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

Abstract

A method for operating a first communication node in a communication system includes generating a first sequence and a second sequence, generating a first signal sequence based on the first sequence and the second sequence, and transmitting a first signal generated by modulating the first signal sequence, wherein even-numbered elements and odd-numbered elements of the first signal sequence are classified into a first element group and a second element group, respectively, and one of the first sequence and the second sequence may be mapped in ascending order in the first element group, and the other may be mapped in descending order in the second element group.

Description

[Technical Field]

[0001] This disclosure relates to wireless signal transmission and reception technology in communication systems, and more specifically, to technology for improving the performance of wireless signal transmission and reception in communication systems. [Background technology]

[0002] With the advancement of information and communication technology, various wireless communication technologies have been developed. Representative wireless communication technologies include LTE (Long Term Evolution) and NR (New Radio), which are defined by the 3GPP (3rd Generation Partnership Project) standards. LTE is one of the wireless communication technologies within 4G (4th Generation) wireless communication technologies, and NR can be one of the wireless communication technologies within 5G (5th Generation) wireless communication technologies. Wireless communication technologies beyond 5G (for example, 6G (6th Generation)) can be referred to as B5G (Beyond 5G) wireless communication technologies.

[0003] In one embodiment of a communication system, a user can perform serving cell identification after obtaining time / frequency synchronization with the network in order to connect to a wireless network. Such operations, such as obtaining synchronization and serving cell identification, may be performed based on a synchronization signal. Here, the synchronization signal may be a primary synchronization signal (PSS), a secondary synchronization signal (SSS), or a synchronization signal block (SSB) composed of a PSS and an SSS.

[0004] In one embodiment of a communication system, high levels of CFO (carrier frequency offset), PhN (Phase Noise), DE (Doppler effect), etc., can degrade the synchronization estimation performance. In one embodiment of a communication system, when performing synchronization estimation based on a synchronization signal, a complex multiplication operation may be required for each sample or resource element to which the synchronization signal is transmitted. Such synchronization estimation operations involving complex multiplication may require a large amount of computation (or computational resources) and may be highly complex. Techniques to improve the efficiency and performance of synchronization estimation operations may be required in wireless communication systems.

[0005] The information contained in this background section is intended to enhance understanding of the background of the invention and may include matters that are not prior art and are already known to a person with ordinary skill in the art to which this art belongs. [Overview of the project] [Problems that the invention aims to solve]

[0006] The purpose of this disclosure to achieve the above requirements is to provide a radio signal transmission and reception method and apparatus for reducing the complexity of calculations for synchronization estimation operations based on radio signals in a communication system and improving the performance of synchronization estimation operations. [Means for solving the problem]

[0007] In one embodiment of a communication system for achieving the above objective, the operation method of a first communication node includes the steps of: generating a first sequence; generating a second sequence; generating a first signal sequence based on the first sequence and the second sequence; and transmitting a first signal generated by modulating the first signal sequence, wherein the even-numbered elements and odd-numbered elements of the first signal sequence are classified into a first element group and a second element group, respectively, and either the first sequence or the second sequence may be mapped in ascending order in the first element group, and the other may be mapped in descending order in the second element group.

[0008] The step of generating the second sequence may include the step of modifying the first sequence to generate the second sequence.

[0009] The first sequence is a binary sequence, and the second sequence may be a sequence obtained by a replication operation or a polarity inversion operation from the first sequence.

[0010] The first sequence is a complex sequence, and the second sequence may be a sequence to which at least some of the following operations are applied: duplication, polarity inversion, conjugate, or complex multiplication.

[0011] The first signal can be generated such that it has real or purely imaginary values ​​in the time domain.

[0012] The step of generating the first signal sequence may include the steps of mapping the elements of the first sequence in ascending order to the even-numbered elements included in the first element group of the elements of the first signal sequence, and the steps of mapping the elements of the second sequence in descending order to the odd-numbered elements included in the second element group of the elements of the elements of the first signal sequence.

[0013] The step of generating the first signal sequence may include the steps of mapping the elements of the first sequence in descending order to the odd-numbered elements included in the second element group from among the elements of the first signal sequence, and mapping the elements of the second sequence in ascending order to the even-numbered elements included in the first element group from among the elements of the first signal sequence.

[0014] In one embodiment of a communication system for achieving the above objective, the operation method of a first communication node includes the steps of: generating a first sequence; generating a second sequence; generating a first signal sequence based on the first and second sequences; and transmitting a first signal generated by modulating the first signal sequence, wherein even-numbered and odd-numbered elements among the elements corresponding to a first range in the first signal sequence are classified into a first element group and a second element group, respectively; even-numbered and odd-numbered elements among the elements corresponding to a second range in the first signal sequence are classified into a third element group and a fourth element group, respectively; the first sequence can be mapped in ascending and descending order in the first and fourth element groups; and the second sequence can be mapped in ascending and descending order in the third and fourth element groups.

[0015] The first sequence is a complex sequence, and the second sequence may be a sequence to which at least some of the following operations are applied: duplication, polarity inversion, conjugate, or complex multiplication.

[0016] The first sequence is a complex ZC (Zadoff-Chu) sequence, and the first signal is generated such that every P elements in the time domain periodically have a value of 0, where P can be a natural number greater than 1.

[0017] The step of generating the first sequence includes the steps of generating a third sequence, mapping the elements of the third sequence in ascending order to the elements of the first sequence that correspond to the third range, and mapping the elements of the third sequence in descending order to the elements of the first sequence that correspond to the fourth range, wherein the first signal is generated such that it periodically has a value of 0 for every P elements in the time domain, and P can be a natural number greater than 1.

[0018] The step of generating the first signal sequence may include the steps of: mapping the elements of the first sequence to the elements of the first element group in ascending order; mapping the elements of the second sequence to the elements of the second element group in ascending order; mapping the elements of the second sequence to the elements of the third element group in descending order; and mapping the elements of the first sequence to the elements of the fourth element group in descending order.

[0019] The step of generating the first signal sequence may include the steps of: mapping the elements of the first sequence to the elements of the first element group in descending order; mapping the elements of the second sequence to the elements of the second element group in descending order; mapping the elements of the second sequence to the elements of the third element group in ascending order; and mapping the elements of the first sequence to the elements of the fourth element group in ascending order.

[0020] In one embodiment of a communication system for achieving the above objective, the first communication node includes a processor, the processor operates to cause the first communication node to generate a first sequence, generate a second sequence, generate a first signal sequence based on the first and second sequences, and transmit a first signal generated by modulating the first signal sequence, wherein even-numbered and odd-numbered elements among the elements corresponding to a first range in the first signal sequence are classified into a first element group and a second element group, respectively, and even-numbered and odd-numbered elements among the elements corresponding to a second range in the first signal sequence are classified into a third element group and a fourth element group, respectively, the first sequence is mapped in ascending order in the first and fourth element groups, and the second sequence can be mapped in ascending and descending order in the third and fourth element groups.

[0021] The first sequence is a complex ZC (Zadoff-Chu) sequence, and the first signal is generated such that every P elements in the time domain periodically have a value of 0, where P can be a natural number greater than 1.

[0022] When generating the first sequence, the processor operates to cause the first communication node to generate a third sequence, map the elements of the third sequence in ascending order to the elements of the first sequence that fall within a third range, and further map the elements of the third sequence in descending order to the elements of the first sequence that fall within a fourth range, so that the first signal is generated such that it periodically has a value of 0 for every P elements in the time domain, where P can be a natural number greater than 1.

[0023] When generating the first signal sequence, the processor may operate in such a way that it causes the first communication node to further map the elements of the first sequence to the elements of the first element group in ascending order, the elements of the second sequence to the elements of the second element group in ascending order, the elements of the second sequence to the elements of the third element group in descending order, and the elements of the first sequence to the elements of the fourth element group in ascending order.

[0024] When generating the first signal sequence, the processor may operate in such a way that the first communication node maps the elements of the first sequence to the elements of the first element group in ascending order, the elements of the second sequence to the elements of the second element group in descending order, the elements of the second sequence to the elements of the third element group in ascending order, and further maps the elements of the first sequence to the elements of the fourth element group in ascending order. [Effects of the Invention]

[0025] According to one embodiment of a wireless signal transmission and reception method and apparatus in a communication system, the performance of synchronization estimation operation based on wireless signals transmitted and received between a transmitting node and a receiving node can be improved. The first wireless signal according to one embodiment of a wireless signal transmission and reception method and apparatus in a communication system can be generated based on a distributed forward / reverse connection method, a distributed half forward / reverse connection method, a distributed full / half forward / reverse connection method, and the like. With the first wireless signal generated in this way, the complexity of the synchronization estimation operation can be reduced. The first wireless signal according to one embodiment of a wireless signal transmission and reception method and apparatus in a communication system can support robust time synchronization estimation performance for high CFO, PhN, DE, etc. [Brief explanation of the drawing]

[0026] [Figure 1] This is a conceptual diagram showing one embodiment of a communication system. [Figure 2] This is a block diagram showing one embodiment of a communication node that constitutes a communication system. [Figure 3] This is a conceptual diagram showing one embodiment of the structure of a wireless frame in a communication system. [Figure 4] This is a flowchart illustrating a first embodiment of a signal transmission and reception method in a communication system. [Figure 5] This is a conceptual diagram illustrating a first embodiment of a wireless signal structure in a communication system. [Figure 6] This is a conceptual diagram illustrating a first embodiment of a wireless signal generation method in a communication system. [Figure 7] This is a conceptual diagram illustrating a second embodiment of a wireless signal generation method in a communication system. [Figure 8a] This is a conceptual diagram illustrating a second embodiment of the wireless signal structure in a communication system. [Figure 8b] This is a conceptual diagram illustrating a second embodiment of the wireless signal structure in a communication system. [Figure 9a] This is a conceptual diagram illustrating a second embodiment of the wireless signal structure in a communication system. [Figure 9b] This is a conceptual diagram illustrating a second embodiment of the wireless signal structure in a communication system. [Figure 9c] This is a conceptual diagram illustrating embodiments of the first and second sequences in a communication system. [Figure 10] This is a conceptual diagram illustrating a third embodiment of a wireless signal generation method in a communication system. [Modes for carrying out the invention]

[0027] While this disclosure can be modified in various ways and may have various embodiments, specific embodiments are illustrated and described in detail in the drawings. However, this should not be understood as limiting this disclosure to specific embodiments, but rather as including all modifications, equivalents, or substitutions that fall within the spirit and technical scope of this disclosure.

