Electronic device and method for acquiring narrowband random access signal

Abstract

According to one embodiment, a method performed by an electronic device may comprise an operation of acquiring multiple symbol groups related to narrowband random access channel (NPRACH) transmission of a narrowband-Internet of things (NB-IoT) device. The method may comprise an operation of dividing the multiple symbol groups into one or more combined groups on the basis of a designated number of symbol groups. The method may comprise an operation of acquiring power values regarding the one or more combined groups, respectively, thereby acquiring power values regarding the one or more combined groups. The method may comprise an operation of acquiring a random access signal of the NB-IoT device on the basis of the power values regarding the one or more combined groups.

Description

Electronic device and method for obtaining narrowband random access signals

[0001] The present disclosure relates to a wireless communication system. More specifically, the present disclosure relates to an electronic device and method for obtaining a narrowband random access signal in a wireless communication system.

[0002] Narrowband (NB) technology is used in mobile communication networks for the Internet of Things (IoT). NB-IoT technology has a small bandwidth and low transmission speed, but can provide wide coverage. NB-IoT technology enables low-cost IoT devices to support improved coverage and longer battery life. Furthermore, NB-IoT technology can collect information data from numerous IoT devices with low power consumption.

[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 is applicable as prior art related to the present disclosure.

[0004] According to one embodiment, an electronic device may include a transceiver, at least one processor including processing circuitry, and one or more storage media, and a memory storing instructions. The instructions, when individually or collectively executed by the at least one processor, may cause the electronic device to obtain a plurality of symbol groups for a narrowband random access channel (NPRACH) transmission of a narrowband-internet of things (NB-IoT) device. The instructions, when individually or collectively executed by the at least one processor, may cause the electronic device to divide the plurality of symbol groups into one or more combined groups based on a specified number of symbol groups. The instructions, when individually or collectively executed by the at least one processor, may cause the electronic device to obtain power values ​​for the one or more combined groups by obtaining a power value for each of the one or more combined groups. The instructions, when individually or collectively executed by the at least one processor, may cause the electronic device to obtain a random access signal of the NB-IoT device based on the power values ​​for the one or more combined groups.

[0005] According to one embodiment, a method performed by an electronic device may include obtaining a plurality of symbol groups for a narrowband random access channel (NPRACH) transmission of an NB-IoT (narrowband-internet of things) device. The method may include dividing the plurality of symbol groups into one or more combined groups based on a specified number of symbol groups. The method may include obtaining power values ​​for the one or more combined groups by obtaining a power value for each of the one or more combined groups. The method may include obtaining a random access signal of the NB-IoT device based on the power values ​​for the one or more combined groups.

[0006] 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 an electronic device, cause the electronic device to obtain a plurality of symbol groups for a narrowband random access channel (NPRACH) transmission of a narrowband-internet of things (NB-IoT) device. The one or more programs may include instructions that, when executed by the processor of the electronic device, cause the electronic device to divide the plurality of symbol groups into one or more combined groups based on a specified number of symbol groups. The one or more programs may include instructions that, when executed by the processor of the electronic device, cause the electronic device to obtain power values ​​for the one or more combined groups by obtaining a power value for each of the one or more combined groups. The one or more programs may include instructions that, when executed by the processor of the electronic device, cause the electronic device to obtain a random access signal of the NB-IoT device based on the power values ​​for the one or more combined groups.

[0007] Figure 1 illustrates a wireless communication system.

[0008] Figure 2 illustrates an example of a base station.

[0009] Figure 3 illustrates an example of a resource structure in the time domain and frequency domain.

[0010] Figure 4 illustrates an example of a random access procedure.

[0011] Figure 5 illustrates an example of NPRACH (narrowband physical random access channel) transmission.

[0012] Figure 6 illustrates an example of the operation of a base station to compensate for frequency offset and time offset.

[0013] Figure 7 illustrates an example of the operation of a base station to obtain binding information.

[0014] Figure 8 illustrates an example of the operation of a base station to identify energy for detecting a random access signal.

[0015] Figure 9 is a flowchart regarding the operation of an electronic device for obtaining a random access signal.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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"}.

[0020] 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.

[0021] Figure 1 illustrates a wireless communication system.

[0022] 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).

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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).

[0030] FIG. 2 illustrates an example of a base station. FIG. 2 illustrates a DU and an RU, where the functions of the base station are implemented by different entities. A fronthaul interface may be used for communication between the DU and the RU. Unlike the backhaul between the base station and the core network, the fronthaul refers to the entity between the wireless LAN and the base station. FIG. 2 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.

[0031] Referring to FIG. 2, the base station (110) may include a DU (210) and a RU (220). The front hole (215) between the DU (210) and the RU (220) is F x It can be operated through an interface. For operation of the fronthaul (215), interfaces such as eCPRI (enhanced common public radio interface) and ROE (radio over ethernet) can be used, for example.

[0032] 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.

[0033] 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.

[0034] 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, iFFT transformation (or FFT transformation), CP insertion (CP removal), and digital beamforming. 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. According to an embodiment, when the RU (220) complies with the O-RAN standard, it may be referred to as an O-RU (O-RAN RU). RU (220) may be replaced with a second network entity for a base station (e.g., gNB) in embodiments of the present disclosure as needed.

[0035] In FIG. 2, the base station (110) is described as including a DU (210) and a RU (220), but 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. For example, the distributed unit (DU) may include a digital unit (DU) and a radio unit (RU) of FIG. 2. In addition, for example, the base station may be implemented in a structure in which the CU, the DU, and the RU are arranged in that order between a core (e.g., a 5G core (5GC) or a next generation core (NGC)) network and a radio network (RAN). The interface between CU and DU (distributed unit) can be referred to as the F1 interface.

[0036] 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 arrangement including a CU and an arrangement in which a DU is directly connected to a core network (i.e., a base station in which the CU and DU are integrated into a single entity (e.g., an NG-RAN node)).

[0037] Figure 3 illustrates an example of a resource structure in the time domain and frequency domain. Figure 3 illustrates the basic structure of the time-frequency domain, which is a radio resource domain in which data or control channels are transmitted in the downlink or uplink.

[0038] Referring to Figure 3, 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 (orthogonal frequency division multiplexing) symbol, N symbOFDM symbols (302) are grouped to form one slot (306). The length of a subframe is defined as 1.0 ms, and the length of a radio frame (314) is defined as 10 ms. 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 (304).

