Method and apparatus for transmitting and receiving signal in wireless communication system

Abstract

According to various embodiments of the present disclosure, a method performed by a user equipment (UE) in a communication system supporting multiple beams may comprise the steps of: receiving a first synchronization signal for a first beam from a first base station which is one of a plurality of base stations (BS); obtaining a first cell ID for the first base station on the basis of the first synchronization signal; receiving a second synchronization signal for a second beam from one of the first base station and a second base station different from the first base station; obtaining a second cell ID for the base station that has transmitted the second synchronization signal, on the basis of the second synchronization signal; obtaining a synchronization difference between the first beam and the second beam on the basis of the first synchronization signal and the second synchronization signal; and detecting a physical broadcast channel (PBCH) for at least one of the first beam and the second beam on the basis of at least one of the first cell ID, the second cell ID, and the synchronization difference.

Description

Method and device for transmitting and receiving signals in a wireless communication system

[0001] The present disclosure relates to a method and device for beam sweeping in a wireless communication system. Specifically, the present disclosure relates to a method and device for performing beam sweeping using multiple beams and transmitting and receiving signals.

[0002] Wireless access systems are widely deployed to provide various types of communication services, such as voice and data. Typically, wireless access systems are multiple access systems that support communications with multiple users by sharing available system resources (e.g., bandwidth, transmission power). Examples of multiple access systems include code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), and single-carrier frequency division multiple access (SC-FDMA).

[0003] In channel environments utilizing the terahertz (THz) band, a communication environment can be configured using a 3D-based narrow beam with high beam gain to overcome path attenuation. When a communication system performs beam sweeping using narrow beams, the area covered by each beam narrows, which significantly increases the number of beams that the base station must cover. In addition, the terminal must also configure a corresponding narrow beam, which can cause a problem of increased complexity. To overcome the above problems, a discussion is required on a method for the base station and terminal to perform beam sweeping using multiple beams.

[0004] To solve the above-described problems, the present disclosure provides a device and method for performing signal transmission and reception in a wireless communication system.

[0005] Additionally, the present disclosure provides a device and method for performing at least one of beam sweeping, beam forming, beam measurement, and beam refinement in a wireless communication system.

[0006] Additionally, the present disclosure provides a device and method for performing signal transmission and reception based on multiple beams.

[0007] According to various embodiments of the present disclosure, a method performed by a user equipment (UE) in a communication system supporting multiple beams includes the steps of: receiving a first synchronization signal for a first beam from a first base station (BS) that is one of a plurality of base stations (BS); obtaining a first cell ID for the first base station based on the first synchronization signal; receiving a second synchronization signal for a second beam from one of the first base station and a second base station different from the first base station; obtaining a second cell ID for a base station that has transmitted the second synchronization signal based on the second synchronization signal; obtaining a synchronization difference between the first beam and the second beam based on the first synchronization signal and the second synchronization signal; and obtaining a synchronization difference for at least one of the first cell ID, the second cell ID, and the synchronization difference. It may include a step of detecting a PBCH (Physical Broadcast Channel).

[0008] According to various embodiments of the present disclosure, when the first cell ID and the second cell ID are different, the PBCH can be detected using a beam with a higher power among the first beam and the second beam.

[0009] According to various embodiments of the present disclosure, a method wherein, when the first cell ID and the second cell ID are the same, the PBCH is detected based on the synchronization difference.

[0010] According to various embodiments of the present disclosure, when the synchronization difference is smaller than a CP (Cyclic prefix), the PBCH can be detected based on a time domain diversity method.

[0011] According to various embodiments of the present disclosure, the method may further include a step of performing an initial access based on the first beam and the second beam when the PBCH is detected.

[0012] According to various embodiments of the present disclosure, when the synchronization difference is greater than the CP and less than 1 symbol, the PBCH can be detected based on a time domain diversity scheme with synchronization compensation applied.

[0013] According to various embodiments of the present disclosure, the method may further include a step of performing an initial connection based on the first beam and the second beam when the PBCH is detected.

[0014] According to various embodiments of the present disclosure, when the synchronization difference is greater than 1 symbol, the PBCH can be detected based on a frequency domain diversity scheme.

[0015] According to various embodiments of the present disclosure, the method may further include a step of performing an initial connection using a beam having a higher power among the first beam and the second beam when the PBCH is detected.

[0016] According to various embodiments of the present disclosure, when a PBCH is not detected using a diversity scheme, the second synchronization signal is determined to have been received by the second base station, and the PBCH is detected using a beam having a higher power among the first beam and the second beam.

[0017] According to various embodiments of the present disclosure, a method performed by a base station (BS) in a communication system supporting multiple beams includes the steps of transmitting a first synchronization signal for a first beam to a terminal, transmitting a second synchronization signal for a second beam to the terminal, and transmitting a Physical Broadcast Channel (PBCH) to the terminal based on at least one of the first synchronization signal and the second synchronization signal, wherein the terminal can detect the PBCH based on at least one of a first cell ID obtained based on the first synchronization signal, a second cell ID obtained based on the second synchronization signal, and a synchronization difference between the first beam and the second beam.

[0018] According to various embodiments of the present disclosure, when the first cell ID and the second cell ID are different, the terminal can detect the PBCH using a beam with a higher power among the first beam and the second beam.

[0019] According to various embodiments of the present disclosure, the terminal can detect the PBCH based on the synchronization difference when the first cell ID and the second cell ID are the same.

[0020] According to various embodiments of the present disclosure, when the synchronization difference is smaller than a CP (Cyclic prefix), the terminal can detect the PBCH based on a time domain diversity method.

[0021] According to various embodiments of the present disclosure, a terminal operating in a communication system includes a transceiver, at least one processor, and at least one memory operably connectable to the at least one processor and storing instructions that, when executed by the at least one processor, perform operations, wherein the operations may include all steps of a method of operating the terminal according to various embodiments of the present disclosure.

[0022] According to various embodiments of the present disclosure, a base station operating in a communication system includes a transceiver, at least one processor, and at least one memory operably connectable to the at least one processor and storing instructions that, when executed by the at least one processor, perform operations, wherein the operations may include all steps of a method of operating the base station according to various embodiments of the present disclosure.

[0023] According to various embodiments of the present disclosure, a control device for controlling a terminal in a communication system includes at least one processor and at least one memory operably connected to the at least one processor, wherein the at least one memory stores instructions for performing operations based on being executed by the at least one processor, and the operations may include all steps of an operating method of a terminal according to various embodiments of the present disclosure.

[0024] According to various embodiments of the present disclosure, a control device for controlling a base station in a communication system includes at least one processor and at least one memory operably connected to the at least one processor, wherein the at least one memory stores instructions for performing operations based on being executed by the at least one processor, and the operations may include all steps of an operating method of a base station according to various embodiments of the present disclosure.

[0025] According to various embodiments of the present disclosure, one or more non-transitory computer-readable media storing one or more commands, wherein the one or more commands perform operations based on being executed by one or more processors, and the operations may include all steps of a method of operating a terminal according to various embodiments of the present disclosure.

[0026] According to various embodiments of the present disclosure, one or more non-transitory computer-readable media storing one or more commands, wherein the one or more commands, when executed by one or more processors, perform operations, wherein the operations may include all steps of a method of operating a base station according to various embodiments of the present disclosure.

[0027] According to the present disclosure, a device and method for performing signal transmission and reception in a wireless communication system can be provided.

[0028] Additionally, according to the present disclosure, a device and method for performing at least one of beam sweeping, beam forming, beam measurement, and beam refinement in a wireless communication system may be provided.

[0029] Additionally, according to the present disclosure, a device and method for performing signal transmission and reception based on multiple beams can be provided.

[0030] In addition, according to the present disclosure, there is an effect of reducing beam sweeping time in an environment using multiple beams and obtaining diversity gain based on this.

[0031] The accompanying drawings are intended to aid understanding of the present disclosure and may provide embodiments of the present disclosure along with detailed descriptions. However, the technical features of the present disclosure are not limited to specific drawings, and the features disclosed in each drawing may be combined with each other to form new embodiments. Reference numerals in each drawing may indicate structural elements.

[0032] Figure 1 is a diagram illustrating an example of physical channels and general signal transmission used in a 3GPP system.

[0033] Figure 2 is a diagram illustrating the system structure of a New Generation Radio Access Network (NG-RAN).

[0034] Figure 3 is a diagram illustrating the functional division between NG-RAN and 5GC.

[0035] Figure 4 is a diagram illustrating an example of a 5G usage scenario.

[0036] Figure 5 is a diagram illustrating an example of a communication structure that can be provided in a 6G system.

[0037] Figure 6 is a diagram illustrating an example of an electromagnetic spectrum.

[0038] Figure 7 is a diagram illustrating an example of a THz communication application.

[0039] Fig. 8 is a diagram illustrating an example of an electronic component-based THz wireless communication transmitter and receiver.

[0040] FIG. 9 is a diagram illustrating an example of a method for generating a THz signal based on an optical element.

[0041] Fig. 10 is a diagram illustrating an example of an optical element-based THz wireless communication transceiver.

[0042] Fig. 11 is a diagram illustrating the structure of a photon source-based transmitter.

[0043] Figure 12 is a drawing showing the structure of an optical modulator.

[0044] Figure 13 is a drawing for explaining an example of a beam sweeping method.

[0045] Figure 14 is a drawing for explaining a method of performing beam sweeping.

[0046] Figure 15 is a drawing for explaining the efficiency of beam sweeping.

[0047] Fig. 16 is a drawing for explaining a multi-beam based sweeping method.

[0048] FIG. 17 is a diagram for explaining the influence of multiple base stations in a beam sweeping method according to the present disclosure.

[0049] FIG. 18 is a diagram illustrating an example of a communication system to which the present disclosure can be applied.

[0050] FIG. 19 is a drawing for explaining a multi-beam based beam sweeping method according to the present disclosure.

[0051] FIG. 20 is a drawing illustrating an example of a beam sweeping method according to the present disclosure.

[0052] Figure 21 is a diagram for explaining a channel detection method using diversity.

[0053] FIG. 22 is a drawing illustrating another example of a beam sweeping method according to the present disclosure.

[0054] FIG. 23 is another drawing for comparing the beam sweeping method according to the present disclosure with a conventional method.

[0055] FIG. 24 is a drawing for explaining the performance of the beam sweeping method according to the present disclosure.

[0056] FIG. 25 is another drawing for explaining the performance of the beam sweeping method according to the present disclosure.

[0057] FIG. 26 is a diagram illustrating an example of a method for a terminal to transmit and receive signals in a system applicable to the present disclosure.

[0058] FIG. 27 is a diagram illustrating an example of a method for a base station to transmit and receive signals in a system applicable to the present disclosure.

[0059] FIG. 28 illustrates a communication system (1) applicable to various embodiments of the present disclosure.

[0060] FIG. 29 illustrates a wireless device that can be applied to various embodiments of the present disclosure.

[0061] FIG. 30 illustrates another example of a wireless device that can be applied to various embodiments of the present disclosure.

