Method and apparatus for transmitting and receiving radio 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] The present disclosure relates to a radio signal transmission and reception technique in a communication system, and more particularly to a technique for improving the transmission and reception performance of a radio signal in a communication system. [Background technology]

[0002] With the development 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 in the 3GPP (3rd generation partnership project) standard. LTE is one of the 4th Generation (4G) wireless communication technologies, and NR can be one of the 5th Generation (5G) wireless communication technologies. Wireless communication technologies beyond 5G (e.g., 6G (6th Generation)) can be referred to as B5G (beyond 5G) wireless communication technologies.

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

[0004] In one embodiment of the communication system, when carrier frequency offset (CFO), phase noise (PhN), doppler effect (DE), etc. occur highly, synchronization estimation performance may be degraded. In one embodiment of the communication system, when performing a synchronization estimation operation based on a synchronization signal, a complex multiplication operation may be required for each sample or each resource element in which the synchronization signal is transmitted. In a synchronization estimation operation involving such a complex multiplication operation, the required amount of calculation (or amount of calculation resources) may be large, and the calculation complexity may be high. A technique for improving the efficiency and performance of a synchronization estimation operation in a wireless communication system may be required.

[0005] The matters described in this Background Art section are prepared to enhance understanding of the background of the invention, and may include matters that are not prior art already known to those having ordinary skill in the art to which this technology pertains. Summary of the Invention [Problem to be solved by the invention]

[0006] In order to achieve the above-mentioned requirements, an object of the present disclosure is to provide a radio signal transmission / reception method and apparatus for reducing the computational complexity for a synchronization estimation operation based on a radio signal in a communication system and improving the performance of the synchronization estimation operation. [Means for solving the problem]

[0007] In one embodiment of a communication system for achieving the above-mentioned object, an operation method of a first communication node includes a step of generating a first sequence, a step of generating a second sequence, a step of generating a first signal sequence based on the first sequence and the second sequence, and a step of 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.

[0008] Generating the second sequence may include modifying the first sequence to generate the second sequence.

[0009] The first sequence may be a binary sequence, and the second sequence may be a sequence that is a replica or inverted version of the first sequence.

[0010] The first sequence may be a complex sequence, and the second sequence may be a sequence obtained by applying at least some of a duplication operation, a polarity inversion operation, a conjugate operation, or a complex multiplication operation to the first sequence.

[0011] The first signal may be generated to have real or pure imaginary values ​​in the time domain.

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

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

[0014] In one embodiment of a communication system for achieving the above-mentioned object, an 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 elements and odd-numbered elements among elements in the first signal sequence that fall into a first range are classified into a first element group and a second element group, respectively, and even-numbered elements and odd-numbered elements among elements in the first signal sequence that fall into a second range are classified into a third element group and a fourth element group, respectively, and the first sequence is mapped in ascending and descending order in the first and fourth element groups, and the second sequence is mapped in ascending and descending order in the third and fourth element groups.

[0015] The first sequence may be a complex sequence, and the second sequence may be a sequence obtained by applying at least some of a duplication operation, a polarity inversion operation, a conjugate operation, or a complex multiplication operation to the first sequence.

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

[0017] The generating of the first sequence may include generating a third sequence, mapping elements of the third sequence in ascending order to elements of the first sequence that fall within a third range, and mapping elements of the third sequence in descending order to elements of the first sequence that fall within a fourth range, wherein the first signal is generated such that every P elements have a value of 0 periodically in the time domain, where P may be a natural number greater than 1.

[0018] Generating the first signal sequence may include mapping elements of the first sequence to elements of the first element group in ascending order, mapping elements of the second sequence to elements of the second element group in ascending order, mapping elements of the second sequence to elements of the third element group in descending order, and mapping elements of the first sequence to elements of the fourth element group in descending order.

[0019] Generating the first signal sequence may include mapping elements of the first sequence to elements of the first element group in descending order, mapping elements of the second sequence to elements of the second element group in descending order, mapping elements of the second sequence to elements of the third element group in ascending order, and mapping elements of the first sequence to elements of the fourth element group in ascending order.

[0020] In one embodiment of a communication system for achieving the above object, a first communication node includes a processor, the processor is operative 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 elements and odd-numbered elements among elements in the first signal sequence that fall into a first range are classified into a first element group and a second element group, respectively, and even-numbered elements and odd-numbered elements among elements in the first signal sequence that fall into a second range are classified into a third element group and a fourth element group, respectively, and the first sequence is mapped in ascending order in the first and fourth element groups, and the second sequence is mapped in ascending and descending order in the third and fourth element groups.

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

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

[0023] When generating the first signal sequence, the processor may be operable to further cause the first communications node to map elements of the first sequence to elements of the first element group in ascending order, map elements of the second sequence to elements of the second element group in ascending order, map elements of the second sequence to elements of the third element group in descending order, and map elements of the first sequence to elements of the fourth element group in ascending order.

[0024] When generating the first signal sequence, the processor may be operable to further cause the first communications node to map elements of the first sequence to elements of the first element group in ascending order, map elements of the second sequence to elements of the second element group in descending order, map elements of the second sequence to elements of the third element group in ascending order, and map elements of the first sequence to elements of the fourth element group in ascending order. Effect of the Invention

[0025] According to an embodiment of the method and apparatus for transmitting and receiving a wireless signal in a communication system, the performance of a synchronization estimation operation based on a wireless signal transmitted and received between a transmitting node and a receiving node can be improved. The first wireless signal according to the embodiment of the method and apparatus for transmitting and receiving a wireless signal in a communication system can be generated based on a distributed forward and reverse concatenation scheme, a distributed half forward and reverse concatenation scheme, a distributed full / half forward and reverse concatenation scheme, or the like. The first wireless signal generated in this manner can reduce the complexity of a synchronization estimation operation. The first wireless signal according to the embodiment of the method and apparatus for transmitting and receiving a wireless signal in a communication system can support time synchronization estimation performance that is robust against high CFO, PhN, DE, and the like. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a conceptual diagram illustrating an embodiment of a communication system. [Diagram 2] 1 is a block diagram showing an embodiment of a communication node constituting a communication system; [Diagram 3] FIG. 2 is a conceptual diagram illustrating an embodiment of a radio frame structure in a communication system. [Figure 4] 4 is a flowchart for explaining a first embodiment of a signal transmission and reception method in a communication system. [Diagram 5] 1 is a conceptual diagram for explaining a first embodiment of a radio signal structure in a communication system. [Figure 6] 1 is a conceptual diagram for explaining a first embodiment of a wireless signal generation method in a communication system. [Figure 7] FIG. 11 is a conceptual diagram for explaining a second embodiment of a radio signal generation method in a communication system. [Figure 8a] FIG. 11 is a conceptual diagram for explaining a second embodiment of a radio signal structure in a communication system. [Figure 8b] FIG. 11 is a conceptual diagram for explaining a second embodiment of a radio signal structure in a communication system. [Figure 9a] FIG. 11 is a conceptual diagram for explaining a second embodiment of a radio signal structure in a communication system. [Figure 9b] FIG. 11 is a conceptual diagram for explaining a second embodiment of a radio signal structure in a communication system. [Figure 9c] FIG. 2 is a conceptual diagram for explaining embodiments of a first and second sequence in a communication system. [Figure 10] FIG. 11 is a conceptual diagram for explaining a third embodiment of a radio signal generation method in a communication system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] The present disclosure can be modified in various ways and can have various embodiments, and a specific embodiment will be illustrated in the drawings and described in detail. However, this is not intended to limit the present disclosure to the specific embodiment, and it should be understood that the present disclosure includes all modifications, equivalents, and alternatives within the spirit and technical scope of the present disclosure.

