WO2022080530A1 - Method and device for transmitting and receiving signals by using multiple antennas in wireless communication system - Google Patents

Abstract

The present disclosure is to transmit and receive signals by using multiple antennas in a wireless communication system, and an operation method of a first device in a wireless communication system may comprise the steps of: identifying whether a first technique is applied or a second technique is applied to a transmission symbol; when the first technique is applied, generating the transmission symbol by precoding modulation symbols generated on the basis of transmission bits including a first part and a second part; when the second technique is applied, generating the transmission symbol by precoding modulation symbols, which are generated on the basis of the second part, by using a precoding matrix selected on the basis of the first part; and transmitting the transmission symbol to a second device through at least one antenna.

Description

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

The following description relates to a wireless communication system, and to a method and apparatus for transmitting and receiving a signal using multiple antennas in a wireless communication system.

Wireless access systems are being widely deployed to provide various types of communication services such as voice and data. In general, a wireless access system is a multiple access system that can support communication with multiple users by sharing available system resources (bandwidth, transmission power, etc.). Examples of the multiple access system include a code division multiple access (CDMA) system, a frequency division multiple access (FDMA) system, a time division multiple access (TDMA) system, an orthogonal frequency division multiple access (OFDMA) system, and a single carrier frequency (SC-FDMA) system. division multiple access) systems.

In particular, as many communication devices require a large communication capacity, an enhanced mobile broadband (eMBB) communication technology has been proposed compared to the existing radio access technology (RAT). In addition, a communication system that considers reliability and latency sensitive services/user equipment (UE) as well as massive machine type communications (mMTC) that provides various services anytime, anywhere by connecting multiple devices and things has been proposed. . For this purpose, various technical configurations have been proposed.

The present disclosure relates to a method and apparatus for more efficiently transmitting and receiving signals using multiple antennas in a wireless communication system.

The present disclosure relates to a method and apparatus for increasing spectral efficiency by using a spatial domain in a wireless communication system.

The technical objects to be achieved in the present disclosure are not limited to the above, and other technical problems not mentioned are common knowledge in the technical field to which the technical configuration of the present disclosure is applied from the embodiments of the present disclosure to be described below. can be considered by those with

As an example of the present disclosure, a method of operating a first device in a wireless communication system includes checking whether a first technique or a second technique is applied to a transmission symbol, and when the first technique is applied, a first generating the transmission symbol by precoding modulation symbols generated based on transmission bits including a portion and a second portion; when the second technique is applied, a precoding matrix selected based on the first portion generating the transmission symbol by precoding the modulation symbols generated based on the second part using

As an example of the present disclosure, a method of operating a second device in a wireless communication system includes checking whether a first technique or a second technique is applied to a transmission symbol transmitted from the first device, the first technique being If applicable, detecting modulation symbols from a transmission symbol received from the first apparatus, and when the second technique is applied, modulation symbols from a transmission symbol received from the first apparatus and applied to the modulation symbols detecting an index of a precoding matrix, and obtaining transmission bits from at least one of the modulation symbols and the index.

As an example of the present disclosure, a first device in a wireless communication system includes a transceiver and a processor connected to the transceiver. The processor checks whether the first technique or the second technique is applied to the transmission symbol, and when the first technique is applied, generated based on the transmission bits including the first part and the second part The transmission symbol is generated by precoding the modulation symbols, and when the second technique is applied, the modulation symbols generated based on the second part are precoded using a precoding matrix selected based on the first part. By doing so, it is possible to generate the transmission symbol and transmit the transmission symbol to the second device through at least one antenna.

As an example of the present disclosure, a second device in a wireless communication system includes a transceiver and a processor connected to the transceiver. The processor checks whether a first technique or a second technique is applied to a transmission symbol transmitted from the first device, and when the first technique is applied, a modulation symbol from a transmission symbol received from the first device , and when the second technique is applied, modulation symbols and an index of a precoding matrix applied to the modulation symbols are detected from a transmission symbol received from the first apparatus, and the modulation symbols and the index Transmission bits may be obtained from at least one of

Aspects of the present disclosure described above are only some of the preferred embodiments of the present disclosure, and various embodiments in which the technical features of the present disclosure are reflected are detailed descriptions of the present disclosure that will be described below by those of ordinary skill in the art can be derived and understood based on

The following effects may be obtained by the embodiments based on the present disclosure.

According to the present disclosure, spectral efficiency and energy efficiency are increased.

Effects that can be obtained in the embodiments of the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned are the technical fields to which the technical configuration of the present disclosure is applied from the description of the embodiments of the present disclosure below. It can be clearly derived and understood by those of ordinary skill in the art. That is, unintended effects of implementing the configuration described in the present disclosure may also be derived by those of ordinary skill in the art from the embodiments of the present disclosure.

The accompanying drawings below are provided to help understanding of the present disclosure, and together with the detailed description, may provide embodiments of the present disclosure. However, the technical features of the present disclosure are not limited to specific drawings, and features disclosed in each drawing may be combined with each other to constitute a new embodiment. Reference numerals in each drawing may refer to structural elements.

1 is a diagram illustrating an example of a communication system applied to the present disclosure.

2 is a diagram illustrating an example of a wireless device applicable to the present disclosure.

3 is a diagram illustrating another example of a wireless device applied to the present disclosure.

4 is a diagram illustrating an example of a mobile device applied to the present disclosure.

5 is a diagram illustrating an example of a vehicle or autonomous driving vehicle applied to the present disclosure.

6 is a diagram illustrating an example of a movable body applied to the present disclosure.

7 is a diagram illustrating an example of an XR device applied to the present disclosure.

8 is a diagram illustrating an example of a robot applied to the present disclosure.

9 is a diagram illustrating an example of an artificial intelligence (AI) device applied to the present disclosure.

10 is a diagram illustrating physical channels applied to the present disclosure and a signal transmission method using the same.

11 is a diagram illustrating a control plane and a user plane structure of a radio interface protocol applied to the present disclosure.

12 is a diagram illustrating a method of processing a transmission signal applied to the present disclosure.

13 is a diagram illustrating a structure of a radio frame applicable to the present disclosure.

14 is a diagram illustrating a slot structure applicable to the present disclosure.

15 is a diagram illustrating an example of a communication structure that can be provided in a 6G system applicable to the present disclosure.

16 is a diagram illustrating an electromagnetic spectrum applicable to the present disclosure.

17 is a diagram illustrating a THz communication method applicable to the present disclosure.

18 is a diagram illustrating a THz wireless communication transceiver applicable to the present disclosure.

19 is a diagram illustrating a method for generating a THz signal applicable to the present disclosure.

20 is a diagram illustrating a wireless communication transceiver applicable to the present disclosure.

21 is a diagram illustrating a structure of a transmitter applicable to the present disclosure.

22 is a diagram illustrating a modulator structure applicable to the present disclosure.

23A is a diagram illustrating a structure of a transmitter using a transmission technique applicable to the present disclosure.

23B is a diagram illustrating a structure of a receiver using a transmission technique applicable to the present disclosure.

24 is a diagram illustrating an embodiment of a procedure for transmitting a signal in an apparatus applicable to the present disclosure.

25 is a diagram illustrating an embodiment of a procedure for receiving a signal in an apparatus applicable to the present disclosure.

26 is a diagram illustrating an embodiment of a procedure for downlink communication in a base station and a terminal applicable to the present disclosure.

27 is a diagram illustrating an embodiment of a procedure for uplink communication in a base station and a terminal applicable to the present disclosure.

28 is a diagram illustrating an example of a codebook applicable to the present disclosure.

29 is a diagram illustrating an embodiment of a procedure for encoding bits for determining a precoding matrix in an apparatus applicable to the present disclosure.

30 is a diagram illustrating an embodiment of a procedure for decoding bits detected from a precoding matrix in an apparatus applicable to the present disclosure.

31 is a diagram illustrating an embodiment of a procedure for using a decoding result of bits detected from a precoding matrix in an apparatus applicable to the present disclosure.

32A is a diagram illustrating another structure of a transmitter using a transmission technique applicable to the present disclosure.

32B is a diagram illustrating another structure of a receiver using a transmission technique applicable to the present disclosure.

33 is a diagram illustrating an embodiment of a procedure for determining bits for determining a precoding matrix when transmitting a plurality of bit streams in an apparatus applicable to the present disclosure.

34 is a diagram illustrating an embodiment of a procedure for processing bits detected from a precoding matrix when receiving a plurality of bit streams in an apparatus applicable to the present disclosure.

35A is a diagram illustrating another structure of a transmitter using a transmission technique applicable to the present disclosure.

35B is a diagram illustrating another structure of a receiver using a transmission technique applicable to the present disclosure.

36 is a diagram illustrating another embodiment of a procedure for determining bits for determining a precoding matrix when transmitting a plurality of bit streams in an apparatus applicable to the present disclosure.

37 is a diagram illustrating another embodiment of a procedure for processing bits detected from a precoding matrix when receiving a plurality of bit streams in an apparatus applicable to the present disclosure.

38 is a diagram illustrating an embodiment of a procedure for decoding a plurality of bit streams in an apparatus applicable to the present disclosure.

39A is a diagram illustrating another structure of a transmitter using a transmission technique applicable to the present disclosure.

39B is a diagram illustrating another structure of a receiver using a transmission technique applicable to the present disclosure.

The following embodiments combine elements and features of the present disclosure in a predetermined form. Each component or feature may be considered optional unless explicitly stated otherwise. Each component or feature may be implemented in a form that is not combined with other components or features. In addition, some components and/or features may be combined to configure an embodiment of the present disclosure. The order of operations described in embodiments of the present disclosure may be changed. Some configurations or features of one embodiment may be included in other embodiments, or may be replaced with corresponding configurations or features of other embodiments.

In the description of the drawings, procedures or steps that may obscure the gist of the present disclosure are not described, and procedures or steps that can be understood at the level of a person skilled in the art are also not described.

Throughout the specification, when a part is said to "comprising or including" a certain component, it does not exclude other components unless otherwise stated, meaning that other components may be further included. do. In addition, terms such as "...unit", "...group", and "module" described in the specification mean a unit that processes at least one function or operation, which is hardware or software or a combination of hardware and software. can be implemented as Also, "a or an", "one", "the" and like related terms are used differently herein in the context of describing the present disclosure (especially in the context of the following claims). Unless indicated or clearly contradicted by context, it may be used in a sense including both the singular and the plural.

In the present specification, embodiments of the present disclosure have been described focusing on a data transmission/reception relationship between a base station and a mobile station. Here, the base station has a meaning as a terminal node of a network that directly communicates with the mobile station. A specific operation described as being performed by the base station in this document may be performed by an upper node of the base station in some cases.

That is, various operations performed for communication with a mobile station in a network including a plurality of network nodes including the base station may be performed by the base station or other network nodes other than the base station. In this case, the 'base station' is a term such as a fixed station, a Node B, an eNB (eNode B), a gNB (gNode B), an ng-eNB, an advanced base station (ABS) or an access point (access point). can be replaced by

In addition, in embodiments of the present disclosure, a terminal includes a user equipment (UE), a mobile station (MS), a subscriber station (SS), a mobile subscriber station (MSS), It may be replaced by terms such as a mobile terminal or an advanced mobile station (AMS).

In addition, a transmitting end refers to a fixed and/or mobile node that provides a data service or a voice service, and a receiving end refers to a fixed and/or mobile node that receives a data service or a voice service. Accordingly, in the case of uplink, the mobile station may be a transmitting end, and the base station may be a receiving end. Similarly, in the case of downlink, the mobile station may be the receiving end, and the base station may be the transmitting end.

Embodiments of the present disclosure are wireless access systems IEEE 802.xx system, 3GPP (3rd Generation Partnership Project) system, 3GPP LTE (Long Term Evolution) system, 3GPP 5G ( ^5th generation) NR (New Radio) system and 3GPP2 system It may be supported by standard documents disclosed in at least one of, in particular, embodiments of the present disclosure by 3GPP TS (technical specification) 38.211, 3GPP TS 38.212, 3GPP TS 38.213, 3GPP TS 38.321 and 3GPP TS 38.331 documents. can be supported

Also, embodiments of the present disclosure may be applied to other wireless access systems, and are not limited to the above-described system. As an example, it may be applicable to a system applied after the 3GPP 5G NR system, and is not limited to a specific system.

That is, obvious steps or parts not described in the embodiments of the present disclosure may be described with reference to the above documents. In addition, all terms disclosed in this document may be described by the standard document.

Hereinafter, preferred embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. DETAILED DESCRIPTION The detailed description set forth below in conjunction with the appended drawings is intended to describe exemplary embodiments of the present disclosure, and is not intended to represent the only embodiments in which the technical constructions of the present disclosure may be practiced.

In addition, specific terms used in the embodiments of the present disclosure are provided to help the understanding of the present disclosure, and the use of these specific terms may be changed to other forms without departing from the technical spirit of the present disclosure.

The following technologies include code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), etc. It can be applied to various wireless access systems.

For clarity of the description below, although description is based on a 3GPP communication system (eg, LTE, NR, etc.), the technical spirit of the present invention is not limited thereto. LTE may mean 3GPP TS 36.xxx Release 8 or later technology. In detail, LTE technology after 3GPP TS 36.xxx Release 10 may be referred to as LTE-A, and LTE technology after 3GPP TS 36.xxx Release 13 may be referred to as LTE-A pro. 3GPP NR may refer to technology after TS 38.xxx Release 15. 3GPP 6G may refer to technology after TS Release 17 and/or Release 18. "xxx" stands for standard document detail number. LTE/NR/6G may be collectively referred to as a 3GPP system.

For backgrounds, terms, abbreviations, etc. used in the present disclosure, reference may be made to matters described in standard documents published before the present invention. As an example, reference may be made to the 36.xxx and 38.xxx standard documents.

Communication system applicable to the present disclosure

Although not limited thereto, the various descriptions, functions, procedures, suggestions, methods and/or operation flowcharts of the present disclosure disclosed in this document may be applied to various fields requiring wireless communication/connection (eg, 5G) between devices. there is.

Hereinafter, it will be exemplified in more detail with reference to the drawings. In the following drawings/descriptions, the same reference numerals may represent the same or corresponding hardware blocks, software blocks, or functional blocks, unless otherwise indicated.

1 is a diagram illustrating an example of a communication system applied to the present disclosure.

Referring to FIG. 1 , a communication system 100 applied to the present disclosure includes a wireless device, a base station, and a network. Here, the wireless device means a device that performs communication using a wireless access technology (eg, 5G NR, LTE), and may be referred to as a communication/wireless/5G device. Although not limited thereto, the wireless device may include a robot 100a, a vehicle 100b-1, 100b-2, an extended reality (XR) device 100c, a hand-held device 100d, and a home appliance. appliance) 100e, an Internet of Things (IoT) device 100f, and an artificial intelligence (AI) device/server 100g. For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous driving vehicle, a vehicle capable of performing inter-vehicle communication, and the like. Here, the vehicles 100b-1 and 100b-2 may include an unmanned aerial vehicle (UAV) (eg, a drone). The XR device 100c includes augmented reality (AR)/virtual reality (VR)/mixed reality (MR) devices, and includes a head-mounted device (HMD), a head-up display (HUD) provided in a vehicle, a television, It may be implemented in the form of a smartphone, a computer, a wearable device, a home appliance, a digital signage, a vehicle, a robot, and the like. The portable device 100d may include a smart phone, a smart pad, a wearable device (eg, smart watch, smart glasses), and a computer (eg, a laptop computer). The home appliance 100e may include a TV, a refrigerator, a washing machine, and the like. The IoT device 100f may include a sensor, a smart meter, and the like. For example, the base station 120 and the network 130 may be implemented as a wireless device, and a specific wireless device 120a may operate as a base station/network node to other wireless devices.

The wireless devices 100a to 100f may be connected to the network 130 through the base station 120 . AI technology may be applied to the wireless devices 100a to 100f , and the wireless devices 100a to 100f may be connected to the AI server 100g through the network 130 . The network 130 may be configured using a 3G network, a 4G (eg, LTE) network, or a 5G (eg, NR) network. The wireless devices 100a to 100f may communicate with each other through the base station 120/network 130, but communicate directly without going through the base station 120/network 130 (eg, sidelink communication) You may. For example, the vehicles 100b-1 and 100b-2 may perform direct communication (eg, vehicle to vehicle (V2V)/vehicle to everything (V2X) communication). Also, the IoT device 100f (eg, a sensor) may communicate directly with another IoT device (eg, a sensor) or other wireless devices 100a to 100f.

Wireless communication/ connection 150a, 150b, and 150c may be performed between the wireless devices 100a to 100f/base station 120 and the base station 120/base station 120 . Here, wireless communication/connection includes uplink/downlink communication 150a and sidelink communication 150b (or D2D communication), and communication between base stations 150c (eg, relay, integrated access backhaul (IAB)). This may be achieved through radio access technology (eg, 5G NR). Through the wireless communication/ connection 150a, 150b, and 150c, the wireless device and the base station/wireless device, and the base station and the base station may transmit/receive wireless signals to each other. For example, the wireless communication/ connection 150a , 150b , 150c may transmit/receive signals through various physical channels. To this end, based on various proposals of the present disclosure, various configuration information setting processes for transmission/reception of wireless signals, various signal processing processes (eg, channel encoding/decoding, modulation/demodulation, resource mapping/demapping, etc.) , at least a part of a resource allocation process may be performed.

Wireless devices applicable to the present disclosure

2 is a diagram illustrating an example of a wireless device applicable to the present disclosure.

