WO2020060232A1

WO2020060232A1 - Method and apparatus for supporting power sharing and control between iab links in wireless communication system

Info

Publication number: WO2020060232A1
Application number: PCT/KR2019/012153
Authority: WO
Inventors: Yunjung Yi
Original assignee: Lg Electronics Inc.
Priority date: 2018-09-20
Filing date: 2019-09-19
Publication date: 2020-03-26

Abstract

A method and apparatus for supporting power sharing and/or control between integrated access and backhaul (IAB) links in a wireless communication system is provided. When a first node (e.g., IAB node) performs a downlink (DL) transmission to a wireless device (e.g., user equipment (UE)) based on a DL resource and an uplink (UL) transmission to a second node (e.g., another IAB node and/or donor node) based on a UL resource at a same time interval, the DL resource and the UL resource are separated by at least one guard physical resource block (PRB) in a frequency domain.

Description

METHOD AND APPARATUS FOR SUPPORTING POWER SHARING AND CONTROL BETWEEN IAB LINKS IN WIRELESS COMMUNICATION SYSTEM

The present disclosure relates to supporting power sharing and/or control between integrated access and backhaul (IAB) links in a wireless communication system.

3rd generation partnership project (3GPP) long-term evolution (LTE) is a technology for enabling high-speed packet communications. Many schemes have been proposed for the LTE objective including those that aim to reduce user and provider costs, improve service quality, and expand and improve coverage and system capacity. The 3GPP LTE requires reduced cost per bit, increased service availability, flexible use of a frequency band, a simple structure, an open interface, and adequate power consumption of a terminal as an upper-level requirement.

Work has started in international telecommunication union (ITU) and 3GPP to develop requirements and specifications for new radio (NR) systems. 3GPP has to identify and develop the technology components needed for successfully standardizing the new RAT timely satisfying both the urgent market needs, and the more long-term requirements set forth by the ITU radio communication sector (ITU-R) international mobile telecommunications (IMT)-2020 process. Further, the NR should be able to use any spectrum band ranging at least up to 100 GHz that may be made available for wireless communications even in a more distant future.

The NR targets a single technical framework addressing all usage scenarios, requirements and deployment scenarios including enhanced mobile broadband (eMBB), massive machine-type-communications (mMTC), ultra-reliable and low latency communications (URLLC), etc. The NR shall be inherently forward compatible.

One of the potential technologies targeted to enable future cellular network deployment scenarios and applications is the support for wireless backhaul and relay links enabling flexible and very dense deployment of NR cells without the need for densifying the transport network proportionately.

Due to the expected larger bandwidth available for NR compared to LTE (e.g., mmWave spectrum) along with the native deployment of massive multiple-input multiple-output (MIMO) or multi-beam systems in NR creates an opportunity to develop and deploy integrated access and backhaul (IAB) links. This may allow easier deployment of a dense network of self-backhauled NR cells in a more integrated manner by building upon many of the control and data channels/procedures defined for providing access to UEs. Due to deployment of IAB links, relay nodes can multiplex access and backhaul links in time, frequency, or space (e.g., beam-based operation).

In integrated access and backhaul (IAB) scenario, simultaneous transmission to backhaul link and access link and/or simultaneous transmission to multiple backhaul links can be considered. Or, simultaneous reception from backhaul link and access link and/or simultaneous reception from multiple backhaul links can be considered. In this case, multiple links can be multiplexed by frequency division multiplexing (FDM)/spatial division multiplexing (SDM).

Power control is needed for transmission to both nodes and/or reception from both nodes due to interference between signals transmitted or received on both sides. The present disclosure discusses transmission and/or reception power control for both nodes under such a scenario.

In an aspect, a method performed by a first node in a wireless communication system is provided. When the first node performs a downlink (DL) transmission to a wireless device based on a DL resource and an uplink (UL) transmission to a second node based on a UL resource at a same time interval, the DL resource and the UL resource are separated by at least one guard physical resource block (PRB) in a frequency domain.

In another aspect, an apparatus for implementing the above mentioned methods is provided.

Power control for IAB can be supported efficiently by considering simultaneous transmission to multiple nodes and/or simultaneous reception from multiple nodes.

FIG. 1 shows an example of a communication system to which the technical features of the present disclosure can be applied.

FIG. 2 shows an example of wireless devices to which the technical features of the present disclosure can be applied.

FIG. 3 shows an example of a signal processing circuit for a transmission signal to which the technical features of the present disclosure can be applied.

FIG. 4 shows another example of a wireless device to which the technical features of the present disclosure can be applied.

FIG. 5 shows an example of a wireless communication system to which the technical features of the present disclosure can be applied.

FIG. 6 shows another example of a wireless communication system to which the technical features of the present disclosure can be applied.

FIG. 7 shows an example of a frame structure to which technical features of the present disclosure can be applied.

FIG. 8 shows another example of a frame structure to which technical features of the present disclosure can be applied.

FIG. 9 shows an example of a subframe structure used to minimize latency of data transmission when TDD is used in NR.

FIG. 10 shows an example of a resource grid to which technical features of the present disclosure can be applied.

FIG. 11 shows an example of a synchronization channel to which technical features of the present disclosure can be applied.

FIG. 12 shows an example of a frequency allocation scheme to which technical features of the present disclosure can be applied.

FIG. 13 shows an example of multiple BWPs to which technical features of the present disclosure can be applied.

FIG. 14 shows an example of IAB links to which technical features of the present disclosure can be applied.

FIG. 15 shows limits for EVM equalizer spectral flatness with the maximum allowed variation of the coefficients indicated for unshaped modulations.

FIG. 16 shows an example of scenarios in which P-BH and C-PH or P-BH and AC are multiplexed by FDM/SDM to which the technical features of the present disclosure can be applied.

FIG. 17 shows an example of a method for supporting power sharing and/or control between IAB links according to an embodiment of the present disclosure.

The technical features described below may be used by a communication standard by the 3rd generation partnership project (3GPP) standardization organization, a communication standard by the institute of electrical and electronics engineers (IEEE), etc. For example, the communication standards by the 3GPP standardization organization include long-term evolution (LTE) and/or evolution of LTE systems. The evolution of LTE systems includes LTE-advanced (LTE-A), LTE-A Pro, and/or 5G new radio (NR). The communication standard by the IEEE standardization organization includes a wireless local area network (WLAN) system such as IEEE 802.11a/b/g/n/ac/ax. The above system uses various multiple access technologies such as orthogonal frequency division multiple access (OFDMA) and/or single carrier frequency division multiple access (SC-FDMA) for downlink (DL) and/or uplink (UL). For example, only OFDMA may be used for DL and only SC-FDMA may be used for UL. Alternatively, OFDMA and SC-FDMA may be used for DL and/or UL.

In this document, the term "/" and "," should be interpreted to indicate "and/or." For instance, the expression "A/B" may mean "A and/or B." Further, "A, B" may mean "A and/or B." Further, "A/B/C" may mean "at least one of A, B, and/or C." Also, "A, B, C" may mean "at least one of A, B, and/or C."

Further, in the document, the term "or" should be interpreted to indicate "and/or." For instance, the expression "A or B" may comprise 1) only A, 2) only B, and/or 3) both A and B. In other words, the term "or" in this document should be interpreted to indicate "additionally or alternatively."

An example of a communication system to which the technical features of the present disclosure can be applied is described.

Although not limited thereto, various descriptions, functions, procedures, suggestions, methods and/or operational flowcharts of the present disclosure disclosed herein can be applied to various fields requiring wireless communication and/or connection (e.g., 5G) between devices.

Hereinafter, the present disclosure will be described in more detail with reference to drawings. The same reference numerals in the following drawings and/or descriptions may refer to the same and/or corresponding hardware blocks, software blocks, and/or functional blocks unless otherwise indicated.

Referring to FIG. 1, a communication system 1 to which the technical features of the present disclosure can be applied includes a wireless device, a base station and a network. Here, the wireless device refers to a device that performs communication using a radio access technology (e.g., 5G new radio access technology (NR), long-term evolution (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, a home appliance 100e, an internet of things (IoT) device 100f and an artificial intelligence (AI) device / server 400. For example, the vehicle may include a vehicle having a wireless communication function, an autonomous vehicle, a vehicle capable of performing inter-vehicle communication, etc. Here, the vehicle may include an unmanned aerial vehicle (UAV) (e.g., a drone). The XR device may include augmented reality (AR) / virtual reality (VR) / mixed reality (MR) devices. The XR device may be implemented in the form of head-mounted device (HMD), head-up display (HUD) provided in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, a digital signage, a vehicle, a robot, etc. The hand-held device device may include a smartphone, a smart pad, a wearable device (e.g., a smart watch, smart glasses), a computer (e.g., a laptop, etc.). The home appliance may include a TV, a refrigerator, a washing machine, etc. The IoT device may include a sensor, a smart meter, etc. For example, the base station and the network may be implemented as a wireless device. A specific wireless device 200a may operate as a base station / network node to other wireless devices.

