be transmitted via a third frequency region of the extended frequency region. The extended frequency region may include a second frequency region and a third frequency region. The extended frequency region may be composed of the second frequency region and the third frequency region. The first frequency region may include the second frequency region. The first frequency region may include the second frequency region and may be included within the extended frequency region.

[0178] Figures 12a, 12b and 12c show examples of the size of the first frequency domain.

[0179] Referring to FIGS. 12A to 12C, the base station (110) may determine a first frequency range for reference signals based on the communication quality of the channel between the base station (110) and the terminal (120). According to one embodiment, the base station (110) may determine a first frequency range among the extended frequency ranges of the FDSS based on the communication quality of the channel between the base station (110) and the terminal (120).

[0180] According to one embodiment, the base station (110) may determine a first frequency range (or the length of a reference signal) among the extended frequency ranges of the FDSS based on the performance for the channel environment and / or the combined operation. The base station (110) may determine the first frequency range among the extended frequency ranges of the FDSS using mathematical equations 7 to 11 described below. The operation of the base station (110) for determining the first frequency range is an example and is not limited thereto.

[0181] For example, after performing MMSE equalization, the base station (110) can identify the average value of the signal for each tone. The average value of the signal for each tone can be set as in the following mathematical equation.

[0182]

[0183]

[0184]

[0185]

[0186]

[0187] After the base station (110) performs IDFT (inverse discrete Fourier transform), the average of each sample in the time domain can be configured as in the following mathematical formula.

[0188]

[0189] The base station (110) can identify the signal to interference and noise ratio (SINR) based on the average of each sample. The SINR can be configured as shown in the following mathematical formula.

[0190]

[0191] The base station (110) can determine the first frequency range (or the length of the reference signal) based on the SINR according to mathematical equation 10. For example, the base station (110) can determine the first frequency range (or the length of the reference signal) as the value at which the SINR is maximized. The base station can determine the first frequency range (or the length of the reference signal) based on the mathematical equation below.

[0192]

[0193] Referring to mathematical expression 11, P is the length of the first frequency domain (or the number of tones constituting the first frequency domain, the length of the reference signal). In the following Figures 12a to 12c, examples of the first frequency domain (or the length of the reference signal) for the second frequency domain (or the length of the data signal) and the third frequency domain (or the length of the extension signal) will be described.

[0194] In FIGS. 12A to 12C, the first frequency domain may be referred to as the length (P) of the reference signal. The length (P) of the reference signal may refer to the number of tones for transmitting the reference signal. The first frequency domain may be composed of P tones.

[0195] In FIGS. 12A to 12C, the extended frequency domain may be referred to as the length (K) of the data signal and the extended signal. The length (K) of the data signal and the extended signal may refer to the number of tones for the data signal and the extended signal. The extended frequency domain may be composed of K tones.

[0196] In FIGS. 12A to 12C, the second frequency domain may be referred to as the length (M) of the data signal. The length (M) of the data signal may refer to the number of tones for the data signal. The second frequency domain may be composed of M tones.

[0197] In FIGS. 12A to 12C, the third frequency domain may be referred to as the length (KM) of the extension signal. The length (KM) of the extension signal may refer to the number of tones for the data signal. The third frequency domain may be composed of KM tones.

[0198] Referring to FIG. 12A, the base station (110) can set the length (P) of the reference signal to be the same as the lengths (P) of the data signal and the extension signal. When the length (P) of the reference signal is the same as the lengths (K) of the data signal and the extension signal, the base station (110) can estimate all channels corresponding to the K tones. The base station (110) can use the estimated channels for all K tones for the FDSS detection operation (or the combining operation). However, since the third frequency domain where the extension signal is transmitted is a domain where the power of the shaping filter is set small, the influence on the channel estimation may be small. When the length (P) of the reference signal is the same as the lengths (P) of the data signal and the extension signal, resources and / or power for the third frequency domain are used, and therefore, resources and / or power may be used more than necessary.