Referring to FIG. 2 , a first wireless device 200a and a second wireless device 200b may transmit/receive wireless signals through various wireless access technologies (eg, LTE, NR). Here, {first wireless device 200a, second wireless device 200b} is {wireless device 100x, base station 120} of FIG. 1 and/or {wireless device 100x, wireless device 100x) } can be matched.

The first wireless device 200a includes one or more processors 202a and one or more memories 204a, and may further include one or more transceivers 206a and/or one or more antennas 208a. The processor 202a controls the memory 204a and/or the transceiver 206a and may be configured to implement the descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts disclosed herein. For example, the processor 202a may process information in the memory 204a to generate first information/signal, and then transmit a wireless signal including the first information/signal through the transceiver 206a. In addition, the processor 202a may receive the radio signal including the second information/signal through the transceiver 206a, and then store the information obtained from the signal processing of the second information/signal in the memory 204a. The memory 204a may be connected to the processor 202a and may store various information related to the operation of the processor 202a. For example, the memory 204a may provide instructions for performing some or all of the processes controlled by the processor 202a, or for performing the descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts disclosed herein. may store software code including Here, the processor 202a and the memory 204a may be part of a communication modem/circuit/chip designed to implement a wireless communication technology (eg, LTE, NR). The transceiver 206a may be coupled to the processor 202a and may transmit and/or receive wireless signals via one or more antennas 208a. The transceiver 206a may include a transmitter and/or a receiver. The transceiver 206a may be used interchangeably with a radio frequency (RF) unit. In the present disclosure, a wireless device may refer to a communication modem/circuit/chip.

The second wireless device 200b includes one or more processors 202b, one or more memories 204b, and may further include one or more transceivers 206b and/or one or more antennas 208b. The processor 202b controls the memory 204b and/or the transceiver 206b and may be configured to implement the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed herein. For example, the processor 202b may process information in the memory 204b to generate third information/signal, and then transmit a wireless signal including the third information/signal through the transceiver 206b. In addition, the processor 202b may receive the radio signal including the fourth information/signal through the transceiver 206b, and then store information obtained from signal processing of the fourth information/signal in the memory 204b. The memory 204b may be connected to the processor 202b and may store various information related to the operation of the processor 202b. For example, the memory 204b may provide instructions for performing some or all of the processes controlled by the processor 202b, or for performing the descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts disclosed herein. may store software code including Here, the processor 202b and the memory 204b may be part of a communication modem/circuit/chip designed to implement a wireless communication technology (eg, LTE, NR). The transceiver 206b may be coupled to the processor 202b and may transmit and/or receive wireless signals via one or more antennas 208b. Transceiver 206b may include a transmitter and/or receiver. Transceiver 206b may be used interchangeably with an RF unit. In the present disclosure, a wireless device may refer to a communication modem/circuit/chip.

Here, the wireless communication technology implemented in the wireless devices 200a and 200b of the present specification may include a narrowband Internet of Things (NB-IoT) for low-power communication as well as LTE, NR, and 6G. In this case, for example, the NB-IoT technology may be an example of a low power wide area network (LPWAN) technology, and may be implemented in standards such as LTE Cat NB1 and/or LTE Cat NB2, and is limited to the above-mentioned names. not. Additionally or alternatively, the wireless communication technology implemented in the wireless devices 200a and 200b of the present specification may perform communication based on the LTE-M technology. In this case, as an example, the LTE-M technology may be an example of an LPWAN technology, and may be called by various names such as enhanced machine type communication (eMTC). For example, LTE-M technology is 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and/or 7) may be implemented in at least one of various standards such as LTE M, and is not limited to the above-described name. Additionally or alternatively, the wireless communication technology implemented in the wireless devices 200a and 200b of the present specification is at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) in consideration of low power communication. It may include any one, and is not limited to the above-mentioned names. For example, the ZigBee technology can create PAN (personal area networks) related to small/low-power digital communication based on various standards such as IEEE 802.15.4, and can be called by various names.

Hereinafter, hardware elements of the wireless devices 200a and 200b will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors 202a, 202b. For example, one or more processors 202a, 202b may include one or more layers (eg, PHY (physical), MAC (media access control), RLC (radio link control), PDCP (packet data convergence protocol), RRC (radio resource) control) and a functional layer such as service data adaptation protocol (SDAP)). The one or more processors 202a, 202b may be configured to process one or more protocol data units (PDUs) and/or one or more service data units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed herein. can create The one or more processors 202a, 202b may generate messages, control information, data, or information according to the description, function, procedure, proposal, method, and/or flow charts disclosed herein. The one or more processors 202a, 202b generate a signal (eg, a baseband signal) including a PDU, SDU, message, control information, data or information according to the functions, procedures, proposals and/or methods disclosed herein. , may be provided to one or more transceivers 206a and 206b. One or more processors 202a, 202b may receive signals (eg, baseband signals) from one or more transceivers 206a, 206b, and the descriptions, functions, procedures, proposals, methods, and/or flowcharts of operation disclosed herein. PDUs, SDUs, messages, control information, data, or information may be acquired according to the fields.

One or more processors 202a, 202b may be referred to as a controller, microcontroller, microprocessor, or microcomputer. One or more processors 202a, 202b may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more application specific integrated circuits (ASICs), one or more digital signal processors (DSPs), one or more digital signal processing devices (DSPDs), one or more programmable logic devices (PLDs), or one or more field programmable gate arrays (FPGAs) may be included in one or more processors 202a, 202b. The descriptions, functions, procedures, suggestions, methods, and/or flowcharts of operations disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, and the like. The descriptions, functions, procedures, proposals, methods, and/or flow charts disclosed in this document provide that firmware or software configured to perform is included in one or more processors 202a, 202b, or stored in one or more memories 204a, 204b. It may be driven by the above processors 202a and 202b. The descriptions, functions, procedures, proposals, methods, and/or flowcharts of operations disclosed herein may be implemented using firmware or software in the form of code, instructions, and/or a set of instructions.

One or more memories 204a, 204b may be coupled to one or more processors 202a, 202b and may store various types of data, signals, messages, information, programs, codes, instructions, and/or instructions. One or more memories 204a, 204b may include read only memory (ROM), random access memory (RAM), erasable programmable read only memory (EPROM), flash memory, hard drives, registers, cache memory, computer readable storage media and/or It may be composed of a combination of these. One or more memories 204a, 204b may be located inside and/or external to one or more processors 202a, 202b. Additionally, one or more memories 204a, 204b may be coupled to one or more processors 202a, 202b through various technologies, such as wired or wireless connections.

The one or more transceivers 206a, 206b may transmit user data, control information, radio signals/channels, etc. referred to in the methods and/or operational flowcharts of this document to one or more other devices. The one or more transceivers 206a, 206b may receive user data, control information, radio signals/channels, etc. referred to in the descriptions, functions, procedures, suggestions, methods and/or flow charts, etc. disclosed herein, from one or more other devices. there is. For example, one or more transceivers 206a , 206b may be coupled to one or more processors 202a , 202b and may transmit and receive wireless signals. For example, one or more processors 202a, 202b may control one or more transceivers 206a, 206b to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors 202a, 202b may control one or more transceivers 206a, 206b to receive user data, control information, or wireless signals from one or more other devices. Further, one or more transceivers 206a, 206b may be coupled with one or more antennas 208a, 208b, and the one or more transceivers 206a, 206b may be connected via one or more antennas 208a, 208b. , may be set to transmit and receive user data, control information, radio signals/channels, etc. mentioned in procedures, proposals, methods and/or operation flowcharts. In this document, one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (eg, antenna ports). The one or more transceivers 206a, 206b converts the received radio signal/channel, etc. from the RF band signal to process the received user data, control information, radio signal/channel, etc. using the one or more processors 202a, 202b. It can be converted into a baseband signal. One or more transceivers 206a, 206b may convert user data, control information, radio signals/channels, etc. processed using one or more processors 202a, 202b from baseband signals to RF band signals. To this end, one or more transceivers 206a, 206b may include (analog) oscillators and/or filters.

Wireless device structure applicable to the present disclosure

3 is a diagram illustrating another example of a wireless device applied to the present disclosure.

Referring to FIG. 3 , a wireless device 300 corresponds to the wireless devices 200a and 200b of FIG. 2 , and includes various elements, components, units/units, and/or modules. ) can be composed of For example, the wireless device 300 may include a communication unit 310 , a control unit 320 , a memory unit 330 , and an additional element 340 . The communication unit may include communication circuitry 312 and transceiver(s) 314 . For example, communication circuitry 312 may include one or more processors 202a, 202b and/or one or more memories 204a, 204b of FIG. 2 . For example, the transceiver(s) 314 may include one or more transceivers 206a , 206b and/or one or more antennas 208a , 208b of FIG. 2 . The control unit 320 is electrically connected to the communication unit 310 , the memory unit 330 , and the additional element 340 and controls general operations of the wireless device. For example, the controller 320 may control the electrical/mechanical operation of the wireless device based on the program/code/command/information stored in the memory unit 330 . In addition, the control unit 320 transmits the information stored in the memory unit 330 to the outside (eg, another communication device) through the communication unit 310 through a wireless/wired interface, or externally (eg, through the communication unit 310) Information received through a wireless/wired interface from another communication device) may be stored in the memory unit 330 .

The additional element 340 may be configured in various ways according to the type of the wireless device. For example, the additional element 340 may include at least one of a power unit/battery, an input/output unit, a driving unit, and a computing unit. Although not limited thereto, the wireless device 300 may include a robot ( FIGS. 1 and 100a ), a vehicle ( FIGS. 1 , 100b-1 , 100b-2 ), an XR device ( FIGS. 1 and 100c ), and a mobile device ( FIGS. 1 and 100d ). ), home appliances (FIG. 1, 100e), IoT device (FIG. 1, 100f), digital broadcasting terminal, hologram device, public safety device, MTC device, medical device, fintech device (or financial device), security device, climate/ It may be implemented in the form of an environmental device, an AI server/device ( FIGS. 1 and 140 ), a base station ( FIGS. 1 and 120 ), and a network node. The wireless device may be mobile or used in a fixed location depending on the use-example/service.

In FIG. 3 , various elements, components, units/units, and/or modules in the wireless device 300 may be all interconnected through a wired interface, or at least some may be wirelessly connected through the communication unit 310 . For example, in the wireless device 300 , the control unit 320 and the communication unit 310 are connected by wire, and the control unit 320 and the first unit (eg, 130 , 140 ) are connected wirelessly through the communication unit 310 . can be connected In addition, each element, component, unit/unit, and/or module within the wireless device 300 may further include one or more elements. For example, the controller 320 may include one or more processor sets. For example, the control unit 320 may be configured as a set of a communication control processor, an application processor, an electronic control unit (ECU), a graphic processing processor, a memory control processor, and the like. As another example, the memory unit 330 may include RAM, dynamic RAM (DRAM), ROM, flash memory, volatile memory, non-volatile memory, and/or a combination thereof. can be configured.

Mobile device to which the present disclosure is applicable

4 is a diagram illustrating an example of a mobile device applied to the present disclosure.

4 illustrates a portable device applied to the present disclosure. The portable device may include a smart phone, a smart pad, a wearable device (eg, a smart watch, smart glasses), and a portable computer (eg, a laptop computer). The mobile device may be referred to as a mobile station (MS), a user terminal (UT), a mobile subscriber station (MSS), a subscriber station (SS), an advanced mobile station (AMS), or a wireless terminal (WT).

Referring to FIG. 4 , the mobile device 400 includes an antenna unit 408 , a communication unit 410 , a control unit 420 , a memory unit 430 , a power supply unit 440a , an interface unit 440b , and an input/output unit 440c . ) may be included. The antenna unit 408 may be configured as a part of the communication unit 410 . Blocks 410 to 430/440a to 440c respectively correspond to blocks 310 to 330/340 of FIG. 3 .

The communication unit 410 may transmit and receive signals (eg, data, control signals, etc.) with other wireless devices and base stations. The controller 420 may control components of the portable device 400 to perform various operations. The controller 420 may include an application processor (AP). The memory unit 430 may store data/parameters/programs/codes/commands necessary for driving the portable device 400 . Also, the memory unit 430 may store input/output data/information. The power supply unit 440a supplies power to the portable device 400 and may include a wired/wireless charging circuit, a battery, and the like. The interface unit 440b may support a connection between the portable device 400 and other external devices. The interface unit 440b may include various ports (eg, an audio input/output port and a video input/output port) for connection with an external device. The input/output unit 440c may receive or output image information/signal, audio information/signal, data, and/or information input from a user. The input/output unit 440c may include a camera, a microphone, a user input unit, a display unit 440d, a speaker, and/or a haptic module.

For example, in the case of data communication, the input/output unit 440c obtains information/signals (eg, touch, text, voice, image, video) input from the user, and the obtained information/signals are stored in the memory unit 430 . can be saved. The communication unit 410 may convert the information/signal stored in the memory into a wireless signal, and transmit the converted wireless signal directly to another wireless device or to a base station. Also, after receiving a radio signal from another radio device or base station, the communication unit 410 may restore the received radio signal to original information/signal. The restored information/signal may be stored in the memory unit 430 and output in various forms (eg, text, voice, image, video, haptic) through the input/output unit 440c.

Types of wireless devices to which the present disclosure is applicable

5 is a diagram illustrating an example of a vehicle or autonomous driving vehicle applied to the present disclosure.

5 illustrates a vehicle or an autonomous driving vehicle applied to the present disclosure. The vehicle or autonomous driving vehicle may be implemented as a mobile robot, a vehicle, a train, an aerial vehicle (AV), a ship, and the like, but is not limited to the shape of the vehicle.

Referring to FIG. 5 , the vehicle or autonomous driving vehicle 500 includes an antenna unit 508 , a communication unit 510 , a control unit 520 , a driving unit 540a , a power supply unit 540b , a sensor unit 540c and autonomous driving. A unit 540d may be included. The antenna unit 550 may be configured as a part of the communication unit 510 . Blocks 510/530/540a to 540d respectively correspond to blocks 410/430/440 of FIG. 4 .

The communication unit 510 may transmit/receive signals (eg, data, control signals, etc.) to and from external devices such as other vehicles, base stations (eg, base stations, roadside units, etc.), and servers. The controller 520 may control elements of the vehicle or the autonomous driving vehicle 500 to perform various operations. The controller 520 may include an electronic control unit (ECU). The driving unit 540a may cause the vehicle or the autonomous driving vehicle 500 to run on the ground. The driving unit 540a may include an engine, a motor, a power train, a wheel, a brake, a steering device, and the like. The power supply unit 540b supplies power to the vehicle or the autonomous driving vehicle 500 , and may include a wired/wireless charging circuit, a battery, and the like. The sensor unit 540c may obtain vehicle state, surrounding environment information, user information, and the like. The sensor unit 540c includes an inertial measurement unit (IMU) sensor, a collision sensor, a wheel sensor, a speed sensor, an inclination sensor, a weight sensor, a heading sensor, a position module, and a vehicle forward movement. / may include a reverse sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illuminance sensor, a pedal position sensor, and the like. The autonomous driving unit 540d includes a technology for maintaining a driving lane, a technology for automatically adjusting speed such as adaptive cruise control, a technology for automatically driving along a predetermined route, and a technology for automatically setting a route when a destination is set. technology can be implemented.

For example, the communication unit 510 may receive map data, traffic information data, and the like from an external server. The autonomous driving unit 540d may generate an autonomous driving route and a driving plan based on the acquired data. The controller 520 may control the driving unit 540a to move the vehicle or the autonomous driving vehicle 500 along the autonomous driving path (eg, speed/direction adjustment) according to the driving plan. During autonomous driving, the communication unit 510 may obtain the latest traffic information data from an external server non/periodically, and may acquire surrounding traffic information data from surrounding vehicles. Also, during autonomous driving, the sensor unit 540c may acquire vehicle state and surrounding environment information. The autonomous driving unit 540d may update the autonomous driving route and driving plan based on the newly acquired data/information. The communication unit 510 may transmit information about a vehicle location, an autonomous driving route, a driving plan, and the like to an external server. The external server may predict traffic information data in advance using AI technology or the like based on information collected from the vehicle or autonomous driving vehicles, and may provide the predicted traffic information data to the vehicle or autonomous driving vehicles.

6 is a diagram illustrating an example of a movable body applied to the present disclosure.

Referring to FIG. 6 , the moving object applied to the present disclosure may be implemented as at least any one of means of transport, train, aircraft, and ship. In addition, the movable body applied to the present disclosure may be implemented in other forms, and is not limited to the above-described embodiment.

At this time, referring to FIG. 6 , the mobile unit 600 may include a communication unit 610 , a control unit 620 , a memory unit 630 , an input/output unit 640a , and a position measurement unit 640b . Here, blocks 610 to 630/640a to 640b correspond to blocks 310 to 330/340 of FIG. 3 , respectively.

The communication unit 610 may transmit/receive signals (eg, data, control signals, etc.) with other mobile devices or external devices such as a base station. The controller 620 may perform various operations by controlling the components of the movable body 600 . The memory unit 630 may store data/parameters/programs/codes/commands supporting various functions of the mobile unit 600 . The input/output unit 640a may output an AR/VR object based on information in the memory unit 630 . The input/output unit 640a may include a HUD. The position measuring unit 640b may acquire position information of the moving object 600 . The location information may include absolute location information of the moving object 600 , location information within a driving line, acceleration information, and location information with a surrounding vehicle. The position measuring unit 640b may include a GPS and various sensors.