[0062] Figure 31 illustrates a signal processing circuit for a transmission signal.

[0063] FIG. 32 illustrates another example of a wireless device applicable to various embodiments of the present disclosure.

[0064] In various embodiments of the present disclosure, “A or B” may mean “only A,” “only B,” or “both A and B.” In other words, in various embodiments of the present disclosure, “A or B” may be interpreted as “A and / or B.” For example, in various embodiments of the present disclosure, “A, B or C” may mean “only A,” “only B,” “only C,” or “any combination of A, B and C.”

[0065] In various embodiments of the present disclosure, a slash ( / ) or a comma may mean "and / or." For example, "A / B" may mean "A and / or B." Accordingly, "A / B" may mean "only A," "only B," or "both A and B." For example, "A, B, C" may mean "A, B, or C."

[0066] In various embodiments of the present disclosure, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Furthermore, in various embodiments of the present disclosure, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted as equivalent to “at least one of A and B.”

[0067] Additionally, in various embodiments of the present disclosure, “at least one of A, B and C” can mean “only A,” “only B,” “only C,” or “any combination of A, B and C.” Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” can mean “at least one of A, B and C.”

[0068] Additionally, parentheses used in various embodiments of the present disclosure may mean "for example." Specifically, when indicated as "control information (PDCCH)", "PDCCH" may be proposed as an example of "control information." In other words, "control information" in various embodiments of the present disclosure is not limited to "PDCCH", and "PDDCH" may be proposed as an example of "control information." Furthermore, even when indicated as "control information (i.e., PDCCH)", "PDCCH" may be proposed as an example of "control information."

[0069] Technical features individually described in a single drawing in various embodiments of the present disclosure may be implemented individually or simultaneously.

[0070]

[0071] The following technologies can be used in various wireless access systems, such as CDMA, FDMA, TDMA, OFDMA, and SC-FDMA. CDMA can be implemented using wireless technologies such as UTRA (Universal Terrestrial Radio Access) or CDMA2000. TDMA can be implemented using wireless technologies such as GSM (Global System for Mobile communications) / GPRS (General Packet Radio Service) / EDGE (Enhanced Data Rates for GSM Evolution). OFDMA can be implemented using wireless technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (Evolved UTRA). UTRA is a part of UMTS (Universal Mobile Telecommunications System). 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) is a part of E-UMTS (Evolved UMTS) that uses E-UTRA, and LTE-A (Advanced) / LTE-A pro is an evolved version of 3GPP LTE. 3GPP NR (New Radio or New Radio Access Technology) is an evolved version of 3GPP LTE / LTE-A / LTE-A pro. 3GPP 6G may be an evolved version of 3GPP NR.

[0072]

[0073] For clarity, the description is based on 3GPP communication systems (e.g., LTE, NR, etc.), but the technical spirit of the present disclosure is not limited thereto. LTE refers to technology after 3GPP TS 36.xxx Release 8. Specifically, LTE technology after 3GPP TS 36.xxx Release 10 is referred to as LTE-A, and LTE technology after 3GPP TS 36.xxx Release 13 is referred to as LTE-A pro. 3GPP NR refers to technology after TS 38.xxx Release 15. 3GPP 6G may refer to technology after TS Release 17 and / or Release 18. “xxx” refers to a standard document detail number. LTE / NR / 6G may be collectively referred to as a 3GPP system. For background technology, terms, abbreviations, etc. used in the description of the present disclosure, reference may be made to matters described in standard documents published prior to the present disclosure. For example, reference may be made to the following documents.

[0074]

[0075] 3GPP LTE

[0076] - 36.211: Physical channels and modulation

[0077] - 36.212: Multiplexing and channel coding

[0078] - 36.213: Physical layer procedures

[0079] - 36.300: Overall description

[0080] - 36.331: Radio Resource Control (RRC)

[0081] 3GPP NR

[0082] - 38.211: Physical channels and modulation

[0083] - 38.212: Multiplexing and channel coding

[0084] - 38.213: Physical layer procedures for control

[0085] - 38.214: Physical layer procedures for data

[0086] - 38.300: NR and NG-RAN Overall Description

[0087] - 38.331: Radio Resource Control (RRC) protocol specification

[0088]

[0089] Physical Channel and Frame Structure

[0090] Physical channels and general signal transmission

[0091] Figure 1 is a diagram illustrating an example of physical channels and general signal transmission used in a 3GPP system.

[0092] In a wireless communication system, a terminal receives information from a base station via the downlink (DL) and transmits it to the base station via the uplink (UL). The information transmitted and received between the base station and the terminal includes data and various control information, and various physical channels exist depending on the type and purpose of the information being transmitted and received.

[0093] When a terminal is powered on or enters a new cell, it performs an initial cell search operation, such as synchronizing with the base station (S11). To this end, the terminal receives a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS) from the base station to synchronize with the base station and obtain information such as a cell ID. Afterwards, the terminal can receive a Physical Broadcast Channel (PBCH) from the base station to obtain broadcast information within the cell. Meanwhile, the terminal can receive a Downlink Reference Signal (DL RS) during the initial cell search phase to check the downlink channel status.

[0094] A terminal that has completed initial cell search can obtain more specific system information by receiving a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) based on information contained in the PDCCH (S12).

[0095] Meanwhile, when accessing a base station for the first time or when there are no radio resources for signal transmission, the terminal may perform a random access procedure (RACH) for the base station (S13 to S16). To this end, the terminal may transmit a specific sequence as a preamble via a physical random access channel (PRACH) (S13 and S15) and receive a response message (RAR (Random Access Response) message) to the preamble via a PDCCH and a corresponding PDSCH. In the case of a contention-based RACH, a contention resolution procedure may additionally be performed (S16).

[0096] The terminal that has performed the procedure described above can then perform PDCCH / PDSCH reception (S17) and physical uplink shared channel (PUSCH) / physical uplink control channel (PUCCH) transmission (S18) as general uplink / downlink signal transmission procedures. In particular, the terminal can receive downlink control information (DCI) through the PDCCH. Here, the DCI includes control information such as resource allocation information for the terminal, and different formats can be applied depending on the purpose of use.

[0097] Meanwhile, the control information that the terminal transmits to the base station via the uplink or that the terminal receives from the base station may include downlink / uplink ACK / NACK signals, CQI (Channel Quality Indicator), PMI (Precoding Matrix Index), RI (Rank Indicator), etc. The terminal may transmit the above-described control information such as CQI / PMI / RI via PUSCH and / or PUCCH.

[0098]

[0099] Structure of uplink and downlink channels

[0100] Downlink channel structure

[0101] The base station transmits a related signal to the terminal through a downlink channel described below, and the terminal receives the related signal from the base station through a downlink channel described below.

[0102]

[0103] (1) Physical Downlink Shared Channel (PDSCH)

[0104] PDSCH carries downlink data (e.g., DL-shared channel transport block, DL-SCH TB) and modulation methods such as Quadrature Phase Shift Keying (QPSK), 16 Quadrature Amplitude Modulation (QAM), 64 QAM, and 256 QAM are applied. The TB is encoded to generate a codeword. PDSCH can carry multiple codewords. Scrambling and modulation mapping are performed for each codeword, and the modulation symbols generated from each codeword are mapped to one or more layers (Layer mapping). Each layer is mapped to resources along with a Demodulation Reference Signal (DMRS), generated as an OFDM symbol signal, and transmitted through the corresponding antenna port.

[0105]

[0106] (2) Physical downlink control channel (PDCCH)

[0107] The PDCCH carries downlink control information (DCI) and employs modulation methods such as QPSK. A PDCCH consists of 1, 2, 4, 8, or 16 Control Channel Elements (CCEs), depending on the Aggregation Level (AL). Each CCE is comprised of six Resource Element Groups (REGs). Each REG is defined by one OFDM symbol and one (P)RB.

[0108] The UE acquires DCI transmitted via the PDCCH by performing decoding (also known as blind decoding) on ​​a set of PDCCH candidates. The set of PDCCH candidates decoded by the UE is defined as a PDCCH search space set. The search space set may be a common search space or a UE-specific search space. The UE can acquire DCI by monitoring PDCCH candidates within one or more search space sets established by the MIB or higher layer signaling.

[0109]

[0110] Uplink channel structure

[0111] The terminal transmits a related signal to the base station through the uplink channel described below, and the base station receives the related signal from the terminal through the uplink channel described below.

[0112] (1) Physical Uplink Shared Channel (PUSCH)

[0113] PUSCH carries uplink data (e.g., UL-shared channel transport block, UL-SCH TB) and / or uplink control information (UCI), and is transmitted based on a CP-OFDM (Cyclic Prefix - Orthogonal Frequency Division Multiplexing) waveform, a DFT-s-OFDM (Discrete Fourier Transform - spread - Orthogonal Frequency Division Multiplexing) waveform, etc. When the PUSCH is transmitted based on a DFT-s-OFDM waveform, the UE transmits the PUSCH by applying transform precoding. For example, when transform precoding is disabled (e.g., transform precoding is disabled), the UE transmits the PUSCH based on the CP-OFDM waveform, and when transform precoding is enabled (e.g., transform precoding is enabled), the UE can transmit the PUSCH based on the CP-OFDM waveform or the DFT-s-OFDM waveform. PUSCH transmissions can be dynamically scheduled by UL grants in DCI, or semi-statically scheduled (configured grant) based on higher layer (e.g., RRC) signaling (and / or Layer 1 (L1) signaling (e.g., PDCCH)). PUSCH transmissions can be performed in a codebook-based or non-codebook-based manner.

[0114] (2) Physical Uplink Control Channel (PUCCH)

[0115] PUCCH carries uplink control information, HARQ-ACK and / or scheduling request (SR), and can be divided into multiple PUCCHs depending on the PUCCH transmission length.

[0116]

[0117] Below, we describe new radio access technology (new RAT, NR).

[0118] As more and more communication devices demand greater communication capacity, the need for improved mobile broadband communication compared to existing radio access technology (RAT) is emerging. Furthermore, massive Machine Type Communications (MTC), which connects numerous devices and objects to provide various services anytime, anywhere, is also a key issue to be considered in next-generation communication. Furthermore, communication system design that considers reliability and latency-sensitive services / terminals is being discussed. The introduction of next-generation radio access technologies that take into account enhanced mobile broadband communication, massive MTC, and URLLC (Ultra-Reliable and Low Latency Communication) is being discussed, and in various embodiments of the present disclosure, these technologies are conveniently referred to as new RAT or NR.

[0119]

[0120] Figure 2 is a diagram illustrating the system structure of a New Generation Radio Access Network (NG-RAN).

[0121] Referring to FIG. 2, the NG-RAN may include a gNB and / or an eNB that provides user plane and control plane protocol termination to the UE. FIG. 1 illustrates a case where only a gNB is included. The gNB and eNB are connected to each other via an Xn interface. The gNB and eNB are connected to the 5th generation core network (5G Core Network: 5GC) via the NG interface. More specifically, the gNB is connected to the access and mobility management function (AMF) via the NG-C interface, and the gNB is connected to the user plane function (UPF) via the NG-U interface.

