OTFS signal generation method and generation device in wireless communication system

Abstract

The present disclosure relates to a technique for generating an OTFS waveform in a wireless communication system. An embodiment of the present disclosure includes the steps of: performing serial-to-parallel conversion on a sequence of data symbols to obtain a data symbol matrix; generating a logical time-frequency domain sample matrix by applying an inverse symplectic finite Fourier transform (ISFFT) or a two-dimensional reversible transform to the data symbol matrix; obtaining a physical time-frequency domain matrix by inserting at least one pilot column vector into the generated logical time-frequency domain sample matrix; and performing a Heisenberg transform on the physical time-frequency domain matrix.

Description

Method and device for generating OTFS signals in wireless communication systems

[0001] Embodiments disclosed in this document relate to a method and device for generating an OTFS signal in a wireless communication system.

[0002] Looking back at the evolution of wireless communication over successive generations, technologies have primarily been developed for human-facing services such as voice, multimedia, and data. With the commercialization of 5G (5th-generation) communication systems, an explosive increase in connected devices is expected to be connected to communication networks. Examples of networked objects include vehicles, robots, drones, home appliances, displays, smart sensors installed in various infrastructures, construction equipment, and factory equipment. Mobile devices are expected to evolve into diverse form factors, including augmented reality glasses, virtual reality headsets, and holographic devices. In the 6th-generation (6G) era, efforts are being made to develop improved 6G communication systems to connect hundreds of billions of devices and objects and provide diverse services. For this reason, 6G communication systems are often referred to as "beyond 5G."

[0003] The 6G communication system, expected to be realized around 2030, will have a maximum transmission speed of terabytes per second (i.e., 1,000 gigabits per second) and a wireless latency of 100 microseconds (μsec). In other words, compared to 5G, the transmission speed in a 6G communication system will be 50 times faster, while the wireless latency will be reduced to one-tenth.

[0004] To achieve these high data rates and ultra-low latency, 6G communication systems are being considered for implementation in the terahertz band (e.g., from 95 gigahertz (GHz) to 3 terahertz (THz)). Compared to the millimeter wave (mmWave) band introduced in 5G, the terahertz band is expected to experience more severe path loss and atmospheric absorption, making it more crucial to ensure signal reach, or coverage, in this band. Key technologies to ensure coverage include radio frequency (RF) components, antennas, new waveforms that offer better coverage than OFDM (orthogonal frequency division multiplexing), beamforming, and multiple antenna transmission technologies such as massive multiple-input and multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, and large-scale antennas. In addition, new technologies such as metamaterial-based lenses and antennas, high-dimensional spatial multiplexing using orbital angular momentum (OAM), and reconfigurable intelligent surfaces (RIS) are being discussed to improve the coverage of terahertz band signals.

[0005] In addition, in order to improve frequency efficiency and system network, 6G communication systems are developing full duplex technology that utilizes the same frequency resources for uplink and downlink at the same time; network technology that integrates satellites and high-altitude platform stations (HAPS); network structure innovation technology that supports mobile base stations and enables optimization and automation of network operation; dynamic spectrum sharing technology through collision avoidance based on spectrum usage prediction; AI-based communication technology that utilizes artificial intelligence (AI) from the design stage and internalizes end-to-end AI support functions to realize system optimization; and next-generation distributed computing technology that realizes services with complexity that exceeds the limits of terminal computing capabilities by utilizing ultra-high-performance communication and computing resources (mobile edge computing (MEC), cloud, etc.). In addition, efforts are being made to further strengthen connectivity between devices, further optimize networks, promote softwareization of network entities, and increase the openness of wireless communications through the design of new protocols to be used in 6G communication systems, the implementation of hardware-based security environments, the development of mechanisms for the safe use of data, and the development of technologies for maintaining privacy.

[0006] Research and development of these 6G communication systems are expected to enable a new level of hyper-connected experience (the next hyper-connected experience) through the hyper-connectivity of 6G communication systems, which encompass not only connections between things but also connections between people and things. Specifically, 6G communication systems are expected to enable services such as truly immersive extended reality (Truly Immersive XR), high-fidelity mobile holograms, and digital replicas. Furthermore, services such as remote surgery, industrial automation, and emergency response, which are provided through 6G communication systems through enhanced security and reliability, will find application in diverse fields such as industry, medicine, automobiles, and home appliances.

[0007] A method for transmitting an OTFS (Orthogonal Time-Frequency-Space) waveform in a wireless communication system according to one embodiment of the present disclosure includes the steps of: obtaining a data symbol matrix by serial-parallel converting a data symbol sequence; generating a logical time-frequency domain sample matrix by performing an inverse symplectic finite Fourier transform (ISFFT) or a two-dimensional reversible transform on the data symbol matrix; obtaining a physical time-frequency domain matrix by inserting at least one pilot column vector into the generated logical time-frequency domain sample matrix; and performing a Heisenberg transform on the physical time-frequency domain matrix.

[0008] In a wireless communication system according to one embodiment of the present disclosure, a transmitting device for transmitting an OTFS waveform includes a memory storing at least one instruction and at least one processor. The at least one processor, when the at least one instruction is executed, serial-parallel converts a data symbol sequence to obtain a data symbol matrix. The at least one processor, when the at least one instruction is executed, generates a logical time-frequency domain sample matrix by performing an inverse symplectic finite Fourier transform (ISFFT) or a two-dimensional reversible transform on the data symbol matrix. The at least one processor, when the at least one instruction is executed, inserts at least one pilot column vector into the generated logical time-frequency domain symbol matrix to obtain a physical time-frequency domain matrix. The at least one processor, when the at least one instruction is executed, Heisenberg transforms the physical time-frequency domain matrix.

[0009] A method for transmitting an OTFS waveform in a wireless communication system according to one embodiment of the present disclosure comprises the steps of: obtaining a data symbol matrix by serial-parallel converting a data symbol sequence; generating a delayed-logical time-domain sample matrix by a matrix multiplication operation of the data symbol matrix and an N-point Inverse Discrete Fourier Transform (IDFT) matrix or a post-multiplication matrix of a two-dimensional reversible transform; generating a logical time-frequency domain matrix by a matrix multiplication operation of the delayed-logical time-domain matrix and an M-point Discrete Fourier Transform (DFT) matrix or a pre-multiplication matrix of the two-dimensional reversible transform; generating a physical time-frequency domain matrix by arranging column vectors of the generated logical time-frequency domain matrix and at least one pilot column vector in a predetermined order; A step of inserting a zero matrix at the bottom of the physical time-frequency domain matrix and obtaining a third matrix by performing downward cyclic oscillation so that elements of the physical time-frequency domain matrix are arranged at predetermined subcarrier positions; and a step of modulating the third matrix with CP-OFDM (Cyclic Prefix-Orthogonal Frequency Division Multiplexing), wherein N is the number of columns of the data symbol matrix and M is the number of rows of the delay-logical time domain matrix.

[0010] In a wireless communication system according to one embodiment of the present disclosure, a transmitting device for transmitting an OTFS waveform includes a memory and at least one processor. The at least one processor, when the one or more instructions are executed, serial-parallel converts a data symbol string to obtain a data symbol matrix. The at least one processor, when the one or more instructions are executed, generates a delayed-logical time-domain sample matrix by a matrix multiplication operation of the data symbol matrix and an N-point IDFT matrix or a post-multiplication matrix of a two-dimensional reversible transform. The at least one processor, when the one or more instructions are executed, generates a logical time-frequency domain matrix by a matrix multiplication operation of an M-point DFT (Discrete Fourier Transform) matrix or a pre-multiplication matrix of the two-dimensional reversible transform and the delayed-logical time-domain matrix. The at least one processor, when the one or more instructions are executed, arranges the column vectors of the generated logical time-frequency domain matrix and at least one pilot column vector in a predetermined order to generate a physical time-frequency domain matrix. The at least one processor, when the one or more instructions are executed, inserts a zero vector row at the bottom of the physical time-frequency domain matrix, and circularly down-shifts the elements of the physical time-frequency domain matrix so that they are arranged at predetermined subcarrier positions to obtain a third matrix. The at least one processor, when the one or more instructions are executed, modulates the third matrix with CP-OFDM (Cyclic Prefix-Orthogonal Frequency Division Multiplexing).Here, N is the number of columns of the data symbol matrix, and M is the number of rows of the delay-logical time domain matrix.

[0011] A computer-readable recording medium storing a program for performing a method for generating an OTFS signal in a wireless communication system according to an embodiment of the present disclosure, the method comprising the steps of: obtaining a data symbol matrix by serial-parallel converting a data symbol sequence; generating a logical time-frequency domain sample matrix by inverse symplectic finite Fourier transforming or two-dimensional reversible transforming the data symbol matrix; obtaining a physical time-frequency domain matrix by inserting at least one pilot column vector into the generated logical time-frequency domain sample matrix; and Heisenberg transforming the physical time-frequency domain matrix.

[0012] FIG. 1 is a block diagram functionally illustrating an OTFS signal generation device according to one embodiment of the present disclosure.

[0013] Figure 2 shows the OTFS waveform and the generated continuous-time signal with the pilot symbols arranged in the delayed-Doppler domain symbol matrix.

[0014] FIG. 3 is a block diagram illustrating a CP-OFDM transmitting device according to one embodiment of the present disclosure.

[0015] FIG. 4 illustrates pilot symbols allocated to subcarriers when pilot column vectors are arranged in only one column in a time-frequency domain matrix, according to one embodiment of the present disclosure.

[0016] FIG. 5 illustrates a CP-OFDM transmission method according to one embodiment of the present disclosure when a pilot column vector is arranged in only one column in a time-frequency domain matrix.

[0017] FIG. 6 is a block diagram illustrating a DFT-spread OFDM transmitter that uses a DFT-spread pilot symbol as a pilot column vector according to one embodiment of the present disclosure.

[0018] FIG. 7 illustrates a method for generating a time-frequency matrix of DFT-spread OFDM using DFT-spread pilot symbols as pilot column vectors, according to one embodiment of the present disclosure.

[0019] FIG. 8 is a block diagram illustrating a DFT-spread OFDM transmitter that uses a DFT-unspreaded pilot symbol as a pilot column vector according to one embodiment of the present disclosure.

[0020] FIG. 9 illustrates a method for generating a time-frequency matrix of DFT-spread OFDM using DFT-unspreaded pilot symbols as pilot column vectors according to one embodiment of the present disclosure.

[0021] FIG. 10 is a block diagram illustrating an OTFS signal generation device according to one embodiment of the present disclosure.

[0022] FIG. 11 is a block diagram showing a pilot insertion unit of an OTFS signal generation device that uses a DFT-spread pilot symbol as a pilot column vector according to one embodiment of the present disclosure.