The wireless devices 100a to 100f may be connected to the network 300 through the base station 200. 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 400 through the network 300. The network 300 may be configured using a 3G network, a 4G (e.g., LTE) network and/or a 5G (e.g., NR) network. The wireless devices 100a to 100f may communicate with each other via the base station 200 / network 300, but may also communicate directly (e.g., sidelink communication) without passing through the base station 200 / network 300. For example, the vehicles 100b-1 and 100b-2 may perform direct communication (e.g., vehicle-to-vehicle (V2V) / vehicle-to-everything (V2X) communication). In addition, the IoT device (e.g., sensor) may directly communicate with another IoT device (e.g., sensor) or another wireless device 100a to 100f.

Wireless communication /

connections

150a, 150b, and 150c may be performed between the wireless devices 100a to 100f and the base station 200 and/or between the base stations 200. Here, the wireless communication / connection may be performed by various wireless access technologies (e.g., 5G NR) such as uplink / downlink communication 150a, sidelink communication (or device-to-device (D2D)) communication) 150b, inter-base station communication 150c (e.g., relay, integrated access and backhaul (IAB)), etc. The wireless device and the base station / wireless device and/or the base stations may transmit / receive radio signals with each other respectively through the wireless communication /

connection

150a, 150b, and 150c. For example, wireless communications /

connections

150a, 150b, and 150c may transmit / receive signals over various physical channels. To this end, based on various proposals of the present disclosure, at least some of various configuration information setting processes, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / de-mapping, etc.), and resource allocation process for transmitting / receiving a wireless signal may be performed.

Referring to FIG. 2, the first wireless device 100 and the second wireless device 200 may transmit and receive wireless signals through various wireless access technologies (e.g., LTE, NR). Here, {the first wireless device 100 and the second wireless device 200} may correspond to {the wireless device 100x, the base station 200} and/or {the wireless device 100x, the wireless device 100x} in FIG. 1.

The first wireless device 100 may include one or more processors 102 and one or more memories 104. The first wireless device 100 may further include one or more transceivers 106 and/or one or more antennas 108. The processor 102 may control the memory 104 and/or the transceiver 106. The processor 102 may be configured to implement the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein. For example, the processor 102 may process information in the memory 104 to generate the first information/signal, and then transmit a wireless signal including the first information/signal through the transceiver 106. In addition, the processor 102 may receive a wireless signal including the second information/signal through the transceiver 106 and then store information obtained from signal processing of the second information/signal in the memory 104. The memory 104 may be coupled to the processor 102 and may store various information related to the operation of the processor 102. For example, the memory 104 may include software code that includes instructions for performing some or all of the processes controlled by the processor 102 and/or for carrying out the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein. Here, processor 102 and memory 104 may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver 106 may be coupled with the processor 102 and may transmit and/or receive wireless signals via one or more antennas 108. The transceiver 106 may include a transmitter and/or a receiver. The transceiver 106 may be mixed with a radio frequency (RF) unit. In the present disclosure, a wireless device may mean a communication modem / circuit / chip.

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

Hereinafter, hardware elements of the

wireless devices

100, 200 will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or

more processors

102, 202. For example, one or

more processors

102, 202 may implement one or more layers (e.g., functional layers such as physical (PHY), media access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), service data adaptation protocol (SDAP), radio resource control (RRC)). One or

more processors

102, 202 may generate one or more protocol data units (PDUs) and/or one or more service data units (SDUs) in accordance with the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein. One or

more processors

102, 202 may generate messages, control information, data, or information in accordance with the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein. One or

more processors

102, 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information in accordance with the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein, and provide to one or

more transceivers

106, 206. One or

more processors

102, 202 may receive signals (e.g., baseband signals) from one or

more transceivers

106, 206, and obtain PDUs, SDUs, messages, control information, data or information in accordance with the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein.

One or

more processors

102, 202 may be referred to as a controller, a microcontroller, a microprocessor, and/or a microcomputer. One or

more processors

102, 202 may be implemented by hardware, firmware, software, and/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), and/or one or more field programmable gate arrays (FPGAs) may be included in one or

more processors

102, 202. The descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein may be implemented using firmware and/or software, and the firmware and/or software may be implemented to include modules, procedures, functions, etc. Firmware and/or software configured to perform the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein may be included in one or

more processors

102, 202 or stored in one or

more memories

104, 204 and may be driven by one or

more processors

102, 202. The descriptions, functions, procedures, suggestions, methods and/or operational flowcharts 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

104, 204 may be coupled with one or

more processors

102, 202 and may store various forms of data, signals, messages, information, programs, codes, instructions, and/or commands. One or

more memories

104, 204 may be comprised of a read-only memory (ROM), a random access memory (RAM), an erasable programmable read-only memory (EPROM), a flash memory, a hard drive, a register, a cache memory, a computer readable storage medium and/or combinations thereof. One or

more memories

104, 204 may be located inside and/or outside one or

more processors

102, 202. In addition, one or

more memories

104, 204 may be coupled to one or

more processors

102, 202 through various techniques, such as a wired and/or wireless connection.

One or

more transceivers

106, 206 may transmit user data, control information, wireless signals/channels, etc., as mentioned in the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein, to one or more other devices. One or

more transceivers

106, 206 may receive user data, control information, wireless signals/channels, etc., as mentioned in the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein, from one or more other devices. For example, one or

more transceivers

106, 206 may be coupled with one or

more processors

102, 202 and may transmit and/or receive wireless signals. For example, one or

more processors

102, 202 may control one or

more transceivers

106, 206 to transmit user data, control information, wireless signals/channels, etc., to one or more other devices. In addition, one or

more processors

102, 202 may control one or

more transceivers

106, 206 to receive user data, control information, wireless signals/channels, etc., from one or more other devices. In addition, one or

more transceivers

106, 206 may be coupled to one or

more antennas

108, 208. One or

more transceivers

106, 206 may be configured to transmit and/or receive user data, control information, wireless signals/channels, etc., as mentioned in the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein, through one or

more antennas

108, 208. In this document, one or

more antennas

108, 208 may be a plurality of physical antennas and/or a plurality of logical antennas (e.g., antenna ports). In order to process the received user data, control information, wireless signals/channels, etc., using one or

more processors

102, 202, one or

more transceivers

106, 206 may convert the received user data, control information, wireless signals/channels, etc., from an RF band signal to a baseband signal. One or

more transceivers

106, 206 may convert user data, control information, wireless signals/channels, etc., processed by using one or

more processors

102, 202, from a baseband signal to an RF band signal. To this end, one or

more transceivers

106, 206 may include (analog) oscillators and/or filters.

Referring to FIG. 3, the signal processing circuit 1000 may include a scrambler 1010, a modulator 1020, a layer mapper 1030, a precoder 1040, a resource mapper 1050, and a signal generator 1060. Although not limited thereto, operations/functions of FIG. 3 may be performed in

processors

102, 202 and/or

transceivers

106, 206 of FIG. 2. The hardware element of FIG. 3 may be implemented in

processors

102, 202 and/or

transceivers

106, 206 of FIG. 2. For example, blocks 1010 to 1060 may be implemented in

processors

102, 202 of FIG. 2. Further, blocks 1010 to 1050 may be implemented in

processors

102, 202 of FIG. 2, and block 1060 may be implemented in

transceivers

106, 206 of FIG. 2.

The codeword may be converted into a wireless signal via the signal processing circuit 1000 of FIG. 3. Here, the codeword is a coded bit sequence of the information block. The information block may include a transport block (e.g., an uplink shared channel (UL-SCH) transport block, a downlink shared channel (DL-SCH) transport block). The wireless signal may be transmitted through various physical channels (e.g., physical uplink shared channel (PUSCH), physical downlink shared channel (PDSCH)).

In detail, the codeword may be converted into a scrambled bit sequence by the scrambler 1010. The scramble bit sequence used for scrambling may be generated based on initialization value, and the initialization value may include ID information of the wireless device, etc. The scrambled bit sequence may be modulated into a modulation symbol sequence by the modulator 1020. The modulation scheme may include pi/2-binary phase shift keying (pi/2-BPSK), m-phase shift keying (m-PSK), m-quadrature amplitude modulation (m-QAM), etc. The complex modulation symbol sequence may be mapped to one or more transport layers by the layer mapper 1030. The modulation symbols of each transport layer may be mapped to the corresponding antenna port(s) by the precoder 1040 (precoding). The output z of the precoder 1040 may be obtained by multiplying the output y of the layer mapper 1030 with 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 1040 may perform precoding after performing transform precoding (e.g., discrete Fourier transform (DFT)) on the complex modulation symbols. Also, the precoder 1040 may perform precoding without performing transform precoding.