[0028] The terms "First," "Second," etc., may be used to describe various components, but the components should not be limited by such terms. The terms are used solely for the purpose of distinguishing one component from another. For example, without exceeding the scope of the rights of this disclosure, the First component may be named the Second component, and similarly, the Second component may also be named the First component. The terms "and / or" include a combination of multiple related described items or any of multiple related described items.

[0029] When it is mentioned that one component is "linked" or "connected" to another component, it should be understood that it is either directly linked to or connected to the other component, or there may be other components in between. Conversely, when it is mentioned that one component is "directly linked" or "directly connected" to another component, it should be understood that there are no other components in between.

[0030] The terms used in this disclosure are used solely to describe specific embodiments and are not intended to limit the disclosure. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, terms such as “includes” or “having” are intended to specify the existence of features, figures, stages, operations, components, parts, or combinations thereof described in the specification, and should be understood not to preclude the existence or possibility of adding one or more other features, figures, stages, operations, components, parts, or combinations thereof.

[0031] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as those generally understood by a person of ordinary skill in the art to which this disclosure pertains. Terms as defined in commonly used dictionaries should be interpreted as having the meaning consistent with their meaning in the context of the relevant technology, and not as ideal or overly formal unless expressly defined herein.

[0032] This document describes the communication systems to which the embodiments of this disclosure apply. The communication systems to which the embodiments of this disclosure apply are not limited to those described below, and the embodiments of this disclosure can be applied to a variety of communication systems. Here, "communication system" may be used interchangeably with "network."

[0033] Throughout this specification, "network" may include, for example, wireless internet such as WiFi (wireless fidelity), mobile internet such as WiBro (wireless broadband internet) or WiMax (world interoperability for microwave access), 2G mobile communication networks such as GSM (global system for mobile communication) or CDMA (code division multiple access), 3G mobile communication networks such as WCDMA (wideband code division multiple access) or CDMA2000, 3.5G mobile communication networks such as HSDPA (high speed downlink packet access) or HSUPA (high speed uplink packet access), 4G mobile communication networks such as LTE (long term evolution) networks or LTE-Advanced networks, 5G mobile communication networks, B5G mobile communication networks (such as 6G mobile communication networks), etc.

[0034] In this specification, the term "terminal" may also refer to a mobile station, mobile terminal, subscriber station, portable subscriber station, user equipment, access terminal, etc., and may include all or some of the functions of a terminal, mobile station, mobile terminal, subscriber station, portable subscriber station, user equipment, access terminal, etc.

[0035] Here, you can use devices capable of communication as terminals, such as desktop computers, laptop computers, tablet PCs, wireless phones, mobile phones, smartphones, smartwatches, smart glass, e-book readers, portable multimedia players (PMPs), portable game consoles, navigation devices, digital cameras, digital multimedia broadcasting (DMB) players, digital audio recorders, digital audio players, digital picture recorders, digital picture players, digital video recorders, and digital video players.

[0036] Throughout this specification, the term "base station" may also refer to an access point, radio access station, node B, evolved node B, base transceiver station, MMR (mobile multihop relay)-BS, etc., and may include all or some of the functions of a base station, access point, radio access station, node B, eNodeB, base transceiver station, MMR-BS, etc.

[0037] Preferred embodiments of the present disclosure will be described in more detail below with reference to the attached drawings. To facilitate overall understanding in this description, the same reference numerals are used for the same components in the drawings, and redundant descriptions of the same components are omitted.

[0038] Figure 1 is a conceptual diagram showing one embodiment of a communication system.

[0039] Referring to Figure 1, the communication system 100 may include multiple communication nodes 110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6. Multiple communication nodes can support 4G communication (e.g., LTE (Long Term Evolution), LTE-A (Advanced)) and 5G communication (e.g., NR (New Radio)) as defined by 3GPP (3rd Generation Partnership Project) standards. 4G communication may be conducted in frequency bands below 6 GHz, while 5G communication may be conducted not only in frequency bands below 6 GHz but also in frequency bands above 6 GHz.

[0040] For example, for 4G and 5G communication, multiple communication nodes can support communication protocols such as CDMA (code division multiple access), WCDMA (wideband CDMA), TDMA (time division multiple access), FDMA (frequency division multiple access), OFDM (orthogonal frequency division multiplexing), Filtered OFDM, CP (cyclic prefix)-OFDM, DFT-s-OFDM (discrete Fourier transform-spread-OFDM), OFDMA (orthogonal frequency division multiple access), SC (single carrier)-FDMA, NOMA (Non-orthogonal Multiple Access), GFDM (generalized frequency division multiplexing), FBMC (filter bank multi-carrier), UFMC (universal filtered multi-carrier), and SDMA (Space Division Multiple Access).

[0041] Furthermore, the communication system 100 may also include a core network. If the communication system 100 supports 4G communication, the core network may include an S-GW (serving gateway), a P-GW (packet data network gateway), an MME (mobility management entity), etc. If the communication system 100 supports 5G communication, the core network may include a UPF (user plane function), an SMF (session management function), an AMF (access and mobility management function), etc.

[0042] Furthermore, each of the multiple communication nodes 110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 that constitute the communication system 100 may have the following structure.

[0043] Figure 2 is a block diagram showing one embodiment of a communication node that constitutes a communication system.

[0044] Referring to Figure 2, the communication node 200 may include at least one processor 210, memory 220, and a transceiver 230 that communicates with the network. The communication node 200 may also further include an input interface device 240, an output interface device 250, a storage device 260, and so on. Each component included in the communication node 200 can communicate with one another by being connected by a bus 270.

[0045] However, each component included in the communication node 200 can also be connected via individual interfaces or individual buses centered around the processor 210, rather than via the common bus 270. For example, the processor 210 can also be connected via a dedicated interface to at least one of the following: memory 220, transceiver 230, input interface device 240, output interface device 250, and storage device 260.

[0046] The processor 210 can execute program commands stored in at least one of the memory 220 and the storage device 260. The processor 210 means a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which the method according to embodiments of this disclosure is performed. Each of the memory 220 and the storage device 260 may consist of at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 220 may consist of at least one of a read-only memory (ROM) and a random access memory (RAM).

[0047] Referring further to Figure 1, the communication system 100 may also include multiple base stations 110-1, 110-2, 110-3, 120-1, 120-2, and multiple terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6. The communication system 100, including base stations 110-1, 110-2, 110-3, 120-1, 120-2, and terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6, can be called an "access network". The first base station 110-1, the second base station 110-2, and the third base station 110-3 can each form a macro cell. The fourth base station 120-1 and the fifth base station 120-2 can each form a small cell. The cell coverage of the first base station 110-1 may include the fourth base station 120-1, the third terminal 130-3, and the fourth terminal 130-4. The cell coverage of the second base station 110-2 may include the second terminal 130-2, the fourth terminal 130-4, and the fifth terminal 130-5. The cell coverage of the third base station 110-3 may include the fifth base station 120-2, the fourth terminal 130-4, the fifth terminal 130-5, and the sixth terminal 130-6. The cell coverage of the fourth base station 120-1 may include the first terminal 130-1. The cell coverage of the fifth base station 120-2 may include the sixth terminal 130-6.

[0048] Here, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can be referred to as Node B, evolved Node B, BTS (base transceiver station), radio base station, radio transceiver, access point, access node, RSU (roadside unit), RRH (radio remote head), TP (transmission point), TRP (transmission and reception point), eNB, gNB, etc.

[0049] Each of the multiple terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 can be referred to as UE (user equipment), terminal, access terminal, mobile terminal, station, subscriber station, mobile station, portable subscriber station, node, device, IoT (Internet of Things) device, mounted module / device / terminal or onboard device / terminal, etc.

[0050] Each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can operate in different frequency bands or in the same frequency band. Each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can be connected via an ideal backhaul link or a non-ideal backhaul link, and can exchange information with each other via the ideal backhaul link or non-ideal backhaul link. Each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can be connected to the core network via an ideal backhaul link or a non-ideal backhaul link. Each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can transmit signals received from the core network to the terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6, and can transmit signals received from the terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 to the core network.

[0051] Furthermore, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can support MIMO transmission (e.g., SU (single user)-MIMO, MU (multi-user)-MIMO, massive MIMO, etc.), CoMP (coordinated multipoint) transmission, CA (carrier aggregation) transmission, transmission in an unlicensed band, and direct device-to-device communication (D2D) (or ProSe (proximity services)). Here, each of the multiple terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 can perform operations corresponding to base stations 110-1, 110-2, 110-3, 120-1, and 120-2, as well as operations supported by base stations 110-1, 110-2, 110-3, 120-1, and 120-2. For example, the second base station 110-2 can transmit signals to the fourth terminal 130-4 based on the SU-MIMO method, and the fourth terminal 130-4 can receive signals from the second base station 110-2 using the SU-MIMO method. Alternatively, the second base station 110-2 can transmit signals to the fourth terminal 130-4 and the fifth terminal 130-5 based on the MU-MIMO scheme, and the fourth terminal 130-4 and the fifth terminal 130-5 can each receive signals from the second base station 110-2 using the MU-MIMO scheme.

[0052] Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 can transmit signals to the fourth terminal 130-4 based on the CoMP method, and the fourth terminal 130-4 can receive signals from the first base station 110-1, the second base station 110-2, and the third base station 110-3 based on the CoMP method. Each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can send and receive signals to and from terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 belonging to their cell coverage based on the CA method. The first base station 110-1, the second base station 110-2, and the third base station 110-3 can each control D2D between the fourth terminal 130-4 and the fifth terminal 130-5, and the fourth terminal 130-4 and the fifth terminal 130-5 can each perform D2D under the control of the second base station 110-2 and the third base station 110-3, respectively.