[0199] Referring to FIG. 12b, the base station (110) can set the length (P) of the reference signal to be equal to the length (M) of the data signal. When the length (P) of the reference signal is equal to the length (M) of the data signal, the base station (110) can estimate a channel corresponding to the M tones. Based on the channel estimation result corresponding to the M tones, the base station (110) can identify a channel estimation value for the third frequency domain through extrapolation. For example, the base station (110) can perform an FDSS detection operation (or a combining operation) for extended signals by identifying a channel estimation value at the edge of the second frequency domain as a channel estimation value for the third frequency domain based on the channel estimation result corresponding to the M tones.

[0200] For example, identifying a channel estimate value for a third frequency range through extrapolation, or identifying a channel estimate value at the edge of the second frequency range as a channel estimate value for the third frequency range, may result in performance degradation in environments with high channel selectivity. Therefore, when the channel selectivity is low, the performance of channel estimation can be improved by concentrating the reference signal (or the power of the reference signal) in the second frequency range.

[0201] Referring to FIG. 12c, the base station (110) can set the length (P) of the reference signal to be longer than the length (M) of the data signal and shorter than the length (K) of the data signal and the extension signal. For example, the base station (110) can set the length (P) of the reference signal based on the communication quality of the channel (e.g., channel selectivity), the performance of the shaping filter, the ratio of K / M, and / or the combined performance of the spectral extension. In order to reduce PAPR, even when K / M is set to be large, the length (P) of the reference signal can be set to a value between M and K.

[0202] The length (P) of the reference signal according to FIGS. 12A to 12C may be fixed based on the channel environment (or the communication quality of the channel) and / or the combining performance of the spectral extension (or the performance of the shaping filter). According to an embodiment, the length (P) of the reference signal may be dynamically changed based on at least one message exchanged between the terminal (120) and the base station (110). The at least one message may be transmitted through RRC configuration or DCI information. For example, the base station (110) may determine the length (P) of the reference signal and the power of the reference signal based on at least one of the communication quality (or the channel environment) of the channel between the terminal (120) and the base station (110), the performance of the shaping filter, the K / M ratio, and / or the combining performance of the spectral extension. The base station (110) can transmit information for indicating the length (P) of the reference signal (or the first frequency range) and information for indicating the power of the reference signals to the terminal (120). The terminal (120) can transmit an uplink signal including reference signals, data signals, and extension signals to the base station (110) based on the information for indicating the length (P) of the reference signal (or the first frequency range) and the information for indicating the power of the reference signals.

[0203] Figure 13 illustrates an example of the operation of a base station for determining a first frequency range for reference signals.

[0204] Referring to FIG. 13, in operation 1310, the base station (110) may determine a first frequency range for reference signals among the extended frequency range of the FDSS. For example, the base station (110) may determine the first frequency range for reference signals among the extended frequency range of the FDSS based on the communication quality of the channel between the base station (110) and the terminal (120).

[0205] According to one embodiment, the base station (110) can obtain (or identify) the communication quality for the channel between the base station (110) and the terminal (120).

[0206] For example, the base station (110) can obtain communication quality for a channel based on receiving CSI from the terminal (120). The base station (110) can transmit a cell-specific reference signal (CRS) or a channel state information-reference signal (CSI-RS) to the terminal (120). The base station (110) can receive CSI including CQI from the terminal (120) based on transmitting the CRS or CSI-RS to the terminal (120). After transmitting the CRS or CSI-RS to the terminal (120), the base station (110) can receive CSI including CQI from the terminal (120). The base station (110) can obtain (or identify) communication quality for a channel between the base station (110) and the terminal (120) based on the CQI.

[0207] For example, the base station (110) can obtain (or identify) the communication quality for the channel between the base station (110) and the terminal (120) based on receiving an SRS from the terminal (120). For example, the terminal (120) can transmit an SRS in at least one direction. The base station (110) can identify the communication quality for the channel based on the received SRS.

[0208] According to one embodiment, the base station (110) may determine a first frequency range for reference signals among the extended frequency range of the FDSS. The base station (110) may determine a first frequency range for reference signals included in an uplink signal received from a terminal (120).