The resource mapper 1050 may map modulation symbols of each antenna port to time-frequency resources. The time-frequency resource may include a plurality of symbols (e.g., cyclic prefix based OFDMA (CP-OFDMA) symbols, DFT spread OFDMA (DFT-s-OFDMA) symbols) in the time domain, and may include a plurality of subcarriers in the frequency domain. The signal generator 1060 may generate a wireless signal from the mapped modulation symbols, and the generated wireless signal may be transmitted to another device through each antenna. To this end, the signal generator 1060 may include an inverse fast Fourier transform (IFFT) module, a cyclic prefix (CP) inserter, a digital-to-analog converter (DAC), a frequency uplink converter, etc.

The signal processing procedure for a reception signal in the wireless device may be configured in the reverse of the signal processing procedure 1010 to 1060 of FIG. 3. For example, a wireless device (e.g., 100, 200 of FIG. 2) may receive a wireless signal from the outside through an antenna port/transceiver. The received wireless signal may be converted into a baseband signal through a signal recoverer. To this end, the signal recoverer may include a frequency downlink converter, an analog-to-digital converter (ADC), a CP canceller, 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 de-scrambling process. The codeword may be restored to the original information block through decoding. Thus, the signal processing circuit for the reception signal (not shown) may include a signal recoverer, a resource de-mapper, a postcoder, a demodulator, a de-scrambler and a decoder.

The wireless device may be implemented in various forms depending on use cases / services (see FIG. 1). Referring to FIG. 4, the

wireless devices

100, 200 may correspond to the

wireless devices

100, 200 of FIG. 2, and may be composed of various elements, components, units, and/or modules. For example, the

wireless device

100, 200 may include a communication unit 110, a control unit 120, a memory unit 130, and additional components 140. The communication unit 110 may include a communication circuitry 112 and transceiver(s) 114. For example, the communication circuitry 112 may include one or

more processors

102, 202 and/or one or

more memories

104, 204 of FIG. 2. For example, the transceiver(s) 114 may include one or

more transceivers

106, 206 and/or one or

more antennas

108, 208 of FIG. 2. The control unit 120 is electrically connected to the communication unit 110, the memory unit 130, and the additional components 140, and controls various operations of the

wireless device

100, 200. For example, the control unit 120 may control the electrical/mechanical operation of the

wireless device

100, 200 based on the program/code/command/information stored in the memory unit 130. In addition, the control unit 120 may transmit the information stored in the memory unit 130 to the outside (e.g., other communication devices) through the communication unit 110 through a wireless/wired interface, or may store the information received from the outside (e.g., other communication devices) through the wireless/wired interface through the communication unit 110 in the memory unit 130.

The additional components 140 may be variously configured according to the type of the

wireless device

100, 200. For example, the additional components 140 may include at least one of a power unit/battery, an input/output (I/O) unit, a driver, or a computing unit. Although not limited thereto, the

wireless devices

100, 200 may be implemented in the form of robots (FIG. 1, 100a), vehicles (FIG. 1, 100b-1, 100b-2), XR devices (FIG. 1, 100c), hand-held devices (FIG. 1, 100d), home appliances (FIG. 1, 100e), IoT devices (FIG. 1, 100f), terminals for digital broadcasting, hologram devices, public safety devices, machine-type communication (MTC) devices, medical devices, fin-tech devices (or financial devices), security devices, climate/environment devices, an AI server/devices (FIG. 1, 400), a base station (FIG. 1, 200), a network node, etc. The

wireless device

100, 200 may be used in a mobile or fixed location depending on use cases / services.

In FIG. 4, various elements, components, units, and/or modules within the

wireless device

100, 200 may be entirely interconnected via a wired interface, or at least a part of the

wireless device

100, 200 may be wirelessly connected through the communication unit 110. For example, in the

wireless device

100, 200, the control unit 120 and the communication unit 110 may be connected by wire, and the control unit 120 and the first unit (e.g., 130, 140) may be wirelessly connected through the communication unit 110. In addition, each element, component, unit, and/or module in the

wireless device

100, 200 may further include one or more elements. For example, the control unit 120 may be composed of one or more processor sets. For example, the control unit 120 may be configured as a set of a communication control processor, an application processor, an electronic control unit (ECU), a graphics processing processor, a memory control processor, etc. As another example, the memory unit 130 may include RAM, a dynamic RAM (DRAM), ROM, a flash memory, a volatile memory, a non-volatile memory, and/or combinations thereof.

Specifically, FIG. 5 shows a system architecture based on an evolved-UMTS terrestrial radio access network (E-UTRAN). The aforementioned LTE is a part of an evolved-UTMS (e-UMTS) using the E-UTRAN.

Referring to FIG. 5, the wireless communication system includes one or more user equipment (UE) 100, an E-UTRAN and an evolved packet core (EPC). The UE 100 refers to a communication equipment carried by a user. The UE 100 may be fixed or mobile. The UE 100 may be referred to as another terminology, such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), a wireless device, etc. The UE 100 may correspond to the wireless device 100x of FIG. 1, the first wireless device 100 of FIG. 2, or the wireless device 100 of FIG. 4.

The E-UTRAN consists of one or more evolved NodeB (eNB) 200. The eNB 200 provides the E-UTRA user plane and control plane protocol terminations towards the UE 100. The eNB 200 is generally a fixed station that communicates with the UE 100. The eNB 200 hosts the functions, such as inter-cell radio resource management (RRM), radio bearer (RB) control, connection mobility control, radio admission control, measurement configuration/provision, dynamic resource allocation (scheduler), etc. The eNB 200 may be referred to as another terminology, such as a base station (BS), a base transceiver system (BTS), an access point (AP), etc. The eNB 200 may correspond to the base station 200 of FIG. 1, the second wireless device 200 of FIG. 2, or the wireless device 200 of FIG. 4.

A downlink (DL) denotes communication from the eNB 200 to the UE 100. An uplink (UL) denotes communication from the UE 100 to the eNB 200. A sidelink (SL) denotes communication between the UEs 100. In the DL, a transmitter may be a part of the eNB 200, and a receiver may be a part of the UE 100. In the UL, the transmitter may be a part of the UE 100, and the receiver may be a part of the eNB 200. In the SL, the transmitter and receiver may be a part of the UEs 100.

The EPC includes a mobility management entity (MME), a serving gateway (S-GW) and a packet data network (PDN) gateway (P-GW). The MME hosts the functions, such as non-access stratum (NAS) security, idle state mobility handling, evolved packet system (EPS) bearer control, etc. The S-GW hosts the functions, such as mobility anchoring, etc. The S-GW is a gateway having an E-UTRAN as an endpoint. For convenience, MME/S-GW 300 will be referred to herein simply as a "gateway," but it is understood that this entity includes both the MME and S-GW. The P-GW hosts the functions, such as UE Internet protocol (IP) address allocation, packet filtering, etc. The P-GW is a gateway having a PDN as an endpoint. The P-GW is connected to an external network. The MME/S-GW 300 may correspond to the network 300 of FIG. 1.

The UE 100 is connected to the eNB 200 by means of the Uu interface. The UEs 100 are interconnected with each other by means of the PC5 interface. The eNBs 200 are interconnected with each other by means of the X2 interface. The eNBs 200 are also connected by means of the S1 interface to the EPC, more specifically to the MME by means of the S1-MME interface and to the S-GW by means of the S1-U interface. The S1 interface supports a many-to-many relation between MMEs / S-GWs and eNBs.

Specifically, FIG. 6 shows a system architecture based on a 5G NR. The entity used in the 5G NR (hereinafter, simply referred to as "NR") may absorb some or all of the functions of the entities introduced in FIG. 5 (e.g., eNB, MME, S-GW). The entity used in the NR may be identified by the name "NG" for distinction from the LTE/LTE-A.

Referring to FIG. 6, the wireless communication system includes one or more UE 100, a next-generation RAN (NG-RAN) and a 5th generation core network (5GC). The NG-RAN consists of at least one NG-RAN node. The NG-RAN node is an entity corresponding to the eNB 200 shown in FIG. 5. The NG-RAN node consists of at least one gNB 200 and/or at least one ng-eNB 200. The gNB 200 provides NR user plane and control plane protocol terminations towards the UE 100. The ng-eNB 200 provides E-UTRA user plane and control plane protocol terminations towards the UE 100. The gNB 200 and/or ng-eNB 200 may correspond to the base station 200 of FIG. 1, the second wireless device 200 of FIG. 2, or the wireless device 200 of FIG. 4.