[0028] Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only to distinguish one component from another. For example, a first component may be named a second component, and similarly, the second component may be named a first component, without departing from the scope of the present disclosure. The term and / or includes a combination of multiple related listed items or any item of multiple related listed items.

[0029] When a component is said to be "coupled" or "connected" to another component, it should be understood that the component may be directly coupled or connected to the other component, but there may be other components in between. Conversely, when a component is said to be "directly coupled" 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 merely used to describe certain embodiments and are not intended to limit the disclosure. A singular expression includes a plural expression unless the context clearly indicates otherwise. In this application, the terms "include" or "have" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and should be understood not to preclude the presence or additional possibility of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0031] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly 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 to have a meaning consistent with the meaning they have in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense unless expressly defined in this disclosure.

[0032] A communication system to which the embodiments of the present disclosure are applied will be described. The communication system to which the embodiments of the present disclosure are applied is not limited to the contents described below, and the embodiments of the present disclosure can be applied to various communication systems. Here, the communication system may be used in the same sense as a communication network.

[0033] Throughout the specification, a 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 (e.g., 6G mobile communication networks), and the like.

[0034] Throughout the specification, a terminal may 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, the terminals that can be used include a desktop computer, a laptop computer, a tablet PC, a wireless phone, a mobile phone, a smart phone, a smart watch, smart glass, an e-book reader, a portable multimedia player (PMP), a portable game console, a navigation device, a digital camera, a digital multimedia broadcasting (DMB) player, a digital audio recorder, a digital audio player, a digital picture recorder, a digital picture player, a digital video recorder, a digital video player, and the like, which are capable of communication.

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

[0037] Hereinafter, preferred embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. In order to facilitate overall understanding of the present disclosure, the same reference numerals are used for the same components in the drawings, and duplicate descriptions of the same components are omitted.

[0038] FIG. 1 is a conceptual diagram showing an embodiment of a communication system.

[0039] Referring to FIG. 1, a communication system 100 may include a plurality of 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. The plurality of communication nodes may support 4G communication (e.g., LTE (long term evolution), LTE-A (advanced)) and 5G communication (e.g., NR (new radio)) defined in the 3GPP (3rd generation partnership project) standard. The 4G communication may be performed in a frequency band of 6 GHz or less, and the 5G communication may be performed in a frequency band of 6 GHz or more as well as a frequency band of 6 GHz or less.

[0040] For example, for 4G and 5G communications, the communication nodes may support a code division multiple access (CDMA)-based communication protocol, a wideband CDMA (WCDMA)-based communication protocol, a time division multiple access (TDMA)-based communication protocol, a frequency division multiple access (FDMA)-based communication protocol, an orthogonal frequency division multiplexing (OFDM)-based communication protocol, a filtered OFDM-based communication protocol, a cyclic prefix (CP)-OFDM-based communication protocol, a discrete Fourier transform-spread-OFDM (DFT-s-OFDM)-based communication protocol, an orthogonal frequency division multiple access (OFDMA)-based communication protocol, a single carrier (SC)-FDMA-based communication protocol, a non-orthogonal multiple access (NOMA), a generalized frequency division multiplexing (GFDM)-based communication protocol, a filter bank multi-carrier (FBMC)-based communication protocol, a universal filtered multi-carrier (UFMC)-based communication protocol, a space division multiple access (SDMA)-based communication protocol, and the like.

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

[0042] 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 constituting the communication system 100 may have the following structure.

[0043] FIG. 2 is a block diagram showing an embodiment of a communication node constituting the communication system.

[0044] 2, the communication node 200 may include at least one processor 210, a memory 220, and a transceiver 230 coupled to a network for communication. The communication node 200 may further include an input interface device 240, an output interface device 250, a storage device 260, etc. Each component included in the communication node 200 is coupled to a bus 270 and can communicate with each other.

[0045] However, each component included in the communication node 200 may be connected via an individual interface or individual bus centered around the processor 210, instead of the common bus 270. For example, the processor 210 may be connected to at least one of the memory 220, the transceiver 230, the input interface unit 240, the output interface unit 250, and the storage unit 260 via a dedicated interface.

[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 refers to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which the method according to the embodiment of the present disclosure is performed. Each of the memory 220 and the storage device 260 may be composed of at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 220 may be composed of at least one of a read only memory (ROM) and a random access memory (RAM).

[0047] 1, the communication system 100 may include a plurality of base stations 110-1, 110-2, 110-3, 120-1, 120-2, and a plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6. The communication system 100 including the base stations 110-1, 110-2, 110-3, 120-1, 120-2, and the terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6 may be referred to as an "access network." Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may form a macro cell. Each of the fourth base station 120-1 and the fifth base station 120-2 may form a small cell. The fourth base station 120-1, the third terminal 130-3, and the fourth terminal 130-4 may belong to the cell coverage of the first base station 110-1. The second terminal 130-2, the fourth terminal 130-4, and the fifth terminal 130-5 may belong to the cell coverage of the second base station 110-2. The fifth base station 120-2, the fourth terminal 130-4, the fifth terminal 130-5, and the sixth terminal 130-6 may belong to the cell coverage of the third base station 110-3. The first terminal 130-1 may belong to the cell coverage of the fourth base station 120-1. The sixth terminal 130-6 may belong to the cell coverage of the fifth base station 120-2.

[0048] Here, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can be referred to as a Node B, evolved Node B, base transceiver station (BTS), radio base station, radio transceiver, access point, access node, road side unit (RSU), radio remote head (RRH), transmission point (TP), transmission and reception point (TRP), 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 a UE (user equipment), a terminal, an access terminal, a mobile terminal, a station, a subscriber station, a mobile station, a portable subscriber station, a node, a device, an IoT (Internet of Things) device, an on-board device (mounted module / device / terminal or on board device / terminal, etc.), etc.