[0039] The basic unit of resources in the time-frequency domain is a resource element (RE) (312), which can be represented by an OFDM symbol index and a subcarrier index. A resource block may include multiple resource elements. In the LTE system, a resource block (RB) (or physical resource block (PRB)) is N in the time domain. symb N consecutive OFDM symbols and frequency domain SC RB are defined as N consecutive subcarriers. In the NR system, a resource block (RB) (308) is defined as N in the frequency domain. SC RB can be defined as a series of consecutive subcarriers (310). One RB (308) is N in the frequency axis. SC RB It contains REs (312). 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.

[0040] In the NR system, in the case of a frequency division duplex (FDD) system that operates the downlink and uplink by frequency division, the downlink transmission bandwidth and the 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 lower than x GHz (e.g., frequency range (FR) 1 (310 MHz to 7125 MHz)). And [Table 2] shows part of the correspondence between the transmission bandwidth, subcarrier spacing, and channel bandwidth defined in the NR system in a frequency band higher than y GHz (e.g., FR2 (24250 MHz - 52600 MHz) or FR2-2 (52600 MHz to 71000 MHz)). For example, an NR system with a 100 MHz channel bandwidth and a 30 kHz subcarrier spacing has a transmission bandwidth of 273 RBs. In [Table 1] and [Table 2], N / A may be a bandwidth-subcarrier combination not supported by the NR system.

[0041] Channel bandwidth [MHz] SCS 5 10 20 50 80 100 Transmission bandwidth configuration N RB15kHz2552106207N / AN / A30kHz11245113321727360kHzN / A112465107135

[0042] Channel bandwidth [MHz] SCS50100200400 Transmission bandwidth configuration N RB 60kHz66132264N / A120kHz3266132264

[0043] FIG. 4 illustrates an example of a random access procedure. The random access procedure may include signaling between a base station (e.g., base station 110) and a terminal (e.g., terminal 120). Although the operations of the base station (110) are described in FIG. 4 , this description does not exclude that at least some of the operations of the base station (110) are performed by the DU (210) and at least some of the operations are performed by the RU (220). That is, depending on how the base station (110) is implemented, for example, all of the operations described below may be performed by a single network entity, or for example, the operations described below may be divided and performed by multiple network entities (e.g., DU (210), RU (220)). The terminal (120) may utilize NB-IoT technology, which is a technology for transmitting signals on a narrowband (e.g., 180 kHz). Meanwhile, NB-IoT may be referred to as cellular IoT (cIoT) or a term with an equivalent technical meaning.

[0044] Referring to FIG. 4, in operation (401), a terminal (120) may transmit a random access signal to a base station (110). The random access signal may be transmitted on a narrowband physical random access channel (NPRACH). The terminal (120) may receive system information related to the NPRACH from the base station. Based on the system information, the terminal (120) may transmit a random access preamble to the base station (110). The random access signal may be referred to as message 1 (MSG 1), PRACH, N PRACH, preamble, RACH (random access channel) preamble, RACH signal, random access preamble, or a term having an equivalent technical meaning thereto. Depending on the setting of the base station (110), the terminal (120) may repeatedly transmit the random access signal. The number of repetitions of the above random access signal can be configured based on the RRC configuration of the base station (110) or the above system information.

[0045] In operation (402), the base station (110) may transmit a random access response (RAR) to the terminal (120). The random access response may be transmitted on a narrowband physical downlink shared channel (NPDSCH). A message including the random access response may include message 2 (MSG 2). In response to a random access preamble received from the terminal (120), the base station (110) may transmit the message to the terminal (120). Downlink scheduling information for the above message may be CRC masked with a random access-RNTI (radio network temporary identifier) ​​and transmitted on an L1 / L2 control channel (e.g., a narrowband physical control channel (NPDCCH)). A terminal (120) that receives a downlink scheduling signal masked with an RA-RNTI may obtain and decode a random access response on an NPDSCH. For example, the random access response may include scheduling information for an uplink message described below. In addition, for example, the random access response may include information on repetition of the uplink message.

[0046] In operation (403), the terminal (120) may transmit an uplink message to the base station (110). The uplink message may be transmitted on a narrowband physical uplink shared channel (NPUSCH). The uplink message may correspond to scheduled transmission. The terminal (120) may transmit the uplink message to the base station (110) based on radio resource allocation information included in the random access response. The uplink message may be referred to as message 3 (MSG 3). The terminal (120) may repeat the transmission of the uplink message as many times as obtained based on the random access response.

[0047] In operation (404), the base station (110) may transmit a contention resolution message to the terminal (120). The contention resolution message may be transmitted on the NPDSCH. The contention resolution message may be referred to as message 4 (MSG 4). For example, the contention resolution message may include an RRC connection setup message. Although not illustrated in FIG. 4, the terminal (120) may transmit a connection setup completion message to the base station after receiving the contention resolution message from the base station (110).

[0048] Although a contention-based random access procedure is described in FIG. 4, embodiments of the present disclosure are not limited thereto. Operations related to receiving random access signals by an NB-IoT terminal of the present disclosure may also be applied to a non-contention-based random access procedure. In a non-contention-based random access procedure, the base station (110) and the terminal (120) may not perform operations (403) and (404).

[0049] As described through FIG. 4, the base station (110) and the terminal (120) can perform the Internet of Things (i.e., NB-IoT) using a narrowband. For example, the narrowband can be 180 kHz. The terminal (120) using NB-IoT technology can be referred to as an NB-IoT UE. The NB IoT UE can also perform communication in areas with poor channel environments, such as under bridges, under the sea, or at sea. To compensate for poor channel environments, techniques such as repetition and power boosting for specific channels can be used. For example, a technique using power boosting can include a technique that further reduces the frequency resource area to be transmitted within a specific band and concentrates power per hour on a specific resource. For example, the above technique may include a method of concentrating power that would otherwise be distributed throughout the entire RB and allocating it only to a specific RE, instead of allocating REs per RB when transmitting a specific signal through a resource block (RB) composed of 12 REs (resource elements). This method of performing communication by concentrating data and power in a single RE within an RB may be referred to as a single-tone transmission method.

[0050] Figure 5 illustrates an example of NPRACH (narrowband physical random access channel) transmission. NPRACH refers to a physical channel through which a random access signal of an NB-IoT UE is transmitted.

[0051] Referring to FIG. 5, the resource grid (500) represents time and frequency resources through which a random access signal is transmitted. The horizontal axis of the resource grid (500) represents time, and the vertical axis represents frequency. The random access signal may be transmitted in a narrowband. For example, the narrowband may be 180 kHz. One RE corresponds to 15 kHz, and 12 REs may constitute one RB, which may be the narrowband.