The 5GC includes an access and mobility management function (AMF), a user plane function (UPF) and a session management function (SMF). The AMF hosts the functions, such as NAS security, idle state mobility handling, etc. The AMF is an entity including the functions of the conventional MME. The UPF hosts the functions, such as mobility anchoring, PDU handling. The UPF an entity including the functions of the conventional S-GW. The SMF hosts the functions, such as UE IP address allocation, PDU session control.

The gNBs 200 and ng-eNBs 200 are interconnected with each other by means of the Xn interface. The gNBs 200 and ng-eNBs 200 are also connected by means of the NG interfaces to the 5GC, more specifically to the AMF by means of the NG-C interface and to the UPF by means of the NG-U interface.

Hereinafter, frame structure/physical resources in NR is described.

In LTE/LTE-A, one radio frame consists of 10 subframes, and one subframe consists of 2 slots. A length of one subframe may be 1ms, and a length of one slot may be 0.5ms. Time for transmitting one transport block by higher layer to physical layer (generally over one subframe) is defined as a transmission time interval (TTI). A TTI may be the minimum unit of scheduling.

In NR, DL and UL transmissions are performed over a radio frame with a duration of 10ms. Each radio frame includes 10 subframes. Thus, one subframe corresponds to 1ms. Each radio frame is divided into two half-frames.

Unlike LTE/LTE-A, NR supports various numerologies, and accordingly, the structure of the radio frame may be varied. NR supports multiple subcarrier spacings in frequency domain. Table 1 shows multiple numerologies supported in NR. Each numerology may be identified by index μ.

μ	Subcarrier spacing (kHz)	Cyclic prefix	Supported for data	Supported for synchronization
0	15	Normal	Yes	Yes
1	30	Normal	Yes	Yes
2	60	Normal, Extended	Yes	No
3	120	Normal	Yes	Yes
4	240	Normal	No	Yes

Referring to Table 1, a subcarrier spacing may be set to any one of 15, 30, 60, 120, and 240 kHz, which is identified by index μ. However, subcarrier spacings shown in Table 1 are merely exemplary, and specific subcarrier spacings may be changed. Therefore, each subcarrier spacing (e.g., μ=0,1...4) may be represented as a first subcarrier spacing, a second subcarrier spacing...Nth subcarrier spacing.

Referring to Table 1, transmission of user data (e.g., PUSCH, PDSCH) may not be supported depending on the subcarrier spacing. That is, transmission of user data may not be supported only in at least one specific subcarrier spacing (e.g., 240 kHz).

In addition, referring to Table 1, a synchronization channel (e.g., a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH)) may not be supported depending on the subcarrier spacing. That is, the synchronization channel may not be supported only in at least one specific subcarrier spacing (e.g., 60 kHz).

One subframe includes N_symb ^subframe,μ = N_symb ^slot * N_slot ^subframe,μ consecutive OFDM symbols. In NR, a number of slots and a number of symbols included in one radio frame/subframe may be different according to various numerologies, i.e., various subcarrier spacings.

Table 2 shows an example of a number of OFDM symbols per slot (N_symb ^slot), a number of slots per radio frame (N_symb ^frame,μ), and a number of slots per subframe (N_symb ^subframe,μ) for each numerology in normal cyclic prefix (CP).

μ	Number of OFDM symbols per slot(N_symb ^slot)	Number of slots per radio frame (N_symb ^frame,μ)	Number of slots per subframe(N_symb ^subframe,μ)
0	14	10	1
1	14	20	2
2	14	40	4
3	14	80	8
4	14	160	16

Referring to Table 2, when a first numerology corresponding to μ=0 is applied, one radio frame includes 10 subframes, one subframe includes to one slot, and one slot consists of 14 symbols.

Table 3 shows an example of a number of OFDM symbols per slot (N_symb ^slot), a number of slots per radio frame (N_symb ^frame,μ), and a number of slots per subframe (N_symb ^subframe,μ) for each numerology in extended CP.

μ	Number of OFDM symbols per slot(N_symb ^slot)	Number of slots per radio frame (N_symb ^frame,μ)	Number of slots per subframe(N_symb ^subframe,μ)
2	12	40	4

Referring to Table 3, μ=2 is only supported in extended CP. One radio frame includes 10 subframes, one subframe includes to 4 slots, and one slot consists of 12 symbols.

In the present specification, a symbol refers to a signal transmitted during a specific time interval. For example, a symbol may refer to a signal generated by OFDM processing. That is, a symbol in the present specification may refer to an OFDM/OFDMA symbol, or SC-FDMA symbol, etc. A CP may be located between each symbol.

FIG. 7 shows an example of a frame structure to which technical features of the present disclosure can be applied. FIG. 8 shows another example of a frame structure to which technical features of the present disclosure can be applied.

In FIG. 7, a subcarrier spacing is 15 kHz, which corresponds to μ=0. In FIG. 8, a subcarrier spacing is 30 kHz, which corresponds to μ=1.

Meanwhile, a frequency division duplex (FDD) and/or a time division duplex (TDD) may be applied to a wireless communication system to which an embodiment of the present disclosure is applied. When TDD is applied, in LTE/LTE-A, UL subframes and DL subframes are allocated in units of subframes.

In NR, symbols in a slot may be classified as a DL symbol (denoted by D), a flexible symbol (denoted by X), and a UL symbol (denoted by U). In a slot in a DL frame, the UE shall assume that DL transmissions only occur in DL symbols or flexible symbols. In a slot in an UL frame, the UE shall only transmit in UL symbols or flexible symbols. The flexible symbol may be referred to as another terminology, such as reserved symbol, other symbol, unknown symbol, etc.

Table 4 shows an example of a slot format which is identified by a corresponding format index. The contents of the Table 4 may be commonly applied to a specific cell, or may be commonly applied to adjacent cells, or may be applied individually or differently to each UE.

Format

Symbol number in a slot

0

1

2

3

4

5

6

7

8

9

10

11

12

13

0

D

1

U

2

X

3

D

X

...

For convenience of explanation, Table 4 shows only a part of the slot format actually defined in NR. The specific allocation scheme may be changed or added.

The UE may receive a slot format configuration via a higher layer signaling (i.e., RRC signaling). Or, the UE may receive a slot format configuration via downlink control information (DCI) which is received on PDCCH. Or, the UE may receive a slot format configuration via combination of higher layer signaling and DCI.

The subframe structure shown in FIG. 9 may be called a self-contained subframe structure. Referring to FIG. 9, the subframe includes DL control channel in the first symbol, and UL control channel in the last symbol. The remaining symbols may be used for DL data transmission and/or for UL data transmission. According to this subframe structure, DL transmission and UL transmission may sequentially proceed in one subframe. Accordingly, the UE may both receive DL data and transmit UL acknowledgement/non-acknowledgement (ACK/NACK) in the subframe. As a result, it may take less time to retransmit data when a data transmission error occurs, thereby minimizing the latency of final data transmission.

In the self-contained subframe structure, a time gap may be required for the transition process from the transmission mode to the reception mode or from the reception mode to the transmission mode. For this purpose, some symbols at the time of switching from DL to UL in the subframe structure may be set to the guard period (GP).

An example shown in FIG. 10 is a time-frequency resource grid used in NR. An example shown in FIG. 10 may be applied to UL and/or DL.

Referring to FIG. 10, multiple slots are included within one subframe on the time domain. Specifically, when expressed according to the value of "μ", "14·2μ" symbols may be expressed in the resource grid. Also, one resource block (RB) may occupy 12 consecutive subcarriers. One RB may be referred to as a physical resource block (PRB), and 12 resource elements (REs) may be included in each PRB. The number of allocatable RBs may be determined based on a minimum value and a maximum value. The number of allocatable RBs may be configured individually according to the numerology ("μ"). The number of allocatable RBs may be configured to the same value for UL and DL, or may be configured to different values for UL and DL.

Hereinafter, a cell search in NR is described.

The UE may perform cell search in order to acquire time and/or frequency synchronization with a cell and to acquire a cell identifier (ID). Synchronization channels such as PSS, SSS, and PBCH may be used for cell search.

Referring to FIG. 11, the PSS and SSS may include one symbol and 127 subcarriers. The PBCH may include 3 symbols and 240 subcarriers.

The PSS is used for SS/PBCH block symbol timing acquisition. The PSS indicates 3 hypotheses for cell ID identification. The SSS is used for cell ID identification. The SSS indicates 336 hypotheses. Consequently, 1008 physical layer cell IDs may be configured by the PSS and the SSS.

The SS/PBCH block may be repeatedly transmitted according to a predetermined pattern within the 5ms window. For example, when L SS/PBCH blocks are transmitted, all of SS/PBCH block #1 through SS/PBCH block #L may contain the same information, but may be transmitted through beams in different directions. That is, quasi co-located (QCL) relationship may not be applied to the SS/PBCH blocks within the 5ms window. The beams used to receive the SS/PBCH block may be used in subsequent operations between the UE and the network (e.g., random access operations). The SS/PBCH block may be repeated by a specific period. The repetition period may be configured individually according to the numerology.