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

[0051] In addition, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can support MIMO transmission (e.g., single user (SU)-MIMO, multi user (MU)-MIMO, massive MIMO, etc.), coordinated multipoint (CoMP) transmission, carrier aggregation (CA) transmission, transmission in unlicensed bands, direct communication between terminals (device to device communication, D2D) (or proximity services (ProSe)), etc. Here, each of the multiple terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 may perform operations corresponding to the base stations 110-1, 110-2, 110-3, 120-1, and 120-2, and operations supported by the base stations 110-1, 110-2, 110-3, 120-1, and 120-2. For example, the second base station 110-2 may transmit a signal to the fourth terminal 130-4 based on the SU-MIMO scheme, and the fourth terminal 130-4 may receive a signal from the second base station 110-2 using the SU-MIMO scheme. 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 each of the fourth terminal 130-4 and the fifth terminal 130-5 can 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 a signal to the fourth terminal 130-4 based on the CoMP scheme, 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 by the CoMP scheme. Each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can transmit and receive signals to and from terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 that belong to its own cell coverage based on the CA scheme. Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 can control D2D between the fourth terminal 130-4 and the fifth terminal 130-5, and each of the fourth terminal 130-4 and the fifth terminal 130-5 can 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 a wireless signal in a communication system will be described. Here, even when a method (e.g., transmitting or receiving a signal) performed in a first communication node among communication nodes is described, a corresponding second communication node can perform a method (e.g., receiving or transmitting a signal) equivalent to the method performed in the first communication node. For example, when an operation of a receiving node is described, a corresponding transmitting node can perform an operation equivalent to the operation of the receiving node. Conversely, when an operation of a transmitting node is described, a corresponding receiving node can perform an operation equivalent to the operation of the transmitting node.

[0054] FIG. 3 is a conceptual diagram illustrating an embodiment of a radio frame structure in a communication system.

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

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

[0057] Table 1 is merely an example for convenience of explanation, and the embodiment of the numerology used in the communication system is not limited thereto. Each numerology μ can correspond to information on a subcarrier spacing (SCS) Δf and a cyclic prefix (CP). The terminal can check the numerology μ and CP value applied to the downlink bandwidth part or the uplink bandwidth part based on the higher layer parameters "subcarrierSpacing", "cyclicPrefix", etc.

[0058] The time resources in which the wireless signal is transmitted in the communication system 300 include one or more

number

number

number

number

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

[0060] One slot can have 6 (in the case of Extended Cyclic Prefix) or 7 (in the case of Normal Cyclic Prefix) OFDM symbols. The time-frequency region defined as one slot can be called a Resource Block (RB). When one slot has 7 OFDM symbols, one subframe has 14 OFDM symbols.

number

[0061] A subframe may be divided into a control region and a data region. A physical downlink control channel (PDCCH) may be assigned to the control region. A physical downlink shared channel (PDSCH) may be assigned to the data region. Some of the subframes may be special subframes. The special subframe may include a downlink pilot time slot (DwPTS), a guard period (GP), and an uplink pilot time slot (UpPTS). The DwPTS can be used for time and frequency synchronization estimation and cell search of a terminal. The GP can be seen as a section for removing interference caused by multipath delay of a downlink signal.

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

[0063] In one embodiment of the communication system, when carrier frequency offset (CFO), phase noise (PhN), doppler effect (DE), etc. occur highly, synchronization estimation performance may be degraded. In one embodiment of the communication system, when performing a synchronization estimation operation based on a synchronization signal, a complex multiplication operation may be required for each sample or each resource element in which the synchronization signal is transmitted. In a synchronization estimation operation involving such a complex multiplication operation, the required amount of calculation (or amount of calculation resources) may be large, and the calculation complexity may be high. A technique for improving the efficiency and performance of a synchronization estimation operation in a wireless communication system may be required.

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

[0065] FIG. 4 is a flowchart for explaining a first embodiment of a signal transmission and reception method in a communication system.

[0066] Referring to Fig. 4, the communication system 400 may include a plurality of 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 a cell that transmits an estimation signal. The second communication node 402 may be the same as or similar to a receiving node that receives a synchronization signal, as described with reference to Fig. 3. Hereinafter, in describing an embodiment of a signal transmission / reception method in a communication system with reference to Fig. 4, contents that overlap with those described with reference to Figs. 1 to 3 may be omitted.

[0067] In one embodiment of the communication system 400, the first communication node 401 may correspond to a cell, a base station, a network, etc. The first communication node 401 may transmit a first signal. Here, the first signal may be used by other communication nodes (e.g., a user, a UE, a terminal, etc.) in the coverage of the first communication node 401 to acquire synchronization with the first communication node 401. The first signal may be used by other communication nodes in the coverage of the first communication node 401 to estimate identity information (e.g., a physical identity (PID) etc.) associated with the first communication node 401. The first signal may correspond to, for example, a synchronization signal. The first signal may correspond to a PSS or a synchronization signal defined separately from the PSS. However, this is merely an example for convenience 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 be configured of one or more sequences (hereinafter, one or more first signal sequences). The second communication node 402 can receive a first signal transmitted from the first communication node 401. The second communication node 402 can acquire or estimate synchronization with the first communication node 401 based on the received first signal.

[0068] Specifically, the first communication node 401 may generate one or more base sequences (S410). The one or more base sequences may correspond to a binary sequence or a complex sequence. The first communication node 401 may generate one or more first signal sequences based on the one or more base sequences (S420).

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

[0070] The first communication node 401 may transmit a first signal consisting of one or more first signal sequences modulated and mapped to radio resources (S440). In other words, the first communication node 401 may transmit a first signal consisting of one or more modulation symbols modulated with one or more first signal sequences. In step S440, the first communication node 401 may transmit the first signal in a broadcast manner. However, this is merely an example for convenience of explanation, and the first embodiment of the signal transmission / reception method in the communication system 400 is not limited thereto. For example, the first communication node 401 may transmit the first signal in a unicast manner, a multicast manner, etc.

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

[0072] FIG. 5 is a conceptual diagram for explaining a first embodiment of a radio signal structure in a communication system.

[0073] Referring to Fig. 5, a 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. Hereinafter, in describing a first embodiment of a radio signal structure in a communication system with reference to Fig. 5, contents that overlap with those described with reference to Figs. 1 to 4 may be omitted.