[0023] FIG. 12 is a block diagram showing a pilot insertion unit of an OTFS signal generation device that uses a DFT-unspread pilot symbol as a pilot column vector according to one embodiment of the present disclosure.

[0024] FIG. 13 illustrates a Heisenberg transformed signal of an OTFS signal generation device according to one embodiment of the present disclosure.

[0025] FIG. 14 is a block diagram corresponding to a method in which an OTFS signal generation device according to one embodiment of the present disclosure uses a DFT-spread pilot symbol as a pilot column vector.

[0026] FIG. 15 is a block diagram corresponding to a method in which an OTFS signal generation device according to one embodiment of the present disclosure uses a DFT-unspread pilot symbol as a pilot column vector.

[0027] FIG. 16 is a flowchart of an OTFS signal generation method according to one embodiment of the present disclosure.

[0028] FIG. 17 is a flowchart of an OTFS signal generation method according to one embodiment of the present disclosure.

[0029] FIG. 18 is a block diagram illustrating an OTFS signal generation device according to one embodiment of the present disclosure.

[0030] FIG. 19 is a block diagram of an OTFS signal generation device according to one embodiment of the present disclosure.

[0031] In one embodiment of the present disclosure, a method for transmitting an orthogonal time-frequency-space (OTFS) waveform in a wireless communication system may be provided. The method may include the steps of obtaining a data symbol matrix by serial-parallel converting a data symbol sequence, generating a logical time-frequency domain sample matrix by performing an inverse symplectic finite Fourier transform (ISFFT) or a two-dimensional reversible transform on the data symbol matrix, obtaining a physical time-frequency domain matrix by inserting at least one pilot column vector into the generated logical time-frequency domain sample matrix, and performing a Heisenberg transform on the physical time-frequency domain matrix.

[0032] In one embodiment, the step of generating a logical time-frequency domain sample matrix includes: performing a matrix multiplication operation of an M-point Discrete Fourier Transform (DFT) matrix or a pre-multiplication matrix of a two-dimensional reversible transform and a data symbol matrix; and performing a matrix multiplication operation of the data symbol matrix and an N-point Inverse Discrete Fourier Transform (IDFT) matrix or a post-multiplication matrix of a two-dimensional reversible transform, wherein the pre-multiplication matrix is ​​an M-row and M-column invertible matrix, and the post-multiplication matrix is ​​an N-row and N-column invertible matrix, wherein M may be the number of rows of the logical time-frequency domain sample matrix, and N may be the number of columns of the logical time-frequency domain sample matrix.

[0033] In one embodiment, the Heisenberg transform step includes generating a first matrix by inserting a zero vector row at the top or bottom of a physical time-frequency domain matrix; and generating a second matrix by performing a matrix multiplication operation of the K-point IDFT matrix and the first matrix, wherein K is the number of rows of the generated first matrix, and K may be a number greater than or equal to M.

[0034] In one embodiment, the method may further include the steps of inserting a CP (Cyclic Prefix) or ZP (Zero Prefix) into a second matrix; generating a vector by parallel-to-serial converting the matrix into which the CP or ZP is inserted; and converting the parallel-to-serial converted vector to D / A (Digital to Analog).

[0035] In one embodiment, at least one pilot column vector may be a DFT-spread modulation symbol vector or a modulation symbol vector multiplied by a pre-multiplication matrix of a two-dimensional reversible transform.

[0036] In one embodiment, at least one pilot column vector may be a DFT-unspread modulation symbol vector or a symbol vector that has not been multiplied by a pre-multiplication matrix of a two-dimensional reversible transform.

[0037] In one embodiment of the present disclosure, an OTFS signal generation device in a wireless communication system may include a memory; and at least one processor. The at least one processor may convert a data symbol sequence from serial to parallel to obtain a data symbol matrix, generate a logical time-frequency domain sample matrix by performing an inverse symplectic finite Fourier transform (ISFFT) or a two-dimensional reversible transform on the data symbol matrix, insert at least one pilot column vector into the generated logical time-frequency domain sample matrix to obtain a physical time-frequency domain matrix, and Heisenberg transform the physical time-frequency domain matrix.

[0038] In one embodiment, at least one processor may perform a matrix multiplication operation between an M-point Discrete Fourier Transform (DFT) matrix or a pre-multiplication matrix of a two-dimensional reversible transform and a data symbol matrix, and perform a matrix multiplication operation between a data symbol matrix and an N-point Inverse Discrete Fourier Transform (IDFT) matrix or a post-multiplication matrix of a two-dimensional reversible transform, wherein the pre-multiplication matrix is ​​an M-row and M-column invertible matrix, and the post-multiplication matrix is ​​an N-row and N-column invertible matrix, where M is the number of rows of a logical time-frequency domain sample matrix, and N is the number of columns of the logical time-frequency domain sample matrix.

[0039] In one embodiment, at least one processor generates a first matrix by inserting a zero vector row at the top or bottom of a physical time-frequency domain matrix, and performs a matrix multiplication operation of the K-point IDFT matrix and the first matrix to generate a second matrix, wherein K is the number of rows of the generated first matrix, and K may be a number greater than or equal to M.

[0040] In one embodiment, at least one processor can insert a CP (Cyclic Prefix) or ZP (Zero Prefix) into a second matrix, perform parallel-to-serial conversion of the matrix into which the CP or ZP has been inserted to generate a vector, and perform D / A (Digital to Analog) conversion of the parallel-to-serial converted vector.

[0041] In one embodiment, at least one pilot column vector may be a DFT-spread modulation symbol vector or a modulation symbol vector multiplied by a pre-multiplication matrix of a two-dimensional reversible transform.

[0042] In one embodiment, at least one pilot column vector may be a DFT-unspread modulation symbol vector or a symbol vector that has not been multiplied by a pre-multiplication matrix of a two-dimensional reversible transform.

[0043] In one embodiment of the present disclosure, a computer-readable recording medium storing a program for performing a method for generating an OTFS (Orthogonal Time-Frequency-Space) signal in a wireless communication system may be provided. The method may include the steps of: obtaining a data symbol matrix by serial-parallel converting a data symbol sequence; generating a logical time-frequency domain sample matrix by performing an inverse symplectic finite Fourier transform (ISFFT) or a two-dimensional reversible transform on the data symbol matrix; inserting at least one pilot column vector into the generated logical time-frequency domain sample matrix to obtain a physical time-frequency domain matrix; and performing a Heisenberg transform on the physical time-frequency domain matrix.

[0044] In one embodiment, the method includes performing a matrix multiplication operation between an M-point Discrete Fourier Transform (DFT) matrix or a pre-multiplication matrix of a two-dimensional reversible transform and a data symbol matrix; and performing a matrix multiplication operation between the data symbol matrix and an N-point Inverse Discrete Fourier Transform (IDFT) matrix or a post-multiplication matrix of a two-dimensional reversible transform, wherein the pre-multiplication matrix is ​​an M-row and M-column invertible matrix, the post-multiplication matrix is ​​an N-row and N-column invertible matrix, and M may be the number of rows of a logical time-frequency domain sample matrix, and N may be the number of columns of the logical time-frequency domain sample matrix.

[0045] In one embodiment, at least one pilot column vector may be a DFT-spread modulation symbol vector or a modulation symbol vector multiplied by a pre-multiplication matrix of a two-dimensional reversible transform.

[0046] In one embodiment of the present disclosure, a method for generating an orthogonal time-frequency-space (OTFS) signal in a wireless communication system may be provided. The method includes the steps of: obtaining a data symbol matrix by serial-parallel converting a data symbol sequence; generating a delayed-logical time-domain sample matrix by a matrix multiplication operation of the data symbol matrix and an N-point Inverse Discrete Fourier Transform (IDFT) matrix or a post-multiplication matrix of a two-dimensional reversible transform; generating a logical time-frequency domain matrix by a matrix multiplication operation of the delayed-logical time-domain matrix and an M-point Discrete Fourier Transform (DFT) matrix or a pre-multiplication matrix of a two-dimensional reversible transform; generating a physical time-frequency domain matrix by arranging a column vector of the generated logical time-frequency domain matrix and at least one pilot symbol column vector in a predetermined order; The method may include a step of inserting a zero vector row at the bottom of a physical time-frequency domain matrix, performing a circular down-shift to place elements of the physical time-frequency domain matrix at predetermined subcarrier positions, thereby obtaining a third matrix; and a step of performing CP-OFDM (Cyclic Prefix-Orthogonal Frequency Division Multiplexing) modulation on the third matrix. N may be the number of columns of a data symbol matrix, and M may be the number of rows of a delay-logical time domain matrix.

[0047] In one embodiment, the method may further include the steps of performing a matrix multiplication operation on an IDFT matrix and a downward cyclic matrix; inserting a CP (Cyclic Prefix) into the matrix into which the matrix multiplication operation was performed; performing a parallel-to-serial conversion on the matrix into which the cyclic prefix has been inserted; and performing a D / A (digital to analog) conversion on the parallel-to-serial converted matrix.

[0048] In one embodiment of the present disclosure, an OTFS signal generation device in a wireless communication system may include a memory; and at least one processor. At least one processor obtains a data symbol matrix by serial-parallel conversion of a data symbol column, generates a delayed-logical time-domain sample matrix by matrix multiplication of the data symbol matrix and an N-point Inverse Discrete Fourier Transform (IDFT) matrix or a post-multiplication matrix of a two-dimensional reversible transform, generates a delayed-physical time-domain matrix by arranging a column vector of the delayed-logical time-domain matrix and at least one pilot symbol column vector in a predetermined order, generates a physical time-frequency domain matrix by matrix multiplication of the delayed-physical time-domain matrix and an M-point Discrete Fourier Transform (DFT) matrix or a pre-multiplication matrix of a two-dimensional reversible transform, inserts a zero vector row at the bottom of the physical time-frequency domain matrix, and obtains a third matrix by performing a circular down-shift so that elements of the physical time-frequency domain matrix are arranged at predetermined subcarrier positions, and The matrix may be modulated by CP-OFDM (Cyclic Prefix-Orthogonal Frequency Division Multiplexing), where N is the number of columns of the data symbol matrix and M is the number of rows of the delay-logical time domain matrix.

[0049] In one embodiment, at least one processor can perform a matrix multiplication operation on an IDFT matrix and a downward cyclic matrix, insert a CP (Cyclic Prefix) into the matrix multiplied, perform a parallel-to-serial conversion on the matrix into which the cyclic prefix has been inserted, and perform a D / A (digital to analog) conversion on the parallel-to-serial converted matrix.

[0050] In this disclosure, the expression “at least one of a, b or c” may refer to “a”, “b”, “c”, “a and b”, “a and c”, “b and c”, “all of a, b and c”, or variations thereof.