Referring to FIG. 11, the PBCH has a bandwidth of 20 RBs for the 2nd/4th symbols and 8 RBs for the 3rd symbol. The PBCH includes a demodulation reference signal (DM-RS) for decoding the PBCH. The frequency domain for the DM-RS is determined according to the cell ID. Unlike LTE/LTE-A, since a cell-specific reference signal (CRS) is not defined in NR, a special DM-RS is defined for decoding the PBCH (i.e., PBCH-DMRS). The PBCH-DMRS may contain information indicating an SS/PBCH block index.

The PBCH performs various functions. For example, the PBCH may perform a function of broadcasting a master information block (MIB). System information (SI) is divided into a minimum SI and other SI. The minimum SI may be divided into MIB and system information block type-1 (SIB1). The minimum SI excluding the MIB may be referred to as a remaining minimum SI (RMSI). That is, the RMSI may refer to the SIB1.

The MIB includes information necessary for decoding SIB1. For example, the MIB may include information on a subcarrier spacing applied to SIB1 (and MSG 2/4 used in the random access procedure, other SI), information on a frequency offset between the SS/PBCH block and the subsequently transmitted RB, information on a bandwidth of the PDCCH/SIB, and information for decoding the PDCCH (e.g., information on search-space/control resource set (CORESET)/DM-RS, etc., which will be described later). The MIB may be periodically transmitted, and the same information may be repeatedly transmitted during 80ms time interval. The SIB1 may be repeatedly transmitted through the PDSCH. The SIB1 includes control information for initial access of the UE and information for decoding another SIB.

Hereinafter, DL control channel in NR is described.

The search space for the PDCCH corresponds to aggregation of control channel candidates on which the UE performs blind decoding. In LTE/LTE-A, the search space for the PDCCH is divided into a common search space (CSS) and a UE-specific search space (USS). The size of each search space and/or the size of a control channel element (CCE) included in the PDCCH are determined according to the PDCCH format.

In NR, a resource-element group (REG) and a CCE for the PDCCH are defined. In NR, the concept of CORESET is defined. Specifically, one REG corresponds to 12 REs, i.e., one RB transmitted through one OFDM symbol. Each REG includes a DM-RS. One CCE includes a plurality of REGs (e.g., 6 REGs). The PDCCH may be transmitted through a resource consisting of 1, 2, 4, 8, or 16 CCEs. The number of CCEs may be determined according to the aggregation level. That is, one CCE when the aggregation level is 1, 2 CCEs when the aggregation level is 2, 4 CCEs when the aggregation level is 4, 8 CCEs when the aggregation level is 8, 16 CCEs when the aggregation level is 16, may be included in the PDCCH for a specific UE.

The CORESET is a set of resources for control signal transmission. The CORESET may be defined on 1/2/3 OFDM symbols and multiple RBs. In LTE/LTE-A, the number of symbols used for the PDCCH is defined by a physical control format indicator channel (PCFICH). However, the PCFICH is not used in NR. Instead, the number of symbols used for the CORESET may be defined by the RRC message (and/or PBCH/SIB1). Also, in LTE/LTE-A, since the frequency bandwidth of the PDCCH is the same as the entire system bandwidth, so there is no signaling regarding the frequency bandwidth of the PDCCH. In NR, the frequency domain of the CORESET may be defined by the RRC message (and/or PBCH/SIB1) in a unit of RB.

The base station may transmit information on the CORESET to the UE. For example, information on the CORESET configuration may be transmitted for each CORESET. Via the information on the CORESET configuration, at least one of a time duration of the corresponding CORESET (e.g., 1/2/3 symbol), frequency domain resources (e.g., RB set), REG-to-CCE mapping type (e.g., whether interleaving is applied or not), precoding granularity, a REG bundling size (when the REG-to-CCE mapping type is interleaving), an interleaver size (when the REG-to-CCE mapping type is interleaving) and a DMRS configuration (e.g., scrambling ID) may be transmitted. When interleaving to distribute the CCE to 1-symbol CORESET is applied, bundling of two or six REGs may be performed. Bundling of two or six REGs may be performed on the two symbols CORESET, and time first mapping may be applied. Bundling of three or six REGs may be performed on the three symbols CORESET, and a time first mapping may be applied. When REG bundling is performed, the UE may assume the same precoding for the corresponding bundling unit.

In NR, the search space for the PDCCH is divided into CSS and USS. The search space may be configured in CORESET. As an example, one search space may be defined in one CORESET. In this case, CORESET for CSS and CORESET for USS may be configured, respectively. As another example, a plurality of search spaces may be defined in one CORESET. That is, CSS and USS may be configured in the same CORESET. In the following example, CSS means CORESET in which CSS is configured, and USS means CORESET in which USS is configured. Since the USS may be indicated by the RRC message, an RRC connection may be required for the UE to decode the USS. The USS may include control information for PDSCH decoding assigned to the UE.

Since the PDCCH needs to be decoded even when the RRC configuration is not completed, CSS should also be defined. For example, CSS may be defined when a PDCCH for decoding a PDSCH that conveys SIB1 is configured or when a PDCCH for receiving MSG 2/4 is configured in a random access procedure. Like LTE/LTE-A, in NR, the PDCCH may be scrambled by a radio network temporary identifier (RNTI) for a specific purpose.

A resource allocation in NR is described.

In NR, a specific number (e.g., up to 4) of bandwidth parts (BWPs) may be defined. A BWP (or carrier BWP) is a set of consecutive PRBs, and may be represented by a consecutive subsets of common RBs (CRBs). Each RB in the CRB may be represented by CRB1, CRB2, etc., beginning with CRB0.

Referring to FIG. 12, multiple BWPs may be defined in the CRB grid. A reference point of the CRB grid (which may be referred to as a common reference point, a starting point, etc.) is referred to as so-called "point A" in NR. The point A is indicated by the RMSI (i.e., SIB1). Specifically, the frequency offset between the frequency band in which the SS/PBCH block is transmitted and the point A may be indicated through the RMSI. The point A corresponds to the center frequency of the CRB0. Further, the point A may be a point at which the variable "k" indicating the frequency band of the RE is set to zero in NR. The multiple BWPs shown in FIG. 12 is configured to one cell (e.g., primary cell (PCell)). A plurality of BWPs may be configured for each cell individually or commonly.

Referring to FIG. 12, each BWP may be defined by a size and starting point from CRB0. For example, the first BWP, i.e., BWP #0, may be defined by a starting point through an offset from CRB0, and a size of the BWP #0 may be determined through the size for BWP #0.

A specific number (e.g., up to four) of BWPs may be configured for the UE. Even if a plurality of BWPs are configured, only a specific number (e.g., one) of BWPs may be activated per cell for a given time period. However, when the UE is configured with a supplementary uplink (SUL) carrier, maximum of four BWPs may be additionally configured on the SUL carrier and one BWP may be activated for a given time. The number of configurable BWPs and/or the number of activated BWPs may be configured commonly or individually for UL and DL. Also, the numerology and/or CP for the DL BWP and/or the numerology and/or CP for the UL BWP may be configured to the UE via DL signaling. The UE can receive PDSCH, PDCCH, channel state information (CSI) RS and/or tracking RS (TRS) only on the active DL BWP. Also, the UE can transmit PUSCH and/or physical uplink control channel (PUCCH) only on the active UL BWP.

Referring to FIG. 13, 3 BWPs may be configured. The first BWP may span 40 MHz band, and a subcarrier spacing of 15 kHz may be applied. The second BWP may span 10 MHz band, and a subcarrier spacing of 15 kHz may be applied. The third BWP may span 20 MHz band and a subcarrier spacing of 60 kHz may be applied. The UE may configure at least one BWP among the 3 BWPs as an active BWP, and may perform UL and/or DL data communication via the active BWP.

A time resource may be indicated in a manner that indicates a time difference/offset based on a transmission time point of a PDCCH allocating DL or UL resources. For example, the start point of the PDSCH/PUSCH corresponding to the PDCCH and the number of symbols occupied by the PDSCH / PUSCH may be indicated.

Carrier aggregation (CA) is described. Like LTE/LTE-A, CA can be supported in NR. That is, it is possible to aggregate continuous or discontinuous component carriers (CCs) to increase the bandwidth and consequently increase the bit rate. Each CC may correspond to a (serving) cell, and each CC/cell may be divided into a primary serving cell (PSC)/primary CC (PCC) or a secondary serving cell (SSC)/secondary CC (SCC).

Hereinafter, integrated backhaul and access (IAB) is described.

Referring to FIG. 14, multiple nodes (i.e., node A/B/C) may multiplex access and backhaul links in time, frequency, or space (e.g., beam-based operation). Each node may provide access link to UE. Each node may provide backhaul to other node. Each node may referred to as relay transmission and reception point (rTRP).