[0052] An NB-IoT UE (e.g., terminal 120) can transmit a random access signal. For example, the NB-IoT UE can transmit the random access signal based on a repetition number. The repetition number can be indicated by configuration information received through RRC signaling of a base station (e.g., base station 110). The NB-IoT UE can repeat transmission of the random access signal a number of times according to the repetition number. For example, when the repetition number is 1, the NB-IoT UE can transmit the random access signal. For another example, when the repetition number is 4, the NB-IoT UE can transmit the random access signal 4 times. For another example, when the repetition number is 16, the NB-IoT UE can transmit the random access signal 16 times.

[0053] The random access signal that is the basis of repetition may include four symbol groups. One symbol group (520) among the four symbol groups may include one CP (cyclic prefix) and five symbols. The four symbol groups may be arranged without time gaps between the symbol groups. Each symbol group of the four symbol groups may have an independent tone. For example, each symbol group of the four symbol groups may correspond to a specific subcarrier that is distinct from the subcarriers of other symbol groups. The four symbol groups may sequentially include a first symbol group, a second symbol group, a third symbol group, and a fourth symbol group in one cycle. Depending on the preamble format, the length of the CP may vary. For example, the length of the CP (T CP ) and the total length of the five symbols (T SEQ ) can be configured as shown in the table below. Here, the basic time unit is

[0054]

[0055] For example, assume that the number of repetitions is 4. An NB-IoT UE may transmit a random access signal during a first time interval (511) (e.g., 6.4 ms (milliseconds)). Within the first time interval (511), the NB-IoT UE may transmit a preamble of a first symbol group on subcarrier #0. Within the first time interval (511), the NB-IoT UE may transmit a preamble of a second symbol group on subcarrier #1. Within the first time interval (511), the NB-IoT UE may transmit a preamble of a third symbol group on subcarrier #7. Within the first time interval (511), the NB-IoT UE may transmit a preamble of a fourth symbol group on subcarrier #6. An NB-IoT UE can transmit preambles corresponding to a random access signal within a narrowband (e.g., 180 kHz) and a first time interval (511) corresponding to the first cycle through frequency hopping.

[0056] The NB-IoT UE may transmit a random access signal during a second time interval (512). The random access signal of the second time interval (512) is the same as the random access signal of the first time interval (511), but the frequency location may be changed. Within the second time interval (512), the NB-IoT UE may transmit a preamble of the first symbol group on subcarrier #2. Within the second time interval (512), the NB-IoT UE may transmit a preamble of the second symbol group on subcarrier #3. Within the second time interval (512), the NB-IoT UE may transmit a preamble of the third symbol group on subcarrier #9. Within the second time interval (512), the NB-IoT UE may transmit a preamble of the fourth symbol group on subcarrier #8. An NB-IoT UE may transmit preambles corresponding to a random access signal within a narrowband (e.g., 180 kHz) and a second time interval (512) corresponding to the second cycle through frequency hopping.

[0057] The NB-IoT UE may transmit a random access signal during a third time interval (513). Within the third time interval (513), the NB-IoT UE may transmit a preamble of the first symbol group on subcarrier #10. Within the third time interval (513), the NB-IoT UE may transmit a preamble of the second symbol group on subcarrier #11. Within the third time interval (513), the NB-IoT UE may transmit a preamble of the third symbol group on subcarrier #5. Within the third time interval (513), the NB-IoT UE may transmit a preamble of the fourth symbol group on subcarrier #4. The NB-IoT UE may transmit preambles corresponding to the random access signal within the third time interval (513) corresponding to a narrowband (e.g., 180 kHz) and the third time through frequency hopping.

[0058] The NB-IoT UE may transmit a random access signal during a fourth time interval (514). Within the fourth time interval (514), the NB-IoT UE may transmit a preamble of the first symbol group on subcarrier #8. Within the fourth time interval (514), the NB-IoT UE may transmit a preamble of the second symbol group on subcarrier #9. Within the fourth time interval (514), the NB-IoT UE may transmit a preamble of the third symbol group on subcarrier #3. Within the fourth time interval (514), the NB-IoT UE may transmit a preamble of the fourth symbol group on subcarrier #2. The NB-IoT UE may transmit preambles corresponding to the random access signal within the fourth time interval (514) corresponding to a narrowband (e.g., 180 kHz) and the fourth time through frequency hopping.

[0059] As described in FIG. 5, an NB-IoT UE can transmit a random access preamble using a single-tone transmission method within the same symbol group during a single transmission. NPRACH can be used in environments with small channel variations. Meanwhile, since symbol groups are designed with small subcarrier spacing and long CPs, the detection performance of random access signals is more sensitive to frequency offset than time offset. In the single-tone transmission method, when the residual frequency offset is large for subcarrier spacing (SCS), the power of the received NPRACH preamble may leak to adjacent subcarriers, increasing interference with other preambles. The increased interference degrades the detection performance on the receiver side.

[0060] In the following specification, a base station (e.g., base station (110)) or a device of the base station (e.g., DU (210) or RU (220)) for obtaining uplink timing synchronization to compensate for time offset will be described.

[0061] A method for achieving good reception performance in NB-IoT systems involves estimating the frequency offset, using the estimated frequency offset to compensate for the received signal, estimating the uplink timing offset, and then using the energy information of the compensated uplink timing offset to determine whether a random access signal has been received. However, this method suffers from excessively high implementation complexity. Specifically, the following is a detailed explanation.

[0062] A random access signal may include multiple OFDM symbols. For example, a random access signal may include It can contain M symbols. The random access signal contains M symbol groups, and each symbol group can contain L symbols. For example, the received signal in the lth symbol of the mth symbol group among the M symbol groups can be expressed as follows.

[0063]

[0064]

[0065] In mathematical expression 1, A can be expressed as follows.

[0066]

[0067] The random access signal in the frequency domain derived from the above-described mathematical expression 1 according to FFT can be expressed as follows.

[0068]

[0069]

[0070] A base station (e.g., base station (110)) or a DU of a base station (e.g., DU (210)) has a time offset (D) and a frequency A local sequence having a phase shift corresponding to the local sequence can be generated. The base station or DU (210) can identify the correlation between the local sequence and the symbol group (m) and the symbol number (l) within the symbol group based on the local sequence. When the signal exists at a position according to the actual time offset and frequency offset, the base station (110) can obtain the peak energy according to the correlation. For example, the peak energy can be obtained based on the following mathematical equation.