[0051] The terms used in this disclosure are selected from widely used, common terms, taking into account the functions of the disclosure. However, these terms may vary depending on the intentions of those skilled in the art, precedents, the emergence of new technologies, etc. Furthermore, in certain cases, terms may be arbitrarily selected by the applicant, in which case their meanings will be described in detail in the relevant description. Therefore, the terms used in this disclosure should not be defined simply as names, but rather based on the meanings of the terms and the overall content of the disclosure.

[0052] Singular expressions may include plural expressions unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by those of ordinary skill in the art described in this disclosure. Furthermore, terms containing ordinal numbers, such as "first" or "second," used herein may be used to describe various components, but the components should not be limited by these terms. These terms are used solely to distinguish one component from another.

[0053] Throughout this disclosure, when a part is said to "include" a component, unless otherwise specifically stated, this does not exclude other components, but rather implies the inclusion of other components. Furthermore, terms such as "part" and "module" described herein refer to a unit that processes at least one function or operation, which may be implemented in hardware or software, or a combination of hardware and software.

[0054] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings so that those skilled in the art can easily practice the present disclosure. However, the present disclosure may be implemented in various different forms and is not limited to the embodiments described herein. In addition, in the drawings, parts that are not related to the description are omitted to clearly explain the present disclosure, and similar parts are designated with similar reference numerals throughout the present disclosure. In addition, the reference numerals used in each drawing are only for the purpose of describing each drawing, and different reference numerals used in different drawings do not indicate different elements.

[0055] Throughout this disclosure, when a part is said to be "connected" to another part, this includes not only "directly connected" or "physically connected," but also "electrically connected" with another element in between. In this disclosure, the terms "transmit," "receive," and "communicate" include both direct and indirect communication. Furthermore, when a part is said to "include" or "comprise" a component, this does not exclude other components, but rather includes other components, unless specifically stated otherwise.

[0056] Throughout this disclosure, unless specifically stated otherwise, “or” is inclusive and not exclusive. Thus, unless expressly indicated otherwise or the context indicates otherwise, “A or B” can mean “A, B, or both.” Throughout this disclosure, the phrase “at least one of” or “one or more of” can mean that different combinations of one or more of the listed items may be used, or that only any one of the listed items is required. For example, “at least one of A, B, and C” can include any of the following combinations: A, B, C, A and B, A and C, B and C, or A and B and C.

[0057] A “controller” can refer to any device, system, or portion thereof that controls at least one operation. A controller can be implemented in hardware, a combination of hardware and software, or firmware. The functionality associated with a particular controller can be centralized or distributed, localized or remote.

[0058] Additionally, the computer-readable medium may be provided in the form of a non-transitory storage medium. Here, a 'non-transitory storage medium' is a tangible device and may exclude wired, wireless, optical, or other communication links that transmit temporary electrical or other signals. Meanwhile, this 'non-transitory storage medium' does not distinguish between cases where data is permanently stored in the storage medium and cases where it is temporarily stored. For example, a 'non-transitory storage medium' may include a buffer where data is temporarily stored. The computer-readable medium may be any available medium that can be accessed by a computer, and may include both volatile and non-volatile media, and removable and non-removable media. The computer-readable medium includes media on which data can be permanently stored and media on which data can be stored and later overwritten, such as a rewritable optical disk or an erasable memory device.

[0059] According to one embodiment, the method according to various embodiments disclosed in the present document may be provided as a computer program product. The computer program product may be traded between sellers and buyers as a product. The computer program product may be distributed in the form of a device-readable storage medium (e.g., compact disc read only memory (CD-ROM)) or may be provided through an application store (e.g., Play Store). TM) or directly between two user devices (e.g., smartphones), online distribution (e.g., downloading or uploading). In the case of online distribution, at least a portion of the computer program product (e.g., downloadable app) may be at least temporarily stored or temporarily created in a device-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

[0060] Definitions for other specific words and phrases may be provided throughout this disclosure. Those skilled in the art will understand that, in various instances, the defined words and phrases may apply to past and future usages.

[0061] Each component described later in this disclosure may additionally perform some or all of the functions performed by other components in addition to its own main function, and some of the main functions of each component may be performed entirely by other components.

[0062] A method for generating a transmission signal as an orthogonal time-frequency-space (OTFS) waveform according to one embodiment can be expressed by several mathematical equations. For example, if an OTFS signal generation device (100) can generate a continuous-time signal in units of frames and the channel does not change in the delay-Doppler domain during one frame unit, if the OTFS signal generation device transmits J frames, the transmission signal can be expressed as in the following mathematical equation 1.

[0063] [Mathematical Formula 1]

[0064]

[0065] Here, can represent the component of the j-th frame signal among the transmitted signals, can represent a common frame cycle. Since the generation method of each frame signal can be applied in the same way, for the convenience of explanation, the same method can also be applied to the signal generation method of the 0th frame. In the following disclosure, for the convenience of explanation, the signal of the 0th frame is expressed as s(t).

[0066] FIG. 1 is a block diagram illustrating an OTFS signal generation device according to one embodiment.

[0067] Referring to FIG. 1, an OTFS signal generation device (100) may include a serial-to-parallel (S / P) converter (110), an Inverse Symplectic Finite Fourier Transform (ISFFT) converter (130), and a Heisenberg (150) transform unit. The OTFS signal generation device (100) may perform serial-to-parallel conversion, ISFFT, and Heisenberg transform to transmit one frame.

[0068] An OTFS signal generation device (100) according to one embodiment of the present disclosure includes a serial-to-parallel conversion unit (110) that converts a data symbol sequence x[n] into a serial-to-parallel (S / P) signal to generate a symbol matrix of M rows and N columns (hereinafter referred to as MxN) in a delay-Doppler domain (DD domain). can be created.

[0069] The ISFFT unit (130) according to one embodiment of the present disclosure is a delay-Doppler domain symbol matrix By performing the inverse symplectic finite Fourier transform, A time-frequency domain (TF domain) sample matrix of the same size as can be generated. The ISFFT unit (130) is a delay-Doppler domain matrix Multiply the left side by the M-point DFT (discrete Fourier transform) matrix, and the right side by the N-point IDFT (inverse DFT) matrix to obtain an MxN sample matrix. A two-dimensional orthogonal transformation can be performed to obtain . For example, The m row n column component of class The l row k column component of The relationship can be expressed as the following mathematical expression 2.

[0070] [Equation 2]

[0071]

[0072] The operation of the Heisenberg transform unit (150) according to one embodiment of the present disclosure is a TF domain matrix This may be mathematically equivalent to applying a pulse-shaped orthogonal frequency-division multiplexing (OFDM) modulation process to the Heisenberg transform unit (150). The Heisenberg transform unit (150) may generate a continuous-time signal s(t) using the following mathematical expression 3.

[0073] [Equation 3]

[0074]

[0075] Heisenberg transform unit (150) The l-th row symbols can be assigned to the l-th subcarrier, and a generalized pulse-shaped OFDM modulation process can be performed to generate the k-th OFDM symbol using the k-th symbols. Here, may be a sub-carrier spacing, can be the transmit pulse of the kth OFDM symbol, can be the delay time of the kth transmission pulse. For example, And In this case, the above mathematical expression 3 can be simplified as shown in the following mathematical expression 4.

[0076] [Equation 4]

[0077]

[0078] According to mathematical expression 3, the OTFS signal generating device (100) and can be appropriately selected according to k, and the cyclic prefix of the symbol CP (Cyclic Prefix) It can also be combined with all columns, without the symbol CP. After parallel-to-serial conversion, one frame CP (frame cyclic prefix) may be combined, and a combination of the two methods is also possible. Alternatively, according to one embodiment of the present disclosure, the OTFS signal generation device (100) may generate a zero prefix of a symbol ZP (Zero Padding). can be combined in all columns, without the symbol ZP. After parallel-to-serial conversion, one frame zero prefix can be combined, and the two methods can also be combined. For convenience of explanation, the following is explained using mathematical expression 4.

[0079] When an OTFS signal s(t) passes through a channel (10), a continuous-time signal r(t) can be generated. Here, s(t) can be received by an OTFS receiver (200) after passing through a narrowband doubly-selective fading channel. Then, when r(t) is Wigner transformed and Symplectic Finite Fourier Transform (SFFT), a delay-Doppler domain symbol matrix When a 2-D channel matrix having a sparse impulse response in the delay-Doppler domain is subjected to a 2-D circular convolution, the delay-Doppler domain matrix obtained can be obtained as the output Y.

[0080] When the parameters of the channel impulse response are accurately estimated, the OTFS receiver (200) can estimate data symbols in the delay-Doppler domain using various equalization techniques, including 2-D deconvolution in the delay-Doppler domain.

[0081] In order for the OTFS receiver (200) according to one embodiment to perform accurate channel estimation and channel equalization, the OTFS signal generation device (100) may transmit a pilot symbol or a reference signal. Hereinafter, a method for arranging a pilot symbol or a method for generating a reference signal when transmitting an OTFS signal will be described.

[0082] The first method corresponds to the method of transmitting a signal modulated with a pseudo-random sequence as a reference signal before or after transmitting s(t) as disclosed in Reference 1 (KR Murali and A. Chockalingam, "On OTFS modulation for high-Doppler fading channels," in Proc. Inf. Theory Appl. Workshop (ITA), San Diego, CA, USA, Feb. 2018.).

[0083] The above first method generates a reference signal using a method different from the method of generating the OTFS signal s(t), and has the problem of being incompatible with the pilot symbol arrangement or reference signal generation method of the conventional 4G LTE or 5G NR. In the present disclosure, 4G LTE is defined as 3GPP (3 rd 5G NR may refer to a communication system according to the 3GPP TS (Technical Specification) 36 series document, and in the present disclosure, 5G NR may refer to a communication system according to the 3GPP TS 38 series document.

[0084] The second method is to use pilot symbols consisting of impulse symbols with relatively large values ​​and zero guard symbols as a delay-Doppler domain matrix, as disclosed in Reference 2 (P. Raviteja, KT Phan, Y. Hong, "Embedded pilot-aided channel estimation for OTFS in delay-Doppler channels," IEEE Trans. on Vehicular Technol., vol. 68, no. 5, pp. 4906-4917, May 2019). This corresponds to a method of arranging elements of a matrix and arranging pilot symbols in different locations from data symbols.

[0085] The second method mentioned above has the problem that the PAPR (Peak-to-Average Power Ratio) of the transmission signal increases, and is not compatible with the conventional 4G LTE or 5G NR reference signal generation method.

[0086] FIG. 2 illustrates an OTFS waveform according to one embodiment, with pilot symbols arranged in a delay-Doppler domain symbol matrix and a generated continuous-time signal.