The operation of the different links may be on the same or different frequencies (also termed 'in-band' and 'out-band' relays). While efficient support of out-band relays is important for some NR deployment scenarios, it is critically important to understand the requirements of in-band operation which imply tighter interworking with the access links operating on the same frequency to accommodate duplex constraints and avoid/mitigate interference.

In addition, operating NR systems in mmWave spectrum presents some unique challenges including experiencing severe short-term blocking that may not be readily mitigated by present RRC-based handover mechanisms due to the larger time-scales required for completion of the procedures compared to short-term blocking. Overcoming short-term blocking in mmWave systems may require fast RAN-based mechanisms for switching between nodes, which do not necessarily require involvement of the core network. The above described need to mitigate short-term blocking for NR operation in mmWave spectrum along with the desire for easier deployment of self-backhauled NR cells creates a need for the development of an integrated framework that allows fast switching of access and backhaul links. Over-the-air (OTA) coordination between nodes can also be considered to mitigate interference and support end-to-end route selection and optimization.

The following requirements and aspects should be addressed by the IAB for NR:

- Efficient and flexible operation for both in-band and out-band relaying in indoor and outdoor scenarios

- Multi-hop and redundant connectivity

- End-to-end route selection and optimization

- Support of backhaul links with high spectral efficiency

- Support of legacy NR UEs

In the present disclosure, when there are two nodes (DgNB, RN) and each node is node A and node B, and when node A schedules node B (i.e., node B is associated with node A), the backhaul link connecting the two nodes is referred to as nodeA-nodeB backhaul link. Similarly, when node A schedules UE 1 (i.e., UE 1 is associated with node A), the access link connecting node A and UE 1 is referred to as nodeA-UE1 access link. Node A may be called a parent node of node B. Node B may be called a child node of node A.

In the present disclosure, for convenience of description, backhaul links with IAB nodes scheduled by a specific IAB node are referred to as backhaul links of the corresponding IAB node, and an access link with a UE scheduled by a specific IAB node is referred to as an access link of the corresponding IAB node. For example, RN1-RN2 backhaul link and RN1-RN3 backhaul link become backhaul links of RN1, and RN1-UE2 access link and RN1-UE4 access link become access links of RN1.

In the present disclosure, for convenience of description, when there are RNs receiving and transmitting data from a specific DgNB to transmit/receive data to/from the UE, the backhaul links between the DgNB and the RNs are referred to as a backhaul link under the DgNB. Also, the access links between RNs connected by backhaul links under a particular DgNB and UEs are referred to as an access link under the DgNB.

In the present disclosure, the IAB node refers to a node, except the donor node, performing relaying operation between other IAB nodes and/or donor node. That is, the IAB node is connected by backhaul links with other IAB nodes and/or donor node, and connected by access link with UEs.

Transmit signal quality is described.

(1) Frequency error

The UE modulated carrier frequency shall be accurate to within ±0.1 PPM observed over a period of 1 ms compared to the carrier frequency received from the NR Node B.

(2) Transmit modulation quality

Transmit modulation quality defines the modulation quality for expected in-channel RF transmissions from the UE. The transmit modulation quality is specified in terms of:

- Error vector magnitude (EVM) for the allocated resource blocks (RBs)

- EVM equalizer spectrum flatness derived from the equalizer coefficients generated by the EVM measurement process

- Carrier leakage

- In-band emissions for the non-allocated RB

The error vector magnitude is a measure of the difference between the reference waveform and the measured waveform. This difference is called the error vector. Before calculating the EVM, the measured waveform is corrected by the sample timing offset and RF frequency offset. Then the carrier leakage shall be removed from the measured waveform before calculating the EVM.

The measured waveform is further equalized using the　channel estimates subjected to the EVM equalizer spectrum flatness requirement. For DFT-s-OFDM waveforms, the EVM result is defined after the front-end FFT and inverse DFT (IDFT) as the square root of the ratio of the mean error vector power to the mean reference power expressed as a %. For CP-OFDM waveforms, the EVM result is defined after the front-end FFT as the square root of the ratio of the mean error vector power to the mean reference power expressed as a %.

The basic EVM measurement interval in the time domain is one preamble sequence for the physical random access channel (PRACH) and the duration of PUCCH/PUSCH channel, or one hop, if frequency hopping is enabled for PUCCH and PUSCH in the time domain. The EVM measurement interval is reduced by any symbols that contains an allowable power transient.

The root mean square (RMS) average of the basic EVM measurements for 10 sub-frames excluding any transient period for the average EVM case, and 60 sub-frames excluding any transient period for the reference signal EVM case. For EVM evaluation purposes, all PRACH preamble formats 0-4 and all PUCCH formats 1, 1a, 1b, 2, 2a and 2b are considered to have the same EVM requirement as quadrature phase shift keying (QPSK) modulated.

Carrier leakage is an additive sinusoid waveform whose frequency is the same as the modulated waveform carrier frequency. The measurement interval is one slot in the time domain. In the case that uplink sharing, the carrier leakage may have 7.5 kHz shift with the carrier frequency.

The in-band emission is defined as the average emission across 12 sub-carriers and as a function of the RB offset from the edge of the allocated UL transmission bandwidth. The in-band emission is measured as the ratio of the UE output power in a non-allocated RB to the UE output power in an allocated RB.

The basic in-band emissions measurement interval is defined over one slot in the time domain, however, the minimum requirement applies when the in-band emission measurement is averaged over 10 sub-frames. When the PUSCH or PUCCH transmission slot is shortened due to multiplexing with sounding reference signal (SRS), the in-band emissions measurement interval is reduced by one or more symbols, accordingly.

The zero-forcing equalizer correction applied in the EVM measurement process must meet a spectral flatness requirement for the EVM measurement to be valid. The EVM equalizer spectrum flatness is defined in terms of the maximum peak-to-peak ripple of the equalizer coefficients (dB) across the allocated uplink block. The basic measurement interval is the same as for EVM.

For unshaped modulated waveforms, the peak-to-peak variation of the EVM equalizer coefficients contained within the frequency range of the uplink allocation shall not exceed the maximum ripple for normal conditions. For uplink allocations contained within both Range 1 and Range 2, the coefficients evaluated within each of these frequency ranges shall meet the corresponding ripple requirement and the following additional requirement. Referring to FIG. 15, for normal condition, the relative difference between the maximum coefficient in Range 1 and the minimum coefficient in Range 2 must not be larger than 5 dB, and the relative difference between the maximum coefficient in Range 2 and the minimum coefficient in Range 1 must not be larger than 7 dB.

The EVM equalizer spectral flatness shall not exceed the maximum ripple for extreme conditions. For uplink allocations contained within both Range 1 and Range 2, the coefficients evaluated within each of these frequency ranges shall meet the corresponding ripple requirement and the following additional requirement. Referring to FIG. 15, for extreme condition, the relative difference between the maximum coefficient in Range 1 and the minimum coefficient in Range 2 must not be larger than 6 dB, and the relative difference between the maximum coefficient in Range 2 and the minimum coefficient in Range 1 must not be larger than 10 dB.

Currently, since the IAB scenario considers multiple hops, one IAB node has a backhaul link with a parent node, a backhaul link with a child node, and an access link with a UE. First, in the description below, the backhaul link with the parent node may be denoted as "P-BH", the backhaul link with the child node may be denoted as "C-BH", and the access link with the UE may be denoted as "AC". Multiplexing by time division multiplexing (TDM), spatial division multiplexing (SDM), and frequency division multiplexing (FDM) between P-BH, C-BH, and AC are considered. Basically, three or more links may be transmitted and/or received simultaneously considering FDM/SDM, which may require alignment of synchronization timing boundary and/or transmission timing boundary between IAB nodes and/or between IAB node and UE. In this case, depending on which node the transmission is going to be, there is a burden that synchronization timing and/or transmission timing should change continuously.

However, in reality, as FDM/SDM is highly resource efficient, changing the transmission timing for some transmissions and intermittently applying FDM/SDM may contribute to the overall performance, while mitigating the problem of constant timing changes. The present disclosure mainly considers a scenario in which FDM/SDM is applied between P-BH and C-BH or between P-BH and AC, but the present disclosure can be immediately applied to a scenario in which FDM/SDM is applied between C-BH and AC or between ACs.

Currently, there are in-band scenario in which BH and AC operate in the same band and out-band scenario in which BH and AC operate in different bands. Usually, since the influence of interference is dominant in the case of FDM on the same band in the frequency domain, the main scenario of the present disclosure may be the in-band scenario. But if harmonics or harmonic mixing interferences are a problem even in the out-band scenario, the present disclosure can be applied.