[0074] The first communication node can generate and transmit a wireless signal to a second communication node. The first communication node can generate one or more wireless signals. The first communication node can generate one or more wireless signal sequences to generate the one or more wireless signals. The first communication node can modulate one or more elements constituting the generated one or more wireless 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 may be mapped to 2M subcarriers. An index k of the one or more wireless signal sequences may have a natural number value greater than or equal to 0 and less than or equal to 2M-1. That is, k=0, 1, ..., 2M-1. The one or more wireless signal sequences may be generated based on a predetermined index u, where the index u may correspond to a PID index. However, this is merely an example for convenience of explanation, and the first embodiment of the wireless signal structure is not limited thereto. The one or more wireless signal sequences may be, for example, a PID index. u (k) or the one or more radio signal sequences may be distinguished by their generation scheme, P u、1 (k), P u、2 (k), P u、3 (k), etc. The one or more wireless signal sequences may be expressed as P u [k], P u、1 [k], P u、2 [k], P u、3 It can also be expressed as [k] etc.

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

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

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

[0079] One or more null subcarriers may be arranged around the 2M subcarriers constituting the first subcarrier group or between the 2M subcarriers. The null subcarriers may not carry signals. In other words, the null subcarriers may not be assigned modulation symbols. The null subcarriers may have a value of 0. The null subcarriers may also correspond to gap subcarriers, direct current (DC) subcarriers, etc. The null subcarriers may be arranged to easily identify each subcarrier.

[0080] A null subcarrier may be arranged at the front end and / or rear end of the first subcarrier group in the frequency domain. For example, a null subcarrier may be arranged at the front end of a subcarrier corresponding to subcarrier index 0 and / or the rear end of a subcarrier corresponding to subcarrier index 2M-1. Also, one or more null subcarriers may be arranged among 2M subcarriers constituting the first subcarrier group. For example, a null subcarrier may be arranged at the front end and / or rear end of one or more subcarriers (hereinafter, central subcarriers) located in the center of the 2M subcarriers constituting the first subcarrier group. Alternatively, the first subcarrier group may be divided into a plurality of subgroups each including one or more subcarriers. A null subcarrier may be arranged at the front end and / or rear end of each subgroup.

[0081] In one embodiment of the first wireless signal structure 500, the wireless signal sequence P u (k) may be modulated and mapped to second subcarrier group 520 and third subcarrier group 530, each of which is composed of M subcarriers. Null subcarriers may be arranged at the front end and / or rear end of second subcarrier group 520 and third subcarrier group 530 in the frequency domain. For example, null subcarriers may be arranged at at least a portion of the front end of the subcarrier corresponding to index 0, the rear end of the subcarrier corresponding to index M-1, the front end of the subcarrier corresponding to index M, and the rear end of the subcarrier corresponding to index 2M-1.

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

[0083] In one embodiment of the first wireless 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 be configured to 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. It is noted that the first subcarrier group may be configured to further include the first reference subcarrier and a second reference subcarrier that is a null subcarrier located at the front end of the second subcarrier group. In this case, the first subcarrier group may include 2M+2 subcarriers. It is noted that 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 wireless signal structure 500, a frequency domain signal carried on a subcarrier may be transformed into a time domain signal based on an N-point inverse fast Fourier transform (IFFT) scheme. In the N-point IFFT scheme, a wireless signal carried on N subcarriers in the frequency domain may be transformed 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. The remaining subcarriers (e.g., N-2M subcarriers) of the N subcarriers, 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 wireless signal structure 500, the first subcarrier group may be located in the center of the 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. N / 2=2M+2. For example, N=256 and M=63. However, this is merely an example for convenience of explanation, and the first embodiment of the wireless signal structure is not limited thereto.

[0086] FIG. 6 is a conceptual diagram for explaining a first embodiment of a radio signal generation method in a communication system.

[0087] Referring to Fig. 6, a 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. In the following, when describing a first embodiment of a wireless signal generation method in a communication system with reference to Fig. 6, the contents that overlap with those described with reference to Figs. 1 to 5 may be omitted.

[0088] <First embodiment of wireless signal generation method> In one embodiment of the communication system, the first communication node may generate a radio signal according to a first embodiment of a radio signal generation scheme. The first embodiment of the radio signal generation scheme may be referred to as a "Distributed Forward / Reverse Concatenation (DFRC) scheme."

[0089] In the first 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 first wireless signal sequences. The one or more first wireless signal sequences may be generated based on one or more base sequences. In other words, the one or more first wireless signal sequences may correspond to a result of one or more base sequences being converted by the first embodiment of the wireless signal generation method. The one or more base sequences may correspond to a binary sequence, a pseudo-noise (PN) sequence, a binary PN sequence, or an m-sequence. The one or more base sequences may be composed of a gold sequence generated through an element-wise exclusive-OR (XOR) operation on two different PN sequences. Alternatively, the one or more base sequences may correspond to a complex sequence.

[0090] In one embodiment of the communication system, the first radio signal sequence comprises: u、1 , P u、1 (k), P u、1 [k], where u may correspond to a first identification (e.g., a PID) associated with the first communication node. Note that k may correspond to the first wireless signal sequence P u、1(k) denotes the index of the subcarrier to be modulated and mapped. As described with reference to FIG. 5, k may have a natural number value greater than or equal to 0 and less than 2M. That is, k=0, 1, ..., 2M-1. Alternatively, k=0, 1, ..., 2M. M is the number of subcarriers to be modulated and mapped. u The length of the

[0091] First radio signal sequence P u、1 is the base sequence b u , and the modified sequence b generated based on the base sequence ′ u The 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 the base sequence b u The result of mapping the elements of in ascending order (i.e.,

number

number

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

number

[0095] Base sequence b u and the modified sequence b′ u According to the generation method of the first radio signal (or the time domain signal p u、1 The implementation of the base sequence b u and the modified sequence b′ u The cases of the first wireless signal classified according to the generation method may be the same as or similar to those shown in Table 4. [Table 4]

[0096] In Table 4, b u、I is a complex sequence, ucan be the real component of b u、Q is the base sequence b u The base sequence b u If is a binary sequence, then the modified sequence b′ u is the base sequence b u The base sequence b can be generated based on a duplication or polarity reversal operation on u If is a complex sequence, then the modified sequence b′ u is the base sequence b u may be generated based on at least a part of a duplication operation, a polarity inversion operation, a conjugate operation, or a complex multiplication operation on . Table 4 is merely an example for convenience of explanation, and the first embodiment of the wireless signal generation method is not limited thereto.

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

number

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

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

number

[0100] The time domain signal p expressed as Equation 4 u、1 [n] may have element values ​​in real form for all n. This may reduce the estimation complexity at the receiving node by half (or more). The first wireless signal according to Case #1-2 may support robust time synchronization estimation performance for high CFO, PhN, DE, etc.

[0101] Case #1-3: Base sequence b u The modified sequence b′ can be a complex sequence. u is the base sequence b u This corresponds to the result of performing a polarity inversion operation on b′ u =-b u ). In this case, the time domain signal p u、1 [n] may be expressed the same as or similar to Equation 5.

number

[0102] The time domain signal p expressed as Equation 5 u、1 [n] may have element values ​​in complex form for all n. The first wireless signal according to Case #1-3 may support time synchronization estimation performance that is robust to high CFO, PhN, DE, and the like.