[0087] Referring to Fig. 2, the method of placing embedded pilots in the delay-Doppler domain and the method of appearing reference signal components in the one-dimensional time domain in the OTFS transmission method using a rectangular waveform are exemplified. The ISFFT unit (130) and the Heisenberg transform unit (150) according to one embodiment are delay-Doppler domain matrices. It can be simplified by multiplying the N-point IDFT matrix (210) on the right side and then performing a parallel-to-serial conversion.

[0088] Delay-Doppler domain symbol matrix according to one embodiment An impulse symbol (201) having a relatively large value in may be surrounded by guard symbols having a value of 0. For example, a pilot sub-matrix portion consisting of an impulse symbol (201) and guard symbols may be a delay-Doppler domain symbol matrix When the NxN IDFT matrix (210) is multiplied on the right side, the delay-time domain MxN matrix can be converted to

[0089] Corresponds to the row where the impulse pilot symbol was placed in All matrix elements of the impulse symbol can be represented as a spread matrix element (203), and the spread matrix elements (203) are a delay-Doppler domain symbol matrix. In the case where the impulse pilot symbol is spread, the energy of each spread matrix element (203) can be reduced to 1 / N. In this case, the matrix elements (203) where the impulse pilot symbol is spread have values ​​that are significantly larger than those of other data matrix elements.

[0090] one side, Corresponding to rows where only guard symbols were placed Only 0 symbols can appear in all matrix elements. Therefore, in the one-dimensional time domain where the P / S+CP (230) conversion is performed, the strong vector element (205) is surrounded by 0 vector elements and may have a periodically arranged form. Therefore, since s(t), which is a continuous-time signal obtained after the digital-to-analog (D / A) (250) conversion, has a pilot signal component or reference signal component in which a large value periodically appears before and after a relatively small value, the PAPR of s(t) may become very large.

[0091] The third method is the Superimposed Pilot method, which is a method disclosed in Reference 3 (H.B. Mishra, P. Singh, A.K. Prasad, and R. Budhiraja, "OTFS channel estimation and data detection designs with superimposed pilots," IEEE Trans. Wireless Commun., vol. 21, no. 4, pp. 2258―2274, Apr. 2022.), which uses the delay-Doppler domain matrix This corresponds to a method of placing only data symbols in some elements and placing values ​​that overlap data symbols and pilot symbols in some elements. Here, when overlapping pilot symbols and data symbols, the sum of the two symbols can be placed.

[0092] The third method requires a complex channel and symbol estimation method because pilot symbols and data symbols overlap, and there is a problem that it is not compatible with the pilot symbol arrangement or reference signal generation method of conventional 4G LTE or 5G NR.

[0093] To ensure flexibility in 6G waveforms, consistent pilot symbol or reference signal generation methods may be required for various levels of mobility. The three pilot symbol placement or reference signal generation methods described above for OTFS waveforms are incompatible with the existing pilot symbol placement and reference signal generation methods used in 4G LTE or 5G NR.

[0094] Below, the conventional 4G LTE or 5G NR pilot symbol placement and reference signal generation methods are described.

[0095] FIG. 3 is a block diagram illustrating a CP-OFDM transmission device used in a 5G NR uplink according to one embodiment.

[0096] Referring to FIG. 3, the CP (Cyclic Prefix)-OFDM transmitter (300) can generate a continuous-time signal in slot units. The method by which the CP-OFDM transmitter (300) generates the continuous-time signal can be the same method as the method by which the OTFS signal generator (100) described above generates a frame signal. Here, s(t) can be a signal component corresponding to one slot.

[0097] A CP-OFDM transmitter (300) according to one embodiment converts a data symbol sequence x[n] into serial / parallel (S / P) and places pilot symbols to generate a time-frequency domain (TF domain) symbol matrix of size MxN. can be obtained. The CP-OFDM transmitter (300) can be obtained By inputting it into the CP-OFDM modulation unit (330), a continuous-time signal s(t) can be obtained.

[0098] The CP-OFDM modulator (330) according to one embodiment can perform IDFT of K-points using K having a value greater than or equal to M for analog filtering and computationally efficient modulation. For example, the CP-OFDM modulator (330) To assign each row to a designated subcarrier location. By inserting 0 row vectors at the top, middle, bottom, etc., an extended time-frequency domain KxN matrix can be created.

[0099] According to one embodiment, a CP-OFDM modulator (330) multiplies the left side of an extended time-frequency domain KxN matrix by a K-point IDFT matrix to generate a delay-time domain (DT domain: delay-time domain) KxN sample matrix. can be obtained. Here, the IFFT algorithm can be applied for computationally efficient multiplication. Next, the CP-OFDM modulation unit (330) generates a KxN matrix For each column, a symbol CP is inserted, and the one-dimensional time-domain vector obtained by parallel-to-serial (P / S) conversion is converted to digital-to-analog (D / A) and analog filtered to obtain the transmission signal s(t). Here, each column of the delay-time domain KxN matrix can represent an OFDM symbol vector.

[0100] For CP-OFDM used in the uplink of 5G NR, pilot symbols are an MxN time-frequency domain symbol matrix. can be arranged in one or more columns. In the following Figures 4 and 5, for convenience of explanation, the operation of the CP-OFDM modulation unit (330) is described when pilot symbols are arranged in only one column, K=M+2, and CP is one sample length.

[0101] FIG. 4 illustrates pilot symbols assigned to subcarriers when pilot column vectors are arranged in only one column in a time-frequency domain matrix, according to one embodiment.

[0102] Referring to FIG. 4, the CP-OFDM modulation unit (330) has a pilot symbol (401) placed in only one column. It can take as input, insert 0 vectors into the lowest and highest rows, and generate an extended time-frequency domain KxN matrix.

[0103] FIG. 5 illustrates a CP-OFDM transmission method according to one embodiment when a pilot column vector is arranged in only one column in a time-frequency domain matrix.

[0104] Referring to FIG. 5, the CP-OFDM modulation unit (330) multiplies the left side of the extended time-frequency domain KxN sample matrix (510) by the K-point IDFT matrix (530). , and after attaching a symbol CP of length 1 to each column, s(t) can be obtained by performing P / S conversion and D / A conversion. Here, the pilot symbol component (501) can exist only in the corresponding OFDM symbol vector even after obtaining a delay-time domain KxN matrix by multiplying the K-point IDFT matrix. The pilot symbol component (501) can have a value of a similar size to the matrix elements obtained by performing K-point IDFT on data symbols.

[0105] The output (503) of the CP+P / S (550) transition may have a characteristic in that one OFDM symbol vector component containing pilot symbols appears as continuous vector elements on a one-dimensional time axis, and corresponds to a different form from the D / A input of the embedded pilot OTFS of Fig. 2. In addition, the output (503) of the CP+P / S (550) transition has a different characteristic from not only the OTFS transmission method of transmitting a pseudo-random sequence modulated reference signal but also the OTFS transmission method of arranging superimposed pilot symbols.

[0106] In the present disclosure, the pilot symbol arrangement method of the OTFS waveform generation method can be applied in the same manner as the uplink reference signal generation method in the conventional 4G LTE and 5G NR. The pilot symbol arrangement method of the OTFS waveform generation method according to one embodiment can have a characteristic in that a single pilot symbol vector component containing pilot symbols, such as the output (503) of the CP+P / S (550) transition, appears as continuous vector elements on a one-dimensional time axis. Accordingly, the pilot symbol arrangement method of the OTFS waveform generation method according to one embodiment can maintain compatibility with conventional standard documents in the reference signal generation method of the OTFS waveform.

[0107] Below we describe how pilot column vectors are generated when using DFT-spread OFDM in the uplink of 4G LTE and 5G NR.

[0108] FIG. 6 is a block diagram illustrating a DFT-spread OFDM transmitter that uses a DFT-spread pilot symbol as a pilot column vector, according to one embodiment.

[0109] Referring to FIG. 6, a model of a DFT-spread-OFDM transmitter and a receiving signal used in the uplink of 4G LTE and 5G NR can be expressed by several mathematical formulas, and a DFT-spread OFDM transmitter (600) that uses a DFT-spread pilot symbol as a pilot column vector can use a DFT-spread pilot symbol among the mathematical formulas expressed by several mathematical formulas as a pilot column vector. Similar to the CP-OFDM transmitter (300) described above, a method for generating a signal corresponding to one slot will be described. Here, s(t) may be a signal component corresponding to one slot.

[0110] A DFT-spread OFDM transmitter (600) using a DFT-spread pilot symbol as a pilot column vector according to one embodiment may perform serial-parallel (S / P) conversion of a data symbol sequence x[n] through an S / P conversion unit (610), place pilot symbols to generate a symbol matrix X of size MxN, and perform DFT-spreading for each column by multiplying an M-point DFT matrix on the left side of the symbol matrix X of size MxN through a DFT spreading unit (630). The DFT-spread OFDM transmitter (600) using a DFT-spread pilot symbol as a pilot column vector may output a time-frequency matrix of size MxN. By inputting it into the CP-OFDM modulation unit (650), a continuous time signal s(t) can be obtained.

[0111] Here, the CP-OFDM modulation unit (650) The method of converting to s(t) may be the same as the conversion method of CP-OFDM described above. Therefore, the CP-OFDM modulation unit (650) according to one embodiment may directly apply the examples of FIGS. 4 and 5.

[0112] FIG. 7 illustrates a method for generating a time-frequency matrix of DFT-spread OFDM using DFT-spread pilot symbols as pilot column vectors, according to one embodiment.

[0113] Referring to Fig. 7, according to the 4G LTE and 5G NR uplink standard documents, in the case of DFT-spread OFDM that uses DFT-spread pilot symbols as pilot column vectors, the spread pilot symbols are arranged in an MxN time-frequency domain symbol matrix. , and in FIG. 7, the pilot symbols (701) are placed in only one column and then M-point DFT-spread.

[0114] MxN time-frequency domain matrix of Fig. 7 and MxN time-frequency domain matrix of Fig. 4 All pilot symbol components can be arranged in column units. Therefore, in the DFT-spread OFDM that uses the DFT-spreaded pilot symbol according to one embodiment of the present disclosure as a pilot column vector, one OFDM symbol vector component containing pilot symbols may have a characteristic that it appears as continuous vector elements on the one-dimensional time axis, as in the output (503) of the CP+P / S (550) conversion of FIG. 5. The characteristic that one OFDM symbol vector component containing pilot symbols appears as continuous vector elements on the one-dimensional time axis is different from the D / A input of the embedded pilot OTFS of FIG. 2, and may also be different from the OTFS transmission method that transmits with a pseudo-random sequence modulated reference signal as well as the OTFS transmission method that arranges superimposed pilot symbols.

[0115] FIG. 8 is a block diagram illustrating a DFT-spread OFDM transmitter using a DFT-unspreaded pilot symbol as a pilot column vector according to one embodiment.