[0053] Next, a method for transmitting and receiving wireless signals in a communication system will be described. Here, even when describing a method performed by a first communication node (for example, signal transmission or reception), the corresponding second communication node can perform a method equivalent to that performed by the first communication node (for example, signal reception or transmission). For example, when describing the operation of a receiving node, the corresponding transmitting node can perform an operation equivalent to that of the receiving node. Conversely, when describing the operation of a transmitting node, the corresponding receiving node can perform an operation equivalent to that of the transmitting node.

[0054] Figure 3 is a conceptual diagram showing one embodiment of the structure of a wireless frame in a communication system.

[0055] Referring to Figure 3, in a communication system, one radio frame may consist of 10 subframes, and one subframe may consist of 2 time slots. One time slot may have multiple symbols in the time domain and may include multiple subcarriers in the frequency domain. The multiple symbols in the time domain may be OFDM symbols. For convenience, an OFDM transmission mode in which the multiple symbols in the time domain are OFDM symbols will be used as an example to describe one embodiment of the radio frame structure in a communication system. However, this is merely an example for the sake of explanation, and the embodiments of the radio frame structure in a communication system are not limited to this. For example, other embodiments of the radio frame structure in a communication system may be configured to support other transmission modes, such as the SC (single carrier) transmission mode.

[0056] In one embodiment of the communication system, one or more of the numerologies in Table 1 can be used to suit various purposes, such as reducing inter-carrier interference (ICI) due to frequency band characteristics and reducing latency due to service characteristics. [Table 1]

[0057] Table 1 is merely an example for illustrative purposes, and the embodiments of numerology used in communication systems are not limited thereto. Each numerology μ can correspond to information on subcarrier spacing (SCS) Δf and cyclic prefix (CP). A terminal can determine the numerology μ and CP values ​​applied to the downlink bandwidth part or uplink bandwidth part based on higher-level parameters such as "subcarrierSpacing" and "cyclicPrefix".

[0058] In the communication system 300, the time resources on which the wireless signal is transmitted are one or more

number

number

number

number

[0059] In one embodiment of the communication system, a frame 330 may have a length of 10 ms, and a subframe 320 may have a length of 1 ms. Each frame 330 may be divided into two half-frames of the same length, with the first half-frame (half-frame 0) consisting of subframes 320 numbered 0 through 4, and the second half-frame (half-frame 1) consisting of subframes 320 numbered 5 through 9. A carrier may have a set of uplink frames and a set of downlink frames.

[0060] A single slot can have 6 OFDM symbols (for Extended Cyclic Prefix) or 7 (for Normal Cyclic Prefix). The time-frequency domain defined as a single slot can be called a Resource Block (RB). If a single slot has 7 OFDM symbols, then a single subframe has 14 OFDM symbols.

number

[0061] A subframe can be divided into a control region and a data region. The control region may be assigned a PDCCH (Physical Downlink Control Channel). The data region may be assigned a PDSCH (Physical Downlink Shared Channel). Some of the subframes may be special subframes. Special subframes may include DwPTS (Downlink Pilot Time Slot), GP (Guard Period), and UpPTS (Uplink Pilot Time Slot). DwPTS can be used for terminal time and frequency synchronization estimation and cell discovery. GP can be seen as a section for eliminating interference caused by multiple path delays in the downlink signal.

[0062] In one embodiment of a communication system, a user can perform serving cell identification after obtaining time / frequency synchronization with the network in order to connect to a wireless network. Such operations, such as obtaining synchronization and serving cell identification, may be performed based on a synchronization signal. Here, the synchronization signal may be a primary synchronization signal (PSS), a secondary synchronization signal (SSS), or a synchronization signal block (SSB) composed of a PSS and an SSS.

[0063] In one embodiment of a communication system, high levels of CFO (carrier frequency offset), PhN (Phase Noise), DE (Doppler effect), etc., can degrade the synchronization estimation performance. In one embodiment of a communication system, when performing synchronization estimation based on a synchronization signal, a complex multiplication operation may be required for each sample or resource element to which the synchronization signal is transmitted. Such synchronization estimation operations involving complex multiplication may require a large amount of computation (or computational resources) and may be highly complex. Techniques to improve the efficiency and performance of synchronization estimation operations may be required in wireless communication systems.

[0064] In one embodiment of a communication system, a synchronization signal may be composed of one or more sequences. The one or more sequences constituting the synchronization signal may be arranged in the time domain in a frame 330, a subframe 320, a slot 310, or an OFDM symbol constituting slot 310. Furthermore, the one or more sequences constituting the synchronization signal may be modulated and mapped to multiple subcarriers in the frequency domain. In one embodiment of a communication system, the one or more sequences constituting the synchronization signal may correspond to one or more binary sequences or complex sequences.

[0065] Figure 4 is a flowchart illustrating a first embodiment of a signal transmission and reception method in a communication system.

[0066] Referring to Figure 4, the communication system 400 may include multiple communication nodes. For example, the communication system 400 may include at least a first communication node 401 and a second communication node 402. The first communication node 401 may be the same as or similar to the cell that transmits the estimation signal. The second communication node 402 may be the same as or similar to the receiving node that receives the synchronization signal, as described with reference to Figure 3. Hereafter, when describing an embodiment of the signal transmission and reception method in the communication system with reference to Figure 4, we may omit content that is redundant with what has been described with reference to Figures 1 to 3.

[0067] In one embodiment of the communication system 400, the first communication node 401 may correspond to a cell, base station, network, etc. The first communication node 401 may transmit a first signal, which may be used by other communication nodes within the coverage of the first communication node 401 (e.g., users, UEs, terminals, etc.) to achieve synchronization with the first communication node 401. The first signal may be used by other communication nodes within the coverage of the first communication node 401 to estimate identification information (e.g., PID (physical identity), etc.) associated with the first communication node 401. The first signal may correspond to a synchronization signal, for example. The first signal may correspond to a PSS, or to a synchronization signal defined separately from a PSS. However, this is merely an example for the sake of explanation, and the first embodiment of the signal transmission and reception method in the communication system 400 is not limited thereto. The first signal may consist of one or more sequences (hereinafter, one or more first signal sequences). The second communication node 402 can receive the first signal transmitted from the first communication node 401. Based on the received first signal, the second communication node 402 can acquire or estimate synchronization with the first communication node 401.

[0068] Specifically, the first communication node 401 can generate one or more base sequences (S410). One or more base sequences may be binary sequences or complex sequences. Based on one or more base sequences, the first communication node 401 can generate one or more first signal sequences (S420).

[0069] The first communication node 401 can modulate one or more first signal sequences generated in step S420 and assign (or map) them to radio resources (S430). For example, the first communication node 401 can modulate one or more generated first signal sequences to generate one or more modulation symbols. The first communication node 401 can assign one or more generated modulation symbols to time resources and / or frequency resources.

[0070] The first communication node 401 can transmit a first signal consisting of one or more first signal sequences that have been modulated and mapped to radio resources (S440). In other words, the first communication node 401 can transmit a first signal consisting of one or more modulated symbols from which one or more first signal sequences have been modulated. At step S440, the first communication node 401 can transmit the first signal in a broadcast manner. However, this is merely an example for the sake of explanation, and the first embodiment of the signal transmission and reception method in the communication system 400 is not limited thereto. For example, the first communication node 401 can also transmit the first signal in a unicast manner, a multicast manner, or the like.

[0071] The second communication node 402 can receive the first signal transmitted from the first communication node 401 (S440). Based on the first signal received in step S440, the second communication node 402 can perform a synchronization estimation operation (S450). In step S450, the second communication node 402 can perform an operation to acquire time / frequency synchronization with the first communication node 401 based on the first signal. In step S450, the second communication node 402 can acquire information about the first communication node 401 contained in the first signal (e.g., PID). The operation in step S450 may be performed, for example, based on a cross-correlation calculation based on the received signal.

[0072] Figure 5 is a conceptual diagram illustrating a first embodiment of the wireless signal structure in a communication system.

[0073] Referring to Figure 5, the communication system may include multiple communication nodes. The communication system may be the same as or similar to the communication system 400 described with reference to Figure 4. Hereafter, when describing the first embodiment of the wireless signal structure in the communication system with reference to Figure 5, we may omit content that is redundant with what was described with reference to Figures 1 to 4.

[0074] The first communication node can generate radio signals and transmit them to the second communication node. The first communication node can generate one or more radio signals. The first communication node can generate one or more radio signal sequences in order to generate one or more radio signals. The first communication node can modulate one or more elements constituting the generated one or more radio signal sequences and map them to one or more subcarriers in the frequency domain.

[0075] In one embodiment of the communication system, one or more wireless signal sequences can be mapped to 2M subcarriers. The index k of one or more wireless signal sequences can have a natural number value of 0 or more and 2M - 1 or less. That is, k can be 0, 1, ..., 2M - 1. One or more wireless signal sequences can be generated based on a predetermined index u. Here, the index u can correspond to the PID index. However, this is merely an example for the sake of explanation, and the first embodiment of the wireless signal structure is not limited thereto. One or more wireless signal sequences can be, for example, P u (k). Or, one or more wireless signal sequences can be distinguished by the generation method, and can be expressed as P u、1 (k), P u、2 (k), P u、3 (k), etc. One or more wireless signal sequences can be expressed as P u [k], P u、1 [k], P u、2 [k], P u、3 [k], etc.

[0076] In one embodiment of the communication system, the first wireless signal can correspond to the first signal described with reference to FIG. 4. The first wireless signal can correspond to a synchronization signal, PSS, etc. Or, the first wireless signal can correspond to a newly defined signal for synchronization estimation.

[0077] In one embodiment of the communication system, the wireless signal sequence P u (k) can be generated based on two binary sequences. The wireless signal sequence P u (k) can be composed of 2M elements (P u (0), P u (1),..., P u (2M - 1)). The wireless signal sequence P u (k) can be modulated and mapped to 2M subcarriers. That is, in FIG. 5, the wireless signal sequence P uIt can be seen that the case in which (k) is modulated and mapped to multiple subcarriers has been demonstrated. However, this is merely an example for the sake of explanation, and the first embodiment of the radio signal structure in a communication system is not limited thereto.