[0071]

[0072] Based on Equations 3 and 4, the correlation between the time offset and the frequency offset can be constructed based on the following mathematical equation. Given the joint estimation of the time offset and the frequency offset, the time offset and the frequency offset can be estimated to have the largest correlation value (i.e., the largest peak energy).

[0073]

[0074] Based on Equation 5, a two-dimensional FFT can be used to estimate the time offset and frequency offset that provide the greatest correlation. For example, the right-hand side of Equation 5 can be transformed into the following equation.

[0075]

[0076]

[0077] The random access signal of 3GPP NB-IoT uses a multi-level frequency hopping method that uses a single tone and changes the tone at regular intervals. As described above, jointly estimating the frequency offset and time offset (or uplink timing) and identifying the energy for detecting the random access signal has the problem of high implementation complexity in detecting the random access signal. To solve the above-described problem, embodiments of the present disclosure may relate to a method for identifying the energy of an optimized received signal for detecting a random access signal (or NPRACH signal) optimized for multi-level frequency hopping.

[0078] Figure 6 illustrates an example of the operation of a base station for compensating for frequency offset and time offset. Figure 6 illustrates functional blocks for processing signals received via an antenna. Each functional block can be understood as an operation within a network entity (e.g., a base station (110), a unit (DU) (210), or an RU (220)).

[0079] Referring to FIG. 6, in operation (611), the base station (110) can perform gap and CP removal. Random access signals received from each antenna can have gaps and CPs removed according to the 3GPP NB-IoT standard.

[0080] In operation (613), the base station (110) can perform frequency shifting. The base station (110) can perform frequency shifting on a signal from which gaps and CPs have been removed.

[0081] In operation (615), the base station (110) can perform automatic gain control (AGC). The base station can determine the gain and phase to be applied to the signal through AGC for the signal acquired through operation (613).

[0082] In operation (617), the base station (110) can perform FFT. The base station (110) can perform FFT on the signal acquired through operation (615) to change the signal from the time domain to the frequency domain.

[0083] In operation (619), the base station (110) may perform subcarrier demapping. For example, the base station (110) may demap the output signal of operation (617) to subcarriers used for the random access signal (e.g., 48 = 12 x 4 subcarriers).

[0084] In operation (621), the base station (110) may perform subcarrier buffering. The demapped signal may be buffered until the result of frequency offset estimation is derived.

[0085] In operation (623), the base station (110) can estimate a frequency offset. The base station (110) can estimate the frequency offset based on an inter-symbol correlation operation. The estimated frequency offset can be used to compensate for a frequency difference present in the random access signal. For example, the functional block corresponding to operation (623) (i.e., a frequency offset estimator) can include a total noise estimator, a frequency correlator, and a frequency offset decision block.

[0086] In operation (625), the base station (110) can perform frequency offset compensation. The base station (110) can perform frequency offset compensation by applying the estimated frequency offset result to the demapped signal.

[0087] In operation (627), the base station (110) may perform subcarrier buffering. The signal with the frequency offset compensated may be buffered until the result of the time offset estimation is derived.

[0088] In operation (629), the base station (110) can estimate a time offset. The base station (110) can estimate the time offset based on inter-symbol correlation operations. The estimated time offset can be used to compensate for a time difference present in a random access signal.

[0089] In operation (631), the base station (110) can perform time offset compensation. The base station (110) can perform time offset compensation by applying the estimated time offset result to a signal for which the frequency offset has been compensated.

[0090] In operation (633), the base station (110) may perform subcarrier buffering. The time offset compensated signal may be buffered until the energy of the signal is identified.

[0091] In operation (635), the base station (110) may generate (or obtain) combine information. For example, the base station (110) may generate (or obtain) combine information for determining the number of symbol groups for which coherent combining is to be performed. The base station (110) may generate (or obtain) combine information based on correlation values ​​between symbol groups within a time interval (e.g., the first time interval (511)) during which a random access signal is transmitted.

[0092] In operation (637), the base station (110) can obtain (or calculate) energy for a signal classified based on the combination information. The energy for the signal classified based on the combination information can be used to determine whether a random access signal (or NPRACH signal) is received. For example, if the magnitude of the energy is less than or equal to a specified value, the base station (110) can identify (or determine) that a random access signal (or NPRACH signal) is not received. If the magnitude of the energy exceeds a specified value, the base station (110) can identify (or determine) that a random access signal (or NPRACH signal) is received.

[0093] In FIG. 6, operations (611) to (637) are described as operations of the base station (110), but embodiments of the present disclosure are not limited thereto. The operations described in FIG. 6 may be divided among a plurality of network entities (e.g., DU (210), RU (220)), and each network entity may be configured to perform the corresponding operation. In other words, in order to lower the transmission capacity of the wired network and reduce the installation cost of the wired network, 'function split' may be used, which transfers some functions of the modem of the DU to the RU to lower the transmission capacity of the fronthaul. In order to reduce the burden on the DU, the role of the RU, which is currently responsible for only RF functions, may be expanded to include some functions of the physical layer. As the RU performs higher layer functions, the throughput of the RU increases, which increases the transmission bandwidth in the fronthaul and at the same time reduces the delay time requirement constraint due to response processing. Meanwhile, as RUs perform higher-layer functions, virtualization benefits diminish and their size, weight, and cost increase. Considering the trade-offs between the advantages and disadvantages described above, implementing optimal functional separation is required.

[0094] In the case of downlink (DL) that transmits a signal to a terminal (120) through a wireless network, network entities 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. In the case of uplink (UL) that receives a signal from a terminal (120) through a wireless network, network entities 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 functions and downlink functions can be defined in various types depending on the needs of vendors, discussions in standards, etc., according to the above-described trade-offs. According to one embodiment, in a specific functional separation (e.g., Option 7-2x), the RU (220) may perform iFFT transform / CP insertion in the DL and FFT transform / CP removal in the UL of the PHY function, and the DU (210) may perform the remaining PHY functions. For example, the operations (611) to (617) described above may be performed in the RU (220), and the operations (619) to (637) may be performed in the DU (210). According to another embodiment, in a specific functional separation (e.g., Option 7-2), the RU (220) may perform RE mapping (or RE demapping) in both the DL and UL, and the DU (210) may perform upper PHY functions after the RE mapping (or RE demapping). For example, the above-described operations (611) to (621) may be performed in the RU (220), and operations (623) to (637) may be performed in the DU (210).In another embodiment, in a specific functional separation (e.g., Option 6), the RU (220) may perform encoding / scrambling (or decoding / descrambling) in both the DL and UL, and the DU (210) may perform subsequent higher PHY functions up to modulation (or demodulation). For example, the operations (611) to (637) described above may be performed in the RU (220).