[0122] Figure 3 is a diagram illustrating the functional division between NG-RAN and 5GC.

[0123] Referring to FIG. 3, the gNB can provide functions such as inter-cell radio resource management (Inter Cell RRM), radio bearer management (RB control), connection mobility control (Connection Mobility Control), radio admission control (Radio Admission Control), measurement configuration and provision, and dynamic resource allocation. The AMF can provide functions such as NAS security and idle state mobility processing. The UPF can provide functions such as mobility anchoring and PDU processing. The SMF (Session Management Function) can provide functions such as terminal IP address allocation and PDU session control.

[0124] Figure 4 is a diagram illustrating an example of a 5G usage scenario.

[0125] The 5G usage scenario illustrated in FIG. 4 is merely exemplary, and the technical features of various embodiments of the present disclosure can also be applied to other 5G usage scenarios not illustrated in FIG. 4.

[0126] Referring to Figure 4, the three key requirements areas for 5G include (1) enhanced mobile broadband (eMBB), (2) massive machine type communication (mMTC), and (3) ultra-reliable and low latency communications (URLLC). Some use cases may require optimization across multiple areas, while others may focus on just one key performance indicator (KPI). 5G supports these diverse use cases in a flexible and reliable manner.

[0127] eMBB focuses on improving data speeds, latency, user density, and overall capacity and coverage of mobile broadband connections. It targets throughputs of around 10 Gbps. eMBB significantly exceeds basic mobile internet access, enabling rich interactive experiences, media and entertainment applications in the cloud, and augmented reality. Data is a key driver of 5G, and for the first time, dedicated voice services may not be available in the 5G era. In 5G, voice is expected to be handled as an application, simply using the data connection provided by the communication system. The increased traffic volume is primarily due to the increasing content size and the growing number of applications that require high data rates. Streaming services (audio and video), interactive video, and mobile internet connectivity will become more prevalent as more devices connect to the internet. Many of these applications require always-on connectivity to push real-time information and notifications to users. Cloud storage and applications are rapidly growing on mobile communication platforms, and this can be applied to both work and entertainment. Cloud storage is a particular use case driving the growth of uplink data rates. 5G is also used for remote work in the cloud, requiring significantly lower end-to-end latency to maintain a superior user experience when tactile interfaces are used. In entertainment, for example, cloud gaming and video streaming are other key factors driving the demand for mobile broadband. Entertainment is essential on smartphones and tablets, regardless of location, including in highly mobile environments like trains, cars, and airplanes. Another use case is augmented reality and information retrieval for entertainment, where augmented reality requires extremely low latency and instantaneous data volumes.

[0128] mMTC is designed to enable communication between a large number of low-cost, battery-powered devices, supporting applications such as smart metering, logistics, field, and body sensors. mMTC targets a battery life of approximately 10 years and / or a population of approximately 1 million devices per square kilometer. mMTC enables seamless connectivity of embedded sensors across all sectors and is one of the most anticipated 5G use cases. The number of IoT devices is projected to reach 20.4 billion by 2020. Industrial IoT is one area where 5G will play a key role, enabling smart cities, asset tracking, smart utilities, agriculture, and security infrastructure.

[0129] URLLC is ideal for vehicle communications, industrial control, factory automation, remote surgery, smart grids, and public safety applications by enabling devices and machines to communicate with high reliability, very low latency, and high availability. URLLC targets latency on the order of 1 ms. URLLC encompasses new services that will transform industries through ultra-reliable, low-latency links, such as remote control of critical infrastructure and autonomous vehicles. This level of reliability and latency is essential for smart grid control, industrial automation, robotics, and drone control and coordination.

[0130] Next, we will look more specifically at a number of usage examples included within the triangle in Fig. 4.

[0131] 5G can complement fiber-to-the-home (FTTH) and cable-based broadband (or DOCSIS) by delivering streams rated at hundreds of megabits per second to gigabits per second. These high speeds may be required to deliver TV at resolutions beyond 4K (6K, 8K, and beyond), as well as virtual reality (VR) and augmented reality (AR). VR and AR applications include near-immersive sports events. Certain applications may require specialized network configurations. For example, for VR gaming, a gaming company may need to integrate its core servers with a network operator's edge network servers to minimize latency.

[0132] Automotive is expected to be a significant new driver for 5G, with numerous use cases for in-vehicle mobile communications. For example, passenger entertainment demands both high capacity and high mobile broadband, as future users will consistently expect high-quality connectivity regardless of their location and speed. Another automotive application is augmented reality dashboards. An AR dashboard allows drivers to identify objects in the dark on top of what they see through the windshield. The AR dashboard overlays information to inform the driver about the distance and movement of objects. In the future, wireless modules will enable vehicle-to-vehicle communication, information exchange between vehicles and supporting infrastructure, and information exchange between vehicles and other connected devices (e.g., devices accompanying pedestrians). Safety systems can guide drivers to safer driving behaviors, reducing the risk of accidents. The next step will be remotely controlled or autonomous vehicles, which require highly reliable and fast communication between different autonomous vehicles and / or between vehicles and infrastructure. In the future, autonomous vehicles will perform all driving tasks, leaving drivers to focus solely on traffic anomalies that the vehicle itself cannot detect. The technological requirements for autonomous vehicles will require ultra-low latency and ultra-high-speed reliability, increasing traffic safety to levels unattainable by humans.

[0133] Smart cities and smart homes, often referred to as smart societies, will be embedded with dense wireless sensor networks. A distributed network of intelligent sensors will identify conditions for cost- and energy-efficient maintenance of cities or homes. Similar setups can be implemented for individual homes. Temperature sensors, window and heating controllers, burglar alarms, and appliances will all be wirelessly connected. Many of these sensors typically require low data rates, low power, and low cost. However, for example, real-time HD video may be required from certain types of devices for surveillance purposes.

[0134] The consumption and distribution of energy, including heat and gas, are becoming increasingly decentralized, requiring automated control of distributed sensor networks. Smart grids interconnect these sensors using digital information and communication technologies to collect and act on information. This information can include the behavior of suppliers and consumers, enabling smart grids to improve efficiency, reliability, economic efficiency, sustainable production, and the automated distribution of fuels like electricity. Smart grids can also be viewed as another low-latency sensor network.

[0135] The health sector has numerous applications that can benefit from mobile communications. Telecommunications systems can support telemedicine, which provides clinical care in remote locations. This can help reduce distance barriers and improve access to health services that are otherwise unavailable in remote rural areas. It can also be used to save lives in critical care and emergency situations. Mobile-based wireless sensor networks can provide remote monitoring and sensors for parameters such as heart rate and blood pressure.

[0136] Wireless and mobile communications are becoming increasingly important in industrial applications. Wiring is expensive to install and maintain. Therefore, the potential to replace cables with reconfigurable wireless links presents an attractive opportunity for many industries. However, achieving this requires wireless connections to operate with similar latency, reliability, and capacity to cables, while simplifying their management. Low latency and extremely low error rates are new requirements for 5G connectivity.

[0137] Logistics and freight tracking are important use cases for mobile communications, enabling the tracking of inventory and packages anywhere using location-based information systems. Logistics and freight tracking typically require low data rates but may require wide-range and reliable location information.

[0138] Below, examples of next-generation communications (e.g., 6G) that can be applied to various embodiments of the present disclosure will be described.

[0139]

[0140] 6G system in general

[0141] The 6G (wireless communication) system aims to achieve (i) very high data rates per device, (ii) a very large number of connected devices, (iii) global connectivity, (iv) very low latency, (v) low energy consumption for battery-free IoT devices, (vi) ultra-reliable connectivity, and (vii) connected intelligence with machine learning capabilities. The vision of the 6G system can be divided into four aspects: intelligent connectivity, deep connectivity, holographic connectivity, and ubiquitous connectivity, and the 6G system can satisfy the requirements as shown in Table 1 below. In other words, Table 1 is a table showing an example of the requirements of a 6G system.

[0142] Per device peak data rate1TbpsE2E latency1msMaximum spectral efficiency100bps / HzMobility supportUp to 1000km / hrSatellite integrationFullyAIFullyAutonomous vehicleFullyXRFullyHaptic CommunicationFully

[0143] 6G systems can have key factors such as enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLLC), massive machine-type communication (mMTC), AI integrated communication, tactile internet, high throughput, high network capacity, high energy efficiency, low backhaul and access network congestion, and enhanced data security.

[0144] Figure 5 is a diagram illustrating an example of a communication structure that can be provided in a 6G system.

[0145] 6G systems are expected to have 50 times the simultaneous wireless connectivity of 5G systems. URLLC, a key feature of 5G, will become even more crucial in 6G communications by providing end-to-end latency of less than 1 ms. 6G systems will have significantly higher volumetric spectral efficiency, compared to the commonly used area spectral efficiency. 6G systems can offer extremely long battery life and advanced battery technologies for energy harvesting, eliminating the need for separate charging for mobile devices in 6G systems. New network characteristics in 6G may include:

[0146] - Satellite integrated network: 6G is expected to integrate with satellites to provide a global mobile network. The integration of terrestrial, satellite, and airborne networks into a single wireless communications system is crucial for 6G.

[0147] Connected Intelligence: Unlike previous generations of wireless communication systems, 6G is revolutionary, upgrading the wireless evolution from "connected objects" to "connected intelligence." AI can be applied at every stage of the communication process (or at every signal processing step, as described below).

[0148] - Seamless integration of wireless information and energy transfer: 6G wireless networks will transfer power to charge the batteries of devices such as smartphones and sensors. Therefore, wireless information and energy transfer (WIET) will be integrated.

[0149] - Ubiquitous super 3D connectivity: Access to networks and core network functions of drones and very low Earth orbit satellites will create super 3D connectivity in 6G ubiquitous.

[0150] Some general requirements for the new network characteristics of 6G, such as the above, may be as follows:

[0151] - Small cell networks: The concept of small cell networks was introduced to improve received signal quality in cellular systems by increasing throughput, energy efficiency, and spectral efficiency. Consequently, small cell networks are essential for 5G and beyond-5G (5GB) communication systems. Accordingly, 6G communication systems also adopt the characteristics of small cell networks.

[0152] Ultra-dense heterogeneous networks: Ultra-dense heterogeneous networks will be another key feature of 6G communication systems. Multi-tier networks comprised of heterogeneous networks improve overall QoS and reduce costs.

[0153] High-capacity backhaul: Backhaul connections are characterized by high-capacity backhaul networks to support high-volume traffic. High-speed fiber optics and free-space optics (FSO) systems may be potential solutions to this problem.

[0154] - Radar technology integrated with mobile technology: High-precision localization (or location-based services) through communications is a key feature of 6G wireless communication systems. Therefore, radar systems will be integrated with 6G networks.

[0155] - Softwarization and virtualization: Softwarization and virtualization are two critical features that form the foundation of the design process for 5GB networks to ensure flexibility, reconfigurability, and programmability. Furthermore, billions of devices can be shared on a shared physical infrastructure.