[0116] Referring to Fig. 8, a DFT-spread OFDM signal transmission device (800) used in the uplink of 4G LTE and 5G NR can use a pilot symbol that has not been DFT-spread as a pilot column vector. Similar to the method of using a DFT-spread pilot symbol as a pilot column vector in Fig. 6, a method of generating a signal corresponding to one slot by using a pilot symbol that has not been DFT-spread as a pilot column vector is described. Here, s(t) may be a signal component corresponding to one slot.

[0117] A DFT-spread OFDM transmitter (800) using a DFT-unspreaded pilot symbol as a pilot column vector according to an embodiment of the present disclosure can generate a delay-time domain symbol matrix X of an MxN size by S / P converting a data symbol sequence x[n] and first placing a 0 symbol in a column where a pilot symbol is to be placed. An M-DFT (830) according to an embodiment can perform DFT-spreading for each column by multiplying an M-point DFT matrix on the left side of X. Subsequently, a pilot placement unit (850) places pilot symbols in columns where pilot symbols are to be placed in a matrix of an MxN size to generate a time-frequency matrix. can generate, and the CP-OFDM modulation unit (870) is a time-frequency matrix A continuous time signal s(t) can be generated by taking as input.

[0118] Here, the CP-OFDM modulation unit (870) The method of converting to s(t) may be the same as the conversion method of CP-OFDM described above. Therefore, the CP-OFDM modulation unit (650) according to one embodiment may directly apply the examples of FIGS. 4 and 5.

[0119] FIG. 9 illustrates a method for generating a time-frequency matrix of DFT-spread OFDM using DFT-unspreaded pilot symbols according to one embodiment of the present disclosure.

[0120] Referring to Fig. 9, according to the 4G LTE and 5G NR uplink standard documents, in the case of DFT-spread OFDM that uses DFT-unspreaded pilot symbols as pilot column vectors, the pilot symbols are arranged in an MxN time-frequency domain symbol matrix. , and can be placed in one or more columns. FIG. 9 shows a case where pilot symbols (901) are placed in only one column.

[0121] MxN time-frequency domain matrix of Fig. 4 MxN time-frequency domain matrix of Fig. 9 may all have in common that the pilot symbol components are arranged in units of columns. Accordingly, in the DFT-spread OFDM that uses the DFT-unspreaded pilot symbol according to one embodiment of the present disclosure as a pilot column vector, one OFDM symbol vector component containing pilot symbols may have the characteristic that it appears as continuous vector elements on the one-dimensional time axis, as in the output (503) of the CP+P / S (550) conversion of FIG. 5. The CP+P / S (550) conversion may represent a process of inserting a CP (cyclic prefix) and performing parallel-to-serial conversion. The characteristic that one OFDM symbol vector component containing pilot symbols appears as continuous vector elements on the one-dimensional time axis is different from the D / A input of the embedded pilot OTFS of FIG. 2, and is different from not only the OTFS transmission method that transmits with a pseudo-random sequence modulated reference signal, but also the OTFS transmission method that arranges superimposed pilot symbols.

[0122] The method of placing pilot symbols and generating reference signals in conventional 4G LTE and 5G NR standard documents differs from the method of placing pilot symbols or generating reference signals in OTFS.

[0123] Much research has focused on OTFS, which outperforms OFDM in high-mobility channel environments. Unlike OFDM, where each symbol experiences different channel gains in the time-frequency domain, OTFS spreads the energy of each symbol across multiple subcarriers and simultaneously in the time domain. Therefore, even if the channel is selective in both frequency and time, if the channel response is designed to remain largely unchanged in the delay-Doppler domain over a single frame, all data symbols within a single frame experience relatively similar channel gains, enabling high performance. Referring to Reference 4 (R. Bomfin, M. Chafii, A Nimr, and G. Fettweis, "A robust baseband transceiver design for doubly-dispersive channels," IEEE Trans. Wireless Commun., vol. 20, no. 8, pp. 4781―4796, Aug. 2021.), the term Equal Gain Criterion (EGC) can refer to a waveform design criterion that designs the channel response in the delay-Doppler domain to have little change over one frame time.

[0124] Referring to Reference 5 (T. Thaj, E. Viterbo, and Yi Hong, "Orthogonal time sequence multiplexing modulation: analysis and low-complexity receiver design," IEEE Trans. Wireless Commun., vol. 20, no. 12, pp. 7842--7855, May 2019.), new waveforms similar to but different from OTFS were proposed based on the equal-gain criterion. The Orthogonal Time-Sequency Multiplexing (OTSM) of Reference 5 can show a method to reduce computational complexity while achieving similar performance to OTFS by replacing the N-point IDFT matrix of Fig. 2 with a Walsh-Hadamard Transform (WHT) matrix.

[0125] Also, Reference 6 (R. Bomfin, A. Nimr, M. Chafii, and G. Fettweis, "A robust and low-complexity Walsh-Hadamard modulation for Doubly-Dispersive Channels," IEEE Commun. Letters, vol. 25, no. 3, pp. 897-901, Mar. 2021.) presents a method to reduce computational complexity while achieving similar or better performance than OTFS in doubly-dispersive fading channels by not only replacing the N-point IDFT matrix in Fig. 2 with a (sparse) WHT matrix, but also multiplying the left side of the data symbol matrix by an M-point (sparse) WHT matrix.

[0126] According to the above method, in order to design a robust waveform in a dual-selective channel environment, it is not necessary to perform ISFFT and Heisenberg transform in the same manner as in OTFS, and if the data symbol is spread to some extent in the time-frequency domain through a two-dimensional invertible transformation to satisfy EGC, better performance than OFDM can be obtained in the channel.

[0127] According to the above method, the sparse WHT matrix has the disadvantage that it is defined only in powers of 2, and compared to OTFS using a DFT matrix, these new waveforms have the disadvantage of being restricted in the selection of M or N values. For example, one slot of 4G LTE corresponds to N=7, and one slot of 5G NR corresponds to N=14.

[0128] A method and device for transmitting an OTFS waveform according to one embodiment of the present disclosure relate to a method and device that overcomes the above-described disadvantages while maintaining the advantages of OTFS using a DFT matrix. The method and device for transmitting an OTFS waveform according to one embodiment may be a method for modifying an OTFS transmission method to follow an equal gain criterion while maintaining compatibility with pilot allocation methods or reference signal generation methods of conventional 4G LTE and 5G NR.

[0129] However, the method and device for transmitting an OTFS waveform according to one embodiment may be combined or replaced with some configurations within a range not aligned with the above-described method, but are not limited thereto.

[0130] Fig. 10 is a block diagram illustrating an OTFS signal generation device according to one embodiment.

[0131] Referring to FIG. 10, an OTFS signal generation device (1000) according to an embodiment of the present disclosure may include a serial to parallel (S / P) conversion unit (1010), an ISFFT unit (1030), a pilot insertion unit (1050), and a Heisenberg transform unit (1070). In the present disclosure, for convenience of explanation, the functions of the OTFS signal generation device (1000) are described as conceptually separate blocks, but are not limited thereto. Each block of the OTFS signal generation device (1000) may be implemented by being combined or omitted. In addition, each block is not limited to the expressed name, and may represent a block that performs the described function.

[0132] According to one embodiment, the S / P conversion unit (1010) converts the data symbol sequence x[n] serially to parallelly to generate an MxN symbol matrix in the delay-logical Doppler domain (DlD domain). can be created.

[0133] The ISFFT section (1030) is a delay-logical Doppler domain symbol matrix By performing ISFFT or 2D reversible transform, MxN logical time-frequency domain (lTF domain: logical Time-Frequency domain) sample matrix can be obtained. For example, the ISFFT unit (1030) is a delay-logical Doppler domain symbol matrix The MxN sample matrix is ​​obtained by multiplying the M-point DFT matrix or the pre-multiplication matrix of the two-dimensional reversible transformation on the left side and the N-point IDFT matrix or the post-multiplication matrix of the two-dimensional reversible transformation on the right side. A two-dimensional orthogonal transformation can be performed to obtain . Here, The m row n column component of class The l row k column component of The relationship can be as shown in mathematical expression 2.

[0134] The pilot insertion unit (1050) is an MxN logical time-frequency domain symbol matrix As input, insert (N'-N) Mx1 pilot column vectors to create an MxN' physical time-frequency domain (pTF domain: physical Time-Frequency domain) symbol matrix. In one embodiment, the pilot insertion unit (1050) may select N' as 7 or 14, which is one slot length, instead of N, to maintain backward compatibility with 4G LTE and 5G NR.

[0135] According to one embodiment, at least one pilot column vector may be a DFT-spread modulation symbol vector or a modulation symbol vector multiplied by a pre-multiplication matrix of a two-dimensional reversible transform.

[0136] Additionally, at least one pilot column vector according to one embodiment may be a DFT-unspread modulation symbol vector or a symbol vector that is not multiplied by a pre-multiplication matrix of a two-dimensional reversible transform.

[0137] According to one embodiment, the Heisenberg transform unit (1070) generates a physical time-frequency domain symbol matrix In an OFDM transmitter, after serial-parallel conversion of a symbol sequence, a process mathematically equivalent to applying a pulse-shaped orthogonal frequency-division multiplexing (OFDM) process can be performed. For example, the Heisenberg transform unit (1070) can be converted to a continuous-time signal using the following mathematical expression 5. can be created.

[0138] [Equation 5]

[0139]

[0140] Here, is the subcarrier spacing, is the transmission pulse of the kth OFDM symbol, can represent the delay time of the kth transmission pulse.

[0141] Heisenberg Transformer (1070) A generalized pulse-shaped OFDM modulation can be performed by assigning the l-th row symbols to the l-th subcarrier and generating the k-th OFDM symbol with the k-th symbols. According to mathematical expression 5, when the Heisenberg transform is viewed as a pulse-shaped OFDM modulation, the Heisenberg transform unit (1070) is a rectangular wave and By appropriately selecting k, the symbol CP can be added to each column, without symbol CP After converting the P / S (parallel-to-serial), only one frame CP can be added, and the two methods can be combined. According to one embodiment of the present disclosure, the Heisenberg transform unit (1070) adds the zero prefix of the symbol ZP. can be combined in all columns, without the symbol ZP. After parallel-to-serial conversion, one frame zero prefix can be combined, and it is also possible to combine the two methods, for example, And Then, the above mathematical expression 5 can be simplified as shown in the following mathematical expression 6.

[0142] [Equation 6]

[0143]

[0144] In 4G LTE and 5G NR, pilot column vectors using DFT-spread pilot symbols may be deployed, and pilot column vectors using non-DFT-spread pilot symbols may be deployed. Accordingly, the pilot insertion unit (1050) may have different structures depending on whether pilot column vectors using DFT-spread pilot symbols are deployed or pilot column vectors using non-DFT-spread pilot symbols are deployed.