[0095] According to the above-described operations (629) and (631), the base station (110) can identify the delay value (or time offset) of the random access signal. The base station (110) can use the delay value as information for uplink synchronization acquisition of the NB-IoT system. The base station (110) can remove the frequency offset generated during the uplink transmission and reception process from the random access signal in the frequency domain. The random access signal with the frequency offset removed can be expressed as follows.

[0096]

[0097]

[0098]

[0099]

[0100]

[0101] Figure 7 illustrates an example of the operation of a base station to obtain binding information.

[0102] Referring to FIG. 7, the base station (110) may perform operations (701) to (709) to obtain binding information. Operations (701) to (709) described below may correspond to operation (635) of FIG. 6.

[0103] The base station (110) can identify a correlation value between two symbol groups using a random access signal (700). The random access signal (700) may be a random access signal (e.g., a signal according to Equation 8) with a frequency offset and a time offset corrected.

[0104] For example, a random access signal (e.g., a PRACH signal) transmitted in NPRACH may include four groups of symbols within a designated resource (e.g., a designated time interval and / or a designated frequency range). The random access signal may be repeatedly transmitted according to a designated number of repetitions. One random access signal may be transmitted within one designated time interval. The random access signal may be repeatedly transmitted in the repeated designated time intervals.

[0105] For example, the base station (110) can identify the correlation value between two symbol groups among four symbol groups within one designated time interval. For example, the base station (110) can identify the correlation value between the first symbol group and the fourth symbol group among four symbol groups within one designated time interval. Referring to FIG. 5, the base station (110) can identify the correlation value between the first symbol group (or the preamble of the first symbol group) transmitted on subcarrier #0 and the fourth symbol group (or the preamble of the fourth symbol group) transmitted on subcarrier #6 within the time interval (511). The first symbol group and the fourth symbol group selected within the time interval (511) are exemplary and are not limited thereto.

[0106] In operation (701), the base station (110) may select (or identify) an antenna and subcarrier corresponding to a first symbol group (e.g., a first symbol group among four symbol groups) of a random access signal (700). The base station (110) may obtain a first signal corresponding to the selected subcarrier.

[0107] In operation (702), the base station (110) may select (or identify) an antenna and subcarrier corresponding to a second symbol group (e.g., a fourth symbol group among four symbol groups) among the random access signal (700). The base station (110) may obtain a second signal corresponding to the selected subcarrier.

[0108] In operation (703), the base station (110) may perform coherent combining on symbols included in the first symbol group based on the first signal. For example, the base station (110) may obtain the first combined signal by performing coherent combining on five symbols included in the first symbol groups.

[0109] In operation (704), the base station (110) may perform coherent combining on symbols included in the second symbol group based on the second signal. For example, the base station (110) may obtain a second combined signal by performing coherent combining on five symbols included in the second symbol groups.

[0110] In operation (705), the base station (110) can identify a correlation value between the first combined signal and the second combined signal. The correlation value between the first combined signal and the second combined signal can be expressed as follows.

[0111]

[0112] Referring to mathematical equation 9, is a correlation value between a first combined signal for a first symbol group among four symbol groups and a second combined signal for a fourth symbol group among four symbol groups. This is exemplary and not limiting. For example, a correlation value between a first combined signal for a second symbol group among four symbol groups and a second combined signal for a third symbol group among four symbol groups can be expressed as follows.

[0113]

[0114] According to the embodiment, can be identified (or constructed, obtained) based on a combination of correlation values ​​between the combined signals. For example, can be identified based on a combination of a first correlation value and a second correlation value. The first correlation value may be a correlation value between two combined signals. The second correlation value may be a correlation value between two combined signals. For example, the first correlation value may be a correlation value between a first combined signal for a first symbol group among four symbol groups and a second combined signal for a fourth symbol group among the four symbol groups. The second correlation value may be a correlation value between a first combined signal for a second symbol group among the four symbol groups and a second combined signal for a third symbol group among the four symbol groups.

[0115] for example, is constructed based on a first correlation value (e.g., a correlation value according to Equation 9), and a second correlation value (e.g., a correlation value according to Equation 10) It can be used as an auxiliary for identification (or composition, acquisition).

[0116] for example, can be identified (or constructed, obtained) by applying a first weight to a first correlation value and a second weight to a second correlation value. can be expressed as the following mathematical formula.

[0117]

[0118]

[0119] In operation (706), the base station (110) may accumulate (or sum) the identified correlation values ​​according to a specified number of repetitions (e.g., 4 times). Through operation (706), the base station (110) may identify a first cumulative correlation value. The first cumulative correlation value may be expressed as follows.

[0120]

[0121] Referring to Equation 12, corr_1 is the first cumulative correlation value.

[0122] In operation (707), the base station (110) can accumulate (or sum) the first accumulated correlation value as many times as the number of antennas of the base station (110). Through operation (707), the base station (110) can identify the second accumulated correlation value. The second accumulated correlation value can be expressed as follows.

[0123]

[0124]

[0125] In operation (708), the base station (110) may select a real part for the second cumulative correlation value (corr). The base station (110) may identify the real part for the second cumulative correlation value (corr). The second cumulative correlation value (corr) is a complex number. The base station (110) may identify the value of the real part for the second cumulative correlation value (corr). The value of the real part for the second cumulative correlation value (corr) may be expressed as follows.

[0126]

[0127] Referring to mathematical expression 14, corr_info is the real part of the second cumulative correlation value (corr).

[0128] In operation (709), the base station (110) can obtain (or generate) combine information by using the real part value (corr_info) for the second accumulated correlation value.

[0129] For example, if the specified number of repetitions is 4, the combination information can be obtained according to the size of corr_info. The combination information according to the size of corr_info can be configured as shown in the table below.

[0130]

[0131] Referring to Table 4, th0, th1, th2, and th3 are designated threshold values ​​for identifying (or determining) the combine information (α). The designated threshold values ​​may be changed. Table 4 shows an example in which the combine information (α) is identified as one of four values ​​(16, 8, 4, and 2) according to the size of corr_info, but this is exemplary and not limited thereto. The size of Table 4 may be changed, and the range of the combine information (α) may be set to one of 1 to M. M is the number of all symbol groups according to the designated repetition number. If four symbol groups are included in the designated time interval and the repetition number is R, M is For example, the random access signal in the frequency domain used by each NB-IoT UE is It can be composed of symbol groups. R can be the number of repetitions assigned to each NB-IoT UE.