[0156]

[0157] Core implementation technology of 6G systems

[0158] THz (Terahertz) communication

[0159] Data rates can be increased by increasing bandwidth. This can be achieved by utilizing sub-THz communications with wide bandwidths and applying advanced massive MIMO technology. THz waves, also known as sub-millimeter waves, typically refer to the frequency range between 0.1 THz and 10 THz, with corresponding wavelengths ranging from 0.03 mm to 3 mm. The 100 GHz to 300 GHz band (sub-THz band) is considered a key part of the THz band for cellular communications. Adding the sub-THz band to the mmWave band will increase the capacity of 6G cellular communications. Among the defined THz bands, 300 GHz to 3 THz lies in the far infrared (IR) frequency band. While part of the optical band, the 300 GHz to 3 THz band lies at the boundary of the optical band, immediately following the RF band. Therefore, this 300 GHz to 3 THz band exhibits similarities to RF.

[0160] Figure 13 is a diagram illustrating an example of the electromagnetic spectrum.

[0161] The main characteristics of THz communication are (i) Fig. 6 is a diagram showing an example of the electromagnetic spectrum.

[0162] Key characteristics of THz communications include (i) the widely available bandwidth to support very high data rates and (ii) the high path loss that occurs at high frequencies (requiring highly directional antennas). The narrow beamwidths generated by highly directional antennas reduce interference. The small wavelength of THz signals allows for a significantly larger number of antenna elements to be integrated into devices and base stations operating in this band. This enables the use of advanced adaptive array technologies to overcome range limitations.

[0163] Optical wireless technology

[0164] OWC technology is designed for 6G communications, in addition to RF-based communications for all possible device-to-access networks. These networks connect to network-to-backhaul / fronthaul networks. OWC technology has already been used in 4G communication systems, but it will be used more widely to meet the demands of 6G communication systems. OWC technologies such as light fidelity, visible light communication, optical camera communication, and wideband-based FSO communication are already well-known. Communications based on optical wireless technology can provide very high data rates, low latency, and secure communications. LiDAR can also be used for ultra-high-resolution 4D mapping in 6G communications based on wideband.

[0165] FSO backhaul network

[0166] The transmitter and receiver characteristics of an FSO system are similar to those of a fiber-optic network. Therefore, data transmission in an FSO system is similar to that of a fiber-optic system. Therefore, FSO can be a promising technology for providing backhaul connectivity in 6G systems, in conjunction with fiber-optic networks. Using FSO, ultra-long-distance communications are possible, even over distances exceeding 10,000 km. FSO supports high-capacity backhaul connectivity for remote and non-remote areas, such as the ocean, space, underwater, and isolated islands. FSO also supports cellular base station (BS) connections.

[0167] Massive MIMO technology

[0168] One of the key technologies for improving spectral efficiency is the application of MIMO technology. As MIMO technology improves, spectral efficiency also improves. Therefore, massive MIMO technology will be crucial in 6G systems. Because MIMO technology utilizes multiple paths, multiplexing technology must be considered to ensure that data signals can be transmitted along more than one path, as well as beam generation and operation technologies suitable for the THz band.

[0169] Blockchain

[0170] Blockchain will become a crucial technology for managing massive amounts of data in future communication systems. Blockchain is a form of distributed ledger technology. A distributed ledger is a database distributed across numerous nodes or computing devices. Each node replicates and stores an identical copy of the ledger. Blockchains are managed by a peer-to-peer network and can exist without being managed by a central authority or server. Data on a blockchain is collected and organized into blocks. Blocks are linked together and protected using cryptography. Blockchain perfectly complements large-scale IoT with its inherently enhanced interoperability, security, privacy, reliability, and scalability. Therefore, blockchain technology offers several features, such as interoperability between devices, traceability of large amounts of data, autonomous interaction with other IoT systems, and the massive connectivity stability of 6G communication systems.

[0171] 3D networking

[0172] 6G systems integrate terrestrial and airborne networks to support vertically expanded user communications. 3D BS will be provided via low-orbit satellites and UAVs. Adding a new dimension in altitude and associated degrees of freedom, 3D connections differ significantly from existing 2D networks.

[0173] Quantum communication

[0174] Unsupervised reinforcement learning holds promise in the context of 6G networks. Supervised learning approaches cannot label the massive amounts of data generated by 6G networks. Unsupervised learning does not require labeling. Therefore, this technology can be used to autonomously build representations of complex networks. Combining reinforcement learning and unsupervised learning allows for truly autonomous network operation.

[0175] drone

[0176] Unmanned Aerial Vehicles (UAVs), or drones, will be a key element in 6G wireless communications. In most cases, high-speed wireless connections will be provided using UAV technology. BS entities are installed on UAVs to provide cellular connectivity. UAVs offer specific capabilities not found in fixed BS infrastructure, such as easy deployment, robust line-of-sight links, and controlled mobility. During emergencies such as natural disasters, deploying terrestrial communication infrastructure is not economically feasible, and sometimes, volatile environments make it impossible to provide services. UAVs can easily handle these situations. UAVs will become a new paradigm in wireless communications. This technology facilitates three fundamental requirements for wireless networks: enhanced mobile broadband (eMBB), URLLC, and mMTC. UAVs can also support various purposes, such as enhancing network connectivity, fire detection, disaster emergency services, security and surveillance, pollution monitoring, parking monitoring, and accident monitoring. Therefore, UAV technology is recognized as one of the most important technologies for 6G communications.

[0177] Cell-free Communication

[0178] Tight integration of multiple frequencies and heterogeneous communication technologies is crucial in 6G systems. As a result, users will be able to seamlessly move from one network to another without requiring any manual configuration on their devices. The best network will be automatically selected from available communication technologies. This will break the limitations of the cell concept in wireless communications. Currently, user movement from one cell to another in dense networks results in excessive handovers, resulting in handover failures, handover delays, data loss, and a ping-pong effect. 6G cell-free communications will overcome all of these challenges and provide better QoS. Cell-free communications will be achieved through multi-connectivity and multi-tier hybrid technologies, as well as heterogeneous radios on devices.

[0179] Integration of wireless information and energy transmission

[0180] WIET uses the same fields and waves as wireless communication systems. Specifically, sensors and smartphones will be charged using wireless power transfer during communication. WIET is a promising technology for extending the life of battery-powered wireless systems. Therefore, battery-less devices will be supported by 6G communications.

[0181] Integration of sensing and communication

[0182] Autonomous wireless networks are capable of continuously sensing dynamically changing environmental conditions and exchanging information between different nodes. In 6G, sensing will be tightly integrated with communications to support autonomous systems.

[0183] Integration of Access Backhaul Networks

[0184] In 6G, the density of access networks will be enormous. Each access network will be connected to backhaul connections, such as fiber optics and FSO networks. To accommodate the massive number of access networks, there will be tight integration between access and backhaul networks.

[0185] Holographic beam forming

[0186] Beamforming is a signal processing procedure that adjusts an antenna array to transmit a wireless signal in a specific direction. It is a subset of smart antennas or advanced antenna systems. Beamforming technology offers several advantages, including high signal-to-noise ratio, interference avoidance and rejection, and high network efficiency. Holographic beamforming (HBF) is a novel beamforming method that differs significantly from MIMO systems because it uses software-defined antennas. HBF will be a highly effective approach for efficient and flexible signal transmission and reception in multi-antenna communication devices in 6G.

[0187] Big Data Analysis

[0188] Big data analytics is a complex process for analyzing diverse, large-scale data sets, or "big data." This process uncovers hidden data, unknown correlations, and customer trends, ensuring complete data management. Big data is collected from various sources, such as video, social networks, images, and sensors. This technology is widely used to process massive amounts of data in 6G systems.

[0189] Large Intelligent Surface (LIS)

[0190] THz-band signals have strong linearity, which can create many shadow areas due to obstacles. LIS technology, which enables expanded communication coverage, enhanced communication stability, and additional value-added services by installing LIS near these shadow areas, is becoming increasingly important. LIS is an artificial surface made of electromagnetic materials that can alter the propagation of incoming and outgoing radio waves. While LIS can be viewed as an extension of massive MIMO, it differs from massive MIMO in its array structure and operating mechanism. Furthermore, LIS operates as a reconfigurable reflector with passive elements, passively reflecting signals without using active RF chains, which offers the advantage of low power consumption. Furthermore, because each passive reflector in LIS must independently adjust the phase shift of the incoming signal, this can be advantageous for wireless communication channels. By appropriately adjusting the phase shift via the LIS controller, the reflected signal can be collected at the target receiver to boost the received signal power.

[0191]

[0192] Terahertz (THz) wireless communications in general

[0193] THz wireless communication is a wireless communication using THz waves with a frequency of approximately 0.1 to 10 THz (1 THz = 10^12 Hz). It can refer to terahertz (THz) band wireless communication using a very high carrier frequency of 100 GHz or higher. THz waves are located between the RF (Radio Frequency) / millimeter (mm) and infrared bands, and (i) compared to visible light / infrared light, they penetrate non-metallic / non-polarizable materials well, and compared to RF / millimeter waves, they have a shorter wavelength, so they have high linearity and can focus beams. In addition, since the photon energy of THz waves is only a few meV, they have the characteristic of being harmless to the human body. The frequency bands expected to be used for THz wireless communication may be the D-band (110 GHz to 170 GHz) or H-band (220 GHz to 325 GHz), which have low propagation loss due to molecular absorption in the air. Discussions on standardization of THz wireless communication are being centered around the IEEE 802.15 THz working group in addition to 3GPP, and standard documents issued by the IEEE 802.15 Task Group (TG3d, TG3e) may specify or supplement the contents described in various embodiments of the present disclosure. THz wireless communication can be applied to wireless cognition, sensing, imaging, wireless communication, THz navigation, etc.

[0194] Figure 7 is a diagram illustrating an example of a THz communication application.

[0195] As illustrated in Figure 7, THz wireless communication scenarios can be categorized into macro networks, micro networks, and nanoscale networks. In macro networks, THz wireless communication can be applied to vehicle-to-vehicle and backhaul / fronthaul connections. In micro networks, THz wireless communication can be applied to fixed point-to-point or multi-point connections, such as indoor small cells, wireless connections in data centers, and near-field communications, such as kiosk downloads.

[0196] Table 2 below shows examples of technologies that can be used in THz waves.

[0197] Transceivers DeviceAvailable immature: UTC-PD, RTD and SBDModulation and CodingLow order modulation techniques (OOK, QPSK), LDPC, Reed Soloman, Hamming, Polar, TurboAntennaOmni and Directional, phased array with low number of antenna elementsBandwidth69GHz (or 23 GHz) at 300GHzChannel modelsPartiallyData rate100GbpsOutdoor deploymentNoFree space lossHighCoverageLowRadio Measurements300GHz indoorDevice sizeFew micrometers

[0198] THz wireless communications can be categorized based on the methods used to generate and receive THz waves. THz generation methods can be categorized as either optical or electronic-based.