[0145] FIG. 11 is a block diagram illustrating a pilot insertion unit of an OTFS signal generation device in which a pilot column vector using a DFT-spread pilot symbol is placed according to one embodiment. In the present disclosure, the term "pilot" may be used interchangeably with or interchangeably with the terms "pilot vector" and "pilot column vector."

[0146] Referring to FIG. 11, a pilot insertion unit (1050) of an OTFS signal generation device (1000) according to one embodiment of the present disclosure may include a logical time-frequency domain sample vector arrangement unit (1110), a DFT-spread pilot vector arrangement unit (1130), and a physical time-frequency domain sample matrix generation unit (1150).

[0147] A logical time-frequency domain sample vector arrangement unit (1110) according to one embodiment is an MxN logical time-frequency domain sample matrix It can perform the function of placing N Mx1 sample column vectors into N columns out of N' columns of an MxN' physical time-frequency domain sample matrix.

[0148] According to one embodiment, the DFT-spread pilot vector placement unit (1130) M-point DFT-spreading of Mx1 pilot column vectors into MxN' physical time-frequency domain sample matrix of It can perform the function of placing the dog in a column.

[0149] According to one embodiment, the physical time-frequency domain sample matrix generation unit (1150) generates an MxN' physical time-frequency domain sample matrix can perform the function of generating. For example, for an MxN' zero matrix, the DFT-spread pilot vector placement unit (1130) generates a physical time-frequency domain sample matrix Among the N' columns of The DFT-spread pilot column vectors can be placed in the columns of the dog. In addition, the logical time-frequency domain sample vector placement unit (1130) Logical time-frequency domain sample matrix in the remaining N columns where no pilot vectors are placed The N column vectors can be arranged sequentially or in a non-sequential order promised to the receiver.

[0150] FIG. 12 is a block diagram illustrating a pilot insertion unit of an OTFS signal generation device using a DFT-unspread pilot according to one embodiment.

[0151] Referring to FIG. 12, a pilot insertion unit (1050) of an OTFS signal generation device (1000) according to one embodiment of the present disclosure may include a logical time-frequency domain sample vector arrangement unit (1210), a pilot vector arrangement unit (1230), and a physical time-frequency domain sample matrix generation unit (1250).

[0152] According to one embodiment, the logical time-frequency domain sample vector arrangement unit (1210) is an MxN logical time-frequency domain sample matrix The N Mx1 sample column vectors can be placed in N columns of the N' columns of the MxN' physical time-frequency domain sample matrix.

[0153] According to one embodiment, the pilot vector placement unit (1230) Mx1 pilot column vectors of the dog to an MxN' physical time-frequency domain sample matrix of It can be placed in the dog's column.

[0154] According to one embodiment, the physical time-frequency domain symbol matrix generator (1250) generates an MxN' physical time-frequency domain sample matrix can be created.

[0155] For example, as an MxN' zero matrix For the pilot vector arrangement unit (1210), the physical time-frequency domain sample matrix Among the N' columns of A pilot column vector can be placed in the column of the dog. In addition, the logical time-frequency domain sample vector placement unit (1230) Logical time-frequency domain sample matrix in the remaining N columns where no pilot vectors are placed The N column vectors can be arranged sequentially or in a non-sequential order promised to the receiver.

[0156] Fig. 13 shows a Heisenberg transformed signal of an OTFS signal generation device according to one embodiment.

[0157] Referring to FIG. 13, according to one embodiment of the present disclosure, the OTFS signal generation device (1000) can perform a Heisenberg transform when pilot column vectors are arranged in one or more columns in a physical time-frequency domain matrix. The Heisenberg transform unit (1070) according to one embodiment can perform a Heisenberg transform on an MxN' physical time-frequency domain matrix in which pilot column vectors using DFT-spread or non-DFT-spread pilot symbols are arranged. A matrix can be generated by inserting a zero row vector (or a row vector with a value of 0) above or below. For example, if K = M + 2, the Heisenberg transform unit (1070) generates a physical time-frequency domain matrix By inserting one zero row vector above and below each other, a KxN' matrix (1310) can be generated. In addition, the Heisenberg transform unit (1070) can obtain a KxN' matrix (1330) by multiplying the left side of this matrix by a K-point IDFT matrix.

[0158] Here, K may be the number of rows of a KxN' matrix (1310) generated by inserting a zero vector row at the top or bottom of a physical time-frequency domain matrix. In one embodiment, K may be a number greater than or equal to M.

[0159] Next, the Heisenberg transform unit (1070) inserts CP into the KxN' matrix (1330), performs the CP + P / S (1350) operation of parallel-to-serial conversion, and converts the continuous-time signal through D / A (1370) conversion. can be obtained. Here, the pilot symbol (1301) can be expressed in the same form as the OFDM transmission method of Fig. 5 by the effect of the pilot of the output (1303) of CP + P / S (1350). Therefore, the signal generated by the Heisenberg transform unit (1070) Since it can have a form similar to how the reference signal is generated in the uplink of the 4G LTE and 5G NR standards, it can have various effects, including the effect of being compatible with 4G LTE and 5G NR.

[0160] FIG. 14 is a block diagram corresponding to a method of arranging pilot column vectors using DFT-spread pilot symbols in an OTFS signal generation device according to one embodiment.

[0161] Referring to FIG. 14, an OTFS signal generation device (1400) according to an embodiment of the present disclosure can be represented to be consistent with the way in which DFT-spread pilot symbols are arranged in the DFT-spread OFDM transmission method of 4G LTE and 5G NR. A signal generated by the OTFS signal generation device (1400) It can have the same form as how the reference signal is generated in the uplink of 4G LTE and 5G NR standards.

[0162] According to one embodiment, the S / P conversion unit (1410) receives a data symbol sequence x[n] as input and generates an MxN delay-logical Doppler domain symbol matrix In addition, the S / P conversion unit (1410) can multiply the left side of the MxN matrix obtained by serial-parallel conversion of x[n] by an MxM diagonal matrix in which all diagonal elements are of the same size, or multiply the MxM diagonal matrix and the right side by an NxN diagonal matrix in which all diagonal elements are of the same size, which is predetermined for the receiver, to thereby rotate each matrix element in phase. can be created.

[0163] According to one embodiment, the N-IDFT matrix multiplication unit (1420) Multiply the N-point IDFT matrix on the right side of the MxN delay-logical time-domain sample matrix can be created.

[0164] According to one embodiment, the pilot-vector insertion unit (1430) N Mx1 column vectors of MxN' delay-physical time domain sample matrix by arranging the Mx1 pilot column vectors of the dog in a predetermined order. can be generated. For example, the pilot-vector insertion unit (1430) can be set to N=12, N'=14 to be compatible with 5G NR. Place the pilot column vectors in the third and twelfth columns, and in the remaining columns The N Mx1 column vectors can be arranged sequentially or in a non-sequential order promised to the receiver.

[0165] According to one embodiment, the M-DFT matrix multiplication unit (1440) Multiply the M-point DFT matrix on the left side to obtain the MxN' physical time-frequency domain sample matrix can be created.

[0166] The subcarrier allocation unit (1450) is After attaching a (KM)xN' zero matrix to the bottom of the matrix, circular down-shift it to the desired subcarrier position. We can create a KxN' matrix with assigned elements.

[0167] According to one embodiment, the K-IDFT matrix multiplication unit (1460) can take the KxN' matrix as input, multiply the K-IDFT matrix on the left side, and generate a KxN' matrix.

[0168] The operations of the cyclic prefix insertion unit (1470), P / S conversion unit (1480), and D / A conversion unit (1490) are as described above or are widely known technologies, so a detailed description thereof is omitted in the present disclosure.

[0169] FIG. 15 is a block diagram corresponding to a method of arranging pilot column vectors using DFT-unspread pilot symbols in an OTFS signal generation device according to one embodiment.

[0170] Referring to FIG. 15, an OTFS signal generation device (1500) according to an embodiment of the present disclosure may be represented to be consistent with a method of arranging pilot column vectors using DFT-unspread pilot symbols in DFT-spread OFDM transmission methods of 4G LTE and 5G NR. A signal generated by the OTFS signal generation device (1500) It can have the same form as how the reference signal is generated in the uplink of 4G LTE and 5G NR standards.

[0171] According to one embodiment, the S / P conversion unit (1510) receives a data symbol sequence x[n] as input and generates an MxN delay-logical Doppler domain symbol matrix In addition, the S / P conversion unit (1510) can multiply the left side of the MxN matrix obtained by serial-parallel conversion of x[n] by an MxM diagonal matrix in which all diagonal elements are of the same size, or multiply the MxM diagonal matrix and the right side by an NxN diagonal matrix in which all diagonal elements are of the same size, which is predetermined for the receiver, and rotate each matrix element in phase. can be created.

[0172] According to one embodiment, the N-IDFT matrix multiplication unit (1520) Multiply the N-point IDFT matrix on the right side of the MxN delay-logical time-domain sample matrix can be created.

[0173] According to one embodiment, the M-DFT matrix multiplication unit (1530) Multiply the M-point DFT matrix on the left side to obtain an MxN logical time-frequency domain sample matrix can be created.

[0174] According to one embodiment, the pilot-vector insertion unit (1540) N Mx1 column vectors of MxN' physical time-frequency domain sample matrix by arranging the Mx1 pilot column vectors of the dog in a predetermined order. can be generated. For example, the pilot-vector insertion unit (1540) can be set to N=12, N'=14 to be compatible with 5G NR. Place the pilot column vectors in the third and twelfth columns, and in the remaining columns The N Mx1 column vectors can be arranged sequentially or in a non-sequential order promised to the receiver.

[0175] The subcarrier allocation unit (1550) is After attaching a (KM)xN' zero matrix to the bottom of the matrix, circular down-shift it to the desired subcarrier position. We can create a KxN' matrix with assigned elements.

[0176] According to one embodiment, the K-IDFT matrix multiplication unit (1560) can take the KxN' matrix as input, multiply the K-IDFT matrix on the left side, and generate a KxN' matrix.

[0177] The operations of the cyclic prefix insertion unit (1570), P / S conversion unit (1580), and D / A conversion unit (1590) are as described above or are widely known technologies, so a detailed description thereof is omitted in the present disclosure.

[0178] FIG. 16 is a flowchart of an OTFS signal generation method according to one embodiment of the present disclosure.

[0179] Referring to FIG. 16, the OTFS signal generation device (1000) can obtain a data symbol matrix by serial-parallel converting a data symbol column (S1610).

[0180] For example, the OTFS signal generation device (1000) generates an MxN delay-logical Doppler domain symbol matrix containing MN data symbols through S / P conversion. can be created.