Referring to FIG. 16, Case 1-1 shows multiplexing between transmission on P-BH (i.e., uplink backhaul) and transmission on AC (i.e., downlink access). Case 1-2 shows multiplexing between transmission on P-BH (i.e., uplink backhaul) and transmission on C-BH (i.e., downlink backhaul). Case 2-1 shows multiplexing between reception on P-BH (i.e., downlink backhaul) and reception on AC (i.e., uplink access). Case 2-2 shows multiplexing between reception on P-BH (i.e., downlink backhaul) and reception on C-BH (i.e., uplink backhaul). The embodiment of the present disclosure described below can be applied to all of cases described above.

For the convenience of the description, the Case 1-1 is exemplarily described. For power control between transmission on P-BH and transmission on AC, the following two principles may be considered.

(1) Prioritize UL transmission (i.e., prioritize P-BH)

(2) Prioritize DL transmission (i.e., prioritize AC)

Depending on a type of channel to be transmitted, (1) or (2) or hybrid of (1) and (2) may be considered. For example, if SS/PBCH block transmissions or measurement related signals are to be transmitted to UEs, (2) may be considered. For URLLC traffic or high priority UL data or HARQ-ACK transmission, (1) may be considered. Furthermore, (1) and (2) may be utilized simultaneously per each slot or per each channel or any TDM manner. Whether to use (1) or (2) may be configured by donor by donor node or parent node. This type of mixing alternatives in different time/channels or configuration may also be applied to other proposals mentioned in the present disclosure.

The prioritization of specific link/transmission may mean at least one of the followings.

- When transmit power is limited to support both links, transmit power may be allocated firstly to the prioritized link/transmission, and transmit power for non-prioritized link(s)/transmission(s) may be scaled and/or dropped. How to scale and/or drop transmit power for non-prioritized link(s)/transmission(s) may also be dependent on other constraints, such as power spectrum density (PSD) requirements and/or dynamic power requirements and/or in-band emission requirements/impacts.

- Any transmission related and/or reception related requirements may be firstly ensured for the prioritized link/transmission. That is, adaptation on non-prioritized link(s)/transmission(s) may be considered to ensure the requirements in the prioritized link/transmission. If the requirements on the prioritized link/transmission cannot be ensured, one or more of non-prioritized link(s)/transmission(s) may be dropped.

For transmission related and/or reception related requirements/constraints, the followings may be considered.

- Power dynamics at TX side for access DL: PSD of a subcarrier should be within a range of [X-d, X+d], where X is the average PSD of the entire bandwidth of transmission. PSD may be interchangeable with RE power.

- Received power dynamics: From perspective of reception, it may also be considered to have limited power dynamics in reception, which may or may not be possible to guarantee given that each frequency can go over different channels.

- Maximum allowable interference by in-band emission (or interference from adjacent carrier): As two links may be multiplexed by FDM with resource allocation (reduced DL transmission + UL transmission) or with in-band carrier aggregation (UL carrier + adjacent DL carrier), some interference from UL to DL and/or DL to UL may be considered.

Given the transmission related and/or reception related requirements/constraints mentioned above, for the Case 1-1, the above mentioned "(1) Prioritize UL transmission (i.e., prioritize P-BH)" or "(2) Prioritize DL transmission (i.e., prioritize AC)" may be considered as follows.

(1) Prioritize UL transmission (i.e., prioritize P-BH)

To give higher priority to UL link/transmission, the following approaches may be considered.

- Power may be dynamically allocated to UL link/transmission by power control function between parent node and IAB node. IAB node may use the remaining power for DL link/transmission with keeping the necessary requirements. To allow this, UL scheduling may occur a bit early (i.e., k2 values of PUSCH scheduling is relatively large or larger than the minimum required time for DL scheduling).

Even with dynamic case, it may be beneficial to semi-statically configure the frequency range of DL and UL respectively such that adaptation of power can be done. If this approach is used, based on transmit power control (TPC) command from the parent node, IAB node may adapt its DL power (e.g., if TPC indicates increased power in UL link/transmission, based on FDM portions between DL/UL, power for DL link/transmission can be decreased). By this way, rather than depending on UL scheduling, overall power may be defined by TPC functionality.

As mentioned above, dynamic power adaptation may not be applied for some measurement related signals which require constant power. If IAB node cannot transmit the measurement related signals without adapting or changing power, other signals may be dropped or such measurement related signals may be dropped.

- Power and allocated resources may be semi-statically configured to IAB node, and dynamic UL scheduling may still change modulation and coding scheme (MCS). IAB node may use the remaining power not allocated to UL link/transmission for DL link/transmission with keeping the necessary requirements.

When there is no UL transmission in a given slot, total power may be allocated to DL link/transmission by IAB node.

When IAB node can handle UL and DL power separately (e.g., by separate power amplifier), the capability may be indicated to the parent node, and no dependency between UL link/transmission and DL link/transmission can be considered.

When IAB node has multiple DL links/transmissions (e.g., to UE and to child nodes), regardless of the number of DL links/transmissions, single DL link/transmission may be considered in terms of power control, and further power control on each DL link/transmission may be further considered.

The IAB node may calculate PSD based on UL power configured to a slot n. The maximum DL PSD may be determined within a tolerance level based on the calculated PSD, and DL transmission may be performed by using the PSD. The total power of DL may be calculated by subtracting the UL power or may be scaled if it exceeds P_CMAX. When scaling is performed, different scaling factors may be given to DL/UL respectively in a manner that satisfies maximally the PSD according to the IAB implementation. In order to satisfy this operation, for example, it is possible to reduce the power with the total allocated RB. For example, if the power configured to the SS/PBCH block and/or CSI-RS is satisfied, DL/UL may be transmitted at the same time. For example, if the power configured to the SS/PBCH block and/or CSI-RS is not satisfied, UL transmission may be dropped. For example, if the UL power can be adjusted by changing within the maximum power reduction (MPR) or power tolerance value, the UL transmission may be transmitted, and otherwise, the UL transmission may be dropped. That is, in a slot where DL power for signal transmission should not be changed, the UL power may be adjusted based on the DL power. Otherwise, the DL power may be changed based on the UL power.

(2) Prioritize DL transmission (i.e., prioritize AC)

To give higher priority to DL link/transmission, the following approaches may be considered.

- Transmit power for DL link/transmission may be semi-statically allocated, and UL power may be restricted by IAB total power - allocated power to DL link/transmission. Maximum power usable by DL link/transmission and/or minimum power usable by DL link/transmission may be defined. The reason of maximum power usable by DL link/transmission may be to ensure no UL scheduling beyond what could be necessary in DL link/transmission in worst case. The reason of minimum power usable by DL link/transmission may be to maximize power sharing, as IAB node can allocate more power to DL link/transmission based on UL scheduling as UL scheduling comes earlier than the DL link/transmission from the parent node. Though, if IAB node cannot dynamically adapt DL scheduling, this information may not be so useful. So, if minimum power usable by DL link/transmission is used, UL scheduling may occur a bit early (i.e., k2 values of PUSCH scheduling is relatively large or larger than the minimum required time for DL scheduling).

- Average PSD (or average power on each RE) on DL link/transmission may be semi-statically allocated and informed to parent node. UL power control of the parent node may also ensure PSD of UL within a tolerable range based on average PSD. In addition, total power on DL link/transmission may also be configured.

As mentioned above in the present disclosure, when DL transmission occurs, a UE or child node may expect that dynamic power range is restricted within a range depending on modulation compared to the average power. This may be also to handle EVM at the transmitter side. In general, this may be also applied to UL transmission as well. When, at least, power control is done based on DL link/transmission (or prioritize DL link/transmission), the following shows an example of power control in DL link/transmission and UL link/transmission.

(1) Approach 1

The IAB node may information on (average) PSD "X" to be used in DL link/transmission and total power "Y" (or, RB set to be used in DL link/transmission) to the parent node. It may be assumed that the total power is same as the entire bandwidth including DL/UL * X.

The parent node may perform power control and/or resource allocation to ensure during UL power control that the PSD is [X-k or -infinite, X+k] (e.g., k = 6 or 12) or that the power of each RE satisfies the RE power dynamic range. It may be assumed that this is also necessary for the EVM of each modulation symbol transmitted in UL. In other words, the average RE of DL may be indicated, and UL transmission may be occurred as long as average RE power of UL is lower than X + d. If the allocated/configured power is larger than X+d in terms of average RE power, UL power may be reduced up to the point where the average RE power becomes less than X+d. In DL, average power may be maintained as X by scheduling/power allocation.

Also, the total power may also be configured so that it does not exceed P_CMAX - Y. Or, scaling may be performed when the total power exceeds PCMAX - Y in the child node.