[0078] In one embodiment of the first wireless signal structure 500, the wireless signal sequence P u (k) can be modulated and mapped to 2M subcarriers represented by index k (k=0, 1, ..., 2M-1). Radio signal sequence P u (k) consists of 2M elements (P u (0), P u (1), ..., P u (2M-1)) Each can be mapped to a subcarrier having a corresponding index. Here, the radio signal sequence P u (k) is mapped to 2M subcarriers (i.e., radio signal sequence P u (k) may consist of 2M subcarriers to which modulated modulation symbols are mapped. The 2M subcarriers constituting the first subcarrier group may be adjacent or separated from each other in the frequency domain. Figure 5 shows a case where at least some of the 2M subcarriers constituting the first subcarrier group are arranged adjacent to each other, but this is merely an example for the sake of explanation, and the first embodiment of the radio signal structure in a communication system is not limited thereto. For example, the first subcarrier group may consist of 2M subcarriers that are separated from each other. In other words, the first subcarrier group may consist of 2M subcarriers that are not adjacent to each other.

[0079] One or more null subcarriers may be placed around or between the 2M subcarriers that make up the first subcarrier group. Null subcarriers may not carry a signal. In other words, null subcarriers may not be assigned a modulation symbol. Null subcarriers can have a value of 0. Null subcarriers may also be gap subcarriers, direct current (DC) subcarriers, etc. Null subcarriers may be placed to easily distinguish each subcarrier.

[0080] A null subcarrier may be positioned at the leading and / or trailing end of a first subcarrier group in the frequency domain. For example, a null subcarrier may be positioned at the leading end of a subcarrier corresponding to subcarrier index 0, and / or at the trailing end of a subcarrier corresponding to subcarrier index 2M-1. Alternatively, one or more null subcarriers may be positioned between the 2M subcarriers constituting the first subcarrier group. For example, a null subcarrier may be positioned at the leading and / or trailing end of one or more subcarriers located in the center of the 2M subcarriers constituting the first subcarrier group (hereinafter referred to as the central subcarrier). Or, the first subcarrier group may be divided into multiple subgroups, each containing one or more subcarriers. A null subcarrier may be positioned at the leading and / or trailing end of each subgroup.

[0081] In one embodiment of the first wireless signal structure 500, the wireless signal sequence P u (k) can be modulated and mapped to a second subcarrier group 520 and a third subcarrier group 530, each consisting of M subcarriers. A null subcarrier can be placed at the leading and / or trailing ends of the second subcarrier group 520 and the third subcarrier group 530 in the frequency domain. For example, a null subcarrier can be placed at least some of the leading ends of the subcarriers corresponding to index 0, the trailing ends of the subcarriers corresponding to index M-1, the leading ends of the subcarriers corresponding to index M, and the trailing ends of the subcarriers corresponding to index 2M-1.

[0082] In one embodiment of the first radio signal structure 500, the second subcarrier group 520 and the third subcarrier group 530 may be arranged with reference to one subcarrier (hereinafter referred to as the first reference subcarrier). For example, the second subcarrier group 520 can be seen as being located at the front end of the first reference subcarrier, and the third subcarrier group 530 can be seen as being located at the rear end of the first reference subcarrier. In other words, the first reference subcarrier can be seen as being located in the middle of the second subcarrier group 520 and the third subcarrier group 530. In this case, the first reference subcarrier can be referred to as the "central subcarrier".

[0083] In one embodiment of the first radio signal structure 500, the second subcarrier group 520 and the third subcarrier group 530 can be considered as subgroups constituting the first subcarrier group. The first subcarrier group may further include a first reference subcarrier located between the second subcarrier group 520 and the third subcarrier group 530. In this case, the first subcarrier group may include 2M+1 subcarriers. The first subcarrier group may further include a first reference subcarrier and a second reference subcarrier which is a null subcarrier located at the leading end of the second subcarrier group. In this case, the first subcarrier group may include 2M+2 subcarriers. The first subcarrier group may be configured not to include the first and second reference subcarriers. In this case, the first subcarrier group may include 2M subcarriers.

[0084] In one embodiment of the first radio signal structure 500, a frequency-domain signal carried on a subcarrier can be converted into a time-domain signal based on an N-point IFFT (N-point inverse fast Fourier transform) scheme. In the N-point IFFT scheme, a radio signal carried on N subcarriers in the frequency domain can be converted into a time-domain signal. The natural number N may be greater than or equal to 2M, which is the number of subcarriers included in the second subcarrier group 520 and the third subcarrier group 530. Of the N subcarriers, the remaining subcarriers (e.g., N-2M subcarriers) after excluding the 2M subcarriers included in the second subcarrier group 520 and the third subcarrier group 530 may have a value of 0 and may correspond to null subcarriers.

[0085] In one embodiment of the first radio signal structure 500, a first subcarrier group may be located in the center of N subcarriers. The number of subcarriers included in the first subcarrier group may be 2M, 2M+1, or 2M+2. The number of subcarriers included in the first subcarrier group may be N / 2, where "N / 2 = 2M+2". For example, N = 256 and M = 63. However, this is merely an example for the sake of explanation, and the first embodiment of the radio signal structure is not limited thereto.

[0086] Figure 6 is a conceptual diagram illustrating a first embodiment of a wireless signal generation method in a communication system.

[0087] Referring to Figure 6, the communication system may include multiple communication nodes. The communication system may be the same as or similar to the communication system 400 described with reference to Figure 4. Hereafter, when describing the first embodiment of the wireless signal generation method in the communication system with reference to Figure 6, we may omit content that is redundant with what was described with reference to Figures 1 to 5.

[0088] <First Embodiment of Wireless Signal Generation Method> In one embodiment of the communication system, a first communication node can generate a wireless signal using a first embodiment of a wireless signal generation method. The first embodiment of the wireless signal generation method can be referred to as the "Distributed Forward / Reverse Concatenation (DFRC) method".

[0089] In a first embodiment of the wireless signal generation method, the first wireless signal may be generated based on a wireless signal structure identical or similar to the first embodiment of the wireless signal structure described with reference to Figure 5. The first wireless signal may be generated based on one or more first wireless signal sequences. One or more first wireless signal sequences may be generated based on one or more base sequences. In other words, one or more first wireless signal sequences may be the result of one or more base sequences being transformed by the first embodiment of the wireless signal generation method. One or more base sequences may be binary sequences, pseudo-noise (PN) sequences, binary PN sequences, or m-sequences. One or more base sequences may consist of gold sequences generated through element-wise exclusive-OR (XOR) operations on two different PN sequences. Alternatively, one or more base sequences may be complex sequences.

[0090] In one embodiment of the communication system, the first radio signal sequence is P u、1 , P u、1 (k), P u、1 It can be written as [k], etc. Here, u can correspond to the first identification information (e.g., PID) associated with the first communication node. Note that k is the first radio signal sequence P u、1(k) represents the index of the subcarrier to which it is modulated and mapped. As explained with reference to Figure 5, k can have a value of a natural number greater than or equal to 0 and less than 2M. That is, it can be "k = 0, 1, ..., 2M-1". Or it can be "k = 0, 1, ..., 2M". M is the base sequence b u It can correspond to a length.

[0091] First radio signal sequence P u、1 is the base sequence b u , and modified sequence b generated based on the base sequence ′ u It can be generated based on modified sequence b. ′ u teeth,

number

number

number

[0092] Referring to Equation 1,

number

[0093] In equation 1, the first radio signal sequence P u、1 Element group #1 (or even-numbered elements) of [m] is in base sequence b u The result of mapping the elements in ascending order (i.e.,

number

number

[0094] First radio signal sequence P u、1 [m] is a time-domain signal p based on N-point IFFT calculation. u、1 It can be converted to [n], where n means the sample index in the time domain and can be an integer greater than or equal to 0 and less than N. The N-point IFFT operation is performed as element exp{j2πnk / N}(i.e., e j2πnk / N This can be done based on the following: Here, k can correspond to the index of the subcarrier corresponding to each element. When M is odd, the time-domain signal p u、1 [n] can be determined to be identical or similar to that in equation 2.

number

[0095] Base sequence b u and modified sequence b′ u Depending on the generation method, the first radio signal (or the time-domain signal p of the first radio signal) u、1 [n]) Embodiments can be classified into various cases. Base sequence b u and modified sequence b′ u The cases of the first radio signal, classified by its generation method, may be the same as or similar to those shown in Table 4. [Table 4]

[0096] In Table 4, b u、I The base sequence b is a complex sequence. ucan correspond to the real component of, and b u、Q is the base sequence b u can correspond to the imaginary component of. When the base sequence b u is a binary sequence, the modified sequence b′ u can be generated based on a replication operation or a polarity inversion operation on the base sequence b u . When the base sequence b u is a complex sequence, the modified sequence b′ u can be generated based on at least a part of a replication operation, a polarity inversion operation, a conjugate operation, or a complex multiplication operation on the base sequence b u . Table 4 is an illustration for convenience of explanation only, and the first embodiment of the wireless signal generation method is not limited thereto.

[0097] Case #1-1: The base sequence b u can be a binary sequence. The modified sequence b′ u can correspond to the result of performing a polarity inversion operation on the base sequence b u (that is, b′ u = -b u ). In this case, the time-domain signal p u、1 [n] can be expressed in the same or similar way as Equation 3. [Equation]

[0098] The time-domain signal p u、1 [n] expressed as in Equation 3 can have element values in imaginary form for all n. As a result, the estimation complexity at the receiving node can be reduced by half (or more). The first wireless signal according to Case #1-1 can support strong time synchronization estimation performance for high CFO, PhN, DE, etc.

[0099] Case #1-2: The base sequence b u can be a binary sequence. The modified sequence b′ uis the base sequence b u can be generated identically (i.e., b′ u = b u ). In this case, the time-domain signal p u、1 [n] can be expressed identically or similarly to Equation 4.

Equation

[0100] The time-domain signal p u、1 [n] expressed as in Equation 4 can have element values in real form for all n. As a result, the estimation complexity at the receiving node can be reduced by half (or more). The first radio signal according to Case #1-2 can support strong time synchronization estimation performance against high CFO, PhN, DE, etc.