[0199] Fig. 15 is a diagram illustrating an example of an electronic component-based THz wireless communication transmitter and receiver.

[0200] THz wireless communications using electronic components can be classified based on the method used to generate and receive THz. THz generation methods can be classified as optical or electronic component-based technologies.

[0201] Fig. 8 is a diagram illustrating an example of an electronic component-based THz wireless communication transmitter and receiver.

[0202] Methods for generating THz using electronic components include a method using semiconductor components such as a resonant tunneling diode (RTD), a method using a local oscillator and a multiplier, a MMIC (Monolithic Microwave Integrated Circuits) method using an integrated circuit based on a compound semiconductor HEMT (High Electron Mobility Transistor), and a method using a Si-CMOS-based integrated circuit. In the case of Fig. 8, a multiplier (doubler, tripler, multiplier) is applied to increase the frequency, and it passes through a subharmonic mixer and is radiated by an antenna. Since the THz band forms a high frequency, a multiplier is essential. Here, the multiplier is a circuit that has an output frequency that is N times that of the input, and matches it to the desired harmonic frequency and filters out all remaining frequencies. In addition, beamforming can be implemented by applying an array antenna or the like to the antenna of Fig. 8. In Fig. 8, IF represents intermediate frequency, tripler and multiplexer represent multipliers, PA represents a power amplifier, LNA represents a low noise amplifier, and PLL represents a phase-locked loop.

[0203] FIG. 9 is a diagram illustrating an example of a method for generating a THz signal based on an optical element.

[0204] Fig. 10 is a diagram illustrating an example of an optical element-based THz wireless communication transceiver.

[0205] Optical device-based THz wireless communication technology refers to a method of generating and modulating THz signals using optical devices. Optical device-based THz signal generation technology generates an ultra-high-speed optical signal using a laser and an optical modulator, and converts it into a THz signal using an ultra-high-speed photodetector. Compared to technologies that use only electronic devices, this technology makes it easy to increase the frequency, generate high-power signals, and obtain flat response characteristics over a wide frequency band. As illustrated in Figure 9, optical device-based THz signal generation requires a laser diode, a wideband optical modulator, and an ultra-high-speed photodetector. In the case of Figure 9, the light signals of two lasers with different wavelengths are combined to generate a THz signal corresponding to the wavelength difference between the lasers. In Fig. 9, an optical coupler refers to a semiconductor device that transmits an electrical signal using optical waves to provide electrical isolation and coupling between circuits or systems, and a UTC-PD (Uni-Travelling Carrier Photo-Detector) is a type of photodetector that uses electrons as active carriers and reduces the travel time of electrons with bandgap grading. The UTC-PD is capable of detecting light at 150 GHz or higher. In Fig. 17, an EDFA (Erbium-Doped Fiber Amplifier) ​​represents an erbium-doped fiber amplifier, a PD (Photo Detector) represents a semiconductor device that can convert an optical signal into an electrical signal, an OSA represents an optical module (Optical Sub Assembly) that modularizes various optical communication functions (photoelectric conversion, electro-optical conversion, etc.) into a single component, and a DSO represents a digital storage oscilloscope.

[0206] The structure of a photoelectric converter (or photoelectric converter) is described with reference to FIGS. 11 and 12.

[0207] Fig. 11 is a diagram illustrating the structure of a photon source-based transmitter.

[0208] Figure 12 is a drawing showing the structure of an optical modulator.

[0209] In general, the phase of a signal can be changed by passing the optical source of a laser through an optical wave guide. At this time, data is loaded by changing the electrical characteristics through a microwave contact, etc. Therefore, the optical modulator output is formed as a modulated waveform. An opto-electrical modulator (O / E converter) can generate THz pulses by optical rectification operation by a nonlinear crystal, photoelectric conversion by a photoconductive antenna, emission from a bunch of relativistic electrons, etc. Terahertz pulses generated in the above manner can have a length in units of femtoseconds to picoseconds. An optical / electronic converter (O / E converter) performs down conversion by utilizing the non-linearity of the device.

[0210] Considering the THz spectrum usage, it is likely that THz systems will use multiple contiguous gigahertz bands for fixed or mobile service purposes. Based on the outdoor scenario criteria, the available bandwidth can be classified based on the oxygen attenuation of 10^2 dB / km in the spectrum up to 1 THz. Accordingly, a framework in which the available bandwidth is composed of multiple band chunks can be considered. As an example of the above framework, if the THz pulse length for one carrier is set to 50 ps, ​​the bandwidth (BW) becomes approximately 20 GHz.

[0211] Effective down-conversion from the infrared band (IR band) to the terahertz band (THz band) depends on how to utilize the nonlinearity of the optical / electrical converter (O / E converter). In other words, to down-convert to the desired terahertz band (THz band), it is necessary to design an optical / electrical converter (O / E converter) with the most ideal non-linearity for transferring to the corresponding terahertz band (THz band). If an optical / electrical converter (O / E converter) that is not suitable for the target frequency band is used, errors are likely to occur in the amplitude and phase of the corresponding pulse.

[0212] In a single-carrier system, a terahertz transmission and reception system can be implemented using a single optical-to-electrical converter. Depending on the channel environment, in a multi-carrier system, the number of optical-to-electrical converters may be equal to the number of carriers. This phenomenon will be particularly noticeable in a multi-carrier system that utilizes multiple broadbands according to the aforementioned spectrum usage plan. In this regard, a frame structure for the multi-carrier system may be considered. A signal down-converted using an optical-to-electrical converter may be transmitted in a specific resource region (e.g., a specific frame). The frequency region of the specific resource region may include multiple chunks. Each chunk may be composed of at least one component carrier (CC).

[0213]

[0214] Specific description of various embodiments of the present disclosure

[0215] Hereinafter, various embodiments of the present disclosure will be described in more detail.

[0216] The present disclosure proposes a method for performing beam sweeping using multiple beams.

[0217] To overcome path loss in 6G channel environments using the THz band, 3D (elevation and azimuth)-based narrow beams with high beam gain can be utilized. When communicating based on 3D narrow beams, the number of narrow beams a base station must generate can significantly increase, and the area allocated to each beam can narrow, significantly increasing the time required for beam sweeping. Similarly, terminals may be forced to use narrow beams to overcome path loss.

[0218] The total beam sweeping time required for initial access (IA) is proportional to the number of transmit beam sweeps x the number of receive beam sweeps, so the beam sweeping time may increase significantly when a narrow beam is used. In addition, considering the 1 Tbps achievement KPI (Key Performance Indicator) of the 6G environment, the number of MIMO layers that a base station must have will be more than 10, so multiple beam generation of the base station may be essential. Meanwhile, multiple beam generation based on multiple RF chains may also be essential for the terminal to receive MIMO signals.

[0219] To address these issues, the present disclosure proposes a method for reducing the overall beam sweeping time and obtaining diversity gains by using multiple beams.

[0220] Figure 13 is a drawing for explaining an example of a beam sweeping method.

[0221] Beam sweeping can refer to the process of sequentially transmitting beams across a specific area covered by a base station to select the optimal beam. Figure 13 illustrates the characteristics of exhaustive beam sweeping and iterative beam sweeping methods.

[0222] Exhaustive beam sweeping involves sequentially searching all possible beam directions. This can mean the base station forms beams in all available directions and selects the optimal beam among them. Exhaustive beam sweeping provides relatively accurate measurement results, but can be resource-intensive.

[0223] Iterative beam sweeping is a method of selecting an optimal beam by iteratively adjusting the beam based on an initial estimate. This can mean that the base station forms a beam using the initial estimate, and then adjusts it based on feedback on signal or performance. While iterative methods can reduce resource consumption, they can also suffer from the drawback that the final result can vary depending on the initial estimate.

[0224] Figure 14 is a drawing for explaining a method of performing beam sweeping.

[0225] During a single SS burst, each beam can transmit a synchronization signal block (SSB) at a time allocated to each beam. As the number of supported beams increases, the number of symbols requiring SSB transmission may increase, and the time required for the entire beam sweep may also increase.

[0226] While the base station performs beam sweeping, the terminal must fix the receiving beam, and beam sweeping must be performed as many times as the number of receiving beams to complete the entire initial connection process. In other words, reducing the number of beam sweeps at the base station as well as the number of beam sweeps at the terminal can be effective ways to reduce the overall beam sweeping time.

[0227] Meanwhile, SSB can include a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and a Physical Broadcast Channel (PBCH). An SSB can consist of four symbols, with the PSS in symbol 0, the PBCH in symbols 1 and 3, and the PBCH and SSS in symbol 2. A complete SSB can consist of 20 RBs.

[0228] Figure 15 is a drawing for explaining the efficiency of beam sweeping.

[0229] Figure 15 illustrates beam sweeping results in several communication environments over a 120-degree area. In 6G systems, communications can be performed based on 3D beams. To achieve high beam gain, 3D beamforming, which converges beams in both horizontal and vertical directions, can be performed. Referring to Figure 15, it can be confirmed that the number of beams required in the 160 GHz region increases by approximately 3 to 5 times compared to 28 GHz.

[0230] The antenna array size examples presented in Figure 15 may have been determined by considering path loss in the 28 GHz band under consideration for 5G and the 160 GHz band under consideration for 6G. As the number of beams increases, the number of SSB transmissions also increases, which may significantly increase the number and frequency of pilot signals for beam sweeping. Therefore, a solution to address this issue may be required.

[0231] Fig. 16 is a drawing for explaining a multi-beam based beam sweeping method.

[0232] Figure 16 illustrates a situation where both a base station and a terminal perform beam sweeping using multiple beams. The present disclosure proposes a method for minimizing the number of beam sweeps in cases where both the base station and the terminal can use multiple beams.

[0233] FIG. 17 is a diagram for explaining the influence of multiple base stations in a beam sweeping method according to the present disclosure.

[0234] Figure 17 illustrates a situation where a terminal performs beam sweeping using multiple beams. When a terminal uses multiple reception beams, interference signals may be received from multiple base stations. The present disclosure proposes a method for minimizing interference between base stations in such situations.

[0235]

[0236] Referring to FIGS. 18 to 27 below, a beam sweeping method according to the present disclosure will be described.

[0237] FIG. 18 is a diagram illustrating an example of a communication system to which the present disclosure can be applied.

[0238] The communication system assumed in the present disclosure is any system capable of generating multiple beams, capable of transmitting independent pilot signals based on multiple beams, and capable of independently steering each of the multiple beams. The system example of FIG. 26 can be described using a system based on a sub-array (SA). Each SA can control the beam direction through a beamformer (BF) and perform data transmission through a digital to analog converter (DAC). Each SA BF and SA can mean an antenna system capable of beam control, and can include a beam control system using a meta surface, a beamforming matrix using Rotman lenses, a Butler matrix, etc. In addition, each DAC can be used in all full-digital forms connected to one SA to all SAs. Here, if the full-digital condition is satisfied, the SA can be a single antenna.

[0239] FIG. 19 is a drawing for explaining a multi-beam based beam sweeping method according to the present disclosure.