[0209] According to one embodiment, the first frequency domain can be determined based on the performance of a shaping filter for an uplink signal configured based on FDSS and communication quality for a channel.

[0210] According to one embodiment, the base station (110) may transmit information for indicating a first frequency domain and information for indicating the power of reference signals within the first frequency domain to the terminal (120). For example, the base station (110) may transmit the information for indicating the first frequency domain and the information for indicating the power of reference signals within the first frequency domain to the terminal (120) via at least one of a radio resource control (RRC) message, a medium access control (MAC) control element (CE), or a downlink control indicator (DCI). For example, the information for indicating the first frequency domain may indicate a ratio of the first frequency domain to an extended frequency domain. For example, the information for indicating the power of reference signals may be configured based on an energy per resource element (EPRE).

[0211] In operation 1320, the base station (110) may transmit resource allocation information for a second frequency region for data signals among the extended frequency regions to the terminal (120). For example, the base station (110) may transmit resource allocation information for the second frequency region to the terminal (120) using DCI. For example, the second frequency region may be included in the first frequency region. According to an embodiment, information for indicating the first frequency region and information for indicating the power of reference signals within the first frequency region may be transmitted to the terminal (120) together with the resource allocation information.

[0212] In operation 1330, the base station (110) can receive uplink signals including reference signals and data signals, configured based on the FDSS, through an extended frequency range. For example, the uplink signal can be configured based on the FDSS. The uplink signal can include a reference signal, a data signal, and an extension signal. The extension signal can correspond to at least a portion of the data signal. The extension signal can be configured based on the FDSS with at least a portion of the data signal.

[0213] For example, the base station (110) can receive a reference signal through a first frequency region among the extended frequency regions. The base station (110) can receive a data signal and an extended signal through the extended frequency region. The base station (110) can receive a data signal through a second frequency region among the extended frequency regions. The base station (110) can receive an extended signal through a third frequency region.

[0214] In operation 1340, the base station (110) may perform channel estimation for the second frequency domain based on a reference signal received through the first frequency domain. For example, the base station (110) may identify a channel estimation value for the second frequency domain based on the channel estimation result for the first frequency domain.

[0215] According to one embodiment, the base station (110) may identify a channel estimation value for a third frequency domain based on a channel estimation result for a first frequency domain. For example, the base station (110) may identify a channel estimation value for a third frequency domain through extrapolation based on a channel estimation result for the first frequency domain. For example, the base station (110) may identify a channel estimation value at the edge of a second frequency domain as a channel estimation value for the third frequency domain based on a channel estimation result for the first frequency domain.

[0216] According to one embodiment, the base station (110) can identify a channel estimation value for an extended frequency range based on a channel estimation result for the first frequency range.

[0217] In operation 1350, the base station (110) may acquire data signals based on the results of channel estimation for the second frequency domain. For example, the base station (110) may acquire data signals based on the results of channel estimation for the second frequency domain. For example, the base station (110) may acquire extension signals based on the results of channel estimation for the third frequency domain. The base station (110) may improve the accuracy of the data signals based on the extension signals in which the data signals are replicated.

[0218] According to one embodiment, a device of a base station may include a transceiver, a memory storing instructions, and a processor. The one or more instructions, when individually or collectively executed by the at least one processor, may cause the device to determine a first frequency region for reference signals among an extended frequency region of frequency domain spectrum shaping (FDSS) based on a communication quality of a channel between the base station and a terminal. The one or more instructions, when individually or collectively executed by the at least one processor, may cause the device to transmit resource allocation information for a second frequency region for data signals among the extended frequency region to the terminal. The one or more instructions, when individually or collectively executed by the at least one processor, may cause the device to receive uplink signals including the reference signals and data signals, configured based on the FDSS, through the extended frequency region. The one or more instructions, when individually or collectively executed by the at least one processor, may cause the device to perform channel estimation for the second frequency domain using the reference signal received through the first frequency domain. The one or more instructions, when individually or collectively executed by the at least one processor, may cause the device to obtain the data signals based on a result of the channel estimation for the second frequency domain.