[0101] Case #1-3: The base sequence b u can be a complex sequence. The modified sequence b′ u can correspond to the result of performing a polarity inversion operation on the base sequence b u (i.e., b′ u = -b u ). In this case, the time-domain signal p u、1 [n] can be expressed identically or similarly to Equation 5.

Equation

[0102] The time-domain signal p u、1 [n] expressed as in Equation 5 can have element values in complex form for all n. The first radio signal according to Case #1-3 can support strong time synchronization estimation performance against high CFO, PhN, DE, etc.

[0103] [[ID=5l]] Case #1-4: The base sequence b u can be a complex sequence. The modified sequence b′ u is the base sequence b uIt can be generated identically to (i.e., b' u =b u In this case, the time-domain signal p u、1 [n] can be expressed identically or similarly to equation 6.

number

[0104] The time-domain signal p is expressed as shown in equation 6. u、1 [n] can have element values ​​in complex form for all n. The first radio signal according to Case #1-4 can support robust time synchronization estimation performance for high CFO, PhN, DE, etc.

[0105] Case #1-5: Base Sequence b u This can be a complex sequence. Modified sequence b' u is the base sequence b u This can be the result of performing a conjugate operation on (i.e., b') u =b * u ). In other words, modified sequence b' u is the base sequence b u It can be generated as the complex conjugate of . In this case, the time-domain signal p u、1 [n] can be expressed identically or similarly to equation 7.

number

[0106] The time-domain signal p is expressed as shown in equation 7. u、1 [n] can have element values ​​in real form for all n. This can reduce the estimation complexity at the receiving node by half (or more). The first radio signal according to case #1-5 can support robust time-synchronization estimation performance for high CFO, PhN, DE, etc.

[0107] Case #1-6: Base Sequence bu This can be a complex sequence. Modified sequence b' u is the base sequence b u This can be equivalent to the result of performing a polarity reversal operation on the complex conjugate of (i.e., b' u =-b * u In this case, the time-domain signal p u、1 [n] can be expressed identically or similarly to equation 8.

number

[0108] The time-domain signal p is expressed as shown in equation 8. u、1 [n] can have imaginary form element values ​​for all n. This can reduce the estimation complexity at the receiving node by half (or more). The first radio signal according to case #1-6 can support robust time-synchronized estimation performance for high CFO, PhN, DE, etc.

[0109] Case #1-7: Base Sequence b u This can be a complex sequence. Modified sequence b' u is the base sequence b u This can be the result of performing polarity inversion and imaginary (j) multiplication on the complex conjugate of (i.e., b' u =-jb * u In this case, the time-domain signal p u、1 [n] can be expressed identically or similarly to equation 9.

number

[0110] The time-domain signal p expressed as shown in equation 9 u、1 [n] can have element values ​​in complex form for all n. The first radio signal according to Case #1-7 can support robust time synchronization estimation performance for high CFO, PhN, DE, etc.

[0111] Case #1-8: Base Sequence b u This can be a complex sequence. Modified sequence b' u is the base sequence b u This can be equivalent to the result of performing an imaginary multiplication operation on the complex conjugate of (i.e., b'). u =jb * u In this case, the time-domain signal p u、1 [n] can be expressed identically or similarly to equation 10.

number

[0112] The time-domain signal p, expressed as shown in equation 10. u、1 [n] can have element values ​​in complex form for all n. The first radio signal according to Case #1-8 can support robust time synchronization estimation performance for high CFO, PhN, DE, etc.

[0113] Case #1-9: Base Sequence b u This can be a complex sequence. Modified sequence b' u is the base sequence b u This can be equivalent to the result of performing an imaginary number (j) multiplication operation (i.e., b'). u =jb u In this case, the time-domain signal p u、1 [n] can be expressed identically or similarly to equation 11.

number

[0114] The time-domain signal p expressed as shown in equation 11 u、1 [n] can have element values ​​in complex form for all n. The first radio signal according to Case #1-9 can support robust time synchronization estimation performance for high CFO, PhN, DE, etc.

[0115] Case #1-10: Base Sequence b u This can be a complex sequence. Modified sequence b' u is the base sequence b u This can be the result of performing polarity inversion and imaginary (j) multiplication operations (i.e., b' u =-jb u In this case, the time-domain signal p u、1 [n] can be expressed identically or similarly to equation 12.

number

[0116] The time-domain signal p expressed as shown in equation 12 u、1 [n] can have element values ​​in complex form for all n. The first radio signal according to case #1-10 can support robust time synchronization estimation performance for high CFO, PhN, DE, etc.

[0117] Figure 6 can be seen as a specific example of the first embodiment of the wireless signal generation method, and the first embodiment of the wireless signal generation method is not limited thereto. For example, the first embodiment of the wireless signal generation method can be embodied in the following specific case.

[0118] Case #1-11: The first reference subcarrier (e.g., DC) is excluded from the indexing associated with the subcarrier (e.g., k or m). Among the elements of the first radio signal sequence corresponding to the frequency domain subcarrier, the elements of the base sequence are assigned in ascending order to the even-numbered element groups, and the elements of the modified sequence are assigned in descending order to the odd-numbered element groups.

[0119] Case #1-12: The first reference subcarrier is excluded from the indexing associated with the subcarrier. Of the elements of the first radio signal sequence, the elements of the base sequence are assigned in descending order to the even-numbered element groups, and the elements of the modification sequence are assigned in ascending order to the odd-numbered element groups.

[0120] Case #1-13: The first reference subcarrier is excluded from the subcarrier-related indexing. Of the elements of the first radio signal sequence, the elements of the base sequence are assigned in ascending order to the odd-numbered subcarrier groups, and the elements of the modified sequence are assigned in descending order to the even-numbered subcarrier groups.

[0121] Case #1-14: The first reference subcarrier is excluded from the subcarrier-related indexing. Of the elements of the first radio signal sequence, the elements of the base sequence are assigned in descending order to the odd-numbered subcarrier groups, and the elements of the modification sequence are assigned in ascending order to the even-numbered subcarrier groups.

[0122] Case #1-15: In cases #1-1 to #1-14, the positions to which elements of the base sequence are assigned and the positions to which elements of the modified sequence are assigned are interchangeable.

[0123] Cases #1-16: Cases #1-1 to #1-15 are modified so that the first reference subcarrier is included in the indexing associated with the subcarrier.

[0124] In the first embodiment of the wireless signal generation method, at least some of the configurations described with reference to cases #1-1 to #1-16 may be combined with each other. The first embodiment of the wireless signal generation method can be extended based on various wireless signal (e.g., synchronization signal) design or assignment methods in addition to the embodiments described with reference to cases #1-1 to #1-16.

[0125] The first communication node can transmit a first radio signal generated based on a first embodiment of the radio signal generation method. The second communication node can receive the first radio signal transmitted by the first communication node. The second communication node can perform time synchronization, frequency synchronization, partial PCI estimation (or PID estimation), etc., based on the first radio signal.

[0126] In one embodiment of a communication system, the first communication node is a base station, the second communication node is a terminal, and the first radio signal may be a synchronization signal. The second communication node can acquire time synchronization with respect to the first communication node based on the first radio signal and connect to the first communication node. The second communication node can estimate time synchronization by performing correlation using the synchronization signal obtained by converting the frequency domain signal to the time domain. A cross-correlation method may be used for such time synchronization estimation. The cross-correlation method can have advantages in terms of resource efficiency and estimation performance compared to methods such as auto-correlation or differential correlation. The first radio signal generated by the first embodiment of the radio signal generation method can support robust time synchronization performance with high CFO, PhN, DE, etc., and can support cross-correlation operation with low estimation complexity.

[0127] Figure 7 is a conceptual diagram illustrating a second embodiment of a wireless signal generation method in a communication system.

[0128] Referring to Figure 7, the communication system may include multiple communication nodes. The communication system may be the same as or similar to the communication system 400 described with reference to Figure 4. Hereafter, when describing the second embodiment of the wireless signal generation method in the communication system with reference to Figure 7, we may omit content that is redundant with what was described with reference to Figures 1 to 6.

[0129] <Second Embodiment of Wireless Signal Generation Method> In one embodiment of the communication system, the first communication node can generate a wireless signal using a second embodiment of the wireless signal generation method. The second embodiment of the wireless signal generation method can be referred to as the "Distributed Half Forward / Reverse Concatenation (DHFRC) method".

[0130] In a second embodiment of the wireless signal generation method, the first wireless signal may be generated based on a wireless signal structure identical or similar to that of the first embodiment of the wireless signal structure described with reference to Figure 5. The first wireless signal may be generated based on one or more second wireless signal sequences. The second wireless signal sequence is P u、2 , P u、2 (k), P u、2 It may be written as [k], etc. Second radio signal sequence P u、2 This is the first sequence b u and second sequence b' u It can be generated based on the first sequence b. u This can correspond to the base sequence, and the second sequence b' u This can correspond to a modified sequence generated based on the base sequence. However, this is merely an example for the sake of explanation, and the second embodiment of the wireless signal generation scheme is not limited thereto. The second wireless signal sequence is the first sequence b u and second sequence b' u Based on this, it can be defined identically or similarly to Equation 13.

number

[0131] Referring to Equation 13, the second radio signal sequence P u、2 The elements constituting it can be classified into element group #1 and element group #2. Here, element group #1 can correspond to the second subcarrier group 520 described with reference to Figure 5. Element group #2 can correspond to the third subcarrier group 530 described with reference to Figure 5. Element group #1 is the second radio signal sequence P u、2 [m] may include elements where m is 0 or greater and less than M. Element group #2 is the second radio signal sequence P u、2[m] may include elements where m is greater than or equal to M and less than 2M. However, this is merely an example for the sake of explanation, and the second embodiment of the wireless signal generation scheme is not limited thereto. For example, element group #1 may correspond to the third subcarrier group 530 described with reference to Figure 5, and element group #2 may correspond to the second subcarrier group 520 described with reference to Figure 5. Element group #1 and element group #2 may be positioned at the front and rear ends of the first reference subcarrier, where the first reference subcarrier may be the same as or similar to the first reference subcarrier described with reference to Figure 5. The first reference subcarrier may be a null subcarrier, a DC subcarrier, etc. The first reference subcarrier may be a central subcarrier.