[0240] According to FIG. 19, both the base station and the terminal can transmit and receive SSB using multiple beams. The present disclosure proposes a method for distinguishing whether each signal is from the same base station when signals are received through multiple reception beams in a reception multi-beam situation.

[0241] FIG. 20 is a drawing illustrating an example of a beam sweeping method according to the present disclosure.

[0242] Figure 20 is a block diagram illustrating the operation of a terminal in a situation where the terminal receives SSB from different reception beams.

[0243] For example, the terminal can receive SSB through a first beam (beam a) and a second beam (beam b). d1 and d2 may represent a signal (or a first synchronization signal) of the first beam and a signal (or a second synchronization signal) of the second beam, respectively. At this time, the terminal can acquire PSS and SSS based on the SSB received through each beam and perform synchronization based on the same. At this time, the terminal can acquire a first synchronization difference (t1) for the first beam and a second synchronization difference (t2) for the second beam. In addition, the terminal can acquire a first cell ID (cell ID_1) from the first beam and a second cell ID (cell ID_2) from the second beam. Meanwhile, P a can mean the power of the first beam, and P b may refer to the power of the second beam.

[0244] 1. If the first cell ID and the second cell ID are different, the terminal can detect the PBCH by selecting a beam with higher power.

[0245] 2. When the first cell ID and the second cell ID are the same, the terminal can select diversity and beam based on the following method.

[0246] A) If the difference between the first synchronization difference and the second synchronization difference is less than or equal to the length of the CP (Cyclic Prefix), the terminal can detect the PBCH using time domain diversity (B1). In this case, if the PBCH detection is successful, the terminal can perform initial access and subsequent communication using multiple beams (the first beam and the second beam).

[0247] B) If the difference between the first synchronization difference and the second synchronization difference is greater than or equal to the length of the CP and less than or equal to 1 symbol, the terminal can detect the PBCH using delay compensation or synchronization compensation and time domain diversity (B2) for time synchronization. In this case, if the PBCH detection is successful, the terminal can perform initial access and subsequent communication using multiple beams (the first beam and the second beam).

[0248] C) If the difference between the first synchronization difference and the second synchronization difference is greater than or equal to 1 symbol, the terminal can detect the PBCH using frequency domain diversity (B3). In this case, if the PBCH detection is successful, the terminal can perform initial access and subsequent communication using a beam with a higher power among multiple beams (the first beam and the second beam).

[0249] In this case, using a single beam may cause problems due to transmission and reception delays when synchronization differences are large. Furthermore, since diversity is used only for PBCH reception, communication may have to be performed via a single beam.

[0250] 3. If the terminal fails to detect PBCH using diversity, the first and second beams may be determined to be beams from other base station signals with the same cell ID. In this case, PBCH detection (B4) may be performed using a beam with a higher power among the multiple beams (the first and second beams).

[0251] Figure 21 is a diagram for explaining a channel detection method using diversity.

[0252] Figures 21(a) and 21(b) each illustrate a block diagram of the channel detection method of B1 to B4 of Figure 20.

[0253] For example, B1 can perform an operation like the following mathematical expression 1.

[0254] [Mathematical Formula 1]

[0255] PBCH detection (d1+ d2) with min(t1,t2)

[0256] When B1 is performed, the first beam and the second beam have a synchronization difference less than CP, so the two beams can be processed with the same signal, and time domain diversity gain can be secured.

[0257] As another example, B2 can perform an operation like the following mathematical expression 2.

[0258] [Equation 2]

[0259] Combine (PBCH using d1) and (PBCH using d2)

[0260] When B2 is performed, since the first and second beams have a synchronization difference greater than CP, delay compensation is performed to compensate for the synchronization difference between the two beams, and PBCH detection can be performed. Based on this, time domain diversity gain can be secured.

[0261] As another example, B3 can perform an operation like the following mathematical expression 3.

[0262] [Equation 3]

[0263] Combine (PBCH using d1) and (PBCH using d2)

[0264] When B3 is performed, since the first and second beams have a synchronization difference greater than the CP, the two signals can be regarded as independent signals in the time domain without compensation. Each signal can be detected as an individual signal in the frequency domain, and then combined to perform PBCH detection. Based on this, frequency domain diversity gain can be secured.

[0265] As another example, B4 can perform an operation like the following mathematical expression 4.

[0266] [Equation 4]

[0267] PBCH detection with max power beam

[0268] If PBCH detection fails using the first and second beams, the PBCH can be detected using only the signal of the beam with the maximum power.

[0269] FIG. 22 is a drawing illustrating another example of a beam sweeping method according to the present disclosure.

[0270] Figure 22 is a block diagram illustrating the operation of a terminal in a situation where the terminal receives SSB in the same reception beam.

[0271] For example, if SSBs are received from multiple beams, each with a different cell ID, the terminal can perform PBCH detection using a high-power signal. Meanwhile, if the cell IDs are the same, unlike the block diagram in Figure 20, there is no RF chain to separately process the multiple signals (d1 and d2), so the following method can be utilized.

[0272] For example, a terminal may receive an SSB through a first beam (beam a). In FIG. 22, d1 and d2 may represent a first signal (or a first synchronization signal) and a second signal (or a second synchronization signal) acquired through the first beam. At this time, the terminal may acquire a PSS and an SSS based on a plurality of SSBs received through the first beam and perform synchronization based on the PSS and SSS. At this time, the terminal may acquire a first synchronization difference (t1) for the first signal and a second synchronization difference (t2) for the second signal. In addition, the terminal may acquire a first cell ID (cell ID_1) from the first signal and a second cell ID (cell ID_2) from the second signal.

[0273] 1. If the first cell ID and the second cell ID are different, the terminal can detect the PBCH using a high-power signal.

[0274] 2. When the first cell ID and the second cell ID are the same, diversity and beam can be selected in the following manner.

[0275] A) If the difference between the first synchronization difference and the second synchronization difference is less than or equal to the length of the CP (Cyclic Prefix), the terminal can assume that the first signal and the second signal are the same signal and detect the PBCH.

[0276] B) If the difference between the first synchronization difference and the second synchronization difference is greater than the length of the CP, the PBCH can be detected using an algorithm such as Successive Interference Cancellation (SIC). At this time, the maximum power between the first signal and the second signal can be detected, and PBCH detection can be performed using the synchronization difference between the signals as a standard.

[0277] 3. If PBCH detection fails, the terminal may attempt to separate the first and second signals by changing the reception beam pattern. In this case, if PBCH detection continues to fail because multiple signals are determined to be interference signals, the terminal may change the reception beam pattern in a direction that increases the power of one of the first and second signals.

[0278] FIG. 23 is another drawing for comparing the beam sweeping method according to the present disclosure with a conventional method, and FIG. 24 is a drawing for explaining the performance of the beam sweeping method according to the present disclosure.

[0279] Fig. 23 compares a conventional beam sweeping method with a beam sweeping method according to the present disclosure. In Fig. 23, the spacing between each SSB can be constant. When both the transmitter and receiver use multiple beams, it is assumed that up to four RF beams can be generated simultaneously with four RF sub-arrays (SA). Referring to Fig. 24, the gain increases with the number of sub-arrays (the number of multiple beams generated), and the latency can be reduced by up to 3.9% at a cell radius of 100 m.

[0280] FIG. 25 is another drawing for explaining the performance of the beam sweeping method according to the present disclosure.

[0281] Figure 25 illustrates the performance of the present disclosure in terms of the BER (Bit Error Rate) of the PBCH. Assuming that the same SSB is received from two beams, the BER for frequency diversity was measured by applying a Fast Fourier Transform (FFT) at the receiver and then averaging the demodulated signals of the subcarriers. Meanwhile, the BER for time diversity was measured using the signal after adding the two signals and applying the FFT. Referring to Figure 25, a 3 dB gain can exist in a situation where the power of the two signals is equal.

[0282] According to the present disclosure, SSB-based beam sweeping time can be reduced, interference between base stations can be eliminated, and the probability of PBCH detection can be increased. Consequently, the time required for beam management, including initial access, can be significantly reduced.

[0283] FIG. 26 is a diagram illustrating an example of a method for a terminal to transmit and receive signals in a system applicable to the present disclosure.

[0284] The embodiments described below are specifically described with reference to FIG. 26 in terms of terminal operation. The methods described below are distinguished for convenience of explanation, and it is understood that, unless mutually exclusive, some components of one method may be substituted for or combined with some components of another method.

[0285] Referring to FIG. 26, a method performed by a user equipment (UE) in a communication system supporting multiple beams includes the steps of: receiving a first synchronization signal for a first beam from a first base station, which is one of a plurality of base stations (BSs) (S2610); obtaining a first cell ID for the first base station based on the first synchronization signal (S2620); receiving a second synchronization signal for a second beam from one of the first base station and a second base station different from the first base station (S2630); obtaining a second cell ID for a base station that has transmitted the second synchronization signal based on the second synchronization signal (S2640); obtaining a synchronization difference between the first beam and the second beam based on the first synchronization signal and the second synchronization signal (S2650); and obtaining the first cell ID, the second cell ID, and Based on at least one of the above synchronization differences, the method may include a step (S2660) of detecting a Physical Broadcast Channel (PBCH) for at least one of the first beam and the second beam.

[0286] According to various embodiments of the present disclosure, when the first cell ID and the second cell ID are different, the PBCH can be detected using a beam with a higher power among the first beam and the second beam.

[0287] According to various embodiments of the present disclosure, a method wherein, when the first cell ID and the second cell ID are the same, the PBCH is detected based on the synchronization difference.

[0288] According to various embodiments of the present disclosure, when the synchronization difference is smaller than a CP (Cyclic prefix), the PBCH can be detected based on a time domain diversity method.

[0289] According to various embodiments of the present disclosure, the method may further include a step of performing an initial access based on the first beam and the second beam when the PBCH is detected.

[0290] According to various embodiments of the present disclosure, when the synchronization difference is greater than the CP and less than 1 symbol, the PBCH can be detected based on a time domain diversity scheme with synchronization compensation applied.

[0291] According to various embodiments of the present disclosure, the method may further include a step of performing an initial connection based on the first beam and the second beam when the PBCH is detected.

[0292] According to various embodiments of the present disclosure, when the synchronization difference is greater than 1 symbol, the PBCH can be detected based on a frequency domain diversity scheme.

[0293] According to various embodiments of the present disclosure, the method may further include a step of performing an initial connection using a beam having a higher power among the first beam and the second beam when the PBCH is detected.

[0294] According to various embodiments of the present disclosure, when a PBCH is not detected using a diversity scheme, the second synchronization signal is determined to have been received by the second base station, and the PBCH is detected using a beam having a higher power among the first beam and the second beam.

[0295] According to various embodiments of the present disclosure, a terminal may be provided in a communication system. The terminal may include a transceiver and at least one processor, wherein the at least one processor may be configured to perform the operating method of the terminal according to FIG. 26.