For example, the communication unit 610 of the mobile unit 600 may receive map information, traffic information, and the like from an external server and store it in the memory unit 630 . The position measurement unit 640b may obtain information about the location of the moving object through GPS and various sensors and store it in the memory unit 630 . The controller 620 may generate a virtual object based on map information, traffic information, and location information of a moving object, and the input/output unit 640a may display the generated virtual object on a window inside the moving object (651, 652). Also, the control unit 620 may determine whether the moving object 600 is normally operating within the driving line based on the moving object location information. When the moving object 600 abnormally deviates from the travel line, the control unit 620 may display a warning on the glass window of the moving object through the input/output unit 640a. Also, the control unit 620 may broadcast a warning message regarding the driving abnormality to surrounding moving objects through the communication unit 610 . Depending on the situation, the control unit 620 may transmit the location information of the moving object and information on the driving/moving object abnormality to the related organization through the communication unit 610 .

7 is a diagram illustrating an example of an XR device applied to the present disclosure. The XR device may be implemented as an HMD, a head-up display (HUD) provided in a vehicle, a television, a smart phone, a computer, a wearable device, a home appliance, a digital signage, a vehicle, a robot, and the like.

Referring to FIG. 7 , the XR device 700a may include a communication unit 710 , a control unit 720 , a memory unit 730 , an input/output unit 740a , a sensor unit 740b , and a power supply unit 740c . . Here, blocks 710 to 730/740a to 740c may correspond to blocks 310 to 330/340 of FIG. 3 , respectively.

The communication unit 710 may transmit/receive signals (eg, media data, control signals, etc.) to/from external devices such as other wireless devices, portable devices, or media servers. Media data may include images, images, and sounds. The controller 720 may perform various operations by controlling the components of the XR device 700a. For example, the controller 720 may be configured to control and/or perform procedures such as video/image acquisition, (video/image) encoding, and metadata generation and processing. The memory unit 730 may store data/parameters/programs/codes/commands necessary for driving the XR device 700a/creating an XR object.

The input/output unit 740a may obtain control information, data, etc. from the outside, and may output the generated XR object. The input/output unit 740a may include a camera, a microphone, a user input unit, a display unit, a speaker, and/or a haptic module. The sensor unit 740b may obtain an XR device state, surrounding environment information, user information, and the like. The sensor unit 740b includes a proximity sensor, an illuminance sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertial sensor, a red green blue (RGB) sensor, an infrared (IR) sensor, a fingerprint recognition sensor, an ultrasonic sensor, an optical sensor, a microphone and / or radar or the like. The power supply unit 740c supplies power to the XR device 700a, and may include a wired/wireless charging circuit, a battery, and the like.

For example, the memory unit 730 of the XR device 700a may include information (eg, data, etc.) necessary for generating an XR object (eg, AR/VR/MR object). The input/output unit 740a may obtain a command to operate the XR device 700a from the user, and the controller 720 may drive the XR device 700a according to the user's driving command. For example, when the user intends to watch a movie or news through the XR device 700a, the controller 720 transmits the content request information through the communication unit 730 to another device (eg, the mobile device 700b) or can be sent to the media server. The communication unit 730 may download/stream contents such as movies and news from another device (eg, the portable device 700b) or a media server to the memory unit 730 . The controller 720 controls and/or performs procedures such as video/image acquisition, (video/image) encoding, and metadata generation/processing for the content, and is acquired through the input/output unit 740a/sensor unit 740b It is possible to generate/output an XR object based on information about one surrounding space or a real object.

Also, the XR device 700a is wirelessly connected to the portable device 700b through the communication unit 710 , and the operation of the XR device 700a may be controlled by the portable device 700b. For example, the portable device 700b may operate as a controller for the XR device 700a. To this end, the XR device 700a may obtain 3D location information of the portable device 700b, and then generate and output an XR object corresponding to the portable device 700b.

8 is a diagram illustrating an example of a robot applied to the present disclosure. For example, the robot may be classified into industrial, medical, home, military, etc. according to the purpose or field of use. In this case, referring to FIG. 8 , the robot 800 may include a communication unit 810 , a control unit 820 , a memory unit 830 , an input/output unit 840a , a sensor unit 840b , and a driving unit 840c . . Here, blocks 810 to 830/840a to 840c may correspond to blocks 310 to 330/340 of FIG. 3 , respectively.

The communication unit 810 may transmit and receive signals (eg, driving information, control signals, etc.) with external devices such as other wireless devices, other robots, or control servers. The controller 820 may control components of the robot 800 to perform various operations. The memory unit 830 may store data/parameters/programs/codes/commands supporting various functions of the robot 800 . The input/output unit 840a may obtain information from the outside of the robot 800 and may output information to the outside of the robot 800 . The input/output unit 840a may include a camera, a microphone, a user input unit, a display unit, a speaker, and/or a haptic module.

The sensor unit 840b may obtain internal information, surrounding environment information, user information, and the like of the robot 800 . The sensor unit 840b may include a proximity sensor, an illumination sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertial sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, an optical sensor, a microphone, a radar, and the like.

The driving unit 840c may perform various physical operations, such as moving a robot joint. Also, the driving unit 840c may cause the robot 800 to travel on the ground or to fly in the air. The driving unit 840c may include an actuator, a motor, a wheel, a brake, a propeller, and the like.

9 is a diagram illustrating an example of an AI device applied to the present disclosure. For example, AI devices include TVs, projectors, smartphones, PCs, laptops, digital broadcasting terminals, tablet PCs, wearable devices, set-top boxes (STBs), radios, washing machines, refrigerators, digital signage, robots, vehicles, etc. It may be implemented as a device or a mobile device.

Referring to FIG. 9 , the AI device 900 includes a communication unit 910 , a control unit 920 , a memory unit 930 , input/output units 940a/940b , a learning processor unit 940c and a sensor unit 940d. may include Blocks 910 to 930/940a to 940d may correspond to blocks 310 to 330/340 of FIG. 3 , respectively.

The communication unit 910 uses wired/wireless communication technology to communicate with external devices such as other AI devices (eg, FIGS. 1, 100x, 120, 140) or an AI server ( FIGS. 1 and 140 ) and wired/wireless signals (eg, sensor information, user input, learning model, control signal, etc.). To this end, the communication unit 910 may transmit information in the memory unit 930 to an external device or transmit a signal received from the external device to the memory unit 930 .

The controller 920 may determine at least one executable operation of the AI device 900 based on information determined or generated using a data analysis algorithm or a machine learning algorithm. In addition, the controller 920 may control the components of the AI device 900 to perform the determined operation. For example, the control unit 920 may request, search, receive, or utilize the data of the learning processor unit 940c or the memory unit 930, and may be a predicted operation among at least one executable operation or determined to be preferable. Components of the AI device 900 may be controlled to execute the operation. In addition, the control unit 920 collects history information including user feedback on the operation contents or operation of the AI device 900 and stores it in the memory unit 930 or the learning processor unit 940c, or the AI server ( 1 and 140), and the like may be transmitted to an external device. The collected historical information may be used to update the learning model.

The memory unit 930 may store data supporting various functions of the AI device 900 . For example, the memory unit 930 may store data obtained from the input unit 940a , data obtained from the communication unit 910 , output data of the learning processor unit 940c , and data obtained from the sensing unit 940 . Also, the memory unit 930 may store control information and/or software codes necessary for the operation/execution of the control unit 920 .

The input unit 940a may acquire various types of data from the outside of the AI device 900 . For example, the input unit 920 may obtain training data for model learning, input data to which the learning model is applied, and the like. The input unit 940a may include a camera, a microphone, and/or a user input unit. The output unit 940b may generate an output related to sight, hearing, or touch. The output unit 940b may include a display unit, a speaker, and/or a haptic module. The sensing unit 940 may obtain at least one of internal information of the AI device 900 , surrounding environment information of the AI device 900 , and user information by using various sensors. The sensing unit 940 may include a proximity sensor, an illuminance sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, an optical sensor, a microphone, and/or a radar. there is.

The learning processor unit 940c may train a model composed of an artificial neural network by using the training data. The learning processor unit 940c may perform AI processing together with the learning processor unit of the AI server ( FIGS. 1 and 140 ). The learning processor unit 940c may process information received from an external device through the communication unit 910 and/or information stored in the memory unit 930 . Also, the output value of the learning processor unit 940c may be transmitted to an external device through the communication unit 910 and/or stored in the memory unit 930 .

Physical channels and general signal transmission

In a radio access system, a terminal may receive information from a base station through downlink (DL) and transmit information to a base station through uplink (UL). Information transmitted and received between the base station and the terminal includes general data information and various control information, and various physical channels exist according to the type/use of the information they transmit and receive.

10 is a diagram illustrating physical channels applied to the present disclosure and a signal transmission method using the same.

In a state in which the power is turned off, the power is turned on again, or a terminal newly entering a cell performs an initial cell search operation such as synchronizing with the base station in step S1011. To this end, the terminal receives a primary synchronization channel (P-SCH) and a secondary synchronization channel (S-SCH) from the base station, synchronizes with the base station, and obtains information such as cell ID. .

Thereafter, the terminal may receive a physical broadcast channel (PBCH) signal from the base station to obtain intra-cell broadcast information. Meanwhile, the UE may receive a downlink reference signal (DL RS) in the initial cell search step to check the downlink channel state. After completing the initial cell search, the UE receives a physical downlink control channel (PDCCH) and a physical downlink control channel (PDSCH) according to physical downlink control channel information in step S1012 and receives a little more Specific system information can be obtained.

Thereafter, the terminal may perform a random access procedure, such as steps S1013 to S1016, to complete access to the base station. To this end, the UE transmits a preamble through a physical random access channel (PRACH) (S1013), and RAR for the preamble through a physical downlink control channel and a corresponding physical downlink shared channel (S1013). random access response) may be received (S1014). The UE transmits a physical uplink shared channel (PUSCH) using scheduling information in the RAR (S1015), and a contention resolution procedure such as reception of a physical downlink control channel signal and a corresponding physical downlink shared channel signal. ) can be performed (S1016).

After performing the procedure as described above, the terminal receives a physical downlink control channel signal and/or a physical downlink shared channel signal (S1017) and a physical uplink shared channel as a general uplink/downlink signal transmission procedure thereafter. channel, PUSCH) signal and/or a physical uplink control channel (PUCCH) signal may be transmitted ( S1018 ).

Control information transmitted by the terminal to the base station is collectively referred to as uplink control information (UCI). UCI is HARQ-ACK / NACK (hybrid automatic repeat and request acknowledgment / negative-ACK), SR (scheduling request), CQI (channel quality indication), PMI (precoding matrix indication), RI (rank indication), BI (beam indication) ) information, etc. In this case, the UCI is generally transmitted periodically through the PUCCH, but may be transmitted through the PUSCH according to an embodiment (eg, when control information and traffic data are to be transmitted at the same time). In addition, according to a request/instruction of the network, the UE may aperiodically transmit the UCI through the PUSCH.

11 is a diagram illustrating a control plane and a user plane structure of a radio interface protocol applied to the present disclosure.

Referring to FIG. 11 , entity 1 may be a user equipment (UE). In this case, the term "terminal" may be at least one of a wireless device, a portable device, a vehicle, a mobile body, an XR device, a robot, and an AI to which the present disclosure is applied in FIGS. 1 to 9 described above. In addition, the terminal refers to a device to which the present disclosure can be applied and may not be limited to a specific device or device.

Entity 2 may be a base station. In this case, the base station may be at least one of an eNB, a gNB, and an ng-eNB. In addition, the base station may refer to an apparatus for transmitting a downlink signal to the terminal, and may not be limited to a specific type or apparatus. That is, the base station may be implemented in various forms or types, and may not be limited to a specific form.

Entity 3 may be a network device or a device performing a network function. In this case, the network device may be a core network node (eg, a mobility management entity (MME), an access and mobility management function (AMF), etc.) that manages mobility. In addition, the network function may mean a function implemented to perform a network function, and entity 3 may be a device to which the function is applied. That is, the entity 3 may refer to a function or device that performs a network function, and is not limited to a specific type of device.

The control plane may refer to a path through which control messages used by a user equipment (UE) and a network to manage a call are transmitted. In addition, the user plane may mean a path through which data generated in the application layer, for example, voice data or Internet packet data, is transmitted. In this case, the physical layer, which is the first layer, may provide an information transfer service to a higher layer by using a physical channel. The physical layer is connected to the upper medium access control layer through a transport channel. In this case, data may be moved between the medium access control layer and the physical layer through the transport channel. Data can be moved between the physical layers of the transmitting side and the receiving side through a physical channel. In this case, the physical channel uses time and frequency as radio resources.

A medium access control (MAC) layer of the second layer provides a service to a radio link control (RLC) layer, which is an upper layer, through a logical channel. The RLC layer of the second layer may support reliable data transmission. The function of the RLC layer may be implemented as a function block inside the MAC. The packet data convergence protocol (PDCP) layer of the second layer may perform a header compression function that reduces unnecessary control information in order to efficiently transmit IP packets such as IPv4 or IPv6 in a narrow-bandwidth air interface. . A radio resource control (RRC) layer located at the bottom of the third layer is defined only in the control plane. The RRC layer may be in charge of controlling logical channels, transport channels and physical channels in relation to configuration, re-configuration, and release of radio bearers (RBs). RB may mean a service provided by the second layer for data transfer between the terminal and the network. To this end, the UE and the RRC layer of the network may exchange RRC messages with each other. A non-access stratum (NAS) layer above the RRC layer may perform functions such as session management and mobility management. One cell constituting the base station may be set to one of various bandwidths to provide downlink or uplink transmission services to multiple terminals. Different cells may be configured to provide different bandwidths. The downlink transmission channel for transmitting data from the network to the terminal includes a broadcast channel (BCH) for transmitting system information, a paging channel (PCH) for transmitting a paging message, and a downlink shared channel (SCH) for transmitting user traffic or control messages. there is. In the case of a downlink multicast or broadcast service traffic or control message, it may be transmitted through a downlink SCH or may be transmitted through a separate downlink multicast channel (MCH). Meanwhile, as an uplink transmission channel for transmitting data from the terminal to the network, there are a random access channel (RACH) for transmitting an initial control message and an uplink shared channel (SCH) for transmitting user traffic or a control message. A logical channel that is located above the transport channel and is mapped to the transport channel includes a broadcast control channel (BCCH), a paging control channel (PCCH), a common control channel (CCCH), a multicast control channel (MCCH), and a multicast (MTCH) channel. traffic channels), etc.

12 is a diagram illustrating a method of processing a transmission signal applied to the present disclosure. As an example, the transmission signal may be processed by a signal processing circuit. In this case, the signal processing circuit 1200 may include a scrambler 1210 , a modulator 1220 , a layer mapper 1230 , a precoder 1240 , a resource mapper 1250 , and a signal generator 1260 . In this case, as an example, the operation/function of FIG. 12 may be performed by the processors 202a and 202b and/or the transceivers 206a and 206b of FIG. 2 . Also, as an example, the hardware elements of FIG. 12 may be implemented in the processors 202a and 202b and/or the transceivers 206a and 206b of FIG. 2 . As an example, blocks 1010 to 1060 may be implemented in the processors 202a and 202b of FIG. 2 . In addition, blocks 1210 to 1250 may be implemented in the processors 202a and 202b of FIG. 2 , and block 1260 may be implemented in the transceivers 206a and 206b of FIG. 2 , and the embodiment is not limited thereto.

The codeword may be converted into a wireless signal through the signal processing circuit 1200 of FIG. 12 . Here, the codeword is a coded bit sequence of an information block. The information block may include a transport block (eg, a UL-SCH transport block, a DL-SCH transport block). The radio signal may be transmitted through various physical channels (eg, PUSCH, PDSCH) of FIG. 10 . Specifically, the codeword may be converted into a scrambled bit sequence by the scrambler 1210 . A scramble sequence used for scrambling is generated based on an initialization value, and the initialization value may include ID information of a wireless device, and the like. The scrambled bit sequence may be modulated by a modulator 1220 into a modulation symbol sequence. The modulation method may include pi/2-binary phase shift keying (pi/2-BPSK), m-phase shift keying (m-PSK), m-quadrature amplitude modulation (m-QAM), and the like.

The complex modulation symbol sequence may be mapped to one or more transport layers by a layer mapper 1230 . Modulation symbols of each transport layer may be mapped to corresponding antenna port(s) by the precoder 1240 (precoding). The output z of the precoder 1240 may be obtained by multiplying the output y of the layer mapper 1230 by the precoding matrix W of N*M. Here, N is the number of antenna ports, and M is the number of transport layers. Here, the precoder 1240 may perform precoding after performing transform precoding (eg, discrete fourier transform (DFT) transform) on the complex modulation symbols. Also, the precoder 1240 may perform precoding without performing transform precoding.

The resource mapper 1250 may map modulation symbols of each antenna port to a time-frequency resource. The time-frequency resource may include a plurality of symbols (eg, a CP-OFDMA symbol, a DFT-s-OFDMA symbol) in the time domain and a plurality of subcarriers in the frequency domain. The signal generator 1260 generates a radio signal from the mapped modulation symbols, and the generated radio signal may be transmitted to another device through each antenna. To this end, the signal generator 1260 may include an inverse fast fourier transform (IFFT) module and a cyclic prefix (CP) inserter, a digital-to-analog converter (DAC), a frequency uplink converter, and the like. .

The signal processing process for the received signal in the wireless device may be configured in reverse of the signal processing process 1210 to 1260 of FIG. 12 . For example, the wireless device (eg, 200a or 200b of FIG. 2 ) may receive a wireless signal from the outside through an antenna port/transceiver. The received radio signal may be converted into a baseband signal through a signal restorer. To this end, the signal restorer may include a frequency downlink converter, an analog-to-digital converter (ADC), a CP remover, and a fast fourier transform (FFT) module. Thereafter, the baseband signal may be restored to a codeword through a resource de-mapper process, a postcoding process, a demodulation process, and a descrambling process. The codeword may be restored to the original information block through decoding. Accordingly, the signal processing circuit (not shown) for the received signal may include a signal restorer, a resource de-mapper, a post coder, a demodulator, a descrambler, and a decoder.