[0103] Case #1-4: Base sequence b u The modified sequence b′ can be a complex sequence. u is the base sequence b u(i.e., b′ u =b u ). In this case, the time domain signal p u、1 [n] may be expressed the same as or similar to Equation 6.

number

[0104] The time domain signal p expressed as Equation 6 u、1 [n] may have element values ​​in complex form for all n. The first wireless signal according to Cases #1-4 may support time synchronization estimation performance that is robust to high CFO, PhN, DE, and the like.

[0105] Case #1-5: Base sequence b u The modified sequence b′ can be a complex sequence. u is the base sequence b u (i.e., b′ u =b * u ). In other words, the modified sequence b′ u is the base sequence b u In this case, the time domain signal p u、1 [n] may be expressed the same as or similar to Equation 7.

number

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

[0107] Case #1-6: Base sequence bu The modified sequence b′ can be a complex sequence. u is the base sequence b u It can be said that b′ corresponds to the result of performing a polarity inversion operation on the complex conjugate of u =-b * u ). In this case, the time domain signal p u、1 [n] may be expressed the same as or similar to Equation 8.

number

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

[0109] Case #1-7: Base sequence b u The modified sequence b′ can be a complex sequence. u is the base sequence b u It can be said that b′ corresponds to the result of performing a polarity inversion operation and an imaginary number (j) multiplication operation on the conjugate complex number of u =-jb * u ). In this case, the time domain signal p u、1 [n] can be expressed the same as or similar to Equation 9.

number

[0110] The time domain signal p expressed as Equation 9 u、1 [n] may have element values ​​in complex form for all n. The first wireless signal according to Cases #1-7 may support time synchronization estimation performance that is robust to high CFO, PhN, DE, and the like.

[0111] Case #1-8: Base sequence b u The modified sequence b′ can be a complex sequence. u is the base sequence b u It can be said that b′ corresponds to the result of multiplying the conjugate complex number of b′ by an imaginary number (j). u =jb * u ). In this case, the time domain signal p u、1 [n] can be expressed the same as or similar to Equation 10.

number

[0112] The time domain signal p expressed as Equation 10 u、1 [n] may have element values ​​in complex form for all n. The first wireless signal according to Cases #1-8 may support time synchronization estimation performance that is robust to high CFO, PhN, DE, and the like.

[0113] Case #1-9: Base sequence b u The modified sequence b′ can be a complex sequence. u is the base sequence b u It can be said that b′ corresponds to the result of performing an imaginary number (j) multiplication operation on u =jb u ). In this case, the time domain signal p u、1 [n] can be expressed the same as or similar to Equation 11.

number

[0114] The time domain signal p expressed as Equation 11 u、1 [n] may have element values ​​in complex form for all n. The first wireless signal according to Cases #1-9 may support time synchronization estimation performance that is robust to high CFO, PhN, DE, and the like.

[0115] Case #1-10: Base sequence b u The modified sequence b′ can be a complex sequence. u is the base sequence b u It can be said that b′ corresponds to the result of performing polarity inversion and imaginary (j) multiplication on u =-jb u ). In this case, the time domain signal p u、1 [n] can be expressed the same as or similarly to Equation 12.

number

[0116] The time domain signal p expressed as Equation 12 u、1 [n] may have element values ​​in complex form for all n. The first wireless signal according to Cases #1-10 may support time synchronization estimation performance that is robust to high CFO, PhN, DE, and the like.

[0117] 6 may be regarded 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 may be embodied in the following specific cases.

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

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

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

[0121] Case #1-14: The first reference subcarrier is excluded from the indexing associated with the subcarriers. Among the elements of the first wireless signal sequence, the elements of the base sequence are assigned to odd-numbered subcarrier groups in descending order, and the elements of the modified sequence are assigned to even-numbered subcarrier groups in ascending order.

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

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

[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 may be extended based on various wireless signal (e.g., synchronization signal) design or allocation methods other than the embodiments described with reference to cases #1-1 to #1-16.

[0125] The first communication node can transmit a first wireless signal generated based on a first embodiment of the wireless signal generation scheme. The second communication node can receive the first wireless 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 wireless signal.

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

[0127] FIG. 7 is a conceptual diagram for explaining a second embodiment of a radio signal generation method in a communication system.

[0128] Referring to Fig. 7, a 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. In the following, when describing a second embodiment of a wireless signal generation method in a communication system with reference to Fig. 7, the contents that overlap with those described with reference to Figs. 1 to 6 may be omitted.

[0129] <Second embodiment of wireless signal generation method> In an embodiment of the communication system, the first communication node may generate a radio signal according to a second embodiment of the radio signal generation scheme. The second embodiment of the radio signal generation scheme may be referred to as a "Distributed Half Forward / Reverse Concatenation (DHFRC) scheme."

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

number

[0131] Referring to Equation 13, the second wireless signal sequence P u、2 The elements constituting the second wireless signal sequence P may be classified into element group #1 and element group #2. Here, element group #1 may correspond to the second subcarrier group 520 described with reference to FIG. 5. Element group #2 may correspond to the third subcarrier group 530 described with reference to FIG. 5. Element group #1 may correspond to the second wireless signal sequence P u、2 In [m], m may include elements greater than or equal to 0 and less than M. The element group #2 includes the second wireless signal sequence P u、2In [m], m may include elements that are equal to or larger than M and smaller than 2M. However, this is merely an example for convenience of explanation, and the second embodiment of the wireless signal generation method is not limited thereto. For example, element group #1 may correspond to the third subcarrier group 530 described with reference to FIG. 5, and element group #2 may correspond to the second subcarrier group 520 described with reference to FIG. 5. Element group #1 and element group #2 may be disposed at the front end and rear end of the first reference subcarrier. Here, the first reference subcarrier may be the same as or similar to the first reference subcarrier described with reference to FIG. 5. The first reference subcarrier may correspond to a null subcarrier, a DC subcarrier, or the like. The first reference subcarrier may correspond to a center subcarrier.

[0132] The element group #1 can be classified into an element group #1-1 and an element group #1-2. The element group #1-1 is a group that receives the second wireless signal sequence P u、2 The element group #1-2 may include even-numbered elements of [m] in the element group #1 (where m is less than M). u、2 The element group #2 may include odd-numbered elements of the second wireless signal sequence P [m]. The element group #2 may be classified into an element group #2-1 and an element group #2-2. The element group #2-1 may include odd-numbered elements of the second wireless signal sequence P u、2 The element group #2-2 may include even-numbered elements of the second wireless signal sequence P u、2 It may contain odd-numbered elements of [m].