[0296] According to various embodiments of the present disclosure, a device for controlling a terminal in a communication system may be provided. The device may include at least one processor and at least one memory operably connected to the at least one processor. The at least one memory may be configured to store instructions for performing the operating method of the terminal according to FIG. 26 based on instructions executed by the at least one processor.

[0297] According to various embodiments of the present disclosure, one or more non-transitory computer-readable media (CRM) storing one or more commands may be provided. The one or more commands, when executed by one or more processors, perform operations, and the operations may include the operating method of the terminal according to FIG. 26.

[0298] FIG. 27 is a diagram illustrating an example of a method for a base station to transmit and receive signals in a system applicable to the present disclosure.

[0299] The embodiments described below are specifically described in terms of terminal operation with reference to FIG. 38. The methods described below are distinguished for convenience of explanation, and it is understood that, unless mutually exclusive, some components of one method may be substituted for or combined with some components of another method.

[0300] Referring to FIG. 27, a method performed by a base station (BS) in a communication system supporting multiple beams includes a step of transmitting a first synchronization signal for a first beam to a terminal (S2710), a step of transmitting a second synchronization signal for a second beam to the terminal (S2720), and a step of transmitting a PBCH (Physical Broadcast Channel) to the terminal based on at least one of the first synchronization signal and the second synchronization signal (S2730), wherein the terminal can detect the PBCH based on at least one of a first cell ID obtained based on the first synchronization signal, a second cell ID obtained based on the second synchronization signal, and a synchronization difference between the first beam and the second beam.

[0301] According to various embodiments of the present disclosure, when the first cell ID and the second cell ID are different, the terminal can detect the PBCH using a beam with a higher power among the first beam and the second beam.

[0302] According to various embodiments of the present disclosure, the terminal can detect the PBCH based on the synchronization difference when the first cell ID and the second cell ID are the same.

[0303] According to various embodiments of the present disclosure, when the synchronization difference is smaller than a CP (Cyclic prefix), the terminal can detect the PBCH based on a time domain diversity method.

[0304] According to various embodiments of the present disclosure, a base station may be provided in a communication system. The base station may include a transceiver and at least one processor, wherein the at least one processor may be configured to perform the operating method of the base station according to FIG. 27.

[0305] According to various embodiments of the present disclosure, a device for controlling a base station in a communication system may be provided. The device may include at least one processor and at least one memory operably connected to the at least one processor. The at least one memory may be configured to store instructions for performing the operating method of the base station according to FIG. 27 based on instructions executed by the at least one processor.

[0306] According to various embodiments of the present disclosure, one or more non-transitory computer-readable media (CRM) storing one or more commands may be provided. The one or more commands, when executed by one or more processors, perform operations, and the operations may include an operating method of a base station according to FIG. 27.

[0307]

[0308] Communication system applicable to the present disclosure

[0309] FIG. 28 illustrates a communication system (1) applicable to various embodiments of the present disclosure.

[0310] Referring to FIG. 28, a communication system (1) applied to various embodiments of the present disclosure includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using a wireless access technology (e.g., 5G NR (New RAT), LTE (Long Term Evolution), 6G wireless communication), and may be referred to as a communication / wireless / 5G device / 6G device. Although not limited thereto, the wireless device may include a robot (100a), a vehicle (100b-1, 100b-2), an XR (eXtended Reality) device (100c), a hand-held device (100d), a home appliance (100e), an IoT (Internet of Things) device (100f), and an AI device / server (400). For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous vehicle, a vehicle capable of performing vehicle-to-vehicle communication, etc. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices, and may be implemented in the form of a Head-Mounted Device (HMD), a Head-Up Display (HUD) installed in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, digital signage, a vehicle, a robot, etc. Mobile devices may include a smartphone, a smart pad, a wearable device (e.g., a smart watch, smart glasses), a computer (e.g., a laptop, etc.), etc. Home appliances may include a TV, a refrigerator, a washing machine, etc. IoT devices may include a sensor, a smart meter, etc. For example, a base station and a network may also be implemented as a wireless device, and a specific wireless device (200a) may act as a base station / network node to other wireless devices.

[0311] Wireless devices (100a to 100f) can be connected to a network (300) via a base station (200). Artificial Intelligence (AI) technology can be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) via the network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, or a 6G network. The wireless devices (100a to 100f) can communicate with each other via the base station (200) / network (300), but can also communicate directly (e.g., sidelink communication) without going through the base station / network. For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to Everything) communication). In addition, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0312] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a~100f) / base stations (200), and base stations (200) / base stations (200). Here, wireless communication / connection can be achieved through various wireless access technologies (e.g., 5G NR) such as uplink / downlink communication (150a), sidelink communication (150b) (or D2D communication), and base station-to-base station communication (150c) (e.g., relay, IAB (Integrated Access Backhaul). Through wireless communication / connection (150a, 150b, 150c), wireless devices and base stations / wireless devices, and base stations and base stations can transmit / receive wireless signals to each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, at least some of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes can be performed based on various proposals of various embodiments of the present disclosure.

[0313] Meanwhile, NR supports multiple numerologies (or subcarrier spacing (SCS)) to support various 5G services. For example, an SCS of 15 kHz supports a wide area in traditional cellular bands; an SCS of 30 kHz / 60 kHz supports dense urban areas, lower latency, and wider carrier bandwidth; and an SCS of 60 kHz or higher supports a bandwidth greater than 24.25 GHz to overcome phase noise.

[0314] The NR frequency band can be defined by two types of frequency ranges (FR1, FR2). The numerical values ​​of the frequency ranges can be changed, and for example, the frequency ranges of the two types (FR1, FR2) can be as shown in Table 3 below. For convenience of explanation, among the frequency ranges used in the NR system, FR1 can mean the "sub 6 GHz range", and FR2 can mean the "above 6 GHz range" and can be called millimeter wave (mmW).

[0315] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1450MHz-6000MHz15, 30, 60kHzFR224250MHz-52600MHz60, 120, 240kHz

[0316] As described above, the numerical value of the frequency range of the NR system can be changed. For example, FR1 may include a band from 410 MHz to 7125 MHz, as shown in Table 4 below. That is, FR1 may include a frequency band above 6 GHz (or 5850, 5900, 5925 MHz, etc.). For example, the frequency band above 6 GHz (or 5850, 5900, 5925 MHz, etc.) included within FR1 may include an unlicensed band. The unlicensed band may be used for various purposes, such as for vehicular communications (e.g., autonomous driving).

[0317] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR141MHz-7125MHz15, 30, 60kHzFR224250MHz-52600MHz60, 120, 240kHz

[0318] According to various embodiments of the present disclosure, the communication system (1) can support terahertz (THz) wireless communication. THz wireless communication is a wireless communication using THz waves having a frequency of approximately 0.1 to 10 THz (1 THz = 10^12 Hz), and may refer to terahertz (THz) band wireless communication using a very high carrier frequency of 100 GHz or higher. The frequency band expected to be used for THz wireless communication may be a D-band (110 GHz to 170 GHz) or H-band (220 GHz to 325 GHz) band where propagation loss due to absorption of molecules in the air is small.

[0319]

[0320] Wireless devices applicable to the present disclosure

[0321] Below, examples of wireless devices to which various embodiments of the present disclosure are applied are described.

[0322] FIG. 29 illustrates a wireless device that can be applied to various embodiments of the present disclosure.

[0323] Referring to FIG. 29, the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals through various wireless access technologies (e.g., LTE, NR). Here, {the first wireless device (100), the second wireless device (200)} can correspond to {the wireless device (100x), the base station (200)} and / or {the wireless device (100x), the wireless device (100x)} of FIG. 28.

[0324] A first wireless device (100) includes one or more processors (102) and one or more memories (104), and may further include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memories (104) and / or the transceivers (106), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (102) may process information in the memory (104) to generate first information / signal, and then transmit a wireless signal including the first information / signal via the transceiver (106). In addition, the processor (102) may receive a wireless signal including second information / signal via the transceiver (106), and then store information obtained from signal processing of the second information / signal in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may perform some or all of the processes controlled by the processor (102), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE, NR). The transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals via one or more antennas (108). The transceiver (106) may include a transmitter and / or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit. In various embodiments of the present disclosure, a wireless device may mean a communication modem / circuit / chip.

[0325] The second wireless device (200) includes one or more processors (202), one or more memories (204), and may further include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memories (204) and / or the transceivers (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (202) may process information in the memory (204) to generate third information / signals, and then transmit a wireless signal including the third information / signals via the transceivers (206). Furthermore, the processor (202) may receive a wireless signal including fourth information / signals via the transceivers (206), and then store information obtained from signal processing of the fourth information / signals in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may perform some or all of the processes controlled by the processor (202), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via one or more antennas (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF unit. In various embodiments of the present disclosure, a wireless device may also mean a communication modem / circuit / chip.

[0326] Hereinafter, the hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and / or methods disclosed herein, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein.

[0327] One or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software configured to perform one or more processors (102, 202) or stored in one or more memories (104, 204) and executed by one or more processors (102, 202). The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions.

[0328] One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. The one or more memories (104, 204) may be configured as ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. The one or more memories (104, 204) may be located internally and / or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

[0329] One or more transceivers (106, 206) can transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or flowcharts of this document, to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts of this document, from one or more other devices. For example, one or more transceivers (106, 206) can be connected to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be coupled to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, or the like, as referred to in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein, via one or more antennas (108, 208). In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using one or more processors (102, 202).One or more transceivers (106, 206) may convert user data, control information, wireless signals / channels, etc. processed by one or more processors (102, 202) from baseband signals to RF band signals. For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or filter.

[0330] FIG. 30 illustrates another example of a wireless device that can be applied to various embodiments of the present disclosure.

[0331] According to FIG. 30, the wireless device may include at least one processor (102, 202), at least one memory (104, 204), at least one transceiver (106, 206), and one or more antennas (108, 208).

[0332] The difference between the example of the wireless device described in FIG. 29 and the example of the wireless device in FIG. 30 is that in FIG. 29, the processor (102, 202) and the memory (104, 204) are separated, but in the example of FIG. 30, the memory (104, 204) is included in the processor (102, 202).

[0333] Here, the specific description of the processor (102, 202), memory (104, 204), transceiver (106, 206), and one or more antennas (108, 208) is as described above, so in order to avoid unnecessary repetition of description, the description of the repeated description is omitted.

[0334] Below, examples of signal processing circuits to which various embodiments of the present disclosure are applied are described.

[0335] Figure 31 illustrates a signal processing circuit for a transmission signal.

[0336] Referring to FIG. 31, the signal processing circuit (1000) may include a scrambler (1010), a modulator (1020), a layer mapper (1030), a precoder (1040), a resource mapper (1050), and a signal generator (1060). Although not limited thereto, the operations / functions of FIG. 31 may be performed in the processor (102, 202) and / or the transceiver (106, 206) of FIG. 29. The hardware elements of FIG. 31 may be implemented in the processor (102, 202) and / or the transceiver (106, 206) of FIG. 29. For example, blocks 1010 to 1060 may be implemented in the processor (102, 202) of FIG. 29. Additionally, blocks 1010 to 1050 may be implemented in the processor (102, 202) of FIG. 29, and block 1060 may be implemented in the transceiver (106, 206) of FIG. 29.