13 is a diagram illustrating a structure of a radio frame applicable to the present disclosure.

Uplink and downlink transmission based on the NR system may be based on a frame as shown in FIG. 13 . In this case, one radio frame has a length of 10 ms and may be defined as two 5 ms half-frames (HF). One half-frame may be defined as 5 1ms subframes (subframe, SF). One subframe is divided into one or more slots, and the number of slots in a subframe may depend on subcarrier spacing (SCS). In this case, each slot may include 12 or 14 OFDM(A) symbols according to a cyclic prefix (CP). When a normal CP (normal CP) is used, each slot may include 14 symbols. When an extended CP (CP) is used, each slot may include 12 symbols. Here, the symbol may include an OFDM symbol (or a CP-OFDM symbol) and an SC-FDMA symbol (or a DFT-s-OFDM symbol).

Table 1 shows the number of symbols per slot, the number of slots per frame, and the number of slots per subframe according to the SCS when the normal CP is used, and Table 2 shows the number of slots per slot according to the SCS when the extended CSP is used. Indicates the number of symbols, the number of slots per frame, and the number of slots per subframe.

0	14	10	One
One	14	20	2
2	14	40	4
3	14	80	8
4	14	160	16
5	14	320	32

2	12	40	4

In Tables 1 and 2, N ^slot _symb may indicate the number of symbols in a slot, N ^{frame, μ} _slot may indicate the number of slots in a frame, and N ^{subframe, μ} _slot may indicate the number of slots in a subframe. .

In addition, in a system to which the present disclosure is applicable, OFDM(A) numerology (eg, SCS, CP length, etc.) may be set differently between a plurality of cells merged into one UE. Accordingly, an (absolute time) interval of a time resource (eg, SF, slot, or TTI) (commonly referred to as a TU (time unit) for convenience) composed of the same number of symbols may be set differently between the merged cells.

NR may support multiple numerology (or subcarrier spacing (SCS)) to support various 5G services. For example, when SCS is 15kHz, it supports a wide area in traditional cellular bands, and when SCS is 30kHz/60kHz, dense-urban, lower latency and a wider carrier bandwidth, and when the SCS is 60 kHz or higher, it can support a bandwidth greater than 24.25 GHz to overcome phase noise.

The NR frequency band is defined as a frequency range of two types (FR1, FR2). FR1 and FR2 may be configured as shown in the table below. In addition, FR2 may mean a millimeter wave (mmW).

Frequency Range designation	Corresponding frequency range	Subcarrier Spacing
FR1	410MHz - 7125MHz	15, 30, 60 kHz
FR2	24250MHz - 52600MHz	60, 120, 240 kHz

Also, as an example, in a communication system to which the present disclosure is applicable, the above-described pneumatic numerology may be set differently. For example, a terahertz wave (THz) band may be used as a higher frequency band than the above-described FR2. In the THz band, the SCS may be set to be larger than that of the NR system, and the number of slots may be set differently, and it is not limited to the above-described embodiment. The THz band will be described later.

14 is a diagram illustrating a slot structure applicable to the present disclosure.

One slot includes a plurality of symbols in the time domain. For example, in the case of a normal CP, one slot may include 7 symbols, but in the case of an extended CP, one slot may include 6 symbols. A carrier (carrier) includes a plurality of subcarriers (subcarrier) in the frequency domain. A resource block (RB) may be defined as a plurality of (eg, 12) consecutive subcarriers in the frequency domain.

In addition, a bandwidth part (BWP) is defined as a plurality of consecutive (P)RBs in the frequency domain, and may correspond to one numerology (eg, SCS, CP length, etc.).

A carrier may include a maximum of N (eg, 5) BWPs. Data communication is performed through the activated BWP, and only one BWP can be activated for one terminal. Each element in the resource grid is referred to as a resource element (RE), and one complex symbol may be mapped.

6G communication system

6G (wireless) systems have (i) very high data rates per device, (ii) very large number of connected devices, (iii) global connectivity, (iv) very low latency, (v) battery- It aims to reduce energy consumption of battery-free IoT devices, (vi) ultra-reliable connections, and (vii) connected intelligence with machine learning capabilities. The vision of the 6G system may have four aspects such as "intelligent connectivity", "deep connectivity", "holographic connectivity", and "ubiquitous connectivity", and the 6G system may satisfy the requirements shown in Table 4 below. That is, Table 4 is a table showing the requirements of the 6G system.

Per device peak data rate	1 Tbps
E2E latency	1 ms
Maximum spectral efficiency	100 bps/Hz
Mobility support	up to 1000 km/hr
Satellite integration	Fully
AI	Fully
autonomous vehicle	Fully
XR	Fully
Haptic Communication	Fully

At this time, the 6G system includes enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLLC), massive machine type communications (mmTC), AI integrated communication, and tactile Internet (tactile internet), high throughput (high throughput), high network capacity (high network capacity), high energy efficiency (high energy efficiency), low backhaul and access network congestion (low backhaul and access network congestion) and improved data security ( It may have key factors such as enhanced data security.

15 is a diagram illustrating an example of a communication structure that can be provided in a 6G system applicable to the present disclosure.

Referring to FIG. 15 , the 6G system is expected to have 50 times higher simultaneous wireless communication connectivity than the 5G wireless communication system. URLLC, a key feature of 5G, is expected to become an even more important technology by providing an end-to-end delay of less than 1 ms in 6G communication. At this time, the 6G system will have much better volumetric spectral efficiency, unlike the frequently used area spectral efficiency. 6G systems can provide very long battery life and advanced battery technology for energy harvesting, so mobile devices in 6G systems may not need to be charged separately. In addition, new network characteristics in 6G may be as follows.

- Satellites integrated network: 6G is expected to be integrated with satellites to provide a global mobile population. The integration of terrestrial, satellite and public networks into one wireless communication system could be very important for 6G.

- Connected intelligence: Unlike previous generations of wireless communication systems, 6G is revolutionary and will update the evolution of wireless from “connected things” to “connected intelligence”. AI may be applied in each step of a communication procedure (or each procedure of signal processing to be described later).

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

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

In the above new network characteristics of 6G, some general requirements may be as follows.

- Small cell networks: The idea of small cell networks was introduced to improve the received signal quality as a result of improved throughput, energy efficiency and spectral efficiency in cellular systems. As a result, small cell networks are essential characteristics for communication systems beyond 5G and Beyond 5G (5GB). Accordingly, the 6G communication system also adopts the characteristics of the small cell network.

- Ultra-dense heterogeneous network: Ultra-dense heterogeneous networks will be another important characteristic of 6G communication system. A multi-tier network composed of heterogeneous networks improves overall QoS and reduces costs.

- high-capacity backhaul: The backhaul connection is characterized as a high-capacity backhaul network to support high-capacity traffic. High-speed fiber optics and free-space optics (FSO) systems may be possible solutions to this problem.

- Radar technology integrated with mobile technology: High-precision localization (or location-based service) through communication is one of the functions of the 6G wireless communication system. Therefore, the radar system will be integrated with the 6G network.

- Softwarization and virtualization: Softening and virtualization are two important functions that underlie the design process in 5GB networks to ensure flexibility, reconfigurability and programmability. In addition, billions of devices can be shared in a shared physical infrastructure.

Core implementation technology of 6G system

- Artificial Intelligence (AI)

The most important and newly introduced technology for 6G systems is AI. AI was not involved in the 4G system. 5G systems will support partial or very limited AI. However, the 6G system will be AI-enabled for full automation. Advances in machine learning will create more intelligent networks for real-time communication in 6G. Incorporating AI into communications can simplify and enhance real-time data transmission. AI can use numerous analytics to determine how complex target tasks are performed. In other words, AI can increase efficiency and reduce processing delays.

Time-consuming tasks such as handovers, network selection, and resource scheduling can be performed instantly by using AI. AI can also play an important role in M2M, machine-to-human and human-to-machine communication. In addition, AI can be a rapid communication in the BCI (brain computer interface). AI-based communication systems can be supported by metamaterials, intelligent structures, intelligent networks, intelligent devices, intelligent cognitive radios, self-sustaining wireless networks, and machine learning.

Recently, attempts have been made to integrate AI with wireless communication systems, but these are the application layer, network layer, and especially deep learning focused on wireless resource management and allocation. come. However, these studies are gradually developing into the MAC layer and the physical layer, and in particular, attempts to combine deep learning with wireless transmission in the physical layer are appearing. AI-based physical layer transmission means applying a signal processing and communication mechanism based on an AI driver rather than a traditional communication framework in a fundamental signal processing and communication mechanism. For example, deep learning-based channel coding and decoding, deep learning-based signal estimation and detection, deep learning-based multiple input multiple output (MIMO) mechanism, It may include AI-based resource scheduling and allocation.

Machine learning may be used for channel estimation and channel tracking, and may be used for power allocation, interference cancellation, etc. in a physical layer of a downlink (DL). In addition, machine learning may be used for antenna selection, power control, symbol detection, and the like in a MIMO system.

However, the application of DNN for transmission in the physical layer may have the following problems.

Deep learning-based AI algorithms require large amounts of training data to optimize training parameters. However, due to a limitation in acquiring data in a specific channel environment as training data, a lot of training data is used offline. This is because static training on training data in a specific channel environment may cause a contradiction between dynamic characteristics and diversity of a wireless channel.

In addition, current deep learning mainly targets real signals. However, signals of the physical layer of wireless communication are complex signals. In order to match the characteristics of a wireless communication signal, further research on a neural network for detecting a complex domain signal is needed.

Hereinafter, machine learning will be described in more detail.

Machine learning refers to a set of operations that trains a machine to create a machine that can perform tasks that humans can or cannot do. Machine learning requires data and a learning model. In machine learning, data learning methods can be roughly divided into three types: supervised learning, unsupervised learning, and reinforcement learning.

Neural network learning is to minimize output errors. Neural network learning repeatedly inputs training data into the neural network, calculates the output and target errors of the neural network for the training data, and backpropagates the neural network error from the output layer of the neural network to the input layer in the direction to reduce the error. ) to update the weight of each node in the neural network.

Supervised learning uses training data in which the correct answer is labeled in the training data, and in unsupervised learning, the correct answer may not be labeled in the training data. That is, for example, learning data in the case of supervised learning related to data classification may be data in which categories are labeled for each of the training data. The labeled training data is input to the neural network, and an error can be calculated by comparing the output (category) of the neural network with the label of the training data. The calculated error is back propagated in the reverse direction (ie, from the output layer to the input layer) in the neural network, and the connection weight of each node of each layer of the neural network may be updated according to the back propagation. The change amount of the connection weight of each node to be updated may be determined according to a learning rate. The computation of the neural network on the input data and the backpropagation of errors can constitute a learning cycle (epoch). The learning rate may be applied differently depending on the number of repetitions of the learning cycle of the neural network. For example, in the early stage of learning a neural network, a high learning rate can be used to increase the efficiency by allowing the neural network to quickly obtain a certain level of performance, and in the late learning period, a low learning rate can be used to increase the accuracy.

The learning method may vary depending on the characteristics of the data. For example, when the purpose of accurately predicting data transmitted from a transmitter in a communication system is at a receiver, it is preferable to perform learning using supervised learning rather than unsupervised learning or reinforcement learning.

The learning model corresponds to the human brain, and the most basic linear model can be considered. ) is called

The neural network cord used as a learning method is largely divided into deep neural networks (DNN), convolutional deep neural networks (CNN), and recurrent boltzmann machine (RNN) methods. and such a learning model can be applied.

THz (Terahertz) communication

THz communication may be applied in the 6G system. For example, the data rate may be increased by increasing the bandwidth. This can be accomplished by using sub-THz communication with a wide bandwidth and applying advanced large-scale MIMO technology.

16 is a diagram illustrating an electromagnetic spectrum applicable to the present disclosure. As an example, referring to FIG. 16 , a THz wave, also known as sub-millimeter radiation, generally represents a frequency band between 0.1 THz and 10 THz with a corresponding wavelength in the range of 0.03 mm-3 mm. The 100GHz-300GHz band range (Sub THz band) is considered a major part of the THz band for cellular communication. When added to the sub-THz band mmWave band, the 6G cellular communication capacity is increased. Among the defined THz bands, 300GHz-3THz is in the far-infrared (IR) frequency band. The 300 GHz-3 THz band is part of the broad band, but at the edge of the broad band, just behind the RF band. Therefore, this 300 GHz-3 THz band shows similarities to RF.

The main characteristics of THz communication include (i) widely available bandwidth to support very high data rates, and (ii) high path loss occurring at high frequencies (high directional antennas are indispensable). The narrow beamwidth produced by the highly directional antenna reduces interference. The small wavelength of the THz signal allows a much larger number of antenna elements to be integrated into devices and BSs operating in this band. This allows the use of advanced adaptive nesting techniques that can overcome range limitations.

optical wireless technology

Optical wireless communication (OWC) technology is envisaged for 6G communication in addition to RF-based communication for all possible device-to-access networks. These networks connect to network-to-backhaul/fronthaul network connections. OWC technology has already been used since the 4G communication system, but will be used more widely to meet the needs of the 6G communication system. OWC technologies such as light fidelity, visible light communication, optical camera communication, and free space optical (FSO) communication based on a light band are well known technologies. Communication based on optical radio technology can provide very high data rates, low latency and secure communication. Light detection and ranging (LiDAR) can also be used for ultra-high-resolution 3D mapping in 6G communication based on a wide band.

FSO backhaul network

The transmitter and receiver characteristics of an FSO system are similar to those of a fiber optic network. Thus, data transmission in an FSO system is similar to that of a fiber optic system. Therefore, FSO can be a good technology to provide backhaul connectivity in 6G systems along with fiber optic networks. Using FSO, very long-distance communication is possible even at distances of 10,000 km or more. FSO supports high-capacity backhaul connections for remote and non-remote areas such as sea, space, underwater, and isolated islands. FSO also supports cellular base station connectivity.

Massive MIMO technology

One of the key technologies to improve spectral efficiency is to apply MIMO technology. As MIMO technology improves, so does the spectral efficiency. Therefore, large-scale MIMO technology will be important in 6G systems. Since the MIMO technology uses multiple paths, a multiplexing technique and a beam generation and operation technique suitable for the THz band should also be considered important so that a data signal can be transmitted through one or more paths.

blockchain

Blockchain will become an important technology for managing large amounts of data in future communication systems. Blockchain is a form of distributed ledger technology, which is a database distributed across numerous nodes or computing devices. Each node replicates and stores an identical copy of the ledger. The blockchain is managed as a peer-to-peer (P2P) network. It can exist without being managed by a centralized authority or server. Data on the blockchain is collected together and organized into blocks. Blocks are linked together and protected using encryption. Blockchain in nature perfectly complements IoT at scale with improved interoperability, security, privacy, reliability and scalability. Therefore, blockchain technology provides several features such as interoperability between devices, traceability of large amounts of data, autonomous interaction of different IoT systems, and large-scale connection stability of 6G communication systems.

3D Networking

The 6G system integrates terrestrial and public networks to support vertical expansion of user communications. 3D BS will be provided via low orbit satellites and UAVs. Adding a new dimension in terms of elevation and associated degrees of freedom makes 3D connections significantly different from traditional 2D networks.

quantum communication

In the context of 6G networks, unsupervised reinforcement learning of networks is promising. Supervised learning methods cannot label the massive amounts of data generated by 6G. Unsupervised learning does not require labeling. Thus, this technique can be used to autonomously build representations of complex networks. Combining reinforcement learning and unsupervised learning allows networks to operate in a truly autonomous way.

drone

Unmanned aerial vehicles (UAVs) or drones will become an important element in 6G wireless communications. In most cases, high-speed data wireless connections are provided using UAV technology. A base station entity is installed in the UAV to provide cellular connectivity. UAVs have certain features not found in fixed base station infrastructure, such as easy deployment, strong line-of-sight links, and degrees of freedom with controlled mobility. During emergencies such as natural disasters, the deployment of terrestrial communications infrastructure is not economically feasible and sometimes cannot provide services in volatile environments. A UAV can easily handle this situation. UAV will become a new paradigm in the field of wireless communication. This technology facilitates the three basic requirements of wireless networks: eMBB, URLLC and mMTC. UAVs can also serve several purposes, such as improving network connectivity, fire detection, disaster emergency services, security and surveillance, pollution monitoring, parking monitoring, incident monitoring, and more. Therefore, UAV technology is recognized as one of the most important technologies for 6G communication.

Cell-free Communication

Tight integration of multiple frequencies and heterogeneous communication technologies is very important in 6G systems. As a result, users can seamlessly move from one network to another without having to make any manual configuration on the device. The best network is automatically selected from the available communication technologies. This will break the limitations of the cell concept in wireless communication. Currently, user movement from one cell to another causes too many handovers in high-density networks, causing handover failures, handover delays, data loss and ping-pong effects. 6G cell-free communication will overcome all of this and provide better QoS. Cell-free communication will be achieved through multi-connectivity and multi-tier hybrid technologies and different heterogeneous radios of devices.

Wireless information and energy transfer (WIET)

WIET uses the same fields and waves as wireless communication systems. In particular, the sensor and smartphone will be charged using wireless power transfer during communication. WIET is a promising technology for extending the life of battery-charging wireless systems. Therefore, devices without batteries will be supported in 6G communication.