[0132] According to one embodiment, the base station (110) can identify energy for detecting a random access signal using the combined information (α) obtained according to operations (701) to (709). A specific operation for identifying energy for detecting a random access signal using the combined information (α) will be described later in FIG. 8.

[0133] Figure 8 illustrates an example of the operation of a base station to identify energy for detecting a random access signal.

[0134] Referring to FIG. 8, the base station (110) may perform operations (801) to (805) to identify energy for detecting a random access signal. Operations (801) to (805) described below may correspond to operation (637) of FIG. 6.

[0135] The base station (110) can identify energy for detecting a random access signal using a random access signal (700). The random access signal (700) may be a random access signal (e.g., a signal according to Equation 8) with a frequency offset and a time offset corrected.

[0136] In operation (801), the base station (110) may perform coherent combining for each symbol group of the random access signal (700) as many as the number of symbols included in the corresponding symbol group. For example, the number of symbols in the symbol group of the random access signal (700) may be L (e.g., 5). The base station (110) may perform coherent combining on signals of the L symbols. The base station (110) may obtain a combined signal of each symbol group. The base station (110) may perform coherent combining on symbol groups according to combining information. The base station (110) may obtain a combined signal of symbol groups according to combining information. For example, the base station (110) Coherent combining can be performed during the symbol interval of the base station (110). By performing coherent combining during the symbol interval, a combined signal of symbol groups according to combining information can be obtained. The combined signal of symbol groups according to combining information can be expressed as follows.

[0137]

[0138] In operation (803), the base station (110) can accumulate (or sum) the combined signals of the symbol groups according to the combined information as many as the number of antennas (Rx_ant) of the base station (110). The combined signals accumulated (or summed) as many as the number of antennas (Rx_ant) can be expressed as follows.

[0139]

[0140]

[0141]

[0142] Referring to mathematical expression 17, E is the energy for detecting a random access signal. If E exceeds a specified value, the base station (110) can identify (or determine) that a random access signal (or NPRACH signal) has been received. If E is less than or equal to a specified value, the base station (110) can identify (or determine) that a random access signal (or NPRACH signal) has not been received.

[0143] According to the above-described operations (801) to (805), the base station (110) can perform an operation for detecting a random access signal. According to the above-described embodiment, the implementation complexity for detecting a random access signal can be reduced, and the performance for detecting a random access signal can be improved.

[0144] Figure 9 is a flowchart regarding the operation of an electronic device for obtaining a random access signal.

[0145] Referring to FIG. 9, in operation 910, an electronic device (or a processor of the electronic device) may obtain a plurality of symbol groups related to NPRACH transmission of an NB-IoT device. For example, the electronic device may include a digital unit or distributed unit (DU). For example, the electronic device may obtain a signal related to NPRACH transmission. The signal related to NPRACH transmission may be obtained through an antenna (or at least one antenna) of a radio unit (RU). The electronic device may identify a signal related to NRPACH transmission obtained through the RU.

[0146] According to one embodiment, the electronic device can identify a frequency offset and a time offset based on a signal regarding an NPRACH transmission. For example, the operation of identifying a frequency offset based on a signal regarding an NPRACH transmission may be related to operation (623) of FIG. 6. For example, the operation of identifying a time offset based on a signal regarding an NPRACH transmission may be related to operation (629) of FIG. 6. The order of the operations of identifying a frequency offset and the operations of identifying a time offset may be changed. The operations of identifying a frequency offset and the operations of identifying a time offset may also be performed in parallel.

[0147] An electronic device can compensate for frequency and time offsets in a signal related to NPRACH transmission. For example, the electronic device can compensate for the frequency offset in a signal related to NPRACH transmission, and then compensate for the time offset. The order of the frequency offset compensation and time offset compensation operations can be changed.

[0148] An electronic device can obtain multiple symbol groups based on compensating for frequency offset and time offset in a signal for NPRACH transmission.

[0149] For example, a random access signal may be transmitted according to a repetition count set for NPRACH transmission. Multiple symbol groups may be obtained based on repetition of the random access signal according to the repetition count.

[0150] A random access signal can be transmitted through one repetition cycle (e.g., the first time interval (511) of FIG. 5). If the number of repetitions set for NPRACH transmission is 5, the random access signal can be transmitted in each of the 5 repetition cycles. The random access signal transmitted through one repetition cycle can include one or more symbol groups. The number of symbol groups included in the random access signal can be set to 4. For example, if the number of repetitions is 5, since the number of symbol groups included in the random access signal is 4, the number of multiple symbol groups can be 20.

[0151] For example, a symbol group may contain five symbols. A symbol group may contain five symbols organized based on a cyclic prefix (CP) and a specified sequence.

[0152] In operation 920, the electronic device may divide the plurality of symbol groups into one or more combined groups. For example, the electronic device may divide the plurality of symbol groups into one or more combined groups based on a specified number of symbol groups.

[0153] For example, the electronic device may determine (or identify) a specified number of symbols. The electronic device may perform a correlation operation between at least two groups of symbols among a plurality of groups of symbols.

[0154] An electronic device can identify at least two symbol groups among a plurality of symbol groups. For example, the electronic device can identify two symbol groups among the plurality of symbol groups. The electronic device can identify two symbol groups included in one repetition period. The electronic device can perform a correlation operation between the two symbol groups included in one repetition period. The two symbol groups included in one repetition period can include a first symbol and a last symbol within one repetition period.

[0155] An electronic device may perform a coherent combining operation on each of at least two symbol groups. For example, the electronic device may perform a coherent combining operation on symbols included in a first symbol group (e.g., five symbols). The electronic device may obtain a first combined signal based on the coherent combining operation on the symbols included in the first symbol group. The electronic device may perform a coherent combining operation on symbols included in a second symbol group (e.g., five symbols). The electronic device may obtain a second combined signal based on the coherent combining operation on the symbols included in the second symbol group. The electronic device may identify a correlation value based on identifying a correlation value between the first combined signal and the second combined signal. Similar to the operation described above, the electronic device may identify correlation values ​​according to a specified number of repetitions. The electronic device may identify a first accumulated correlation value by accumulating the correlation values. The electronic device may obtain a second accumulated correlation value by accumulating the first accumulated correlation value as many times as the number of antennas. The electronic device can determine the second accumulated correlation value as an output value of the correlation operation. The electronic device can identify the real part of the output value as a result of the correlation operation.