[0219] According to one embodiment, the one or more instructions, when individually or collectively executed by the at least one processor, may cause the device to transmit to the terminal information for indicating the first frequency range and information for indicating power of the reference signals within the first frequency range.

[0220] According to one embodiment, the one or more instructions, when individually or collectively executed by the at least one processor, may cause the device to transmit the information for indicating the first frequency domain and the information for indicating the power of the reference signals to the terminal via at least one of a radio resource control (RRC) message, a medium access control (MAC) control element (CE), or a downlink control indicator (DCI).

[0221] According to one embodiment, the information for indicating the first frequency range may indicate a ratio of the first frequency range to the extended frequency range. The information for indicating the power of the reference signals may be configured based on EPRE (energy per resource element).

[0222] According to one embodiment, the uplink signal may include extension signals configured based on the FDSS. The extension signals may correspond to at least some of the data signals. The extension signals may be transmitted through a third frequency range, distinct from the second frequency range, among the extension frequency ranges.

[0223] In one embodiment, the one or more instructions, when individually or collectively executed by the at least one processor, may cause the device to perform channel estimation for the first frequency domain via the reference signal received via the first frequency domain. The one or more instructions, when individually or collectively executed by the at least one processor, may cause the device to perform channel estimation for the third frequency domain based on a result of the channel estimation for the first frequency domain. The one or more instructions, when individually or collectively executed by the at least one processor, may cause the device to obtain the extension signals based on a result of the channel estimation for the third frequency domain.

[0224] According to one embodiment, the first frequency range may include the second frequency range.

[0225] According to one embodiment, the one or more instructions, when individually or collectively executed by the at least one processor, may cause the device to obtain the communication quality for the channel based on receiving channel state information (CSI) from the terminal.

[0226] According to one embodiment, the one or more instructions, when individually or collectively executed by the at least one processor, may cause the device to obtain the communication quality for the channel based on receiving a sounding reference signal (SRS) from the terminal.

[0227] According to one embodiment, the one or more instructions, when individually or collectively executed by the at least one processor, may cause the device to determine the first frequency domain based on the performance of a shaping filter for the uplink signal configured based on FDSS and the communication quality for the channel.

[0228] According to one embodiment, a method performed in a device of a base station may include an operation of determining a first frequency region for reference signals among an extended frequency region of frequency domain spectrum shaping (FDSS) based on a communication quality for a channel between the base station and a terminal. The method may include an operation of transmitting resource allocation information for a second frequency region for data signals among the extended frequency region to the terminal. The method may include an operation of receiving uplink signals including the reference signals and data signals, configured based on the FDSS, through the extended frequency region. The method may include an operation of performing channel estimation for the second frequency region through the reference signal received through the first frequency region. The method may include an operation of acquiring the data signals based on a result of the channel estimation for the second frequency region.

[0229] According to one embodiment, the method may include transmitting, to the terminal, information for indicating the first frequency range and information for indicating power of the reference signals within the first frequency range.

[0230] According to one embodiment, the method may include an operation of transmitting, to the terminal, the information for indicating the first frequency domain and the information for indicating the power of the reference signals, via at least one of a radio resource control (RRC) message, a medium access control (MAC) control element (CE), or a downlink control indicator (DCI).

[0231] According to one embodiment, the information for indicating the first frequency range may indicate a ratio of the first frequency range to the frequency range for the uplink signal. The information for indicating the power of the reference signals may be configured based on EPRE (energy per resource element).

[0232] According to one embodiment, the uplink signal may include extension signals configured based on the FDSS. The extension signals may correspond to at least some of the data signals. The extension signals may be transmitted through a third frequency range, distinct from the second frequency range, among the extension frequency ranges.

[0233] According to one embodiment, the method may include an operation of performing channel estimation for the first frequency domain through the reference signal received through the first frequency domain. The method may include an operation of performing channel estimation for the third frequency domain based on a result of the channel estimation for the first frequency domain. The method may include an operation of acquiring the extension signals based on a result of the channel estimation for the third frequency domain.