[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 of in ascending order (i.e.,

number

number

number

number

[0134] According to the second embodiment of the wireless signal generation scheme, in element group #1, two elements (i.e., an element of a first sequence and a corresponding element of a second sequence) may be sequentially grouped (or associated) and mapped in ascending order, whereas in element group #2, two elements (i.e., an element of a first sequence and a corresponding element of a second sequence) may be sequentially grouped and mapped in descending order.

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

[0136] Second radio signal sequence P u、2 [m] is the time-domain signal p based on an N-point IFFT or N-point IDFT (N-point inverse fast Fourier transform) operation. u、2 When M is odd, the time domain signal p u、2 [n] can be determined the same as or similar to Equation 14.

number

[0137] In the same or similar manner as described with reference to FIG. 5, if m<0 or m>2M-1, then p u、2 [n] may be 0. Equation 14 may be expressed as Equation 15.

number

[0138] Equation 15 expresses the first wireless signal (or the time domain signal p of the first wireless signal) generated based on the configuration described with reference to FIG. 5 and FIG. u、2 [n]).

[0139] 8a and 8b are conceptual diagrams for explaining a second embodiment of a radio signal structure in a communication system.

[0140] Referring to Figures 8a and 8b, a 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 Figure 4. The communication system may be the same as or similar to the communication system described with reference to Figure 7. Hereinafter, in describing a second embodiment of a wireless signal structure in a communication system with reference to Figures 8a and 8b, contents that overlap with those described with reference to Figures 1 to 7 may be omitted.

[0141] It can be seen that FIG. 8a illustrates an embodiment of an IDFT vector structure according to an IDFT operation method. Referring to FIG. 8a, the IDFT vector structure may have a periodic characteristic (or periodicity). For example, the IDFT vector structure may have a periodicity of exp{j2πnm / N} (i.e., e j2πnm / N ) values. Here, as the value of m changes, the value of exp{j2πnm / N} may change periodically. Such periodicity may be determined or changed by the value of n.

[0142] FIG. 8b shows an embodiment of the periodic characteristic of the IDFT vector structure shown in FIG. 8a. Referring to FIG. 8b, when n=1, the upper half of the IDFT vector structure (e.g., the region where m is less than 0 in FIG. 8a) and the lower half of the IDFT vector structure (e.g., the region where m is greater than 0 in FIG. 8a) can be seen to have a kind of symmetrical structure centered on the element of m=0. Here, the upper half of the IDFT vector structure can be seen to be composed of values ​​whose polarity is inverted (or whose phase is inverted 180 degrees) from the values ​​constituting the lower half of the IDFT vector structure. In addition, 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 of the IDFT vector structure and the lower half of the IDFT vector structure can be configured to be identical to each other. The upper half of the IDFT vector structure and the lower half of the IDFT vector structure can each have an internal structure in which blocks whose patterns are identical to each other and whose phases are inverted are connected in series. In this way, the IDFT vector can have a periodic property in which the same shape (or structure) is repeated about n times as the value of n increases.

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

[0144] 9a to 9c, a 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, in describing an embodiment of the first and second sequences in the communication system with reference to FIGS. 9a to 9c, contents that overlap with those described with reference to FIGS. 1 to 8b may be omitted.

[0145] In a second embodiment of the radio signal generation scheme, the first radio signal may be generated based on a radio signal structure that is the same as or similar to the first embodiment of the radio signal structure described with reference to Fig. 5. The first radio signal may be generated based on one or more second radio signal sequences. u、2 is the first sequence b u and the second sequence b′ u where the first sequence b u can be the base sequence, and the second sequence b′ u may correspond to a modified sequence generated based on a base sequence. In one embodiment of the communication system, the first sequence may correspond to a ZC sequence.

[0146] It can be seen that FIG. 9a illustrates a first embodiment of a ZC sequence structure. A first sequence b, which corresponds to a base sequence composed of ZC sequences, is the same as or similar to that shown in Equation 13. u can be expressed the same as or similar to Equation 16.

number

[0147] Here, referring to Equation 16 and FIG. 9a, etc., a ZC sequence with length M being an odd number may have a symmetric structure around an element with m=0 (e.g., an element corresponding to a central subcarrier). Also, the ZC sequence may have the same or similar periodicity as Equation 17.

number

[0148] First sequence b u and the second sequence b′ u According to the generation method of the first radio signal (or the time domain signal p u、2 The embodiment of the first sequence b u If b is a complex ZC sequence, then the second sequence b′ u The cases of the first wireless signal classified according to the generation method may be the same as or similar to those shown in Table 5. [Table 5]

[0149] When applying 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 taking the inner product of the frequency domain signal vector and the IDFT vector for n=0, 1, ..., N-1. Similarly to what was described with reference to Fig. 9a, the frequency domain signal vector may have a symmetric property. The second wireless signal sequence P u、2 Among the elements of, the element (P u、2 [0], P u、2 [1], ..., P u、2 [M-1]) and the element corresponding to the lower subcarrier in the frequency domain (P u、2 [2M-1], P u、2 [2M-2], ..., P u、2[M]) may have the same or similar values. As a result, the time domain signal p u、2 [n] may periodically have a value of 0. u、2 [n] can have a value of 0 once for every four elements. For example, the time domain signal p u、2 [n] can have a value of 0 when n=2, 6, 10, .... The time domain signal p u、2 The estimation complexity of the first wireless signal may be reduced depending on the number of elements having a value of 0 in [n]. The first wireless signals according to Cases #2-1 to #2-8 may support time synchronization estimation performance that is robust against high CFO, PhN, DE, etc.

[0150] In addition, the second radio signal sequence P u、2 According to the generation method of the first wireless signal, the embodiment of the first wireless signal can be classified into various cases.

[0151] Case #2-9: The second wireless signal sequence P described with reference to FIG. u、2 In the definition of element group #2, the polarity of the region corresponding to element group #2 can be inverted. For example, in case #2-9, the second wireless signal sequence P u、2 may be defined as Equation 18.

number

[0152] Time domain signal p according to case #2-9 u、2 [n] may have a value of 0 periodically (e.g., when n is a multiple of 4). This may reduce estimation complexity. The first wireless signal according to Cases #2-9 may support time synchronization estimation performance that is robust to high CFO, PhN, DE, etc.

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

number

[0154] Referring to FIG. 9b and Equation 19, in case #2-10, the first sequence b u Similar to the ZC sequence described with reference to FIG. 9a, the first sequence b may have a symmetric structure around an element corresponding to index (M-1) / 2 (e.g., an element corresponding to a central subcarrier). u In case #2-10, the elements symmetric to each other in p can have the same value. u、2 [n] may have a value of 0 periodically (e.g., when n=2, 6, 10, ...). This may reduce estimation complexity. The first wireless signal according to Case #2-10 may support time synchronization estimation performance that is robust to high CFO, PhN, DE, etc.