[0132] Element group #1 can be classified into element group #1-1 and element group #1-2. Element group #1-1 is the second radio signal sequence P in element group #1. u、2 [m] may include even-numbered elements. Element group #1-2 is the second radio signal sequence P in element group #1 (where m is less than M) u、2 [m] may include odd-numbered elements. Element group #2 can be classified into element group #2-1 and element group #2-2. Element group #2-1 is the second radio signal sequence P in element group #2. u、2 [m] may include even-numbered elements. Element group #2-2 is the second radio signal sequence P in element group #2. u、2 [m] may include odd-numbered elements.

[0133] In equation 13, the second radio signal sequence P u、2 Element group #1-1 of [m] is the first sequence b u The result of mapping the elements in ascending order (i.e.,

number

number

number

number

[0134] According to the second embodiment of the wireless signal generation method, in element group #1, two elements (i.e., an element from the first sequence and an element from the corresponding second sequence) can be grouped together (or associated) and mapped in ascending order. In element group #2, two elements (i.e., an element from the first sequence and an element from the corresponding second sequence) can be grouped together and mapped in descending order.

[0135] The first sequence can be a binary sequence. The first sequence can be a complex sequence. The first sequence can be a ZC (Zadoff-Chu) sequence. The second sequence may be generated based on the first sequence, or it may be generated separately from the first sequence.

[0136] Second radio signal sequence P u、2 [m] is a time-domain signal p based on N-point IFFT or N-point IDFT (N-point inverse fast Fourier transform) calculations. u、2 It can be converted to [n]. When M is odd, the time-domain signal p u、2 [n] can be determined to be identical or similar to that in equation 14.

number

[0137] As explained with reference to Figure 5, if m < 0 or m > 2M-1, then p u、2 [n] can be 0. Equation 14 can be expressed as equation 15.

number

[0138] Equation 15 represents the first radio signal (or the time-domain signal p of the first radio signal) generated based on the configuration described with reference to Figures 5 and 7. u、2 [n]) can be seen as corresponding to this.

[0139] Figures 8a and 8b are conceptual diagrams illustrating a second embodiment of the wireless signal structure in a communication system.

[0140] Referring to Figures 8a and 8b, the communication system may include multiple communication nodes. The communication system may be the same as or similar to the communication system 400 described with reference to Figure 4. The communication system may be the same as or similar to the communication system described with reference to Figure 7. Hereinafter, when describing the second embodiment of the wireless signal structure in the communication system with reference to Figures 8a and 8b, we can omit any content that is redundant with what was described with reference to Figures 1 to 7.

[0141] Figure 8a can be seen as illustrating one embodiment of an IDFT vector structure using the IDFT calculation method. Referring to Figure 8a, the IDFT vector structure can have periodic characteristics (or periodicity). For example, the IDFT vector structure has exp{j2πnm / N} (i.e., e) which changes depending on the value of m. j2πnm / N It can be composed of the following values. Here, as the value of m changes, the value of exp{j2πnm / N} can change periodically. Such periodicity can be determined or modified by the value of n.

[0142] Figure 8b can be seen as illustrating one embodiment of the periodic characteristics of the IDFT vector structure shown in Figure 8a. Referring to Figure 8b, when n=1, the upper half of the IDFT vector structure (for example, the region where m is less than 0 in Figure 8a) and the lower half of the IDFT vector structure (for example, the region where m is greater than 0 in Figure 8a) can be seen as forming a kind of symmetrical structure around the element where m=0. Here, the upper half of the IDFT vector structure can be seen as being composed of values ​​whose polarity is reversed (or whose phase is reversed by 180 degrees) from the values ​​that constitute the lower half of the IDFT vector structure. When n=2, the IDFT vector can have a structure in which the same shape (or structure) is repeated twice. For example, the upper half and the lower half of the IDFT vector structure can be composed identically to each other. The upper half and the lower half of the IDFT vector structure can each have an internal structure in which blocks with the same pattern and inverted phase are connected in series. Thus, IDFT vectors can have periodic properties in which the same form (or structure) is repeated approximately n times as the n value increases.

[0143] Figures 9a to 9c are conceptual diagrams illustrating embodiments of the first and second sequences in a communication system.

[0144] Referring to FIGS. 9a to 9c, the communication system may include a plurality of communication nodes. The communication system may be the same as or similar to the communication system 400 described with reference to FIG. 4. The communication system may be the same as or similar to the communication system described with reference to FIGS. 8a and 8b. Hereinafter, when describing embodiments of the first and second sequences in the communication system with reference to FIGS. 9a to 9c, the content overlapping with that described with reference to FIGS. 1 to 8b can be omitted.

[0145] In a second embodiment of the wireless signal generation method, the first wireless signal may be generated based on a wireless signal structure that is the same as or similar to the first embodiment of the wireless signal structure described with reference to FIG. 5. The first wireless signal may be generated based on one or more second wireless signal sequences. The second wireless signal sequence P u、2 may be generated based on the first sequence b u and the second sequence b'. u Here, the first sequence b u may correspond to the base sequence, and the second sequence b' u may correspond to a modified sequence generated based on the base sequence. In an embodiment of the communication system, the first sequence may correspond to the ZC sequence.

[0146] It can be seen that FIG. 9a shows a first embodiment of the ZC sequence structure. Similar to or the same as that shown in Equation 13, the first sequence b u corresponding to the base sequence composed of the ZC sequence may be expressed similar to or the same as Equation 16.

Number

[0147] Here, referring to Equation 16 and FIG. 9a, etc., a ZC sequence with an odd length M can have a symmetric structure centered around the element with m = 0 (for example, the element corresponding to the central sub-carrier). Also, the ZC sequence can have periodicity identical or similar to Equation 17. [Number]

[0148] First sequence b u and the second sequence b' u Depending on the generation methods of, the embodiments of the first radio signal (or the time-domain signal p u、2 [n] of the first radio signal) can be classified into various cases. When the first sequence b u corresponds to a complex ZC sequence, the cases of the first radio signal classified by the generation method of the second sequence b' u may be the same as or similar to those shown in Table 5. [Table 5]

[0149] When applying the IDFT to the frequency-domain signal, a time-domain signal can be obtained from the frequency-domain signal. Such an operation may be the same as or similar to obtaining the inner product of the frequency-domain signal vector and the IDFT vector when n = 0, 1,..., N - 1. Similar to the explanation with reference to FIG. 9a, the frequency-domain signal vector can have symmetric characteristics. Among the elements of the second radio signal sequence P u、2 , the elements corresponding to the upper sub-carriers in the frequency domain (P u、2 [0], P u、2 [1],..., P u、2 [M - 1]) and the elements corresponding to the lower sub-carriers in the frequency domain (P u、2 [2M - 1], P u、2 [2M - 2],..., P u、2[M]) can have the same or similar values ​​to each other. Thus, the time-domain signal p from Case #2-1 to Case #2-8 u、2 [n] can periodically have a value of 0. The time-domain signal p of the first radio signal u、2 [n] can have a value of 0 once for every four elements. For example, the time-domain signal p according to Case #2-1 to Case #2-8. u、2 [n] can have a value of 0 when n = 2, 6, 10, .... Time-domain signal p u、2 The estimation complexity of the first radio signal can be reduced by the number of elements with a value of 0 in [n]. The first radio signals in cases #2-1 to #2-8 can support robust time-synchronized estimation performance for high CFO, PhN, DE, etc.

[0150] Note that the second radio signal sequence P u、2 Depending on the generation method, the embodiments of the first radio signal can be classified into various cases.

[0151] Case #2-9: The second radio signal sequence P described with reference to Figure 7 and Equation 13. u、2 In the definition, the polarity of the region corresponding to element group #2 can be reversed. For example, in case #2-9, the second radio signal sequence P u、2 It can be defined as shown in equation 18.

number

[0152] Time-domain signal p from Case #2-9 u、2 [n] can periodically have a value of 0 (for example, when n is a multiple of 4). This can reduce estimation complexity. The first radio signal according to case #2-9 can support robust time-synchronous estimation performance for high CFO, PhN, DE, etc.

[0153] Case #2-10: The first sequence (e.g., the base sequence) may be generated based on a separate sequence (hereinafter referred to as the third sequence s) rather than a complex ZC sequence. Here, the third sequence s can have a length of (1 + (M-1) / 2) and can take various forms such as a binary sequence or a complex sequence. Figure 9b shows the first sequence b based on the third sequence s. u This can be seen as one embodiment of the definition. Referring to Figure 9b, the first sequence b of length M u (t) can be defined based on a third sequence s(t) of length (1+(M-1) / 2). For example, when M is odd, in case #2-10 the first sequence b u (t) can be defined as shown in equation 19.

number

[0154] Referring to Figure 9b and Equation 19, etc., in case #2-10, the first sequence b u Similar to the ZC sequence described with reference to Figure 9a, it can have a symmetrical structure centered on the element corresponding to index (M-1) / 2 (for example, the element corresponding to the central subcarrier). First sequence b u In this case, elements that are symmetric to each other can have the same value. Time-domain signal p according to Case #2-10 u、2 [n] can periodically have a value of 0 (for example, when n = 2, 6, 10, ...). This can reduce estimation complexity. The first radio signal according to case #2-10 can support robust time-synchronous estimation performance for high CFO, PhN, DE, etc.

[0155] Case #2-11: The first sequence (e.g., the base sequence) may be generated based on a separate sequence (hereinafter referred to as the third sequence s) rather than a complex ZC sequence. Here, the third sequence s can have a length of (1 + (M-1) / 2) and can take various forms such as a binary sequence or a complex sequence. Figure 9c shows the first sequence b based on the third sequence s. u This can be seen as one embodiment of the definition. Referring to Figure 9b, the first sequence b of length M u (t) can be defined based on a third sequence s(t) of length (1+(M-1) / 2). For example, when M is odd, in case #2-11 the first sequence b u (t) can be defined as shown in equation 20.

number

[0156] Referring to Figure 9c and Equation 20, etc., in case #2-11, the first sequence b u Similar to the ZC sequence described with reference to Figure 9a, it can have a symmetrical structure centered on the element corresponding to index (M-1) / 2 (for example, the element corresponding to the central subcarrier). First sequence b u Elements that are symmetrical to each other can have values ​​that are polarity-inverted (or phase-inverted) to each other. Time-domain signal p according to Case #2-11 u、2 [n] can periodically have a value of 0 (for example, when n is a multiple of 4). This can reduce estimation complexity. The first radio signal according to case #2-11 can support robust time-synchronous estimation performance for high CFO, PhN, DE, etc.