Integration of sensing and communication

An autonomous wireless network is a function that can continuously detect dynamically changing environmental conditions and exchange information between different nodes. In 6G, sensing will be tightly integrated with communications to support autonomous systems.

Consolidation of access backhaul networks

The density of access networks in 6G will be enormous. Each access network is connected by backhaul connections such as fiber optic and FSO networks. To cope with a very large number of access networks, there will be tight integration between the access and backhaul networks.

holographic beamforming

Beamforming is a signal processing procedure that adjusts an antenna array to transmit a radio signal in a specific direction. A smart antenna or a subset of an advanced antenna system. Beamforming technology has several advantages, such as high signal-to-noise ratio, interference prevention and rejection, and high network efficiency. Hologram beamforming (HBF) is a new beamforming method that is significantly different from MIMO systems because it uses a software-defined antenna. HBF will be a very effective approach for efficient and flexible transmission and reception of signals in multi-antenna communication devices in 6G.

Big Data Analytics

Big data analytics is a complex process for analyzing various large data sets or big data. This process ensures complete data management by finding information such as hidden data, unknown correlations and customer propensity. Big data is gathered from a variety of sources such as videos, social networks, images and sensors. This technology is widely used to process massive amounts of data in 6G systems.

LIS (large intelligent surface)

In the case of the THz band signal, the linearity is strong, so there may be many shaded areas due to obstructions. By installing the LIS near these shaded areas, the LIS technology that expands the communication area, strengthens communication stability and enables additional additional services becomes important. The LIS is an artificial surface made of electromagnetic materials, and can change the propagation of incoming and outgoing radio waves. LIS can be viewed as an extension of massive MIMO, but has a different array structure and operation mechanism from that of massive MIMO. In addition, LIS is low in that it operates as a reconfigurable reflector with passive elements, that is, only passively reflects the signal without using an active RF chain. It has the advantage of having power consumption. Also, since each of the passive reflectors of the LIS must independently adjust the phase shift of the incoming signal, it can be advantageous for a wireless communication channel. By properly adjusting the phase shift via the LIS controller, the reflected signal can be gathered at the target receiver to boost the received signal power.

terahertz (THz) wireless communication

17 is a diagram illustrating a THz communication method applicable to the present disclosure.

Referring to FIG. 17, THz wireless communication uses a THz wave having a frequency of approximately 0.1 to 10 THz (1 THz = 1012 Hz), and uses a very high carrier frequency of 100 GHz or more. It can mean communication. THz wave is located between RF (Radio Frequency)/millimeter (mm) and infrared band, (i) It transmits non-metal/non-polar material better than visible light/infrared light, and has a shorter wavelength than RF/millimeter wave, so it has high straightness. Beam focusing may be possible.

In addition, since the photon energy of the THz wave is only a few meV, it is harmless to the human body. The frequency band expected to be used for THz wireless communication may be a D-band (110 GHz to 170 GHz) or H-band (220 GHz to 325 GHz) band with low propagation loss due to absorption of molecules in the air. Standardization discussion on THz wireless communication is being discussed centered on IEEE 802.15 THz working group (WG) in addition to 3GPP, and standard documents issued by TG (task group) (eg, TG3d, TG3e) of IEEE 802.15 are described in this specification. It can be specified or supplemented. THz wireless communication may be applied to wireless recognition, sensing, imaging, wireless communication, THz navigation, and the like.

Specifically, referring to FIG. 17 , a THz wireless communication scenario may be classified into a macro network, a micro network, and a nanoscale network. In a macro network, THz wireless communication can be applied to a vehicle-to-vehicle (V2V) connection and a backhaul/fronthaul connection. THz wireless communication in micro networks is applied to indoor small cells, fixed point-to-point or multi-point connections such as wireless connections in data centers, and near-field communication such as kiosk downloading. can be Table 5 below is a table showing an example of a technique that can be used in the THz wave.

Transceivers Device	Available immature: UTC-PD, RTD and SBD
Modulation and coding	Low order modulation techniques (OOK, QPSK), LDPC, Reed Soloman, Hamming, Polar, Turbo
Antenna	Omni and Directional, phased array with low number of antenna elements
Bandwidth	69 GHz (or 23 GHz) at 300 GHz
Channel models	Partially
data rate	100 Gbps
outdoor deployment	No
Fee space loss	High
Coverage	Low
Radio Measurements	300 GHz inddor
Device size	Few micrometers

18 is a diagram illustrating a THz wireless communication transceiver applicable to the present disclosure.

Referring to FIG. 18 , THz wireless communication may be classified based on a method for generating and receiving THz. The THz generation method can be classified into an optical device or an electronic device-based technology.

In this case, the method of generating THz using an electronic device is a method using a semiconductor device such as a resonant tunneling diode (RTD), a method using a local oscillator and a multiplier, a compound semiconductor HEMT (high electron mobility transistor) based There are a monolithic microwave integrated circuit (MMIC) method using an integrated circuit, a method using a Si-CMOS-based integrated circuit, and the like. In the case of FIG. 18 , a doubler, tripler, or multiplier is applied to increase the frequency, and it is radiated by the antenna through the sub-harmonic mixer. Since the THz band forms a high frequency, a multiplier is essential. Here, the multiplier is a circuit that has an output frequency that is N times that of the input, matches the desired harmonic frequency, and filters out all other frequencies. Also, an array antenna or the like may be applied to the antenna of FIG. 18 to implement beamforming. In FIG. 18 , IF denotes an intermediate frequency, tripler, and multiplier denote a multiplier, PA denotes a power amplifier, and LNA denotes a low noise amplifier. ), PLL represents a phase-locked loop.

19 is a diagram illustrating a method for generating a THz signal applicable to the present disclosure. In addition, FIG. 20 is a diagram illustrating a wireless communication transceiver applicable to the present disclosure.

19 and 20 , the optical device-based THz wireless communication technology refers to a method of generating and modulating a THz signal using an optical device. The optical element-based THz signal generation technology is a technology that generates a high-speed optical signal using a laser and an optical modulator, and converts it into a THz signal using an ultra-high-speed photodetector. In this technology, it is easier to increase the frequency compared to the technology using only electronic devices, it is possible to generate a high-power signal, and it is possible to obtain a flat response characteristic in a wide frequency band. As shown in FIG. 19 , a laser diode, a broadband optical modulator, and a high-speed photodetector are required to generate an optical device-based THz signal. In the case of FIG. 19 , light signals of two lasers having different wavelengths are multiplexed to generate a THz signal corresponding to a difference in wavelength between the lasers. In FIG. 19 , an optical coupler refers to a semiconductor device that transmits electrical signals using light waves to provide coupling with electrical insulation between circuits or systems, and UTC-PD (uni-travelling carrier photo- The detector) is one of the photodetectors, which uses electrons as active carriers and reduces the movement time of electrons by bandgap grading. UTC-PD is capable of photodetection above 150GHz. In FIG. 20 , an erbium-doped fiber amplifier (EDFA) indicates an erbium-doped optical fiber amplifier, a photo detector (PD) indicates a semiconductor device capable of converting an optical signal into an electrical signal, and the OSA indicates various optical communication functions (eg, .

21 is a diagram illustrating a structure of a transmitter applicable to the present disclosure. Also, FIG. 22 is a diagram illustrating a modulator structure applicable to the present disclosure.

Referring to FIGS. 21 and 22 , in general, a phase of a signal may be changed by passing an optical source of a laser through an optical wave guide. At this time, data is loaded by changing electrical characteristics through microwave contact or the like. Accordingly, an optical modulator output is formed as a modulated waveform. The photoelectric modulator (O/E converter) is an optical rectification operation by a nonlinear crystal (nonlinear crystal), photoelectric conversion (O / E conversion) by a photoconductive antenna (photoconductive antenna), a bunch of electrons in the light beam (bunch of) THz pulses can be generated by, for example, emission from relativistic electrons. A terahertz pulse (THz pulse) generated in the above manner may have a length in units of femtoseconds to picoseconds. An O/E converter performs down conversion by using non-linearity of a device.

Considering the THz spectrum usage, a number of contiguous GHz bands for fixed or mobile service use for the terahertz system are used. likely to use According to the outdoor scenario standard, available bandwidth may be classified based on oxygen attenuation of 10^2 dB/km in a spectrum up to 1 THz. Accordingly, a framework in which the available bandwidth is composed of several band chunks may be considered. As an example of the framework, if the length of a terahertz pulse (THz pulse) for one carrier is set to 50 ps, the bandwidth (BW) becomes about 20 GHz.

Effective down conversion from the infrared band to the THz band depends on how the nonlinearity of the O/E converter is exploited. That is, in order to down-convert to a desired terahertz band (THz band), the O/E converter having the most ideal non-linearity for transfer to the terahertz band (THz band) is design is required. If an O/E converter that does not fit the target frequency band is used, there is a high possibility that an error may occur with respect to the amplitude and phase of the corresponding pulse.

A terahertz transmission/reception system may be implemented using one photoelectric converter in a single carrier system. Although it depends on the channel environment, as many photoelectric converters as the number of carriers may be required in a far-carrier system. In particular, in the case of a multi-carrier system using several broadbands according to the above-described spectrum usage-related scheme, the phenomenon will become conspicuous. In this regard, a frame structure for the multi-carrier system may be considered. The down-frequency-converted signal based on the photoelectric converter may be transmitted in a specific resource region (eg, a specific frame). The frequency domain of the specific resource region may include a plurality of chunks. Each chunk may be composed of at least one component carrier (CC).

Specific embodiments of the present disclosure

The present disclosure is for transmitting and receiving a signal using multiple antennas in a wireless communication system, and relates to a technology capable of increasing spectral efficiency without increasing a multi-input multi-output (MIMO) order. . Specifically, the present disclosure describes embodiments for increasing spectral efficiency without increasing a modulation order or a MIMO order by combining a spatial modulation technique with a spatial multiplexing technique.

In order to support the rapidly increasing amount of data transmission, higher spectral efficiency and energy efficiency are required in a 6G wireless communication system. SM (spatial multiplexing) MIMO technology is in the spotlight as an important technology that enables high spectral efficiency in combination with high-dimensional modulation technology. In order to satisfy the requirements of 6G, it is expected that the MIMO order should be increased by using a higher-dimensional modulation technique or by increasing the number of antennas. However, the high-dimensional modulation scheme has disadvantages in that it is difficult to use in a low SNR region and increases reception complexity. The method of increasing the MIMO order requires an increase in the number of RF chains and antennas, and accordingly increases hardware complexity and reception complexity. In the case of a channel in which spatial diversity is not secured, this only increases interference between antennas, and performance improvement is difficult to expect. In addition, increasing complexity is a factor that reduces energy efficiency. Therefore, many difficulties are expected in satisfying the requirements of 6G only with the existing SM MIMO technology.

Communication nodes using the SM MIMO technique using precoding modulate data, layer-map the modulated data, and perform precoding to transmit the modulated data to another communication node through a plurality of antennas. In general, the receiver provides preferred precoding matrix (PM) information, and the transmitter applies the precoding matrix obtained from the receiver. If two different precoding matrices provide similar performance indicators (eg, transmission capacity, energy efficiency, etc.) and data to be transmitted is arbitrary data, index modulation may be used. Index modulation has been proposed as a communication technology capable of achieving high spectral efficiency and energy efficiency with low system complexity. Spatial modulation is a technique for transmitting data not only in a signal domain but also in a spatial domain by applying index modulation to a MIMO system, and can increase spectral efficiency.

The present disclosure provides spectral efficiency and energy efficiency without significantly increasing complexity while maintaining backward compatibility with the existing spatial multiplexing MIMO system as well as the existing spatial modulation technology by combining spatial multiplexing and spatial modulation. We propose a MIMO transmission/reception technology that can increase Specifically, according to embodiments proposed below, the transmitter may select one precoding matrix from among two or more precoding matrices based on data of one bit or more per MIMO symbol. Accordingly, the receiver may additionally acquire data of one bit or more corresponding to the precoding matrix by detecting the precoding matrix.

According to the embodiments proposed below, the transmitter uses a part of an input bit stream for the purpose of selecting a precoding matrix, and uses the remaining part of the input bit stream for modulation and layer mapping, and then selects the pre-selected precoding matrix. Precoding may be performed using a coding matrix, and the precoded signal may be transmitted through a transmit antenna. The receiver receiving the precoded signal performs precoding matrix detection, layer demapping, and demodulation after estimating the channel of the transmission signal. The receiver recovers the data transferred by the index of the selection result of the detected precoding matrix, and restores the remaining data by a demodulation operation. Hereinafter, in the present disclosure, a transmission technique in which a portion of data is transmitted through selection of the aforementioned precoding matrix and the remainder of data through a modulation symbol is referred to as 'generalized spatial modulation and multiplexing (GSMM)'. The structures of a transmitter and a receiver supporting the GSMM technique may be as follows.

23A is a diagram illustrating a structure of a transmitter using a transmission technique applicable to the present disclosure.

Referring to FIG. 23A , the transmitter includes a spatial/signal bit splitter 2312 , a channel coder 2316 , a PMI mapper 2318 , and a modulation mapper 2320 . , including a layer mapper 2322 and a precoder 2324 .

The space/signal bit separation unit 2312 separates the input transmission bits into bits of the first portion and bits of the second portion. The space/signal bit separation unit 2312 transfers the separated bits of the first part to the PMI mapper 2318 , and transfers the separated bits of the second part to the modulation mapper 2320 . The space/signal bit separation unit 2312 may selectively transmit the separated bits of the first portion to the channel coder 2316 .

The channel coder 2316 encodes the bits of the first portion provided from the spatial/signal bit separation unit 2312 . In addition, the channel coder 2316 may transmit the channel-coded bits to the PMI mapper 2318 . However, according to another embodiment, the channel coder 2316 may be omitted. The PMI mapper 2318 determines a precoding matrix for precoding modulation symbols according to the value of the bits of the first part or the encoding result of the bits of the first part, and determines the precoding matrix or index of the precoding matrix may be transmitted to the precoder 2324 . That is, the PMI mapper 2318 may convert the values of the bits of the first part or the encoding result of the bits of the first part into an index of the precoding matrix.

The modulation mapper 2320 generates modulation symbols from bits of the second portion according to a constellation. The layer mapper 2322 maps the modulation symbols obtained from the modulation mapper 2320 to a plurality of layers. The precoder 2324 precodes modulation symbols mapped to a plurality of layers by using the precoding matrix obtained from the PMI mapper 2318 . That is, the precoder 2324 may multiply the symbol vector including the modulation symbols with the precoding matrix. Thereafter, the precoded modulation symbols are subjected to analog conversion, RF conversion, amplification, etc., and then transmitted through N _t transmit antennas and delivered to a receiver through a MIMO channel.

23B is a diagram illustrating a structure of a receiver using a transmission technique applicable to the present disclosure.

Referring to FIG. 23B , the receiver includes a channel estimator 2362 , a symbol detector 2364 , a PMI demapper 2366 , a channel decoder 2368 , and a layer demapper. a demapper 2372 , a modulation demapper 2374 , and a spatial/signal bit merger 2376 .

The channel estimator 2362 estimates the MIMO channel. Specifically, the channel estimator 2362 may estimate the MIMO channel based on signals (eg, pilot signals and reference signals) received through the N _r reception antennas. The symbol detector 2364 may detect a precoding matrix based on the estimated MIMO channel. In addition, the symbol detector 2364 may detect modulation symbols transmitted from the transmitter based on the MIMO channel. According to an embodiment, the symbol detector 2364 may detect the precoding matrix and the modulation symbols by one detection technique (eg, a maximum likelihood (ML) technique). Alternatively, the symbol detector 2364 may sequentially detect the TPMI and modulation symbols. Also, in detecting the modulation symbols, the symbol detector 2364 may detect the modulation symbols based on the detected precoding matrix. In other words, the device may perform postcoding or de-precoding based on the precoding matrix.

The PMI demapper 2366 outputs bits corresponding to the index of the precoding matrix detected by the symbol detector 2364 . The channel decoder 2368 may decode the bits provided from the PMI demapper 2366 and output the bits of the first part. According to another embodiment, the channel decoder 2368 may be omitted.

The layer demapper 2372 demaps the modulation symbols mapped to the layers. The layer demapper 2372 may demap the modulation symbols mapped to the layers according to a rule corresponding to the layer mapper 2322 of the transmitter 3210 . The modulation demapper 2374 determines the bits of the second portion from the modulation symbols according to the constellation. The spatial/signal bit merging unit 2376 merges the bits of the first part and the bits of the second part, and outputs transmission bits including the bits of the first part and the bits of the second part.

The transmitter and receiver illustrated in FIGS. 23A and 23B may be understood as any one of 'terminal and base station', 'base station and terminal', 'base station and base station', and 'terminal and terminal'. For example, in the case of downlink communication, the transmitter is included in the base station, and the receiver is included in the terminal. As another example, in the case of uplink communication, the transmitter is included in the terminal, and the receiver is included in the base station. As another example, in the case of communication between terminals, the transmitter is included in the first terminal and the receiver is included in the second terminal. As another example, in the case of wireless backhaul communication, the transmitter is included in the first base station, and the receiver is included in the second base station. That is, the transmitter illustrated in FIG. 23A and the receiver illustrated in FIG. 23B or the transmitter and receiver described below may be included in various devices.

24 is a diagram illustrating an embodiment of a procedure for transmitting a signal in an apparatus applicable to the present disclosure. 24 illustrates a method of operating a device including a transmitter (eg, the transmitter of FIG. 23A ). In the following description, the operating subject of FIG. 24 is referred to as a 'device', but may be referred to as a transmitting end, a transmitting device, a transmitter, or other terms having an equivalent technical meaning.