[0156] An electronic device may determine a specified number based on a result of a correlation operation between at least two groups of symbols. The electronic device may determine the specified number based on a result of a correlation operation between at least two groups of symbols. The electronic device may identify the result of the correlation operation as one of a first range to a fourth range. The electronic device may identify the specified number as a first number (e.g., 16) based on identifying that the result of the correlation operation is within the first range. The electronic device may identify the specified number as a second number (e.g., 8) based on identifying that the result of the correlation operation is within the second range. The electronic device may identify the specified number as a third number (e.g., 4) based on identifying that the result of the correlation operation is within the third range. The electronic device may identify the specified number as a fourth number (e.g., 2) based on identifying that the result of the correlation operation is within the fourth range.

[0157] In operation 930, the electronic device may obtain a power value for one or more combined groups. For example, the electronic device may perform a coherent combining operation on each of the one or more combined groups. By obtaining a power value of a signal resulting from the coherent combining operation on each of the one or more combined groups, the electronic device may obtain a power value for each of the one or more combined groups.

[0158] In operation 940, the electronic device may acquire a random access signal of an NB-IoT device. For example, the electronic device may acquire a random access signal of the NB-IoT device based on power values ​​for one or more association groups.

[0159] For example, an electronic device may identify a sum power value of power values ​​for one or more combined groups. The electronic device may acquire a random access signal based on a sum power value that is greater than or equal to a specified power value. If the sum power value is greater than or equal to the specified power value, the electronic device may determine that a random access signal has been received. If the sum power value is less than the specified power value, the electronic device may determine that a random access signal has not been received.

[0160] For example, if there are 16 symbol groups and the specified number is 8, the plurality of symbol groups can be divided into a first combined group and a second combined group. The electronic device can obtain a first power value of a signal according to a coherent combining operation for the first combined group, and can obtain a second power value of the signal according to a coherent combining operation for the second combined group. The electronic device can identify a sum power value of the first power value and the second power value. The electronic device can obtain a random access signal based on a sum power value that is greater than or equal to a specified power value.

[0161] According to one embodiment, an electronic device (e.g., a base station (110) or a DU (320)) may include a transceiver, at least one processor including processing circuitry, and one or more storage media, and may include a memory for storing instructions. The instructions, when individually or collectively executed by the at least one processor, may cause the electronic device to obtain a plurality of symbol groups for a narrowband random access channel (NPRACH) transmission of a narrowband-internet of things (NB-IoT) device. The instructions, when individually or collectively executed by the at least one processor, may cause the electronic device to segment the plurality of symbol groups into one or more combined groups based on a specified number of symbol groups. The instructions, when individually or collectively executed by the at least one processor, may cause the electronic device to obtain power values ​​for the one or more combination groups by obtaining a power value for each of the one or more combination groups. The instructions, when individually or collectively executed by the at least one processor, may cause the electronic device to obtain a random access signal of the NB-IoT device based on the power values ​​for the one or more combination groups.

[0162] According to one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the electronic device to perform a coherent combining operation on each of the one or more combination groups. The instructions, when individually or collectively executed by the at least one processor, may cause the electronic device to obtain a power value for each of the one or more combination groups by obtaining a power value of a signal according to the coherent combining operation for each of the one or more combination groups.

[0163] According to one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the electronic device to perform a correlation operation between at least two symbol groups of the plurality of symbol groups. The instructions, when individually or collectively executed by the at least one processor, may cause the electronic device to determine the specified number based on a result of the correlation operation between the at least two symbol groups.

[0164] In one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the electronic device to identify at least two symbol groups from the plurality of symbol groups. The instructions, when individually or collectively executed by the at least one processor, may cause the electronic device to perform a coherent combining operation on each of the at least two symbol groups. The instructions, when individually or collectively executed by the at least one processor, may cause the electronic device to perform the correlation operation on the at least two symbol groups on which the coherent combining operation was performed.

[0165] In one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the electronic device to identify the real part of the output value of the correlation operation for the at least two symbols as the result of the correlation operation.

[0166] According to one embodiment, the random access signal may be transmitted according to a repetition number set for the NPRACH transmission. The plurality of symbol groups may be obtained based on repetition of the random access signal according to the repetition number.

[0167] According to one embodiment, one of the plurality of symbol groups may include five symbols.

[0168] In one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the electronic device to identify a frequency offset and a time offset based on a signal relating to the NPRACH transmission. The instructions, when individually or collectively executed by the at least one processor, may cause the electronic device to obtain the plurality of symbol groups based on compensating for the frequency offset and the time offset in the signal.

[0169] According to one embodiment, the electronic device may include a digital unit (DU). The signal related to the NPRACH transmission may be acquired through an antenna of a radio unit (RU).

[0170] In one embodiment, the instructions, when individually or collectively executed by the at least one processor, may cause the electronic device to identify a sum power value of the power values ​​for the one or more combined groups. The instructions, when individually or collectively executed by the at least one processor, may cause the electronic device to obtain the random access signal based on the sum power value being greater than or equal to a designated power value.

[0171] According to one embodiment, a method performed by an electronic device may include obtaining a plurality of symbol groups for a narrowband random access channel (NPRACH) transmission of an NB-IoT (narrowband-internet of things) device. The method may include dividing the plurality of symbol groups into one or more combined groups based on a specified number of symbol groups. The method may include obtaining power values ​​for the one or more combined groups by obtaining a power value for each of the one or more combined groups. The method may include obtaining a random access signal of the NB-IoT device based on the power values ​​for the one or more combined groups.

[0172] According to one embodiment, the method may include performing a coherent combining operation on each of the one or more combined groups. The method may include obtaining a power value for each of the one or more combined groups by obtaining a power value of a signal according to the coherent combining operation on each of the one or more combined groups.

[0173] According to one embodiment, the method may include an operation of performing a correlation operation between at least two symbol groups among the plurality of symbol groups. The method may include an operation of determining the specified number based on a result of the correlation operation between the at least two symbol groups.

[0174] According to one embodiment, the method may include an operation of identifying at least two symbol groups among the plurality of symbol groups. The method may include an operation of performing a coherent combining operation on each of the at least two symbol groups. The method may include an operation of performing the correlation operation on the at least two symbol groups on which the coherent combining operation was performed.