[0234] According to one embodiment, the first frequency range may include the second frequency range.

[0235] According to one embodiment, the method may include an operation of obtaining the communication quality for the channel based on receiving channel state information (CSI) from the terminal.

[0236] According to one embodiment, the method may include an operation of obtaining the communication quality for the channel based on receiving a sounding reference signal (SRS) from the terminal.

[0237] According to one embodiment, a non-transitory computer-readable storage medium may store one or more programs. The one or more programs may include instructions that, when executed by a processor of a device of a base station, cause the device to determine a first frequency region for reference signals among an extended frequency region of frequency domain spectrum shaping (FDSS) based on a communication quality of a channel between the base station and a terminal. The one or more programs may include instructions that, when executed by the processor, cause the device to transmit resource allocation information for a second frequency region for data signals among the extended frequency region to the terminal. The one or more programs may include instructions that, when executed by the processor, cause the device to receive uplink signals including the reference signals and data signals, the uplink signals being configured based on the FDSS, through the extended frequency region. The one or more programs may include instructions that, when executed by the processor, cause the device to perform channel estimation for the second frequency domain using the reference signal received through the first frequency domain. The one or more programs may include instructions that, when executed by the processor, cause the device to obtain the data signals based on the results of the channel estimation for the second frequency domain.

[0238] The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0239] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured to be executed by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present disclosure. The one or more programs may be provided as a computer program product. The computer program product may be traded between a seller and a buyer as a commodity. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read only memory (CD-ROM)), or may be distributed online (e.g., downloaded or uploaded) via an application store (e.g., Play Store™) or directly between two user devices (e.g., smart phones). In the case of online distribution, at least a portion of the computer program product may be temporarily stored or temporarily created in a device-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

[0240] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage devices, compact disc-ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage devices, magnetic cassettes, or may be stored in memories formed by a combination of some or all of these. In addition, each configuration memory may include multiple copies.

[0241] Additionally, the program may be stored on an attachable storage device that is accessible via a communication network, such as the Internet, an intranet, a local area network (LAN), a wide area network (WAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communication network may be connected to a device performing an embodiment of the present disclosure.

[0242] In the specific embodiments of the present disclosure described above, components included in the disclosure are expressed in the singular or plural form, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in the plural form may be composed of singular elements, or components expressed in the singular form may be composed of plural elements.

[0243] According to embodiments, one or more of the components or operations of the aforementioned components may be omitted, or one or more other components or operations may be added. Alternatively or additionally, a plurality of components (e.g., modules or programs) may be integrated into a single component. In such a case, the integrated component may perform one or more functions of each of the plurality of components identically or similarly to those performed by the corresponding component among the plurality of components prior to the integration. According to embodiments, the operations performed by a module, program, or other component may be executed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be executed in a different order, omitted, or one or more other operations may be added.

[0244] Meanwhile, although the detailed description of the present disclosure has described specific embodiments, it is obvious that various modifications are possible within the scope of the present disclosure.

Claims

1. In the base station equipment, Transmitter and receiver; A memory storing one or more instructions and including a storage medium; and comprising at least one processor including a processing circuit; The one or more instructions, when individually or collectively executed by the at least one processor, cause the device to: Based on the communication quality of the channel between the base station and the terminal, a first frequency range for reference signals is determined among the extended frequency ranges of FDSS (frequency domain spectrum shaping), Transmit resource allocation information for a second frequency range for data signals among the above extended frequency ranges to the terminal, Receiving uplink signals including the reference signals and data signals, configured based on the above FDSS, through the extended frequency range, Perform channel estimation for the second frequency domain through the reference signal received through the first frequency domain, Based on the result of the channel estimation for the second frequency domain, causing the data signals to be acquired, device.

2. In the first paragraph, when the one or more instructions are individually or collectively executed by the at least one processor, the device: Further causing the terminal to transmit information for indicating the first frequency range and information for indicating the power of the reference signals within the first frequency range. device.