Referring to FIG. 24 , in step S2401, the device may determine a precoding matrix based on the bits of the first part of the transmission bit. The apparatus may divide the transmitted bit into bits of the first part and bits of the second part, and select a precoding matrix corresponding to the value of the bits of the first part. In this case, a rule for separating or extracting the bits of the first part from the transmission bits may be defined in various ways. For example, consecutive bits of any part of the transmission bits may be extracted as the first portion, or bits having a constant interval may be extracted as the first portion.

In step S2403, the apparatus precodes the modulation symbols generated based on the bits of the second part of the transmission bit by using the precoding matrix. The apparatus may generate modulation symbols by modulating bits of the second portion of the transmit bit, and precode the modulation symbols.

In step S2405, the device transmits precoded modulation symbols. The precoded modulation symbols are transmitted through a plurality of antennas. In this case, the set of precoded modulation symbols transmitted during one transmission opportunity may be referred to as a 'transmission symbol', a 'MIMO symbol', a 'GSMM symbol' or other terms having an equivalent technical meaning.

25 is a diagram illustrating an embodiment of a procedure for receiving a signal in an apparatus applicable to the present disclosure. 25 illustrates a method of operating a device including a receiver (eg, the receiver of FIG. 23B ). In the following description, the operating subject of FIG. 25 is referred to as a 'device', but may be referred to as a receiving end, a receiving device, a receiver, or other terms having an equivalent technical meaning.

25 , in step S2501, the device receives a signal. The device receives the signal via at least one antenna. The received signal may include transmit symbols consisting of precoded modulation symbols.

In step S2503, the apparatus detects an index of a precoding matrix of modulation symbols. For example, the device may detect the index of the precoding matrix according to a maximum likelihood (ML) technique. Specifically, the apparatus may identify one combination having a high weighted similarity with a received transmission symbol among candidates of possible precoding matrixes and candidates of possible modulation symbols, and identify a precoding matrix belonging to the confirmed combination.

In step S2505, the apparatus obtains transmission bits from the precoding matrix and the modulation symbols. Specifically, the apparatus determines the bits of the first part from the index of the precoding matrix, and estimates the bits of the second part by performing demodulation and decoding on modulation symbols. Then, the apparatus may obtain the transmission bits by merging the bits of the first part and the bits of the second part.

As described above, according to the GSMM technique, a portion of transmitted data may be transmitted through selection of a precoding matrix, and the remainder of data may be transmitted through modulation symbols. Transmission of data via selection of a precoding matrix is preferably used when selectable candidate precoding matrices can provide similar performance (eg, similar transmission capacity and/or energy efficiency, etc.). Accordingly, according to another embodiment, a device (eg, a base station) including a scheduler uses the above-described GSMM technique according to whether candidate precoding matrices having similar performance, that is, a plurality of mutually substitutable precoding matrices exist. can be adaptively judged whether to use

When it is adaptively determined whether to use the above-described GSMM technique, an operation for determining the transmission technique is performed. Here, the transmission scheme may be determined as one of a GSMM scheme and a non-GSMM scheme. The non-GSMM technique refers to a transmission technique that does not include information transfer through selection of a precoding matrix. For example, a non-GSMM technique may include a spatial multiplexing technique in which all data is transmitted via modulation symbols. The GSMM technique may be further subdivided according to the relationship of a plurality of replaceable precoding matrices. Specifically, in the GSMM technique, a first scheme using precoding matrices in which the used transmit antennas are the same but coefficients of a precoding matrix are different, and a second scheme in which used transmit antennas, ie, active antenna combinations, use different precoding matrices. can be divided into Here, the first method may be referred to as hybrid spatial modulation and multiplexing (HSMM), and the second method may be referred to as spatial modulation (SM) or generalized spatial modulation (GSM).

In this case, the scheduler determines whether to use the GSMM technique according to a predefined condition. According to an embodiment, the scheduler provides a precoding matrix to be applied to modulation symbols among the precoding matrices in the codebook based on channel information (eg, a precoding providing a more preferred performance indicator such as transmission capacity and/or energy efficiency) matrix), it may be determined whether at least one other precoding matrix having similar performance (eg, transmission capacity and/or energy efficiency, etc.) to the selected precoding matrix exists. For example, whether the performance is similar may be determined according to whether a difference between the numerical performance values is less than a threshold value.

According to another embodiment, the scheduler may check whether at least one precoding matrix capable of guaranteeing performance similar to the selected precoding matrix is defined in the codebook or as a separate codebook. That is, when designing a codebook, precoding matrices having similar performance may be predefined to support the GSMM technique. In this case, the scheduler may select a transmission scheme according to the existence of an alternative precoding matrix with similar performance without comparing numerical performance values.

In order to apply the GSMM technique, control signaling between devices may be preceded. Control signaling may include delivery of channel state information, notification of a transmission mode, and the like. A downlink communication operation including control signaling will be described below with reference to FIG. 26 .

26 is a diagram illustrating an embodiment of a procedure for downlink communication in a base station and a terminal applicable to the present disclosure. 26 illustrates an operation method of a terminal including a base station including a transmitter (eg, the transmitter of FIG. 23A ) and a receiver (eg, the receiver of FIG. 23B ). In the following description, the operating entity of FIG. 26 is referred to as a 'base station' and a 'terminal', but may be referred to as other terms having equivalent technical meanings.

Referring to FIG. 26 , in step S2601, the base station may transmit a reference signal to the terminal. The reference signal may include a downlink reference signal, and specifically, may include a CRS and/or a CSI-RS. The reference signal may be referred to as a 'pilot signal'.

In step S2603, the terminal transmits channel state information to the base station. The channel state information may include at least one of a rank, a precoding matrix set, an indicator of whether to use the GSMM technique, and a channel quality indicator (CQI). Here, the precoding matrix set includes at least one precoding matrix corresponding to a rank, and CQIs may be provided for each codeword and/or precoding matrix. The terminal may estimate a channel using the reference signal received in step S2601, and may determine a preferred transmission mode based on the estimated channel. The preferred transmission mode is expressed by items included in the channel state information.

In the example of FIG. 26 , the UE estimates a downlink channel using a downlink signal. However, according to another embodiment, in the case of an environment in which channel reciprocity is guaranteed, steps S2601 and S2603 may be replaced with an operation in which the terminal transmits a reference signal and the base station estimates a channel based on the reference signal. .

In step S2605, the base station transmits control information including downlink assignment to the terminal. The control information includes at least one of rank information, a precoding matrix set, an indicator of whether to use the GSMM technique, and MCS information, and may be referred to as 'downlink control information (DCI)'. Here, the precoding matrix set may include at least one precoding matrix corresponding to a rank, and the MCS information may include MCS values for each codeword. That is, the base station may determine the transmission mode based on the channel state information received from the terminal, and may transmit control information indicating the transmission mode.

In step S2607, the base station transmits a transmission symbol including downlink data to the terminal. When the GSMM technique use indicator transmitted in step S2607 is set to a positive value, the base station uses the precoding matrix determined based on the bits of the first part of the downlink data, the bits of the second part of the downlink data A GSMM symbol can be generated by precoding the modulation symbols generated as a result of the modulation. And, the base station may transmit a GSMM symbol including the precoded modulation symbols to the terminal. Contrary to this, when the indicator whether to use the GSMM technique is set to a negative value, the base station may generate and transmit a transmission symbol including downlink data according to the non-GSMM technique.

Similar to the embodiment described with reference to FIG. 26, control signaling may also be performed during uplink communication. In this case, the base station determines the transmission mode using the pilot signal transmitted by the terminal, and transmits the transmission mode information to the terminal as a part of the uplink data scheduling information of the terminal. An uplink communication procedure using the GSMM technique is described below with reference to FIG. 27 .

27 is a diagram illustrating an embodiment of a procedure for uplink communication in a base station and a terminal applicable to the present disclosure. 27 illustrates a method of operating a base station including a terminal including a transmitter (eg, the transmitter of FIG. 23A ) and a receiver (eg, the receiver of FIG. 23B ). In the following description, the operating entity of FIG. 27 is referred to as a 'terminal' and a 'base station', but may be referred to as other terms having equivalent technical meanings.

Referring to FIG. 27, in step S2701, the terminal transmits a reference signal to the base station. For example, the reference signal may include a sounding reference signal (SRS). Accordingly, the base station can estimate the channel using the reference signal received from the terminal. According to another embodiment, in an environment in which channel reciprocity is guaranteed, step S2701 may be replaced with operations in which the base station transmits a reference signal and the terminal feeds back channel information estimated based on the reference signal. .

In step S2703, the base station transmits control information including an uplink grant to the terminal. The control information includes a rank, a precoding matrix set, an indicator whether to use the GSMM technique, and MCS information, and may be referred to as DCI. Here, the precoding matrix set may include at least one precoding matrix corresponding to a rank, and the MCS information may include MCS values for each codeword. That is, the base station may determine a transmission mode based on a channel estimated using a reference signal and transmit control information indicating the transmission mode.

In step S2705, the terminal transmits a transmission symbol including uplink data to the base station. When the GSMM technique usage indicator transmitted in step S2607 is set to a positive value, the terminal uses the precoding matrix determined based on the bits of the first part of the uplink data, the bit of the second part of the uplink data A GSMM symbol can be generated by precoding the modulation symbols generated as a result of the modulation. And, the base station may transmit a GSMM symbol including the precoded modulation symbols to the terminal. Contrary to this, when the indicator whether to use the GSMM technique is set to a negative value, the base station may generate and transmit a transmission symbol including downlink data according to the non-GSMM technique.

According to the embodiments described with reference to FIGS. 26 and 27 , the UE prefers a rank or number of layers, a set of precoding matrices corresponding to the rank (eg, 2 ^N PMIs), and transmission mode information including a GSMM indicator. , CQI information for each codeword may be transmitted. When two or more codewords can be transmitted, the CQI of each of the codewords can be transmitted. When the size of the precoding matrix set in the transmission mode is greater than 1, that is, when the GSMM technique is available, the UE detects a signal to interference and noise ratio (SINR) and precoding matrix when using each precoding matrix set. CQI for each codeword may be determined based on performance.

26 and 27 , the base station and the terminal notify or report whether the GSMM technique is applied using an explicit indicator (GSMM indicator). According to another embodiment, the base station may implicitly transmit whether the GSMM technique is applied through the size of the precoding matrix set. In the absence of an explicit indicator, if the size of the precoding matrix set is 1 (ie, when N=0), it is treated as indicating a non-GSMM technique. If the size of the precoding matrix set is 2 (ie, N=1) or more, it is treated as indicating the GSMM technique. Here, the GSMM scheme is divided into a first scheme using the same antenna combination, but based on a difference in coefficients of a precoding matrix, and a second scheme based on a difference in an active antenna combination. Accordingly, according to another embodiment, in addition to whether the GSMM technique is applied, information on which scheme of the GSMM technique is used may be further signaled.

The base station may determine the transmission mode based on information provided from the terminal or information obtained through measurement. The preferred transmission mode fed back from the terminal and the transmission mode to be used for actual transmission may be different. For example, the rank provided by the terminal and the rank used for transmission may be different from each other. In addition, the precoding matrix set selected by the terminal and the precoding matrix set to be used for transmission may be different from each other.

The base station may transmit the number of ranks or layers applied to actual transmission, the precoding matrix set corresponding to the rank, transmission mode information including the GSMM indicator, and MCS information for each codeword by signaling to the receiver or transmitter. In the case of precoding and transmitting the reception reference signal as shown in FIG. 39B (eg, DM-RS), the base station may transmit only the number information without transmitting the entire precoding matrix set information.

As described above, the SM technique or the GSM technique using an active antenna combination is a second scheme of the GSMM technique, and may be understood as a special case of the GSMM technique. In order to support both the first scheme and the second scheme of the GSMM scheme, the codebook may be designed as shown in FIG. 28 below.

28 is a diagram illustrating an example of a codebook applicable to the present disclosure. Referring to FIG. 28 , the codebook includes six precoding matrices having indices 0 to 5 . The codebook illustrated in FIG. 28 includes precoding matrices of indices 0 to 3 applied to an antenna port {0,1} and precoding matrices 2820 of indices 4 and 5 for the second method of the GSMM technique. ) is included.

As a result of channel measurement, when the precoding matrices 2810 of indices 1 and 2 having rank 1 provide similar performance indicators, the first method may be applied. In this case, the transmitter selects one of the two precoding matrices 2810 per MIMO symbol based on a part of the data to be transmitted, and transmits the MIMO symbol based on the selected precoding matrix. One bit of data corresponding to the index of may be additionally transmitted.

The second method of transmitting information through active antenna selection may be understood as using the precoding matrices 2820 in which components corresponding to active antennas have the same value other than 0, and the remainder are 0. . For example, the precoding matrices 2820 of indices 4 and 5 in the codebook illustrated in FIG. 28 may be used for the second scheme. That is, one of the precoding matrices 2820 of indices 4 and 5 having a rank of 1 for each MIMO symbol is selected based on a part of data to be transmitted, and precoding is performed using the selected precoding matrix. can This is the SM technique or the GSM technique in which the total number of antennas is two.

As described above, at least one of the transmission bits may be transmitted through the precoding matrix or the index of the precoding matrix. Here, the index of the precoding matrix may be referred to as a 'transmit precoding matrix index (TPMI)'. Since the TPMI is not transmitted in the form of a modulation symbol, a channel for transmitting the TPMI may have a different property from a channel transmitting the modulation symbols. That is, the channel for the TPMI and the channel for the modulation symbol may be understood as different types of channels. Therefore, for convenience of description below, a channel for transmitting TPMI may be referred to as a 'TPMI channel' or another term having an equivalent technical meaning.

When a precoding matrix is used for modulation symbol detection, if a TPMI detection error occurs in the receiver, an incorrect precoding matrix is used in the demodulation process of data carried by modulation symbols. In this case, a burst error may occur due to application of an incorrect precoding matrix. To improve performance degradation due to burst errors, the transmitter and receiver may apply additional channel encoding and decoding to the data carried by the TPMI.

When additional channel coding is used for the TPMI channel, the CQI for the TPMI channel (hereinafter referred to as 'TPMI-CQI') may be provided to the scheduler through the control signaling procedure shown in FIGS. 26 and 27 . Specifically, the TPMI-CQI may be provided to the base station through step S2603 of FIG. 26 or the TPMI-CQI may be generated based on the reference signal received at step S2701 of FIG. 27 .

When the scheduler is included in the transmitter, the receiver may determine the TPMI-CQI based on a separate coding scheme (CS) table configured for the TPMI-CQI. Thereafter, the transmitter transmits coding scheme and coding rate information to the receiver. For example, in a cellular mobile communication system, a base station may transmit a downlink TPMI channel coding scheme and code rate to a terminal along with downlink allocation through a control signal such as DCI.

When the scheduler is included in the receiver, the receiver may determine the TPMI-CQI and determine a coding scheme and a coding rate corresponding to the TPMI-CQI. In addition, the receiver may transmit coding scheme and coding rate information to the transmitter. For example, in a cellular mobile communication system, the base station may indicate to the terminal the coding scheme and the coding rate of the uplink TPMI channel together with the uplink grant through a control signal such as DCI.

Due to the use of additional channel coding for the TPMI channel, the receiver can correct the error of the data carried by the TPMI through channel decoding, and correct the TPMI detection error by re-encoding the corrected data. Due to this, the performance degradation due to the TPMI detection error can be mitigated. Operations of a transmitter and a receiver performing additional channel encoding/decoding on the TPMI channel are as follows.

29 is a diagram illustrating an embodiment of a procedure for encoding bits for determining a precoding matrix in an apparatus applicable to the present disclosure. 29 illustrates a method of operating a device including a transmitter (eg, the transmitter of FIG. 23A ). In the following description, the operating subject of FIG. 29 is referred to as a 'device', but may be referred to as a transmitting end, a transmitting device, a transmitter, or other terms having an equivalent technical meaning.

Referring to FIG. 29 , in step S2901, the device determines a coding rate for the TPMI channel. The coding rate of the TPMI channel may be determined based on the channel quality of the TPMI channel. In this case, the information related to the required channel quality may be directly generated by the device or may be provided from the counterpart device. Alternatively, the device may determine the encoding rate by being notified of the encoding rate determined by the counterpart device. That is, for example, when the apparatus is a base station, the apparatus may determine a coding rate based on information related to channel quality received from the terminal. As another example, when the device is a terminal, the device may transmit information related to channel quality to the base station and receive information related to a coding rate determined based on the channel quality.

In step S2903, the device encodes bits transmitted by the TPMI according to the determined encoding rate. The device may select some of the transmitted bits as bits carried by the TPMI and then encode the selected bits. By the encoding operation, the number of bits used as the TPMI is greater than the number of bits selected. Accordingly, when selecting the bits, the device selects an appropriate number of bits according to the coding rate. For example, when generating one transmission symbol, the device may select as many bits as the number of bits of one TPMI multiplied by a coding rate.

In step S2905, the device determines at least one TPMI based on the encoded bits. In other words, the device determines the at least one TPMI based on a result of encoding some of the transmission bits. In this case, when the number of encoded bits is greater than the number of bits of one TPMI, the device may segment the encoded bits into units of the number of bits of the TPMI. Additionally, according to another embodiment, the device may perform interleaving before dividing the encoded bits.

30 is a diagram illustrating an embodiment of a procedure for decoding bits detected from a precoding matrix in an apparatus applicable to the present disclosure. 30 illustrates a method of operating a device including a receiver (eg, the receiver of FIG. 23B ). In the following description, the operating subject of FIG. 3 is referred to as a 'device', but may be referred to as a receiving end, a receiving device, a receiver, or other terms having an equivalent technical meaning.