[0157] Figure 7 can be seen as showing a specific example of a second embodiment of the wireless signal generation method, and the second embodiment of the wireless signal generation method is not limited thereto. For example, the second embodiment of the wireless signal generation method can be embodied in the following specific case.

[0158] Case #2-12: The first reference subcarrier (e.g., DC) is excluded from the indexing associated with the subcarrier (e.g., k or m). In the frequency domain, the first reference subcarrier is used to distinguish between upper and lower subcarrier groups. The upper subcarrier group in the frequency domain corresponds to element group #1 of the second radio signal sequence, and the lower subcarrier group in the frequency domain corresponds to element group #2 of the second radio signal sequence. In element group #1, two elements are sequentially grouped (or associated) to assign the elements of the first and second sequences in ascending order. In element group #2, two elements are sequentially grouped (or associated) to assign the elements of the first and second sequences in descending order.

[0159] Case #2-13: The first reference subcarrier is excluded from the subcarrier-related indexing. The upper subcarrier group in the frequency domain corresponds to element group #1 of the second radio signal sequence, and the lower subcarrier group in the frequency domain corresponds to element group #2 of the second radio signal sequence. In element group #1, two elements are sequentially grouped (or related) to assign the elements of the first and second sequences in descending order. In element group #2, two elements are sequentially grouped (or related) to assign the elements of the first and second sequences in ascending order.

[0160] Case #2-14: The first reference subcarrier is excluded from the subcarrier-related indexing. The upper subcarrier group in the frequency domain corresponds to element group #2 of the second radio signal sequence, and the lower subcarrier group in the frequency domain corresponds to element group #1 of the second radio signal sequence. In element group #1, two elements are sequentially grouped (or related) to assign the elements of the first and second sequences in ascending order. In element group #2, two elements are sequentially grouped (or related) to assign the elements of the first and second sequences in descending order.

[0161] Case #2-15: The first reference subcarrier is excluded from the indexing related to the subcarriers. The upper subcarrier group in the frequency domain corresponds to the element group #2 of the second radio signal sequence, and the lower subcarrier group in the frequency domain corresponds to the element group #1 of the second radio signal sequence. In the element group #1, two elements are sequentially grouped together (or related) and the elements of the first and second sequences are assigned in descending order. In the element group #2, two elements are sequentially grouped together (or related) and the elements of the first and second sequences are assigned in ascending order.

[0162] Case #2-16: In Case #2-1 to Case #2-15, the positions where the elements of the first sequence are assigned and the positions where the elements of the second sequence are assigned are mutually replaced.

[0163] Case #2-17: Case #2-1 to Case #2-16 are modified such that the first reference subcarrier is included in the indexing related to the subcarriers.

[0164] In the second embodiment of the radio signal generation method, at least a part of the configurations described with reference to Case #2-1 to Case #2-16 may be combined with each other. The second embodiment of the radio signal generation method can be extended based on various radio signal (e.g., synchronization signal) design methods or allocation methods in addition to the embodiments described with reference to Case #2-1 to Case #2-16.

[0165] FIG. 10 is a conceptual diagram for explaining a third embodiment of the radio signal generation method in a communication system.

[0166] Referring to Figure 10, the communication system may include multiple communication nodes. The communication system may be the same as or similar to the communication system 400 described with reference to Figure 4. Hereafter, when describing the third embodiment of the wireless signal generation method in the communication system with reference to Figure 10, we can omit any content that is redundant with the explanation given with reference to Figures 1 to 9c.

[0167] <Third Embodiment of Wireless Signal Generation Method> In one embodiment of the communication system, the first communication node can generate a wireless signal by a third embodiment of the wireless signal generation method. The second embodiment of the wireless signal generation method can be called the "Distributed Full / Half Forward / Reverse Concatenation (DFHFRC) method".

[0168] In a third embodiment of the wireless signal generation method, the first wireless signal may be generated based on a wireless signal structure identical or similar to that of the first embodiment of the wireless signal structure described with reference to Figure 5. The first wireless signal may be generated based on one or more third wireless signal sequences. The third wireless signal sequence is P u、3 , P u、3 (k), P u、3 It may be written as [k], etc. Third radio signal sequence P u、3 This is the first sequence b u and second sequence b' u It can be generated based on the first sequence b. u This can correspond to the base sequence, and the second sequence b' u This can correspond to a modified sequence generated based on the base sequence. However, this is merely an example for the sake of explanation, and the third embodiment of the wireless signal generation scheme is not limited thereto. The third wireless signal sequence is the first sequence b u and second sequence b' u Based on this, it can be defined identically or similarly to Equation 21.

number

[0169] Referring to Equation 21, the third radio signal sequence P u、3 The elements that make up the element can be classified into element group #1 and element group #2. Element group #1 can be further classified into element group #1-1 and element group #1-2. Element group #2 can be further classified into element group #2-1 and element group #2-2. Here, the element groups (element group #1, element group #2, element group #1-1, element group #1-2, element group #2-1, element group #2-2, etc.) can be classified as identical or similar to the element groups described with reference to Figures 9a to 9c.

[0170] In equation 21, the third radio signal sequence P u、3 Element group #1-1 of [m] is the first sequence b u The result of mapping the elements in ascending order (i.e.,

number

number

number

number

[0171] According to the third embodiment of the wireless signal generation method, in element group #1, two elements (i.e., an element from the first sequence and the corresponding element from the second sequence) can be sequentially grouped together and mapped in ascending order. In element group #2, two elements (i.e., an element from the first sequence and the corresponding element from the second sequence) can be sequentially grouped together, with one of them being mapped in ascending order and the other being mapped in descending order.

[0172] Similar to cases #2-1 to #2-11 described with reference to the second embodiment of the wireless signal generation method, the time-domain signal p according to the third embodiment of the wireless signal generation method u、3 [n] can have a value of 0 once for every four elements. Time-domain signal p u、3 The estimation complexity of the first radio signal can be reduced by the number of elements with a value of 0 in [n]. The first radio signal according to the third embodiment of the radio signal generation method can support robust time-synchronization estimation performance for high CFO, PhN, DE, etc.

[0173] Figure 10 can be seen as showing a specific example of a third embodiment of the wireless signal generation method, and the third embodiment of the wireless signal generation method is not limited thereto. For example, the third embodiment of the wireless signal generation method can be embodied in the following specific case.

[0174] Case #3-1: The first reference subcarrier (e.g., DC) is excluded from the indexing associated with the subcarrier (e.g., k or m). In the frequency domain, the first reference subcarrier is used to distinguish between upper and lower subcarrier groups. The upper subcarrier group in the frequency domain corresponds to element group #1 of the third radio signal sequence, and the lower subcarrier group in the frequency domain corresponds to element group #2 of the third radio signal sequence. In element group #1, two elements are grouped (or associated) sequentially to assign the elements of the first and second sequences in ascending order. In element group #2, two elements are grouped (or associated) sequentially to assign the elements of the first sequence in ascending order, and the elements of the second sequence in descending order.

[0175] Case #3-2: The first reference subcarrier is excluded from the subcarrier-related indexing. The upper subcarrier group in the frequency domain corresponds to element group #1 of the third radio signal sequence, and the lower subcarrier group in the frequency domain corresponds to element group #2 of the third radio signal sequence. In element group #1, two elements are grouped (or related) sequentially to assign the elements of the first and second sequences in ascending order. In element group #2, two elements are grouped (or related) sequentially to assign the elements of the first sequence in descending order, and the elements of the second sequence in ascending order.

[0176] Case #3-3: The first reference subcarrier is excluded from the subcarrier-related indexing. The upper subcarrier group in the frequency domain corresponds to element group #1 of the third radio signal sequence, and the lower subcarrier group in the frequency domain corresponds to element group #2 of the third radio signal sequence. In element group #1, two elements are grouped (or related) sequentially to assign the elements of the first and second sequences in descending order. In element group #2, two elements are grouped (or related) sequentially to assign the elements of the first sequence in ascending order, and the elements of the second sequence in descending order.

[0177] Case #3-4: The first reference subcarrier is excluded from the subcarrier-related indexing. The upper subcarrier group in the frequency domain corresponds to element group #1 of the third radio signal sequence, and the lower subcarrier group in the frequency domain corresponds to element group #2 of the third radio signal sequence. In element group #1, two elements are grouped (or related) sequentially to assign the elements of the first and second sequences in descending order. In element group #2, two elements are grouped (or related) sequentially to assign the elements of the first sequence in descending order, and the elements of the second sequence in ascending order.

[0178] Case #3-5: The first reference subcarrier is excluded from the subcarrier-related indexing. The upper subcarrier group in the frequency domain corresponds to element group #2 of the third radio signal sequence, and the lower subcarrier group in the frequency domain corresponds to element group #1 of the third radio signal sequence. In element group #1, two elements are grouped (or related) sequentially to assign the elements of the first and second sequences in ascending order. In element group #2, two elements are grouped (or related) sequentially to assign the elements of the first sequence in ascending order, and the elements of the second sequence in descending order.

[0179] Case #3-6: The first reference subcarrier is excluded from the subcarrier-related indexing. The upper subcarrier group in the frequency domain corresponds to element group #2 of the third radio signal sequence, and the lower subcarrier group in the frequency domain corresponds to element group #1 of the third radio signal sequence. In element group #1, two elements are grouped (or related) sequentially to assign the elements of the first and second sequences in ascending order. In element group #2, two elements are grouped (or related) sequentially to assign the elements of the first sequence in descending order, and the elements of the second sequence in ascending order.

[0180] Case #3-7: The first reference subcarrier is excluded from the subcarrier-related indexing. The upper subcarrier group in the frequency domain corresponds to element group #2 of the third radio signal sequence, and the lower subcarrier group in the frequency domain corresponds to element group #1 of the third radio signal sequence. In element group #1, two elements are grouped (or related) sequentially to assign the elements of the first and second sequences in descending order. In element group #2, two elements are grouped (or related) sequentially to assign the elements of the first sequence in ascending order, and the elements of the second sequence in descending order.