[0175] According to one embodiment, the method may include an operation of identifying the real part of the output value of the correlation operation for the at least two symbols as the result of the correlation operation.

[0176] According to one embodiment, the random access signal may be transmitted according to a repetition number set for the NPRACH transmission. The plurality of symbol groups may be obtained based on repetition of the random access signal according to the repetition number.

[0177] According to one embodiment, one of the plurality of symbol groups may include five symbols.

[0178] According to one embodiment, the method may include an operation of identifying a frequency offset and a time offset based on a signal relating to the NPRACH transmission. The method may include an operation of obtaining the plurality of symbol groups based on compensating for the frequency offset and the time offset in the signal.

[0179] In one embodiment, the method may include an operation of identifying a sum power value of the power values ​​for the one or more combined groups. The method may include an operation of obtaining the random access signal based on the sum power value being greater than or equal to a specified power value.

[0180] 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 an electronic device, cause the electronic device to obtain a plurality of symbol groups for a narrowband random access channel (NPRACH) transmission of a narrowband-internet of things (NB-IoT) device. The one or more programs may include instructions that, when executed by the processor of the electronic device, cause the electronic device to divide the plurality of symbol groups into one or more combined groups based on a specified number of symbol groups. The one or more programs may include instructions that, when executed by the processor of the electronic device, cause the electronic device to obtain power values ​​for the one or more combined groups by obtaining a power value for each of the one or more combined groups. The one or more programs may include instructions that, when executed by the processor of the electronic device, cause the electronic device to obtain a random access signal of the NB-IoT device based on the power values ​​for the one or more combined groups.

[0181] 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.

[0182] 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 for execution 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.

[0183] 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.

[0184] 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 implementing 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 implementing an embodiment of the present disclosure.

[0185] In the specific embodiments of the present disclosure described above, components included in the disclosure are expressed singularly or plurally, 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 plural may be composed of singular elements, or components expressed in singular may be composed of plural elements.

[0186] 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 electronic devices, Transmitter and receiver; At least one processor comprising processing circuitry; and comprising one or more storage media, and including a memory storing instructions; The above instructions, when individually or collectively executed by the at least one processor, Obtain multiple symbol groups for NPRACH (narrowband random access channel) transmission of NB-IoT (narrowband-internet of things) devices, Based on a specified number of symbol groups, the plurality of symbol groups are divided into one or more combined groups, By obtaining a power value for each of the one or more combined groups, power values for the one or more combined groups are obtained, Causing the electronic device to obtain a random access signal of the NB-IoT device based on the power values for the one or more combined groups; Electronic devices.

2. In the first paragraph, when the instructions are individually or collectively executed by the at least one processor, For each of the above one or more combined groups, a coherent combined operation is performed, By obtaining a power value of a signal according to the coherent combining operation for each of the one or more combined groups, the electronic device is further caused to obtain the power value for each of the one or more combined groups. Electronic devices.

3. In the first paragraph, when the instructions are individually or collectively executed by the at least one processor, Performing a correlation operation between at least two symbol groups among the above plurality of symbol groups, Further causing the electronic device to determine the specified number based on the result of the correlation operation between the at least two symbol groups, Electronic devices.

4. In the third paragraph, when the instructions are individually or collectively executed by the at least one processor, Identifying at least two symbol groups among the plurality of symbol groups, Performing a coherent combination operation on each of the at least two symbol groups, Further causing the electronic device to perform the correlation operation on the at least two symbol groups on which the coherent combining operation is performed. Electronic devices.

5. In the fourth paragraph, the instructions, when individually or collectively executed by the at least one processor, further cause the electronic device to identify the real part of the output value of the correlation operation for the at least two symbols as the result of the correlation operation. Electronic devices.

6. In the first paragraph, the random access signal, Transmitted according to the repetition number set for the above NPRACH transmission, The above multiple symbol groups are, Obtained based on the repetition of the random access signal according to the above repetition number, Electronic devices.

7. In the first paragraph, one of the plurality of symbol groups is, Containing 5 symbols, Electronic devices.

8. In the first paragraph, when the instructions are individually or collectively executed by the at least one processor, Based on the signal regarding the above NPRACH transmission, the frequency offset and time offset are identified, Further causing the electronic device to obtain the plurality of symbol groups based on compensating for the frequency offset and the time offset in the signal. Electronic devices.

9. In claim 8, the electronic device, Contains DU(digital unit), The above signal regarding the above NPRACH transmission is, Obtained through the antenna of the RU (radio unit), Electronic devices.

10. In the first paragraph, when the instructions are individually or collectively executed by the at least one processor, Identifying a sum power value of said power values for said one or more combined groups, Further causing the electronic device to obtain the random access signal based on the sum power value being greater than or equal to the specified power value; Electronic devices.

11. In a method performed by an electronic device, An operation of acquiring multiple symbol groups for NPRACH (narrowband random access channel) transmission of an NB-IoT (narrowband-internet of things) device; An operation of dividing a plurality of symbol groups into one or more combined groups based on a specified number of symbol groups; An operation of obtaining power values for one or more of the combined groups by obtaining a power value for each of the one or more combined groups; and An operation of acquiring a random access signal of the NB-IoT device based on the power values for the one or more combined groups, method.

12. In the 11th paragraph, the method, For each of the one or more combined groups, performing a coherent combining operation; and Further comprising an operation of obtaining the power value of the signal according to the coherent combining operation for each of the one or more combined groups, method.

13. In the 11th paragraph, the method, An operation of performing a correlation operation between at least two symbol groups among the plurality of symbol groups; and Further comprising an operation of determining the specified number based on the result of the correlation operation between the at least two symbol groups. method.

14. In the 13th paragraph, the method, An operation of identifying at least two symbol groups among the plurality of symbol groups; An operation of performing a coherent combining operation on each of the at least two symbol groups; and Further comprising an operation of performing the correlation operation on the at least two symbol groups on which the coherent combining operation is performed. 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 an electronic device, Obtain multiple symbol groups for NPRACH (narrowband random access channel) transmission of NB-IoT (narrowband-internet of things) devices, Based on a specified number of symbol groups, the plurality of symbol groups are divided into one or more combined groups, By obtaining a power value for each of the one or more combined groups, power values for the one or more combined groups are obtained, Including instructions causing the electronic device to obtain a random access signal of the NB-IoT device based on the power values for the one or more combined groups. A non-transitory computer-readable storage medium.

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