Referring to FIG. 30 , in step S3001, the device detects at least one TPMI. For example, the device may detect the TPMI according to the ML technique. Specifically, the apparatus may identify one combination having a high weighted similarity with a received signal among possible TPMI candidates and possible modulation symbol candidates, and identify a TPMI corresponding to the confirmed combination.

In step S3003, the device checks the coding rate for the TPMI channel. The coding rate for the TPMI channel is determined before the counterpart device transmits a signal. The coding rate of the TPMI channel may be determined based on the channel quality of the TPMI channel. The device may check the encoding rate determined by the device and notified to the counterpart device, or may check the encoding rate notified from the counterpart device.

In step S3005, the device decodes the detected at least one TPMI. Here, decoding the TPMI may be understood as an operation of decoding bits included in the TPMI or an operation of decoding bits obtained by demapping or detection from the TPMI. Depending on the decoding technique and configuration, the device may collect and then decode a plurality of TPMIs. Through the decoding operation, the device may correct a detection error for at least one TPMI.

31 is a diagram illustrating an embodiment of a procedure for using a decoding result of bits detected from a precoding matrix in an apparatus applicable to the present disclosure. 31 illustrates a method of operating a device including a receiver (eg, the receiver of FIG. 23B ). In the following description, the operating subject of FIG. 31 is referred to as a 'device', but may be referred to as a receiving end, a receiving device, a receiver, or other terms having an equivalent technical meaning.

Referring to FIG. 31 , in step S3101, the device detects TPMI and modulation symbols. Detection of modulation symbols precoded through TPMI and a precoding matrix indicated by TPMI may be detected by one detection technique (eg, ML technique). Alternatively, the TPMI and modulation symbols may be detected sequentially. In this embodiment, modulation symbols may be detected based on the precoding matrix indicated by the TPMI. In other words, the device may perform post-coding or de-precoding based on the precoding matrix.

In step S3103, the device decodes the TPMI. According to the encoding technique and configuration applied to the TPMI, the device may collect a plurality of TPMIs and decode the collected TPMIs. Here, decoding the TPMI may be understood as an operation of decoding bits included in the TPMI or an operation of decoding bits obtained by demapping or detection from the TPMI. While the TPMI is being decoded, the device may buffer the received transmission symbols or the detected modulation symbols to a pre-demodulation state, or may perform a demodulation operation.

In step S3105, the device determines whether the TPMI detection error is corrected. Even if an error occurs in detecting the TPMI, the error generated by the decoding operation can be corrected. Whether or not there is an error may be determined by re-encoding the decoding result and comparing the encoding result with a detection result before decoding. In addition, whether the error is corrected may be determined through a cyclic redundancy check (CRC) test. If the TPMI detection error is not corrected, that is, if there is no error in the TPMI detection, or an error occurs but is not corrected, the device returns the detection result for modulation symbols based on the precoding matrix indicated by the TPMI. Accept and end this procedure.

On the other hand, if the TPMI detection error is corrected, in step S3107, the device re-performs the detection of the modulation symbols. By encoding the bits obtained by decoding the TPMI, the device can obtain an error-corrected TPMI. The error-corrected TPMI indicates a different precoding matrix than before the error correction, and accordingly, the detection result of the modulation symbol may be different. Accordingly, the apparatus re-detects the modulation symbols based on the error corrected TPMI.

In the embodiment described with reference to FIG. 31 , the device may re-detect modulation symbols according to error correction of the TPMI. However, if the device does not have sufficient buffer capacity, it may not be able to buffer the received transmission symbols during decoding of the TPMI. In this case, according to another embodiment, the device may correct the detected modulation symbols, demodulated modulation symbols, or decoded modulation symbols according to the error correction result of the TPMI. For example, the device may treat at least one modulation symbol or at least one bit as an erasure (E) value. Here, the erase value is a bit value or probability value in which a received value does not exist, and may be set to a value having the same probability of 0 and probability of 1 during decoding. The erase value may be recovered by a subsequent decoding operation or a retransmission operation.

In the above-described embodiments, the present disclosure considered the case of single stream transmission. In some cases, multi-bit stream or multi-codeword transmission may be performed. In this case, two or more bit streams may be mapped to multiple layers and then precoded and transmitted. Mapping of bit streams and layers may be static as in 4G LTE and 5G NR, or may be dynamic according to channel conditions.

When the GSMM system according to various embodiments supports multi-bit stream transmission, the selected precoding matrix is applied to all bit streams. Therefore, if an incorrect precoding matrix is applied in the demodulation process due to a TPMI detection error occurring in the receiver, the detection performance of all bit streams is affected. Therefore, there is a need for a method for improving system performance degradation due to a TPMI detection error. Accordingly, the present disclosure proposes several embodiments as follows.

According to an embodiment, bits for generating a TPMI during one transmission opportunity or one transmission opportunity group may be selected from a plurality of bit streams. Structures of a transmitter and a receiver for this will be described below with reference to FIGS. 32A and 32B.

32A is a diagram illustrating another structure of a transmitter using a transmission technique applicable to the present disclosure. 32A illustrates a structure of a transmitter that selects bits for TPMI from transmitted bit streams when transmitting multiple bit streams.

Referring to FIG. 32A , the transmitter includes spatial/signal bit separation units 3212-1 to 3212-I, a merge unit 3214, a channel coder 3216, a PMI mapper 3218, and modulation mappers 3220. -1 to 3220-I), a layer mapper 3222 and a precoder 3224 .

Each of the space/signal bit separation units 3212 - 1 to 3212 -I separates input transmission bits into bits of a first portion and bits of a second portion. The spatial/signal bit separation units 3212-1 to 3212-I include as many divisions as the number of transmitted bit streams, and the i-th separation unit 3212-i, i is 1 to I) is an i-th bit stream. is separated into bits of a first part and bits of a second part. In this case, the sizes of the first portions output from the space/signal bit separation units 3212-1 to 3212-I may be the same or different from each other. The merging unit 3214 generates bits to be transmitted by the TPMI by merging the first portions provided from the spatial/signal bit separation units 3212-1 to 3212-I.

The channel coder 3216 encodes the bits provided from the merging unit 3214 . In addition, the channel coder 3216 transmits the channel-coded bits to the PMI mapper 3218 . However, according to another embodiment, the channel coder 3216 may be omitted. The PMI mapper 3218 determines a precoding matrix for precoding modulation symbols according to the value of the merged bits or the encoding result of the merged bits, and sets the determined precoding matrix or index of the precoding matrix to the precoder 3224 ) can be passed on to That is, the PMI mapper 3218 may convert a value of the merged bits or an encoding result of the merged bits into an index of the precoding matrix.

The modulation mappers 3220-1 to 3220-I generate modulation symbols from the second portions according to a constellation. The layer mapper 3222 maps the modulation symbols obtained from the modulation mappers 3220-1 to 3220-I to a plurality of layers. The precoder 3224 precodes the modulation symbols mapped to the plurality of layers by using the precoding matrix obtained from the PMI mapper 3218 . That is, the precoder 3224 may multiply the symbol vector including the modulation symbols with the precoding matrix. Thereafter, the precoded modulation symbols are subjected to analog conversion, RF conversion, amplification, etc., and then transmitted through N _t transmit antennas and delivered to a receiver through a MIMO channel.

32B is a diagram illustrating another structure of a receiver using a transmission technique applicable to the present disclosure. 32B illustrates a structure of a receiver that distributes bits obtained from TPMI to bit streams when receiving multiple bit streams.

Referring to FIG. 32B, the receiver includes a channel estimator 3262, a symbol detector 3264, a PMI demapper 3266, a channel decoder 3268, a splitter 3270, a layer demapper 3272, modulation demappers 3274-1 to 3274-I, and spatial/signal bit merging units 3276-1 to 3276-I.

The channel estimator 3262 estimates the MIMO channel. The symbol detector 3264 may detect a precoding matrix based on the estimated MIMO channel. In addition, the symbol detector 3264 may detect modulation symbols transmitted from the transmitter based on the MIMO channel. According to an embodiment, the symbol detector 3264 may detect the precoding matrix and the modulation symbols by one detection technique (eg, ML technique). Alternatively, the symbol detector 3264 may sequentially detect the TPMI and modulation symbols. In addition, in detecting the modulation symbols, the symbol detector 3264 may detect the modulation symbols based on the detected precoding matrix. In other words, the apparatus may perform post-coding or inverse-precoding based on the precoding matrix.

The PMI demapper 3266 outputs bits corresponding to the index of the precoding matrix detected by the symbol detector 3264 . The channel decoder 3268 may decode the bits provided from the PMI demapper 3266 and output bits including the first portions of the bit streams. According to another embodiment, the channel decoder 3268 may be omitted. The separation unit 3270 separates bits provided from the PMI demapper 3266 or the channel decoder 3268 into bits for each bit stream. In other words, the separation unit 3270 distributes bits to bit streams.

The layer demapper 3272 demaps the modulation symbols mapped to the layers. The layer demapper 3272 may demap the modulation symbols mapped to the layers according to a rule corresponding to the layer mapper 3222 of the transmitter of FIG. 32A . Each of the modulation demappers 3274-1 to 3274-I determines bits of the second part from the modulation symbols according to a constellation. Each of the spatial/signal bit merging units 3276-1 to 3276-I merges bits of the first part and bits of the second part, and transmits bits including bits of the first part and bits of the second part their output

33 is a diagram illustrating an embodiment of a procedure for determining bits for determining a precoding matrix when transmitting a plurality of bit streams in an apparatus applicable to the present disclosure. 33 illustrates a method of operating a device including a transmitter (eg, the transmitter of FIG. 32A ). In the following description, the operating subject of FIG. 33 is referred to as a 'device', but may be referred to as a receiving end, a receiving device, a receiver, or other terms having an equivalent technical meaning.

Referring to FIG. 33 , in step S3301, the device generates a plurality of bit streams. One bit stream may include one codeword. In this case, the device may generate codewords through channel encoding. In this case, the coding rates applied to each codeword may be the same or different from each other.

In step S3303, the device determines the bits carried by the TPMI by selecting bits from the bit streams. For example, the device may select bits to generate a TPMI from all bit streams. The device may determine the number of bits to be extracted for each bit stream, and may select as many bits as the determined number of bits from the bit streams. In this case, the number of bits to be extracted for each bit stream may be the same or different from each other.

As in the embodiment described with reference to FIG. 33, bits for generating a TPMI may be selected from all bit streams. Here, based on all bit streams means that the range for extracting bits for TPMI includes all bit streams, and it is not necessary that each of all bit streams provide a bit for TPMI. That is, depending on given conditions and circumstances, a certain bit stream may not provide a bit for generating a TPMI.

As described with reference to FIGS. 32A to 34 , bits for generating a TPMI may be selected from a plurality of bit streams. In other words, the precoding matrix may be determined by integrally considering data included in the multi-bit stream. To this end, an operation of determining the number of bits selected for each bit stream and an operation of determining a selected bit position are required.

According to an embodiment, the number of bits per bit stream may be determined based on the size of the bit stream. For example, as the number of bits included in the bit stream increases, the number of bits selected to be transmitted through the TPMI may increase. In other words, the number of bits transmitted through the TPMI and the number of bits transmitted through modulation symbols in the bit stream may maintain a constant ratio. More specifically, if the number of bits selected for each bit stream is expressed by an equation, it is as follows: [Equation 1].

In [Equation 1], B _TPMI is the number of bits that can be transmitted through TPMI in one bit stream set, N is the number of bits that can be transmitted by TPMI in one GSMM symbol, N _symbol is one bit stream the number of GSMM symbols required to transmit the set, B _TPMI,i is the number of bits selected to be carried over TPMI in the i-th bit stream, B _MOD,i is the number of bits to be carried over modulation symbols in the i-th bit stream, N _CW means the number of codewords. If the total sum of B _TPMI,i is smaller than B _TPMI , a padding bit may be added.

If additional channel coding is applied to the TPMI, B _TPMI in [Equation 1] may be changed as shown in [Equation 2] below.

In [Equation 2], B _TPMI is the number of bits that can be transmitted through TPMI in one bit stream set, R is a coding rate of additional channel coding, N is bits that can be transmitted by TPMI in one GSMM symbol The number, N _symbol , means the number of GSMM symbols required to transmit one bit stream set.

According to an embodiment, the bit positions selected for each bit stream may be sequential or discontinuous. When the bit positions are discontinuous, indices of the discontinuous bit positions may be predefined. In this case, the device may select as many bits as necessary according to the order of predefined indices. In addition, the bit position selected for each bit stream may be included in the range of parity bits or the range of information bits.

According to an embodiment, the number of bits and bit positions selected for each bit stream may be determined according to one fixed rule. According to another embodiment, a rule for determining at least one of the number of bits and a bit position may be dynamically controlled. In this case, some rule candidates are predefined or set, and control information indicating a rule to be applied may be signaled between the transmitter and the receiver. Control information indicating a rule to be applied may be signaled together with a downlink assignment or an uplink grant or separately. For example, the control information may be signaled through the procedure illustrated in FIG. 26 or FIG. 27 .

As in the embodiment described with reference to FIGS. 32A to 34 , when a plurality of bit streams are transmitted, bits transmitted by the TPMI may be selected from the plurality of bit streams. Alternatively, according to another embodiment, bits transmitted by the TPMI may be selected from one of a plurality of bit streams. That is, data for selecting a precoding matrix may be selected from one of the bit streams. That is, bits transmitted by the TPMI may be provided from one bit stream among a plurality of bit streams. For convenience of description below, one bit stream providing bits transmitted by TPMI may be referred to as a 'TPMI provided bit stream', a 'bit stream for precoding matrix selection', or a term having an equivalent technical meaning. . Structures of a transmitter and a receiver for this will be described below with reference to FIGS. 35A and 35B.

35A is a diagram illustrating another structure of a transmitter using a transmission technique applicable to the present disclosure. 35A illustrates a structure of a transmitter that selects bits for a TPMI from one of the transmitted bit streams when transmitting multiple bit streams.

Referring to FIG. 35A , the transmitter includes spatial/signal bit separation units 3512-1 to 3512-I, a selection unit 3514, a PMI mapper 3518, modulation mappers 3520-1 to 3520-I, and a layer. It includes a mapper 3522 and a precoder 3524 .

Each of the space/signal bit separation units 3512-1 to 3512-I separates input transmission bits into bits of a first portion and bits of a second portion, or bypasses input bits. In the present embodiment, since bits transmitted by the TPMI are selected from one bit stream, at any one time point, one of the space/signal bit separation units 3512-1 to 3512-I separates the bits, and the other bypasses the bits. In this case, the TPMI provided bit stream may be determined in units of GSMM symbols, in units of codewords, or in other units (eg, time units, data units).

The selector 3514 provides bits selected from the TPMI provided bit stream (eg, bits of the first part) to the PMI mapper 3518 . That is, for a given time, the selection unit 3514 receives bits transmitted by the TPMI from one of the spatial/signal bit separation units 3512-1 to 3512-I, and outputs the bits to the PMI mapper 3518 . Here, the given time may be one of a time for processing one GSMM symbol and a time for processing one set of codewords. In this case, the TPMI provided bit stream may be selected by the selector 3614 or may be selected by a separate controller (not shown).

The PMI mapper 3518 determines a precoding matrix for precoding modulation symbols according to the values of bits extracted from the TPMI-provided bit stream, and provides the determined precoding matrix or index of the precoding matrix to the precoder 3524. can transmit That is, the PMI mapper 3518 may convert the values of bits into indexes of the precoding matrix.

The modulation mappers 3520 - 1 to 3520 - I generate modulation symbols from input bits according to a constellation. The layer mapper 3522 maps the modulation symbols obtained from the modulation mappers 3520 - 1 to 3520 -I to a plurality of layers. The precoder 3524 precodes the modulation symbols mapped to the plurality of layers by using the precoding matrix obtained from the PMI mapper 3518 . That is, the precoder 3524 may multiply the symbol vector including the modulation symbols with the precoding matrix. Thereafter, the precoded modulation symbols are subjected to analog conversion, RF conversion, amplification, etc., and then transmitted through N _t transmit antennas and delivered to a receiver through a MIMO channel.

35B is a diagram illustrating another structure of a receiver using a transmission technique applicable to the present disclosure. 35B illustrates a structure of a receiver that maps bits obtained from TPMI to one bit stream when receiving multiple bit streams.

Referring to FIG. 35B , the receiver includes a channel estimator 3562 , a symbol detector 3564 , a PMI demapper 3566 , a selector 3570 , a layer demapper 3572 , and modulation demappers 3574-1 to 3574-I), and spatial/signal bit merging units 3576-1 to 3576-I.

The channel estimator 3562 estimates the MIMO channel. The symbol detector 3564 may detect a precoding matrix based on the estimated MIMO channel. In addition, the symbol detector 3564 may detect modulation symbols transmitted from the transmitter based on the MIMO channel. According to an embodiment, the symbol detector 3564 may detect the precoding matrix and the modulation symbols by one detection technique (eg, ML technique). Alternatively, the symbol detector 3564 may sequentially detect the TPMI and modulation symbols. Also, in detecting the modulation symbols, the symbol detector 3564 may detect the modulation symbols based on the detected precoding matrix. In other words, the apparatus may perform post-coding or inverse-precoding based on the precoding matrix.

The PMI demapper 3566 outputs bits corresponding to the index of the precoding matrix detected by the symbol detection unit 3564 . The selector 3570 separates bits provided from the PMI demapper 3566 or the channel decoder 3568 into bits for each bit stream. In other words, the selector 3570 distributes the bits to one of the bit streams.