[0337] The codeword can be converted into a wireless signal through the signal processing circuit (1000) of FIG. 31. Here, the codeword is an encoded bit sequence of an information block. The information block can include a transport block (e.g., an UL-SCH transport block, a DL-SCH transport block). The wireless signal can be transmitted through various physical channels (e.g., a PUSCH or a PDSCH).

[0338] Specifically, the codeword can be converted into a bit sequence scrambled by a scrambler (1010). The scramble sequence used for scrambling is generated based on an initialization value, and the initialization value may include ID information of the wireless device, etc. The scrambled bit sequence can be modulated into a modulation symbol sequence by a modulator (1020). The modulation method may include pi / 2-BPSK (pi / 2-Binary Phase Shift Keying), m-PSK (m-Phase Shift Keying), m-QAM (m-Quadrature Amplitude Modulation), etc. The complex modulation symbol sequence can be mapped to one or more transmission layers by a layer mapper (1030). The modulation symbols of each transmission layer can be mapped to the corresponding antenna port(s) by a precoder (1040) (precoding). The output z of the precoder (1040) can be obtained by multiplying the output y of the layer mapper (1030) by a precoding matrix W of N*M. Here, N is the number of antenna ports, and M is the number of transmission layers. Here, the precoder (1040) can perform precoding after performing transform precoding (e.g., DFT transform) on complex modulation symbols. In addition, the precoder (1040) can perform precoding without performing transform precoding.

[0339] The resource mapper (1050) can map modulation symbols of each antenna port to time-frequency resources. The time-frequency resources can include multiple symbols (e.g., CP-OFDMA symbols, DFT-s-OFDMA symbols) in the time domain and multiple subcarriers in the frequency domain. The signal generator (1060) generates a wireless signal from the mapped modulation symbols, and the generated wireless signal can be transmitted to another device through each antenna. To this end, the signal generator (1060) can include an Inverse Fast Fourier Transform (IFFT) module, a Cyclic Prefix (CP) inserter, a Digital-to-Analog Converter (DAC), a frequency uplink converter, etc.

[0340] The signal processing process for receiving signals in a wireless device can be configured in reverse order of the signal processing process (1010 to 1060) of FIG. 31. For example, a wireless device (e.g., 100, 200 of FIG. 29) can receive wireless signals from the outside through an antenna port / transceiver. The received wireless signals can be converted into baseband signals through a signal restorer. For this purpose, the signal restorer can include a frequency downlink converter, an analog-to-digital converter (ADC), a CP remover, and a fast Fourier transform (FFT) module. Thereafter, the baseband signal can be restored to a codeword through a resource demapper process, a postcoding process, a demodulation process, and a descrambling process. The codewords can be restored to the original information blocks through decoding. Accordingly, a signal processing circuit (not shown) for a received signal may include a signal restorer, a resource de-mapper, a postcoder, a demodulator, a de-scrambler, and a decoder.

[0341] Below, examples of wireless device utilization to which various embodiments of the present disclosure are applied are described.

[0342] Figure 32 illustrates another example of a wireless device applicable to various embodiments of the present disclosure. The wireless device may be implemented in various forms depending on the use case / service.

[0343] Referring to FIG. 32, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 29 and may be composed of various elements, components, units / units, and / or modules. For example, the wireless device (100, 200) may include a communication unit (110), a control unit (120), a memory unit (130), and additional elements (140). The communication unit may include a communication circuit (112) and a transceiver(s) (114). For example, the communication circuit (112) may include one or more processors (102, 202) and / or one or more memories (104, 204) of FIG. 29. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and / or one or more antennas (108, 208) of FIG. 29. The control unit (120) is electrically connected to the communication unit (110), the memory unit (130), and the additional elements (140) and controls the overall operation of the wireless device. For example, the control unit (120) may control the electrical / mechanical operation of the wireless device based on the program / code / command / information stored in the memory unit (130). In addition, the control unit (120) may transmit information stored in the memory unit (130) to an external device (e.g., another communication device) via a wireless / wired interface through the communication unit (110), or store information received from an external device (e.g., another communication device) via a wireless / wired interface in the memory unit (130).

[0344] The additional element (140) may be configured in various ways depending on the type of the wireless device. For example, the additional element (140) may include at least one of a power unit / battery, an input / output unit (I / O unit), a driving unit, and a computing unit. Although not limited thereto, the wireless device may be implemented in the form of a robot (Fig. 28, 100a), a vehicle (Fig. 28, 100b-1, 100b-2), an XR device (Fig. 28, 100c), a portable device (Fig. 28, 100d), a home appliance (Fig. 28, 100e), an IoT device (Fig. 28, 100f), a digital broadcasting terminal, a hologram device, a public safety device, an MTC device, a medical device, a fintech device (or a financial device), a security device, a climate / environmental device, an AI server / device (Fig. 28, 400), a base station (Fig. 28, 200), a network node, etc. Wireless devices may be mobile or stationary depending on the use / service.

[0345] In FIG. 32, various elements, components, units / parts, and / or modules within the wireless device (100, 200) may be entirely interconnected via a wired interface, or at least some may be wirelessly connected via a communication unit (110). For example, within the wireless device (100, 200), the control unit (120) and the communication unit (110) may be wired, and the control unit (120) and a first unit (e.g., 130, 140) may be wirelessly connected via the communication unit (110). In addition, each element, component, unit / part, and / or module within the wireless device (100, 200) may further include one or more elements. For example, the control unit (120) may be composed of a set of one or more processors. For example, the control unit (120) may be composed of a set of a communication control processor, an application processor, an electronic control unit (ECU), a graphics processing processor, a memory control processor, etc. As another example, the memory unit (130) may be composed of RAM (Random Access Memory), DRAM (Dynamic RAM), ROM (Read Only Memory), flash memory, volatile memory, non-volatile memory, and / or a combination thereof.

[0346] The claims described in the various embodiments of the present disclosure may be combined in various ways. For example, the technical features of the method claims of the various embodiments of the present disclosure may be combined and implemented as a device, and the technical features of the device claims of the various embodiments of the present disclosure may be combined and implemented as a method. Furthermore, the technical features of the method claims of the various embodiments of the present disclosure may be combined and implemented as a device, and the technical features of the method claims of the various embodiments of the present disclosure may be combined and implemented as a method.

Claims

1. In a method performed by a terminal (user equipment, UE) in a communication system supporting multiple beams, A step of receiving a first synchronization signal for a first beam from a first base station (BS), which is one of a plurality of base stations; A step of obtaining a first cell ID for the first base station based on the first synchronization signal; A step of receiving a second synchronization signal for a second beam from one of the first base station and a second base station different from the first base station; A step of obtaining a second cell ID for a base station that transmitted the second synchronization signal based on the second synchronization signal; A step of obtaining a synchronization difference between the first beam and the second beam based on the first synchronization signal and the second synchronization signal; and A method comprising the step of detecting a Physical Broadcast Channel (PBCH) for at least one of the first beam and the second beam based on at least one of the first cell ID, the second cell ID, and the synchronization difference.

2. In paragraph 1, A method in which, when the first cell ID and the second cell ID are different, the PBCH is detected using a beam with a higher power among the first beam and the second beam.

3. In paragraph 1, A method in which, when the first cell ID and the second cell ID are the same, the PBCH is detected based on the synchronization difference.

4. In paragraph 3, A method in which the PBCH is detected based on a time domain diversity method when the above synchronization difference is smaller than a CP (Cyclic prefix).

5. In paragraph 4, A method further comprising the step of performing an initial access based on the first beam and the second beam when the PBCH is detected.

6. In paragraph 3, A method in which the PBCH is detected based on a time domain diversity scheme with synchronization compensation applied when the above synchronization difference is greater than the CP and less than 1 symbol.

7. In paragraph 6, A method further comprising the step of performing an initial connection based on the first beam and the second beam when the PBCH is detected.

8. In paragraph 3, A method in which the PBCH is detected based on a frequency domain diversity method when the above synchronization difference is greater than 1 symbol.

9. In paragraph 8, A method further comprising a step of performing an initial connection using a beam having a higher power among the first beam and the second beam when the PBCH is detected.

10. In paragraph 3, If the PBCH is not detected using the diversity method, the second synchronization signal is determined to have been received by the second base station, A method in which the above PBCH is detected using a beam having a higher power among the first beam and the second beam.

11. In a method performed by a base station (BS) in a communication system supporting multiple beams, A step of transmitting a first synchronization signal for a first beam to a terminal; a step of transmitting a second synchronization signal for a second beam to the terminal; and A step of transmitting a PBCH (Physical Broadcast Channel) to the terminal based on at least one of the first synchronization signal and the second synchronization signal, A method in which the terminal detects the PBCH based on at least one of a first cell ID obtained based on the first synchronization signal, a second cell ID obtained based on the second synchronization signal, and a synchronization difference between the first beam and the second beam.

12. In paragraph 11, A method in which the terminal detects the PBCH using a beam with a higher power among the first beam and the second beam when the first cell ID and the second cell ID are different.

13. In paragraph 11, A method in which the terminal detects the PBCH based on the synchronization difference when the first cell ID and the second cell ID are the same.

14. In paragraph 13, A method for detecting the PBCH based on a time domain diversity method, when the above synchronization difference is smaller than a CP (Cyclic prefix).

15. In a terminal (user equipment, UE) operating in a communication system, Transmitter and receiver; at least one processor; and At least one memory operably connectable to said at least one processor and storing instructions that, when executed by said at least one processor, perform operations; The above actions are, A terminal comprising all steps of a method according to any one of claims 1 to 10.

16. In a base station (BS) operating in a communication system, Transmitter and receiver; at least one processor; and At least one memory operably connectable to said at least one processor and storing instructions that, when executed by said at least one processor, perform operations; The above actions are, A base station comprising all steps of a method according to any one of claims 11 to 14.

17. In a control device that controls a terminal (user equipment, UE) in a communication system, at least one processor; and comprising at least one memory operably connected to at least one of the processors; The at least one memory stores instructions for performing operations based on being executed by the at least one processor, The above actions are, A control device comprising all steps of a method according to any one of claims 1 to 10.

18. In a control device that controls a base station (BS) in a communication system, at least one processor; and comprising at least one memory operably connected to at least one of the processors; The at least one memory stores instructions for performing operations based on being executed by the at least one processor, The above actions are, A control device comprising all steps of a method according to any one of claims 11 to 14.

19. In one or more non-transitory computer-readable media storing one or more instructions, The one or more instructions perform operations based on being executed by one or more processors, The above actions are, Comprising all steps of the method according to any one of claims 1 to 10, Computer readable medium.

20. In one or more non-transitory computer-readable media storing one or more instructions, The one or more instructions perform operations based on being executed by one or more processors, The above actions are, A computer-readable medium comprising all steps of a method according to any one of claims 11 to 14.

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