[0155] Case #2-11: The first sequence (e.g., base sequence) may be generated based on a separate sequence (hereinafter, third sequence s) rather than a complex ZC sequence. Here, the third sequence s may have a length of (1+(M-1) / 2) and may have various forms such as a binary sequence, a complex sequence, etc. FIG. 9c shows a first sequence b based on the third sequence s. u It can be seen that one embodiment of the definition of is shown. With reference to FIG. 9b, a first sequence b u (t) may 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) may be defined as in Equation 20.

number

[0156] Referring to FIG. 9c and Equation 20, in case #2-11, the first sequence b u Similar to the ZC sequence described with reference to FIG. 9a, the first sequence b may have a symmetric structure around an element corresponding to index (M-1) / 2 (e.g., an element corresponding to a central subcarrier). u In the case of case #2-11, the elements that are symmetric to each other may have values ​​that are polarity-inverted (or phase-inverted) to each other. u、2 [n] may have a value of 0 periodically (e.g., when n is a multiple of 4). This may reduce estimation complexity. The first wireless signal according to Case #2-11 may support time synchronization estimation performance that is robust to high CFO, PhN, DE, etc.

[0157] 7 shows a specific example of the 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 may be embodied in the following specific cases.

[0158] Case #2-12: A first reference subcarrier (e.g., DC) is excluded from the indexing (e.g., k or m) associated with the subcarriers. In the frequency domain, an upper subcarrier group and a lower subcarrier group are divided based on the first reference subcarrier. The upper subcarrier group in the frequency domain corresponds to element group #1 of the second wireless signal sequence, and the lower subcarrier group in the frequency domain corresponds to element group #2 of the second wireless signal sequence. In element group #1, elements of the first and second sequences are assigned in ascending order by gathering (or relating) two elements in sequence. In element group #2, elements of the first and second sequences are assigned in descending order by gathering (or relating) two elements in sequence.

[0159] Case #2-13: The first reference subcarrier is excluded from the indexing associated with the subcarriers. The upper subcarrier group in the frequency domain corresponds to element group #1 of the second wireless signal sequence, and the lower subcarrier group in the frequency domain corresponds to element group #2 of the second wireless signal sequence. In element group #1, elements of the first and second sequences are assigned in descending order by grouping (or relating) two elements in sequence. In element group #2, elements of the first and second sequences are assigned in ascending order by grouping (or relating) two elements in sequence.

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

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

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

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

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

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

[0166] Referring to Fig. 10, a 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. Hereinafter, in describing the third embodiment of the wireless signal generation method in the communication system with reference to Fig. 10, the contents overlapping with those described with reference to Figs. 1 to 9c may be omitted.

[0167] <Third embodiment of wireless signal generation method> In an embodiment of the communication system, the first communication node may generate a radio signal according to a third embodiment of the radio signal generation method. The second embodiment of the radio signal generation method may be referred to as a "Distributed Full / Half Forward / Reverse Concatenation (DFHFRC) method."

[0168] In a third embodiment of the wireless signal generation scheme, 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 third wireless signal sequences. The third wireless signal sequences include P u、3 , P u、3 (k), P u、3 [k], etc. The third radio signal sequence P u、3 is the first sequence b u and the second sequence b′ u where the first sequence b u can be the base sequence, and the second sequence b′ u may correspond to a modified sequence generated based on a base sequence. However, this is merely an example for convenience of explanation, and the third embodiment of the wireless signal generation method is not limited thereto. The third wireless signal sequence may correspond to a modified sequence generated based on a base sequence. u and the second sequence b′ u Based on this, it can be defined the same as or similar to Equation 21.

number

[0169] Referring to Equation 21, the third wireless signal sequence P u、3 The elements constituting the element group #1 may be classified into element group #1 and element group #2. Element group #1 may be classified into element group #1-1 and element group #1-2. Element group #2 may be 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.) may be classified in the same way or similarly 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 of in ascending order (i.e.,

number

number

number

number

[0171] According to the third embodiment of the wireless signal generation scheme, in element group #1, two elements (i.e., an element of a first sequence and an element of a corresponding second sequence) are sequentially collected and may be mapped in ascending order. In addition, in element group #2, two elements (i.e., an element of a first sequence and an element of a corresponding second sequence) are sequentially collected and one of them may be mapped in ascending order and the other may be 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 u、3 [n] can have a value of 0 once every four elements. u、3 The estimation complexity of the first wireless signal may be reduced depending on the number of elements having a value of 0 in [n]. The first wireless signal according to the third embodiment of the wireless signal generation method may support time synchronization estimation performance that is robust against high CFO, PhN, DE, etc.

[0173] 10 shows a specific example of the 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 may be embodied in the following specific case.

[0174] Case #3-1: A first reference subcarrier (e.g., DC) is excluded from the indexing (e.g., k or m) associated with the subcarriers. In the frequency domain, an upper subcarrier group and a lower subcarrier group are divided based on the first reference subcarrier. The upper subcarrier group in the frequency domain corresponds to element group #1 of the third wireless signal sequence, and the lower subcarrier group in the frequency domain corresponds to element group #2 of the third wireless signal sequence. In element group #1, two elements are sequentially gathered (or associated) and the elements of the first and second sequences are assigned in ascending order. In element group #2, two elements are sequentially gathered (or associated) and the elements of the first sequence are assigned in ascending order and the elements of the second sequence are assigned in descending order.

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

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

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

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

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

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

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

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

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

[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 may be extended based on various wireless signal (e.g., synchronization signal) design or allocation methods other than the embodiments described with reference to cases #3-1 to #3-10.

[0185] According to an embodiment of the method and apparatus for transmitting and receiving a wireless signal in a communication system, the performance of a synchronization estimation operation based on a wireless signal transmitted and received between a transmitting node and a receiving node can be improved. The first wireless signal according to the embodiment of the method and apparatus for transmitting and receiving a wireless signal in a communication system can be generated based on a distributed forward and reverse concatenation scheme, a distributed half forward and reverse concatenation scheme, a distributed full / half forward and reverse concatenation scheme, or the like. The first wireless signal generated in this manner can reduce the complexity of a synchronization estimation operation. The first wireless signal according to the embodiment of the method and apparatus for transmitting and receiving a wireless signal in a communication system can support time synchronization estimation performance that is robust against high CFO, PhN, DE, and the like.

[0186] However, the effects that can be achieved by the embodiments of the method and apparatus for transmitting and receiving a wireless signal in a communication system are not limited to those mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the configurations described in the specification of the present disclosure.