The layer demapper 3572 demaps the modulation symbols mapped to the layers. The layer demapper 3572 may demap the modulation symbols mapped to the layers according to a rule corresponding to the layer mapper 3522 of the transmitter 3510 of FIG. 35A . Each of the modulation demappers 3574-1 to 3574-I estimates at least some bits included in a bit stream from modulation symbols according to a constellation. Each of the spatial/signal bit merging units 3576-1 to 3576-I merges bits of the first part and bits of the second part, or bypasses input bits. In the present embodiment, since bits transmitted by the TPMI are included in one bit stream, at any one time point, one of the spatial/signal bit merging units 3576-1 to 3576-I is transmitted from the corresponding modulation mapper. Merges bits (eg, bits of the second part) and bits (eg, bits of the first part) from the selection unit 3570, and bypasses the remaining bits input from the corresponding modulation mapper . At this time, one of the spatial/signal bit merging units 3576-1 to 3576-I that performs the bit merging operation is determined in units of GSMM symbols, determined in units of codewords, or in other units (eg, units of time) , data unit).

In the structure of the transmitter and the receiver illustrated in FIGS. 35A and 35B , bits selected from the TPMI provided bit stream are mapped to the TPMI, and the demapping bits from the TPMI are merged into the TPMI provided bit stream. According to another embodiment, additional channel coding may be performed before mapping to the TPMI, and additional channel decoding may be performed after non-mapping from the TPMI. In this case, the channel coder 3216 shown in FIG. 32A may be added to the transmitter of FIG. 35A , and the channel decoder 3268 shown in FIG. 32B may be added to the receiver of FIG. 35B . Accordingly, error correction of bits transmitted by the TPMI may be possible.

36 is a diagram illustrating another embodiment of a procedure for determining bits for determining a precoding matrix when transmitting a plurality of bit streams in an apparatus applicable to the present disclosure. 36 illustrates a method of operating a device including a transmitter (eg, the transmitter of FIG. 35A ). In the following description, the operating subject of FIG. 36 is referred to as a 'device', but may be referred to as a transmitting end, a transmitting device, a transmitter, or other terms having an equivalent technical meaning.

Referring to FIG. 36 , in step S3601, the device generates a plurality of bit streams. One bit stream may include one codeword. In this case, the device may generate codewords through channel encoding. In this case, the coding rates applied to each codeword may be the same or different from each other.

In step S3603, the device determines the bits carried by the TPMI by selecting at least one bit from one of the bit streams. For example, for a given amount of time, the device may select bits to generate a TPMI from one bit stream. The device may determine a bit stream to provide bits carried by the TPMI, and extract bits from the determined bit stream. For example, one bit stream may be selected based on characteristics of data included in the bit streams (eg, target error rate, decoding success rate, coding rate, modulation order, etc.) or characteristics of the bit stream (eg index, etc.). can The device may identify one bit stream by receiving information indicating one bit stream or determining based on information related to the bit streams.

37 is a diagram illustrating another embodiment of a procedure for processing bits detected from a precoding matrix when receiving a plurality of bit streams in an apparatus applicable to the present disclosure. 37 illustrates a method of operating a device including a receiver (eg, the receiver of FIG. 35B ). In the following description, the operating subject of FIG. 37 is referred to as a 'device', but may be referred to as a receiving end, a receiving device, a receiver, or other terms having an equivalent technical meaning.

Referring to FIG. 37 , in step S3701, the device detects a TPMI. The device may detect the TPMI from the received GSMM symbol. For example, the device may detect the TPMI according to the ML technique. Specifically, the apparatus may identify one combination having a high weighted similarity with a received transmission symbol among candidates of the possible precoding matrix and the candidates of possible modulation symbols, and identify a TPMI belonging to the confirmed combination. Although not shown in FIG. 37 , the apparatus may detect modulation symbols from a GSMM symbol and estimate bit streams from the detected modulation symbols.

In step S3703, the device merges the bits corresponding to the TPMI into one of the plurality of bit streams. The device determines the bits carried by the TPMI from the detected TPMI. For example, the device may perform at least one of an operation of demapping the TPMI into bits and an operation of decoding the demapping bits. Then, the device determines a bit stream to which the determined bits are to be merged, and merges the bits obtained from the TPMI into one determined bit stream. For example, one bit stream may be selected based on characteristics of data included in the bit streams (eg, target error rate, decoding success rate, coding rate, modulation order, etc.) or characteristics of the bit stream (eg index, etc.). can The device may identify one bit stream by receiving information indicating one bit stream or determining based on information related to the bit streams.

As described with reference to FIGS. 35A to 37 , one of a plurality of bit streams may be used as the TPMI provided bit stream. In this case, as a criterion for selecting the TPMI-provided bit stream, various factors may be used. In addition, in order to prevent performance degradation, the TPMI provided bit stream is not fixed and may be adaptively switched.

According to an embodiment, when some or all bit streams are channel-coded, the TPMI-provided bit stream is selected to select a precoding matrix using some data of the bit stream including the codeword with the highest probability of being successfully decoded. can be If channel coding is applied to a part of bit streams and channel coding is not applied to the rest, a bit stream included in the part to which channel coding is applied may be selected as the TPMI provided bit stream. In this case, the receiver can correct the TPMI detection error by first decoding the codeword included in the TPMI-provided bit stream, and re-encoding the data when decoding is successful. Accordingly, it can be alleviated that the performance of other codewords is degraded due to a TPMI detection error. More specific embodiments of switching the TPMI-provided bit stream are as follows.

The receiver gives the transmitter or the scheduler the preferred transmission mode information (eg, rank or layer number, set of precoding matrices corresponding to the rank, CQI for each codeword) with the lowest target BLER, that is, the probability of decoding success. You can pass the index of this highest codeword. If the receiver does not know the target BLER of each codeword or the target BLER of all codewords is the same, the receiver may deliver the index of the codeword that is expected to have the highest SINR. However, when the target BLER of all codewords is the same and the SINRs of all codewords are similar, the index may not be transmitted.

When the scheduler determines the application of the GSMM technique based on the information provided from the receiver, the transmitter or the scheduler selects a part of the codeword with the lowest target BLER, that is, the highest probability of decoding success, as data for selecting the precoding matrix. can When the target BLER of all codewords is the same, the transmitter or the scheduler may select the TPMI provided bit stream based on the index provided by the receiver. When the codeword indicated by the index provided from the receiver is valid, the transmitter or the scheduler may schedule a part of the codeword as data for selecting a precoding matrix. On the other hand, when the receiver does not provide the index or the codeword indicated by the index provided from the receiver is invalid, the transmitter or the scheduler switches the codewords in units of GSMM symbols, so that the bit streams are sequentially provided with the TPMI bit stream It can be scheduled to be used as In addition, when the target BLER of all codewords is the same, the transmitter or the scheduler may schedule the bit streams to be sequentially used as the TPMI provided bit stream by switching the codewords in units of GSMM symbols.

The transmitter or the scheduler may transmit the index of the codeword included in the TPMI-provided bit stream to the receiver. When the transmitter and the scheduler are physically separated, the device including the scheduler may transmit the index to the transmitter. For example, in a cellular mobile communication system, a base station may transmit an index of a codeword included in a TPMI-provided bit stream for downlink or uplink data to a receiver or transmitter of a terminal through downlink control information (DCI). .

38 is a diagram illustrating an embodiment of a procedure for decoding a plurality of bit streams in an apparatus applicable to the present disclosure. 38 illustrates a method of operating a device including a receiver (eg, the receiver of FIG. 35B ). In the following description, the operating subject of FIG. 38 is referred to as a 'device', but may be referred to as a receiving end, a receiving device, a receiver, or other terms having an equivalent technical meaning.

Referring to FIG. 38 , in step S3801, the device decodes the codeword having the lowest target error rate. In other words, the device decodes the codeword having the lowest target error rate among the undecoded codewords. In step S3803, the device determines whether decoding is successful. Whether or not decoding is successful may be determined by a CRC check. If decoding has failed, the device proceeds to step S3809 below.

On the other hand, if decoding is successful, in step S3805, the device corrects an error in the TPMI corresponding to a part of the decoded codeword. In other words, the device may restore the TPMI by re-encoding the decoding result for the codeword, extracting some bits, and mapping the extracted bits. Accordingly, an error occurring during the initial TPMI detection may be corrected. In step S3807, the device corrects errors in modulation symbols using the error-corrected TPMI. For example, the apparatus may re-detect the modulation symbols from the GSMM symbol based on the precoding matrix indicated by the error-corrected TPMI, or treat at least one of the modulation symbols as an cancellation value. However, even if decoding is successful, if the decoded codeword is not a codeword included in the TPMI provided bit stream, steps S3805 and S3807 may be omitted.

In step S3809, the device determines whether decoding of all codewords is completed. If decoding of all codewords is not completed, the device returns to step S3801. On the other hand, if decoding of all codewords is completed, in step S3811, the device determines whether an error-corrected TPMI exists. In other words, the device determines whether step S3805 is performed.

If there is an error-corrected TPMI, in step S3813, the device decodes the failed codeword again. That is, since the detection result of the modulation symbols corresponding to the codeword may be changed by the error correction of the TPMI in steps S3805 and S3807, the device attempts decoding again. On the other hand, if the error-corrected TPMI does not exist, the device ends this procedure without performing step S3813.

According to the embodiment described with reference to FIG. 38 , a device including a receiver may sequentially decode a codeword having the lowest target BLER, and correct a TPMI error and an error of modulation symbols corresponding thereto when decoding is successful. Through this, the apparatus can improve decoding performance of the remaining codewords. Finally, if there is an error-corrected TPMI, the device can decode the failed codeword again.

In order to detect the TPMI and modulation symbols from the GSMM symbol according to the above-described various embodiments, the receiver estimates a MIMO channel. A pilot signal may be used for MIMO channel estimation. In this case, the received signal model is as follows [Equation 3].

In [Equation 3], y is a received signal, H is a channel, W _TPMI is a precoding matrix, x is a modulation symbol vector, and n is interference and noise.

The receiver may detect the modulation symbol vector and the precoding matrix from the received signal using the ML technique. If the ML technique is expressed as an equation, it is as follows [Equation 4].

In [Equation 4],

is the detected TPMI,

is a detected modulation symbol vector, y is a received signal, H is a channel, W _pmi is a precoding matrix candidate, and x _m is an m-th modulation symbol vector candidate.

As in [Equation 4], channel information is used to detect the TPMI and the modulation symbol vector. That is, channel estimation is required to detect the TPMI and the transmitted symbol. The pilot signal for channel estimation may be transmitted without precoding like a cell-specific reference signal (CRS) of LTE, or may be transmitted after being precoded like a UE-specific RS of LTE or NR. Hereinafter, a structure for transmitting a pilot signal without precoding will be described with reference to FIG. 39A , and a structure for transmitting a precoded pilot signal will be described with reference to FIG. 39B .

39A is a diagram illustrating another structure of a transmitter using a transmission technique applicable to the present disclosure. Referring to FIG. 39A , the transmitter includes a data precoding unit 3912 , a resource mapping unit 3914 , and a physical antenna mapping unit 3916 . The data precoding unit 3912 precodes the input modulation symbol vector using a precoding matrix indicated by the TPMI. The resource mapping unit 3914 maps a data signal including a precoded modulation symbol vector and a pilot signal to a time-frequency resource. The physical antenna mapping unit 3916 maps signals mapped to time-frequency resources to a plurality of antennas.

When the pilot signal is not precoded according to the structure shown in FIG. 39A, the detection operation in the receiver may be expressed as Equation 5 below.

In [Equation 5],

is the detected TPMI,

is the detected modulation symbol vector, y is the received signal,

is an estimated channel, W _pmi is a precoding matrix candidate, and x _m is an m-th modulation symbol vector candidate.

39B is a diagram illustrating another structure of a receiver using a transmission technique applicable to the present disclosure. Referring to FIG. 39B , the transmitter includes a pilot precoding unit 3962 , a data precoding unit 3964 , a resource mapping unit 3966 , and a physical antenna mapping unit 3968 . The pilot precoding unit 3962 precodes pilot signals corresponding to each of the 2 ^N precoding matrices. Here, the 2 ^N precoding matrices include candidates of the precoding matrix usable for precoding the modulation symbol vector. Accordingly, the receiver may estimate channels corresponding to all the candidates of the precoding matrix using the pilot signal. The data precoding unit 3964 precodes the input modulation symbol vector using a precoding matrix indicated by the TPMI. The resource mapping unit 3966 maps the data signal including the precoded modulation symbol vector and the precoded pilot signal to time-frequency resources. The physical antenna mapping unit 3968 maps signals mapped to time-frequency resources to a plurality of antennas.

When a pilot signal is precoded according to the structure as shown in FIG. 39A, the receiver estimates an effective channel, which is a product of a channel and a precoding matrix, using the pilot signals precoded with different precoding matrices, and data It is possible to detect the TPMI and modulation symbol vectors included in the signal. The detection operation in the receiver may be expressed as [Equation 6] below.

In [Equation 6],

is the detected TPMI,

is the detected modulation symbol vector, y is the received signal,

is the estimated effective channel, and x _m is the m-th modulation symbol vector candidate.

Since examples of the above-described proposed method may also be included as one of the implementation methods of the present disclosure, it is clear that they may be regarded as a kind of proposed method. In addition, the above-described proposed methods may be implemented independently, or may be implemented in the form of a combination (or merge) of some of the proposed methods. Rules may be defined so that the base station informs the terminal of whether the proposed methods are applied or not (or information on the rules of the proposed methods) through a predefined signal (eg, a physical layer signal or a higher layer signal) to the terminal. .

The present disclosure may be embodied in other specific forms without departing from the technical ideas and essential characteristics described in the present disclosure. Accordingly, the above detailed description should not be construed as restrictive in all respects but as exemplary. The scope of the present disclosure should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present disclosure are included in the scope of the present disclosure. In addition, claims that are not explicitly cited in the claims may be combined to form an embodiment, or may be included as new claims by amendment after filing.

Embodiments of the present disclosure may be applied to various wireless access systems. As an example of various radio access systems, there is a 3rd Generation Partnership Project (3GPP) or a 3GPP2 system.

Embodiments of the present disclosure may be applied not only to the various radio access systems, but also to all technical fields to which the various radio access systems are applied. Furthermore, the proposed method can be applied to mmWave and THz communication systems using very high frequency bands.

Additionally, embodiments of the present disclosure may be applied to various applications such as free-running vehicles and drones.

Claims (15)

1. A method of operating a first device in a wireless communication system, the method comprising:

   checking whether the first technique or the second technique is applied to the transmission symbol;

   generating the transmission symbol by precoding modulation symbols generated based on transmission bits including the first part and the second part when the first technique is applied;

   generating the transmission symbol by precoding modulation symbols generated based on the second part using a precoding matrix selected based on the first part when the second technique is applied; and

   and transmitting the transmit symbol to a second device via at least one antenna.
2. The method according to claim 1,

   The step of determining whether the first technique or the second technique is applied to the transmission symbol comprises:

   selecting a first precoding matrix from among a plurality of precoding matrices based on the channel quality;

   checking a first performance indicator provided by the first precoding matrix and a second performance indicator provided by a second precoding matrix;

   if the difference between the first performance metric and the second performance metric is less than a threshold, selecting the second technique.
3. The method according to claim 1,

   Further comprising the step of transmitting control information related to the second technique,

   The control information includes at least one of an indicator indicating whether the second technique is applied or information related to the number of selectable precoding matrices.
4. The method according to claim 1,

   The first portion includes at least one bit selected from a first bit stream and at least one bit selected from a second bit stream from among a plurality of bit streams.
5. The method according to claim 1,

   The number of bits included in the first portion of the first bit stream is determined based on the number of bits transmitted by a modulation symbol among bits included in the first bit stream.
6. The method according to claim 1,

   wherein the first portion is selected from one bit stream of a plurality of bit streams.
7. 7. The method of claim 6,

   The one bit stream is determined based on at least one of a target error rate and a channel quality of the plurality of bit streams.
8. 7. The method of claim 6,

   The method further comprising transmitting control information related to the one bit stream.
9. The method according to claim 1,

   encoding bits included in the first part:

   The method further comprising determining the precoding matrix based on the encoded bits.
10. The method according to claim 1,

    and transmitting reference signals precoded using each of the precoding matrix candidates for precoding the modulation symbols.
11. A method of operating a second device in a wireless communication system, the method comprising:

    checking whether the first technique or the second technique is applied to a transmission symbol transmitted from the first apparatus;

    detecting modulation symbols from transmission symbols received from the first apparatus when the first technique is applied;

    detecting modulation symbols and indexes of a precoding matrix applied to the modulation symbols from the transmission symbols received from the first apparatus when the second technique is applied; and

    and obtaining transmit bits from at least one of the modulation symbols and the index.
12. 12. The method of claim 11,

    Obtaining the transmission bits comprises:

    encoding a bit stream comprising a first portion of the transmitted bits obtained from the index;

    correcting an error of the index based on a result of encoding the bit stream; and

    and re-detecting the modulation symbols based on the error corrected index.
13. 12. The method of claim 11,

    Obtaining the transmission bits comprises:

    and decoding bits obtained from the index.
14. 12. The method of claim 11,

    Obtaining the transmission bits comprises:

    obtaining a first portion of the transmission bits based on the index;

    and including the first portion in a plurality of bit streams.
15. 12. The method of claim 11,

    Obtaining the transmission bits comprises:

    obtaining a first portion of the transmission bits based on the index;

    and including the first portion in one bit stream of a plurality of bit streams.

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