[0181] Case #3-8: The first reference subcarrier is excluded from the subcarrier-related indexing. The upper subcarrier group in the frequency domain corresponds to element group #2 of the third radio signal sequence, and the lower subcarrier group in the frequency domain corresponds to element group #1 of the third radio signal sequence. In element group #1, two elements are sequentially grouped (or related) to assign the elements of the first and second sequences in descending order. In element group #2, two elements are sequentially grouped (or related) to assign the elements of the first sequence in descending order, and the elements of the second sequence in ascending order.

[0182] Case #3-9: In cases #3-1 to #3-8, the positions to which elements of the first sequence are assigned and the positions to which elements of the second sequence are assigned are interchangeable.

[0183] Case #3-10: Cases #3-1 to #3-9 are modified so that the first reference subcarrier is included in the indexing associated with the subcarrier.

[0184] In the third embodiment of the wireless signal generation method, at least some of the configurations described with reference to cases #3-1 to #3-10 may be combined with each other. The third embodiment of the wireless signal generation method can be extended based on various wireless signal (e.g., synchronization signal) design or assignment methods in addition to the embodiments described with reference to cases #3-1 to #3-10.

[0185] According to one embodiment of a wireless signal transmission and reception method and apparatus in a communication system, the performance of synchronization estimation operation based on wireless signals transmitted and received between a transmitting node and a receiving node can be improved. The first wireless signal according to one embodiment of a wireless signal transmission and reception method and apparatus in a communication system can be generated based on a distributed forward / reverse connection method, a distributed half forward / reverse connection method, a distributed full / half forward / reverse connection method, and the like. With the first wireless signal generated in this way, the complexity of the synchronization estimation operation can be reduced. The first wireless signal according to one embodiment of a wireless signal transmission and reception method and apparatus in a communication system can support robust time synchronization estimation performance for high CFO, PhN, DE, etc.

[0186] However, the effects that can be achieved by embodiments of wireless signal transmission and reception methods and apparatus in a communication system are not limited to those mentioned above, and other effects not mentioned can be clearly understood by a person with ordinary skill in the art to which this disclosure belongs from the configuration described in this specification.

[0187] The operation of the methods according to embodiments of this disclosure can be embodied as a computer-readable program or code on a computer-readable recording medium. A computer-readable recording medium includes all types of recording devices that store information to be read by a computer system. Furthermore, computer-readable recording media can be distributed across a network of computer systems, and computer-readable programs or code can be stored and executed in a distributed manner.

[0188] Furthermore, computer-readable recording media may include hardware devices specially configured to store and execute program instructions, such as ROM, RAM, and flash memory. Program instructions may include not only machine code, such as that created by a compiler, but also high-level language code that can be performed by a computer using an interpreter or the like.

[0189] Some aspects of this disclosure have been described in the portal of apparatus, but they can also be described by corresponding methods, where a block or apparatus corresponds to a method step or a feature of a method step. Similarly, aspects described in the portal of methods can also be described by corresponding blocks or items or features of corresponding apparatus. Some or all of the method steps may be carried out by (or using) hardware devices such as, for example, a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, at least one or more of the most important method steps may be carried out by such devices.

[0190] In embodiments, a programmable logic device (e.g., a field-programmable gate array) may be used to perform some or all of the functions of the methods described herein. In embodiments, a field-programmable gate array may operate in conjunction with a microprocessor to perform one of the methods described herein. Generally, the methods are preferably performed by a hardware device.

[0191] While preferred embodiments of the present disclosure have been described above with reference to those skilled in the art, a person skilled in the art will understand that the present disclosure can be modified and altered in various ways without departing from the spirit and scope of the present disclosure as set forth in the following claims.

Claims

1. A method for operating a first communication node in a communication system, The step of generating the first sequence; The steps include: modifying the first sequence to generate a second sequence; A step of generating a first signal sequence based on the first sequence and the second sequence; The steps include: transmitting a first signal generated by modulating the first signal sequence; The first signal is used for synchronization estimation at the second communication node that receives the first signal. The even-numbered and odd-numbered elements of the first signal sequence are classified into a first element group and a second element group, respectively, and one of the first sequence and the second sequence is mapped in ascending order within the first element group, and the other is mapped in descending order within the second element group. The first signal is generated such that it has a real or purely imaginary value in the time domain. The operation method of the first communication node.

2. The first sequence is a binary sequence, The second sequence is a sequence obtained by performing a replication operation or a polarity inversion operation on the first sequence. The method for operating the first communication node according to claim 1.

3. The first sequence is a complex sequence, The second sequence is a sequence to which at least some of the following operations are applied to the first sequence: a replication operation, a polarity reversal operation, a conjugate operation, or a complex multiplication operation. The method for operating the first communication node according to claim 1.

4. The step of generating the first signal sequence is: The steps include: mapping the elements of the first sequence in ascending order to the even-numbered elements included in the first element group among the elements of the first signal sequence; The steps include: mapping the elements of the second sequence in descending order to the odd-numbered elements included in the second element group among the elements of the first signal sequence; A method for operating the first communication node according to claim 1, including the following:

5. The step of generating the first signal sequence is: The steps include: mapping the elements of the first sequence in descending order to the odd-numbered elements included in the second element group among the elements of the first signal sequence; The steps include: mapping the elements of the second sequence in ascending order to the even-numbered elements included in the first element group of the elements of the first signal sequence; A method for operating the first communication node according to claim 1, including the following:

6. A method for operating a first communication node in a communication system, The step of generating the first sequence; The steps include: modifying the first sequence to generate a second sequence; The steps include: generating a first signal sequence based on the first and second sequences; The steps include: transmitting a first signal generated by modulating the first signal sequence; The first signal is used for synchronization estimation at the second communication node that receives the first signal. In the first signal sequence, the even-numbered and odd-numbered elements among the elements corresponding to the first range are classified into a first element group and a second element group, respectively; the even-numbered and odd-numbered elements among the elements corresponding to the second range in the first signal sequence are classified into a third element group and a fourth element group, respectively; the first sequence is mapped in ascending and descending order within the first and fourth element groups; and the second sequence is mapped in ascending and descending order within the second and third element groups. The first signal is generated such that every P elements in the time domain periodically have a value of 0, the first sequence is a complex ZC (Zadoff-Chu) sequence, and P is a natural number greater than 1. The operation method of the first communication node.

7. The first sequence is a complex sequence, The second sequence is a sequence to which at least some of the following operations are applied to the first sequence: a replication operation, a polarity reversal operation, a conjugate operation, or a complex multiplication operation. The method for operating the first communication node according to claim 6.

8. The step of generating the first sequence is: The steps include: modifying the first sequence to generate a third sequence; The steps include: mapping the elements of the third sequence in ascending order to the elements of the first sequence that fall within the third range; The process includes the step of mapping the elements of the third sequence in descending order to the elements in the fourth range among the elements constituting the first sequence; The first signal is generated such that every P elements in the time domain periodically have a value of 0, where P is a natural number greater than 1. The method for operating the first communication node according to claim 6.

9. The step of generating the first signal sequence is: The steps include: mapping the elements of the first sequence to the elements of the first element group in ascending order; The steps include: mapping the elements of the second sequence to the elements of the second element group in ascending order; The steps include: mapping the elements of the second sequence to the elements of the third element group in descending order; The steps include: mapping the elements of the first sequence to the elements of the fourth element group in descending order; The method for operating the first communication node according to claim 6.

10. The step of generating the first signal sequence is: The steps include: mapping the elements of the first sequence to the elements of the first element group in descending order; The steps include: mapping the elements of the second sequence to the elements of the second element group in descending order; The steps include: mapping the elements of the second sequence to the elements of the third element group in ascending order; The steps include: mapping the elements of the first sequence to the elements of the fourth element group in ascending order; A method for operating the first communication node according to claim 6, including the following:

11. In a communication system, the first communication node is Includes a processor, The processor is such that the first communication node: Generate the first sequence; The first sequence is modified to generate a second sequence; Based on the first and second sequences, a first signal sequence is generated; also, It operates to cause the first signal generated by modulating the first signal sequence to be transmitted, The first signal is used for synchronization estimation at the second communication node that receives the first signal. In the first signal sequence, the even-numbered and odd-numbered elements among the elements corresponding to the first range are classified into a first element group and a second element group, respectively; the even-numbered and odd-numbered elements among the elements corresponding to the second range in the first signal sequence are classified into a third element group and a fourth element group, respectively; the first sequence is mapped in ascending order within the first and fourth element groups; and the second sequence is mapped in ascending and descending order within the second and third element groups. The first signal is generated such that every P elements in the time domain periodically have a value of 0, the first sequence is a complex ZC (Zadoff-Chu) sequence, and P is a natural number greater than 1. First communication node.

12. When generating the first sequence, the processor determines that the first communication node: The first sequence is modified to generate the third sequence; The elements of the third sequence are mapped in ascending order to the elements of the first sequence that fall within the third range; and, The system operates in such a way that it further causes the elements of the third sequence to be mapped in descending order to the elements of the first sequence that fall within the fourth range. The first signal is generated such that every P elements in the time domain periodically have a value of 0, where P is a natural number greater than 1. The first communication node according to claim 11.

13. When generating the first signal sequence, the processor determines that the first communication node: The elements of the first sequence are mapped in ascending order to the elements of the first element group; The elements of the second sequence are mapped in ascending order to the elements of the second element group; The elements of the second sequence are mapped in descending order to the elements of the third element group; and, The system operates to further cause the elements of the first sequence to be mapped in ascending order to the elements of the fourth element group. The first communication node according to claim 11.

14. When generating the first signal sequence, the processor determines that the first communication node: The elements of the first sequence are mapped in ascending order to the elements of the first element group; The elements of the second sequence are mapped in descending order to the elements of the second element group; The elements of the second sequence are mapped in ascending order to the elements of the third element group; and, The system operates to further cause the elements of the first sequence to be mapped in ascending order to the elements of the fourth element group. The first communication node according to claim 11.

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