[0181] An OTFS signal generation device (1000) according to one embodiment can generate a logical time-frequency domain symbol matrix by performing an inverse symplectic finite Fourier transform (ISFFT) or a two-dimensional reversible transform on a data symbol matrix (S1630).

[0182] An OTFS signal generation device (1000) according to one embodiment can perform a matrix multiplication operation between a logical time-frequency M-point DFT (Discrete Fourier Transform) matrix or a pre-multiplication matrix of the two-dimensional reversible transform and the data symbol matrix. Here, M may be the number of rows of a logical time-frequency domain sample matrix, and the pre-multiplication matrix may be an invertible matrix of M rows and M columns.

[0183] In addition, the OTFS signal generation device (1000) can perform a matrix multiplication operation of the data symbol matrix and the N-point IDFT (Inverse Discrete Fourier Transform) matrix or the post-multiplication matrix of the two-dimensional reversible transformation. Here, N may be the number of columns of the logical time-frequency domain sample matrix, and the post-multiplication matrix may be an invertible matrix of N rows and N columns.

[0184] For example, the OTFS signal generation device (1000) is an MxN delay-logical Doppler domain symbol matrix The inverse symplectic finite Fourier transform is performed, and the MxN logical time-frequency domain sample matrix can be generated. Here, the matrix can be calculated by the above mathematical formula 2.

[0185] An OTFS signal generation device (1000) according to one embodiment can obtain a physical time-frequency domain matrix by inserting at least one pilot column vector into a generated logical time-frequency domain sample matrix (S1650).

[0186] For example, the OTFS signal generation device (1000) The Mx1 pilot column vector of the dog By arranging the N Mx1 column vectors as column vectors, an MxN' physical time-frequency domain matrix can be created.

[0187] Here, at least one column vector may be a DFT-spread modulation symbol vector or a DFT-non-spread modulation symbol vector.

[0188] An OTFS signal generation device (1000) according to one embodiment can Heisenberg transform a physical time-frequency domain matrix (S1670).

[0189] An OTFS signal generation device (1000) according to an embodiment of the present disclosure may generate a first matrix by inserting a zero vector row at the top or bottom of a physical time-frequency domain matrix. In addition, the OTFS signal generation device (1000) according to an embodiment of the present disclosure may generate a second matrix by performing a matrix multiplication operation of a K-point IDFT matrix and the first matrix. Here, K is the number of rows of the first matrix, and may be a number greater than or equal to M, which is the number of rows of a logical time-frequency domain sample matrix.

[0190] For example, the OTFS signal generation device (1000) may transmit pulses that are predetermined or determined by transmission specifications. and the delay time of the transmission pulse Select the physical time-frequency domain matrix Heisenberg transform of the elements of a continuous-time signal can be generated. Here, the continuous-time signal can be calculated by mathematical formula 5.

[0191] According to one embodiment of the present disclosure, an OTFS signal generating device (1000) generates a continuous-time signal can be transmitted to the receiver.

[0192] FIG. 17 is a flowchart of an OTFS signal generation method according to one embodiment of the present disclosure.

[0193] Referring to Fig. 17, a flowchart is provided to align the OTFS signal generation method according to the present disclosure with the conventional DFT-spread OFDM transmission method of 4G LTE and 5G NR. The process of performing ISFFT in OTFS is an MxN delay-logical Doppler domain symbol matrix. It can be the same as the two processes of multiplying the M-point DFT matrix or the pre-product matrix of the two-dimensional reversible transformation on the left side and multiplying the N-IDFT matrix or the post-product matrix of the two-dimensional reversible transformation on the right side. Therefore, in the case of separating this process and arranging the pilot column vector using the pilot symbol that has been DFT-spread or multiplied by the pre-product matrix of the two-dimensional reversible transformation, the pilot symbol can be inserted before multiplying the M-DFT matrix or the pre-product matrix of the two-dimensional reversible transformation on the left side, and in the case of arranging the pilot column vector using the pilot symbol that has not been DFT-spread, the pilot symbol can be inserted after multiplying the M-DFT matrix or the pre-product matrix of the two-dimensional reversible transformation on the left side.

[0194] An OTFS signal generation device (1000) according to one embodiment of the present disclosure can obtain a data symbol matrix by serial-parallel converting a data symbol string (S1710).

[0195] For example, the OTFS signal generation device (1000) receives a data symbol sequence x[n] as input and generates an MxN delay-logical Doppler domain symbol matrix containing MN data symbols through S / P conversion. . The OTFS signal generation device (1000) multiplies the left side of the MxN matrix obtained by serial-parallel conversion of x[n] by an appropriate MxM diagonal matrix in which all diagonal elements promised in advance by the receiver are the same size, or multiplies the right side by an appropriate NxN diagonal matrix in which all diagonal elements promised in advance by the receiver are the same size, and then rotates each matrix element in phase. can be created.

[0196] An OTFS signal generation device (1000) according to one embodiment of the present disclosure can generate a delay-logical time domain matrix by a matrix multiplication operation of a data symbol matrix and an IDFT matrix or a post-product matrix of the two-dimensional reversible transformation (S1720).

[0197] For example, the OTFS signal generation device (1000) MxN delayed-logical time domain sample matrix by matrix multiplying the N-point IDFT matrix on the right side or the post-product matrix of the above 2D reversible transformation can be created.

[0198] An OTFS signal generation device (1000) according to one embodiment of the present disclosure can generate a logical time-frequency domain matrix by a matrix multiplication operation of an M-point DFT (Discrete Fourier Transform) matrix or a pre-product matrix of the two-dimensional reversible transform and a delay-logical time-domain matrix (S1730), and can generate a physical time-frequency domain matrix by arranging the column vector of the generated logical time-frequency domain matrix and at least one pilot column vector in a predetermined order (S1740).

[0199] An OTFS signal generation device (1000) according to one embodiment places a pilot column vector using a DFT-spread pilot symbol, N Mx1 column vectors of Arrange the Mx1 pilot column vectors in the appropriate order and create a MxN' delayed-physical time-domain sample matrix. can be generated. For example, to be compatible with 5G NR, set N = 12 and N' = 14. Place the pilot column vector in the second column of the third row and the remaining columns The N Mx1 column vectors can be arranged sequentially or in a non-sequential order promised to the receiver.

[0200] In addition, when the OTFS signal generation device (1000) according to one embodiment places a pilot column vector using a DFT-spread pilot symbol, Multiply the M-point DFT matrix on the left side by the matrix or the pre-product matrix of the above 2D reversible transform to obtain the MxN' physical time-frequency domain sample matrix can be created.

[0201] An OTFS signal generation device (1000) according to one embodiment places a pilot column vector using a DFT-unspread pilot symbol, Multiply the M-point DFT matrix on the left side or the pre-product matrix of the above 2D reversible transform to obtain an MxN logical time-frequency domain sample matrix. can be generated. In addition, the OTFS signal generation device (1000) according to one embodiment N Mx1 column vectors and MxN' physical time-frequency domain sample matrix by arranging the Mx1 pilot column vectors in the appropriate order. can be generated. For example, the OTFS signal generation device (1000) is configured to be compatible with 5G NR with N = 12 and N` = 14. Place the pilot column vectors in the second column of the third row and in the remaining columns. The N Mx1 column vectors can be arranged sequentially or in a non-sequential order promised to the receiver.

[0202] An OTFS signal generation device (1000) according to one embodiment can obtain a third matrix by inserting a zero vector row at the bottom of a physical time-frequency domain matrix and performing downward cyclic processing so that elements of the time-frequency domain matrix are placed at predetermined subcarrier positions (S1750).

[0203] For example, the OTFS signal generation device (1000) After attaching a (KM)xN' zero matrix to the bottom of the matrix, circular down-shift it by an appropriate amount to the desired subcarrier position. We can create a KxN' matrix, which is a third matrix to which the elements are assigned.

[0204] In one embodiment, another OTFS signal generation device (1000) can modulate the third matrix with CP-OFDM (Cyclic Prefix-Orthogonal Frequency Division Multiplexing) (S1760).

[0205] For example, the OTFS signal generation device (1000) can generate a continuous-time signal by performing a matrix multiplication operation on an IDFT matrix and the above-mentioned downward cyclic matrix, inserting a CP (Cyclic Prefix) into the matrix into which the matrix multiplication operation was performed, performing a parallel-to-serial conversion on the matrix into which the cyclic prefix was inserted, and performing a digital-to-analog conversion on the parallel-to-serial converted matrix.

[0206] According to one embodiment of the present disclosure, an OTFS signal generation device (1000) can transmit a generated continuous-time signal to a receiver.

[0207] Fig. 18 is a block diagram illustrating an OTFS signal generation device according to one embodiment.

[0208] Referring to FIG. 18, an OTFS signal generation device (1800) according to an embodiment of the present disclosure may include a serial to parallel (S / P) conversion unit (1810), a 2-D reversible conversion unit (1830), a pilot allocation unit (1850), and a CP-OFDM modulation unit (1870). In the present disclosure, for convenience of explanation, the functions of the modified OTFS signal generation device (1800) are described as conceptually separate blocks, but are not limited thereto. Each block of the modified OTFS signal generation device (1800) may be implemented by being combined or omitted. In addition, each block is not limited to the expressed name and may represent a block that performs the described function.

[0209] According to one embodiment, the S / P conversion unit (1810) may perform the same function as the S / P conversion unit (1010), and the 2-D reversible conversion unit (1830) may be a delay-logical Doppler domain symbol matrix. A two-dimensional reversible transformation is performed to create an MxN logical time-frequency domain (lTF domain) sample matrix. can be obtained.

[0210] For example, the 2-D reversible transform unit (1930) is a delay-logical Doppler domain symbol matrix The MxM inverible matrix P, which is the pre-product matrix of the 2-D reversible transformation, is multiplied on the left side, and the NxN inverible matrix Q, which is the post-product matrix of the 2-D reversible transformation, is multiplied on the right side to obtain an MxN sample matrix. A two-dimensional orthogonal transformation can be performed to obtain . The invertible matrices P and Q are not limited to the DFT matrix and the IDFT matrix, respectively, and the invertible matrices P and Q can include a unitary matrix and an orthogonal matrix.

[0211] The pilot batch unit (1850) is an MxN logical time-frequency domain symbol matrix As input, insert (N'-N) Mx1 pilot column vectors to create an MxN' physical time-frequency domain (pTF domain) sample matrix. In one embodiment, the pilot deployment unit (1950) may select N' as one slot length of 7 or 14, rather than N, to maintain backward compatibility with 4G LTE and 5G NR.

[0212] According to one embodiment, the CP-OFDM modulator (1870) generates a physical time-frequency domain symbol matrix In an OFDM transmitter, a mathematically equivalent process can be performed by applying a pulse-shaped orthogonal frequency-division multiplexing (OFDM) process after serial-to-parallel conversion of a symbol sequence.