3. In the second paragraph, the one or more instructions, when individually or collectively executed by the at least one processor, cause the device to: Further causing the information for indicating the first frequency domain and the information for indicating the power of the reference signals to be transmitted to the terminal through at least one of an RRC (radio resource control) message, a MAC (medium access control) CE (control element), or DCI (downlink control indicator). device.

4. In the second paragraph, the information for indicating the first frequency range is, Indicates the ratio of the first frequency range to the extended frequency range, The above information for indicating the power of the above reference signals is, It is structured based on EPRE (energy per resource element). device.

5. In the first paragraph, the uplink signal, Further including extension signals configured based on the above FDSS, The above extension signals are, Corresponding to at least some of the above data signals, The above extension signals are, Among the commercial extension frequency ranges, transmitted through a third frequency range that is distinct from the second frequency range, device.

6. In the fifth paragraph, the one or more instructions, when individually or collectively executed by the at least one processor, cause the device to: Perform channel estimation for the first frequency domain through the reference signal received through the first frequency domain, Based on the result of the channel estimation for the first frequency domain, the channel estimation for the third frequency domain is performed, Based on the result of the channel estimation for the third frequency domain, further causing the extension signals to be obtained, device.

7. In the fifth paragraph, the first frequency range is, Including the second frequency range, device.

8. In the first paragraph, the one or more instructions, when individually or collectively executed by the at least one processor, cause the device to: Further causing the communication quality for the channel to be obtained based on receiving CSI (channel state information) from the terminal. device.

9. In the first paragraph, the one or more instructions, when individually or collectively executed by the at least one processor, cause the device to: Further causing the communication quality for the channel to be obtained based on receiving the SRS (sounding reference signal) from the terminal. device.

10. In the first paragraph, the one or more instructions, when individually or collectively executed by the at least one processor, cause the device to: Further causing the first frequency range to be determined based on the performance of the shaping filter for the uplink signal configured based on the FDSS and the communication quality for the channel. device.

11. In a method performed in a base station device, An operation of determining a first frequency range for reference signals among the extended frequency ranges of FDSS (frequency domain spectrum shaping) based on the communication quality of the channel between the base station and the terminal; An operation of transmitting resource allocation information for a second frequency range for data signals among the extended frequency ranges to the terminal; An operation of receiving uplink signals including the reference signals and data signals, configured based on the above FDSS, through the extended frequency range; An operation of performing channel estimation for the second frequency domain through the reference signal received through the first frequency domain; and An operation of obtaining the data signals based on the results of the channel estimation for the second frequency domain, method.

12. In the 11th paragraph, the method, Further comprising an operation of transmitting to the terminal information for indicating the first frequency range and information for indicating the power of the reference signals within the first frequency range. method.

13. In the 12th paragraph, the method, Further comprising an operation of transmitting the information for indicating the first frequency domain and the information for indicating the power of the reference signals to the terminal through at least one of an RRC (radio resource control) message, a MAC (medium access control) CE (control element), or DCI (downlink control indicator). method.

14. In the 12th paragraph, the information for indicating the first frequency range is, Indicates the ratio of the first frequency range to the frequency range for the above uplink signal, The above information for indicating the power of the above reference signals is, It is structured based on EPRE (energy per resource element). method.

15. In a non-transitory computer-readable storage medium storing one or more programs, said one or more programs, when executed by a processor of a device of a base station, cause said device to: Based on the communication quality of the channel between the base station and the terminal, a first frequency range for reference signals is determined among the extended frequency ranges of FDSS (frequency domain spectrum shaping), Transmit resource allocation information for a second frequency range for data signals among the above extended frequency ranges to the terminal, Receiving uplink signals including the reference signals and data signals, configured based on the above FDSS, through the extended frequency range, Perform channel estimation for the second frequency domain through the reference signal received through the first frequency domain, Including instructions causing the data signals to be acquired based on the results of the channel estimation for the second frequency domain. A non-transitory computer-readable storage medium.

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