[0187] The operation of the method according to the embodiment of the present disclosure may be embodied as a computer readable program or code in a computer readable recording medium. The computer readable recording medium includes all kinds of recording devices in which information readable by a computer system is stored. In addition, the computer readable recording medium may be distributed among computer systems connected via a network, and the computer readable program or code may be stored and executed in a distributed manner.

[0188] The computer-readable recording medium may also include a hardware device specially configured to store and execute program instructions, such as a ROM, a RAM, a flash memory, etc. The program instructions may include not only machine code, such as produced by a compiler, but also high-level language code that may be executed by a computer using an interpreter, etc.

[0189] Some aspects of the present disclosure have been described in the context of an apparatus, but they can also be described in the context of a corresponding method, where the blocks or apparatus correspond to method steps or features of the method steps. Similarly, aspects described in the context of a method can also be described in the context of a corresponding block or item or feature of the corresponding apparatus. Some or all of the method steps can be performed by (or using) a hardware device, 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 can be performed by such a device.

[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. In general, it is preferred that the methods be performed by some hardware apparatus.

[0191] Although the present disclosure has been described above with reference to preferred embodiments thereof, those skilled in the art will understand that the present disclosure can be modified and changed in various ways without departing from the spirit and scope of the present disclosure as set forth in the claims below.

Claims

1. 1. A method of operating a first communication node in a communication system, comprising: 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; 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 is mapped in ascending order in the first element group, and the other is mapped in descending order in the second element group. A method of operating a first communication node.

2. The step of generating the second sequence comprises: modifying the first sequence to generate the second sequence; A method for operating a first communication node according to claim 1.

3. 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. A method for operating a first communication node according to claim 1.

4. the first sequence is a complex sequence; The second sequence is a sequence obtained by applying at least a part of a duplication operation, a polarity inversion operation, a conjugate operation, or a complex multiplication operation to the first sequence. A method for operating a first communication node according to claim 1.

5. The first signal is generated to have real or pure imaginary values ​​in the time domain. A method for operating a first communication node according to claim 1.

6. The step of generating a first signal sequence comprises: mapping the elements of the first sequence to the even-numbered elements of the first signal sequence in the first element group in ascending order; mapping the elements of the second sequence to the odd-numbered elements of the elements of the first signal sequence in the second element group in descending order; A method of operating a first communication node according to claim 1, comprising:

7. The step of generating a first signal sequence comprises: mapping the elements of the first sequence to the odd-numbered elements of the first signal sequence in the second group of elements in descending order; mapping the elements of the second sequence to the even-numbered elements of the first signal sequence in the first element group in ascending order; A method of operating a first communication node according to claim 1, comprising:

8. 1. A method of operating a first communication node in a communication system, comprising: 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; Among the elements in the first signal sequence that fall within a first range, even-numbered elements and odd-numbered elements are classified into a first element group and a second element group, respectively, and among the elements in the first signal sequence that fall within a second range, even-numbered elements and odd-numbered elements are classified into a third element group and a fourth element group, respectively, the first sequence is mapped in ascending and descending order in the first and fourth element groups, and the second sequence is mapped in ascending and descending order in the third and fourth element groups. A method of operating a first communication node.

9. the first sequence is a complex sequence; The second sequence is a sequence obtained by applying at least a part of a duplication operation, a polarity inversion operation, a conjugate operation, or a complex multiplication operation to the first sequence. A method for operating a first communication node according to claim 8.

10. the first sequence is a complex ZC (Zadoff-Chu) sequence; the first signal is generated in the time domain to periodically have a value of 0 every P elements, where P is a natural number greater than 1; A method for operating a first communication node according to claim 8.

11. The step of generating the first sequence comprises: generating a third sequence; mapping the elements of the third sequence to elements of the first sequence that fall within a third range in ascending order; mapping the elements of the third sequence to elements of the first sequence that fall within a fourth range in descending order; the first signal is generated in the time domain to periodically have a value of 0 every P elements, where P is a natural number greater than 1; A method for operating a first communication node according to claim 8.

12. The step of generating a first signal sequence comprises: mapping the elements of the first sequence to elements of the first group of elements in ascending order; mapping the elements of the second sequence to elements of the second group of elements in ascending order; mapping the elements of the second sequence to elements of the third group of elements in descending order; mapping the elements of the first sequence to the elements of the fourth group of elements in descending order; A method for operating a first communication node according to claim 8.

13. The step of generating a first signal sequence comprises: mapping the elements of the first sequence to elements of the first group of elements in descending order; mapping the elements of the second sequence to elements of the second group of elements in descending order; mapping the elements of the second sequence to elements of the third group of elements in ascending order; mapping the elements of the first sequence to elements of the fourth group of elements in ascending order; A method of operating a first communication node according to claim 8, comprising:

14. A first communication node in a communication system, A processor is included. The processor may further comprise a processor configured to: Generate a first sequence; Generate a second sequence; generating a first signal sequence based on the first and second sequences; and operative to cause transmission of a first signal produced by modulating the first signal sequence; Among the elements in the first signal sequence that fall within a first range, even-numbered elements and odd-numbered elements are classified into a first element group and a second element group, respectively, and among the elements in the first signal sequence that fall within a second range, even-numbered elements and odd-numbered elements are classified into a third element group and a fourth element group, respectively, and the first sequence is mapped in ascending order in the first and fourth element groups, and the second sequence is mapped in ascending and descending order in the third and fourth element groups. A first communication node.

15. the first sequence is a complex ZC (Zadoff-Chu) sequence; the first signal is generated in the time domain to periodically have a value of 0 every P elements, where P is a natural number greater than 1; A first communication node according to claim 14.

16. When generating the first sequence, the processor causes the first communication node to: Generate a third sequence; mapping the elements of the third sequence in ascending order to elements that fall within a third range among the elements constituting the first sequence; and further operable to cause elements of the third sequence to be mapped in descending order to elements of the first sequence that fall within a fourth range; the first signal is generated in the time domain to periodically have a value of 0 every P elements, where P is a natural number greater than 1; A first communication node according to claim 14.

17. When generating the first signal sequence, the processor causes the first communication node to: mapping elements of the first sequence to elements of the first group of elements in ascending order; mapping elements of the second sequence to elements of the second group of elements in ascending order; mapping the elements of the second sequence to the elements of the third group of elements in descending order; and further operative to cause a mapping of elements of the first sequence to elements of the fourth group of elements in ascending order. A first communication node according to claim 14.

18. When generating the first signal sequence, the processor causes the first communication node to: mapping elements of the first sequence to elements of the first group of elements in ascending order; mapping the elements of the second sequence to the elements of the second group of elements in descending order; mapping the elements of the second sequence to the elements of the third group of elements in ascending order; and further operative to cause a mapping of elements of the first sequence to elements of the fourth group of elements in ascending order. A first communication node according to claim 14.

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