[0213] The CP-OFDM modulation unit (1970) can perform the same function as the CP-OFDM modulation unit (650) of FIG. 6.

[0214] FIG. 19 is a block diagram of an OTFS signal generation device according to one embodiment of the present disclosure.

[0215] Referring to FIG. 19, an OTFS signal generation device (1900) according to one embodiment may include a transceiver (1910), a processor (1920), and a memory (1930). According to various embodiments, the configuration of the OTFS signal generation device is not limited to that illustrated in FIG. 18, and may additionally include configurations not illustrated in FIG. 19 or omit some of the configurations illustrated in FIG. 19.

[0216] Additionally, the operation of the processor (1920) may be implemented as a software module stored in the memory (1930). For example, the software module may be stored in the memory (1930) and may be operated by being executed by the processor (1920).

[0217] The transceiver (1910) can support the establishment of a wired or wireless communication channel between the OTFS signal generation device (1900) and another external electronic device and the performance of communication through the established communication channel.

[0218] According to one embodiment, the transceiver (1910) may receive a data symbol string from another electronic device or transmit a generated signal.

[0219] According to various embodiments, the transceiver (1910) may include a wireless communication module (e.g., a cellular communication module, a short-range wireless communication module, or a global navigation satellite system (GNSS) communication module) or a wired communication module (e.g., a local area network (LAN) communication module, or a power line communication module), and may communicate with an external electronic device through a short-range communication network (e.g., Bluetooth, WiFi direct, or IrDA (infrared data association)) or a long-range communication network (e.g., a cellular network, the Internet, or a computer network (e.g., a LAN or WAN)) using the corresponding communication module.

[0220] The processor (1920) is electrically connected to components included in the transmitting device and can perform calculations or data processing related to control and / or communication of the components included in the transmitting device. According to one embodiment, the processor (1920) can load and process commands or data received from at least one of the other components into the memory (1930) and store the resulting data in the memory (1930).

[0221] In addition, in FIG. 19, for the convenience of explanation, the processor (1920) is expressed as operating as a single processor (1920). However, the functions of at least some of the modules included in each section conceptually dividing the functions of the OTFS signal generation device may be implemented as multiple processors. In this case, the processor (1920) may not operate as a single processor (1920), but may be implemented as multiple processors implemented as separate hardware to perform each operation. The present invention is not limited thereto.

[0222] The memory (1930) is electrically connected to the processor (1920) and can store commands or data related to the operation of components included in the electronic device.

[0223] According to one embodiment, the memory (1930) may also store instructions for executing software modules when the functions of the OTFS signal generation device (1900) are implemented as software modules that are conceptually separated and executed by the processor (1920).

[0224] Although the above description has been made with reference to drawings and embodiments, it does not mean that the scope of protection of the present disclosure is limited by the drawings or embodiments, and it will be understood that a person skilled in the art can modify and change the present disclosure in various ways without departing from the spirit and scope of the present disclosure as set forth in the claims below.

[0225] The OTFS signal generation device and transmission method according to the embodiments of the present disclosure described above are downward compatible with the pilot symbol arrangement or reference signal generation method of the existing 4G LTE or 5G NR, and are waveforms that follow an equal gain criterion similar to the delay-logical Doppler orthogonality of OTFS.

[0226] A device-readable storage medium may be provided in the form of a non-transitory storage medium. Here, the term "non-transitory storage medium" simply means a tangible device that does not contain signals (e.g., electromagnetic waves). This term does not distinguish between cases where data is permanently stored in the storage medium and cases where data is temporarily stored. For example, a "non-transitory storage medium" may include a buffer in which data is temporarily stored.

[0227] According to one embodiment, the method according to various embodiments disclosed in the present document may be provided as included in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read-only memory (CD-ROM)), or may be distributed online (e.g., downloaded or uploaded) through an application store or directly between two user devices (e.g., smartphones). In the case of online distribution, at least a portion of the computer program product (e.g., a downloadable app) may be temporarily stored or temporarily generated in a machine-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

Claims

1. A method for generating an OTFS (Orthogonal Time-Frequency-Space) signal in a wireless communication system, A step of obtaining a data symbol matrix by serial-parallel converting a data symbol sequence; A step of generating a logical time-frequency domain sample matrix by performing an inverse symplectic finite Fourier transform (ISFFT) or a two-dimensional reversible transform on the above data symbol matrix; A step of obtaining a physical time-frequency domain matrix by inserting at least one pilot column vector into the above-generated logical time-frequency domain sample matrix; and A method for generating an OTFS signal, comprising the step of performing a Heisenberg transform on the above physical time-frequency domain matrix.

2. In paragraph 1, The step of generating the above logical time-frequency domain sample matrix is: A step of performing a matrix multiplication operation of an M-point DFT (Discrete Fourier Transform) matrix or a pre-multiplication matrix of the two-dimensional reversible transform and the data symbol matrix; and A step of performing a matrix multiplication operation of the above data symbol matrix and an N-point IDFT (Inverse Discrete Fourier Transform) matrix or a post-multiplication matrix of the above two-dimensional reversible transformation, The above pre-product matrix is ​​an M-row, M-column invertible matrix, The above post-product matrix is ​​an N-row, N-column invertible matrix, The above M is the number of rows of the logical time-frequency domain sample matrix, A method for generating an OTFS signal, wherein the above N is the number of columns of the above logical time-frequency domain sample matrix.

3. In paragraph 2, The above Heisenberg transform step is: A step of generating a first matrix by inserting a zero vector row at the top or bottom of the above physical time-frequency domain matrix; and A step of generating a second matrix by performing a matrix multiplication operation of the K-point IDFT matrix and the first matrix, The above K is the number of rows of the generated first matrix, An OTFS signal generation method, wherein the above K is a number greater than or equal to the above M.

4. In paragraph 3, The above method, A step of inserting CP (Cyclic Prefix) or ZP (Zero Prefix) into the second matrix; A step of generating a vector by parallel-serial conversion of a matrix into which the CP or the ZP is inserted; and An OTFS signal generation method further comprising a step of converting the parallel-serial converted vector into a D / A (Digital to Analog) signal.

5. In any one of paragraphs 1 to 4, At least one of the above pilot column vectors A method for generating an OTFS signal, wherein the modulation symbol vector is a DFT-spread modulation symbol vector or a modulation symbol vector multiplied by a pre-product matrix of the above two-dimensional reversible transform.

6. In any one of paragraphs 1 to 4, At least one of the above pilot column vectors A method for generating an OTFS signal, wherein the symbol vector is a DFT-unspread modulation symbol vector or a symbol vector that is not multiplied by a pre-product matrix of the above two-dimensional reversible transform.

7. In an OTFS signal generating device in a wireless communication system, The above generating device memory; and comprising at least one processor, At least one processor of the above, Convert the data symbol column into a serial-parallel format to obtain a data symbol matrix. The above data symbol matrix is ​​transformed into a logical time-frequency domain sample matrix by performing an inverse symplectic finite Fourier transform (ISFFT) or a two-dimensional reversible transform. Obtaining a physical time-frequency domain matrix by inserting at least one pilot column vector into the above-generated logical time-frequency domain sample matrix, An OTFS signal generation device that performs a Heisenberg transform on the above physical time-frequency domain matrix.

8. In paragraph 7, At least one processor of the above, Performing a matrix multiplication operation of the M-point DFT (Discrete Fourier Transform) matrix or the pre-multiplication matrix of the two-dimensional reversible transform and the data symbol matrix, Performing a matrix multiplication operation of the above data symbol matrix and the N-point IDFT (Inverse Discrete Fourier Transform) matrix or the post-multiplication matrix of the above two-dimensional reversible transformation, The above pre-product matrix is ​​an M-row, M-column invertible matrix, The above post-product matrix is ​​an N-row, N-column invertible matrix, The above M is the number of rows of the logical time-frequency domain sample matrix, An OTFS signal generation device, wherein the above N is the number of columns of the above logical time-frequency domain sample matrix.

9. In paragraph 8, At least one processor of the above, Generate a first matrix by inserting a zero vector row at the top or bottom of the above physical time-frequency domain matrix, A second matrix is ​​generated by performing a matrix multiplication operation of the K-point IDFT matrix and the first matrix, The above K is the number of rows of the generated first matrix, An OTFS signal generating device, wherein the above K is a number greater than or equal to the above M.

10. In paragraph 9, At least one processor of the above, Insert CP (Cyclic Prefix) or ZP (Zero Prefix) into the second matrix above, Generate a vector by parallel-serial conversion of the matrix into which the CP or ZP is inserted, An OTFS signal generation device that converts the above parallel-serial converted vector into D / A (Digital to Analog).

11. In any one of paragraphs 7 to 10, At least one of the above pilot column vectors, An OTFS signal generation device, wherein the modulation symbol vector is a DFT-spread modulation symbol vector or a modulation symbol vector multiplied by a pre-product matrix of the above two-dimensional reversible transform.

12. In any one of paragraphs 7 to 10, At least one of the above pilot column vectors An OTFS signal generation device, wherein the DFT-non-spread modulation symbol vector or the symbol vector is not multiplied by the pre-product matrix of the above two-dimensional reversible transform.

13. A computer-readable recording medium storing a program for performing a method of generating an OTFS (Orthogonal Time-Frequency-Space) signal in a wireless communication system, The above method, A step of obtaining a data symbol matrix by serial-parallel converting a data symbol sequence; A step of generating a logical time-frequency domain sample matrix by performing an inverse symplectic finite Fourier transform (ISFFT) or a two-dimensional reversible transform on the above data symbol matrix; A step of obtaining a physical time-frequency domain matrix by inserting at least one pilot column vector into the above-generated logical time-frequency domain sample matrix; and A recording medium comprising a step of performing a Heisenberg transform on the above physical time-frequency domain matrix.

14. In paragraph 13, The above method, A step of performing a matrix multiplication operation of an M-point DFT (Discrete Fourier Transform) matrix or a pre-multiplication matrix of the two-dimensional reversible transform and the data symbol matrix; and A step of performing a matrix multiplication operation of the above data symbol matrix and an N-point IDFT (Inverse Discrete Fourier Transform) matrix or a post-multiplication matrix of the above two-dimensional reversible transformation, The above pre-product matrix is ​​an M-row, M-column invertible matrix, The above post-product matrix is ​​an N-row, N-column invertible matrix, The above M is the number of rows of the logical time-frequency domain sample matrix, A recording medium, wherein N is the number of columns of the logical time-frequency domain sample matrix.

15. In paragraph 13, At least one of the above pilot column vectors A recording medium, which is a DFT-spread modulation symbol vector or a modulation symbol vector multiplied by a pre-product matrix of the above two-dimensional reversible transform.

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