For UL transmission of IAB node, the maximum range of power tolerance (or MPR) value may be set to M. If the PSD of the UL power within the M value can be adjusted within the dynamic power range based on the PSD P1 used for the DL power of the IAB node, the UL transmission may be performed. If not, UL transmission may be dropped. M may mean a tolerance value that the wireless device can lower the power of UL to the maximum, and generally may mean marginal power relaxation for matching the PSD with DL. If PSD and power constraints can be matched only when power should be lowered than the corresponding power (i.e., M), UL transmission and/or DL transmission may be dropped. This tolerance value may be relaxation or incensement. For example, if the PSD can be matched only by increasing the power, the tolerance value may be a setting of how much the power of the corresponding UL transmission can be increased. Alternatively, when the range of the M value is [-P, P] and a value of the M value is negative, it may mean a relaxation about how much it is possible to reduce the configured power. When a value of the M value is positive, it may mean increase of the configured power.

DL/UL operation for FDM / SDM may occur at least at the same duration when a power amplifier is shared. This may be to reduce power transient. Whether such restriction is required for FDM/SDM may be based on UE capability.

(2) Approach 2

Power determination for UL link/transmission and DL link/transmission may be done only by IAB node. The parent node may indicate TPC which may be used to lower or increase RE power on PUSCH or PUCCH or SRS transmission. For example, based on scheduling on UL link/transmission and DL link/transmission, IAB node may determine power on each RE considering MCS. RE power in UL link/transmission may be controlled by the parent node. The parent node may indicate increase or decrease of RE power within the RE power control dynamic range. For example, if the parent node discovers too high power in UL link/transmission, the parent node may request decreasing RE power. For example, if the parent node discovers too low power in UL link/transmission, the parent node may request increasing RE power. It may be based on the assumption that the total power used by IAB node does not vary so dramatically. The parent node may also indicate lowering or increasing RE power on DL link/transmission as well to minimize in-band emission or emission from DL transmission.

As the power is allocated to all frequencies of a carrier by IAB node, there may be no case where power is restricted. Based on RE power request from the parent node, dynamic range may be determined for each channel and transmitted. This may impact high interference at the parent node which may be handled by MCS control at the parent node or controlling RE power. Semi-static partition of frequency region used for DL and UL may be further considered for efficient power handling. Based on the received power from the IAB node, the parent node may determine (i.e., increase or decrease) UL powers. If this is used, MCS may be adapted dynamically to handle channel variation as power may be kept semi-statically.

For Case 2-1 mentioned above, similar mechanism as in-band emission handling scheme of device-to-device (D2D) transmission may be used. In other words, if there are too much interference from an IAB node, TDM may be further considered, or grouping of similar received power at the IAB node may be indicated. In other words, received signal-to-interference and noise ratio (SINR) (or signal-to-noise ratio (SNR)) from each node to the IAB node may be informed, or grouping may be done at the IAB node among links with similar quality. Different group may be scheduled in different timing to minimize in-band emission. As the IAB node does not change dynamically, IAB nodes with similar receiving quality may be grouped to minimize in-band emission. After discovering link quality of each link, FDM/SDM/TDM patterns may be designed to minimize in-band emission.

However, not only in-band emission but also heavy interference may also be considered when the IAB node performs DL transmission and another IAB node and/or UE node performs UL transmission. In other words, high interference may occur in case that Case 1-1 and Case 2-1 mentioned above occur simultaneously. In this case, such issue may be addressed by cross-link interference techniques and/or by TDM between DL link/transmission and UL link/transmission from perspective of a single IAB node. In other words, Case 1-1/1-2 and Case 2-1/2-2 may not occur simultaneously (e.g., Case 1-2 and one IAB node and Case 2-2 to a child node of the IAB node), and TDM pattern between two categories may be used. In other words, if an IAB node is operating category of Case 1, the child node of the IAB node may not operate category of Case 2 type simultaneously (i.e., only DL at a child node). For example, TDM pattern may be configured by the followings.

- IAB nodes with even hop counts may perform category of Case 1 in one slot, and category of Case 2 in the next slot.

- IAB nodes with even hop counts may perform category of Case 1 in 3rd slot, and category of Case 2 in 4th slot.

In other words, category of Case 1 and Case 2 may not occur simultaneously between IAB nodes which have parent-child relationship.

The child node may calculate the average power and PSD based on the pathloss of the parent node. If the calculated value is much larger than the incoming value from the UE or the child node, at least one of the following operation may be considered.

- For UEs that do not increase the UL power, scheduling may be performed by placing a gap in the DL frequency.

- UL power control may be performed by setting receivedTargetPower based on received RSRP.

- A request to reduce the DL power, at least for a specific PRB set, may be transmitted to the parent node.

In all implementations of the present disclosure mentioned above, all configuration information may be exchanged between the parent node and IAB node such that both knows what are the configurations used in each of implementations of the present disclosure. Even though the present disclosure discusses IAB node behavior in terms of power control, the present disclosure may also be applied to the UE/wireless device without loss of generality.

Alternatively, output power dynamics on UL link/transmission may not be applied as follows. Without multiplexing by SDM/FDM, IAB node may perform DL transmission or UL transmission at a given time. When DL transmission and UL transmission occur simultaneously, impact may be different in each case as follows.

(1) Case 1-1

If IAB node uses different power towards parent node and UE respectively, in-band emission from transmission to the parent node to transmission to the UE (or out-of-band emission) may be significant. For example, if DL transmission and UL transmission are semi-statically multiplexed by TDM, and a UE is configured with a carrier whose bandwidth is restricted only to the configured DL portion, interference from UL transmission of the IAB node may be considered as out-of-band interference from a UE perspective. If the bandwidth of DL carrier is defined to include potential UL portion as well, then UL transmission of the IAB node would become in-band emission. Not to deteriorate the quality of UE demodulation performance, potential in-band emission from UL transmission of the IAB node may need to be controlled. To minimize in-band emission or out-of-band emission to UE, the following two approaches may be considered.

- If the first PRB of DL portion is K1 and the last PRB of DL portion is K2, M PRBs before K1 and after K2 may not have high power which will impact as in-band emission to DL reception in perspective of UE. M value may be different depending on DL portions, e.g., before DL portion or after DL portion. To avoid this, there may be guard PRBs of M PRBs between DL and UL portion. M PRBs may be defined such that M PRBs is the number of PRBs which are impacted by UL transmission of the IAB node. M value may be a function of UL portion and/or UL power. M value may be configured by parent node and the parent node may maintain the power not to occur unacceptable emission to UEs.

If the parent node cannot ensure average RE level of scheduled UL transmission within a required range compared to DL average RE power, the node may apply power scaling on UL transmission. Power scaling on UL transmission may occur only in PRBs near to DL transmission or may occur in the entire UL transmission. Or, which option is used may also be configured. Or, if PRB bundling is configured, the same power may be applied at least within bundled PRBs, and thus, if only PRBs near to DL transmission reduces power, then only bundled PRBs near to DL transmission may reduce the power.

The parent node can configure additional tolerance level for power scaling in total power or per average RE level which will be used to determine whether to drop UL transmission. If the IAB node has to scale UL power beyond the configured tolerance level, the IAB node may drop UL transmission. The IAB node may also reduce DL power by implementation to minimize the gap between UL power and DL power as long as it does not impact on the DL quality. After applying DL power adaptation, necessary power adaptation on UL transmission may be performed.

- PRBs which impact on DL PRBs should satisfy the output power dynamics. Or, the average RE power on such PRBs should not exceed a certain value compared to average RE power used in DL PRBs. For example, if average RE power of DL is X, average RE power at such PRBs should not exceed X-d (e.g., d = 6).

(2) Case 1-2

In this case, another IAB node (i.e., childe node) is the recipient. Handling high interference from potential in-band emission at the child node may be addressed by the following two approaches. First, DL performance may be ensured by the IAB node as mentioned in Case 1-1. In this case, the IAB node may control transmission power in UL and DL portions to avoid in-band emission to the childe node. Second, the same approach of Case 2-2 (or Case 2-1) which will be described below may be taken. In this approach, in-band emission may be suppressed or handled by the child node.

(3) Case 2-1

In this case, DL power from parent node is expected to be relatively high and not easy to reduce, as the parent would have other UEs/IAB nodes to support as well. Therefore, even though reducing power of the parent node is one approach, controlling power of UL link/transmission from UE should be focused. To control power of UL link/transmission, the IAB node may need to know the potential DL power from the parent node, and measure pathloss. Based on the potential DL power and the measured pathloss, the IAB node may define 'TargetReceivedSINR' to be comparable to DL SINR. In other words, UL power from UE may be increased up to a point where received quality from UE and the parent node is comparable, and thus, in-band emission from the parent node to UL transmission of the UE can be controlled.

However, as UE has limited power, this approach may always not be feasible. In this case, gap between the parent node and UE may be necessary. In other words, DL portion may be semi-statically determined/configured, and the IAB node may schedule UEs which are apart from DL portion (thus received SINR is low). Further, the IAB node may inform the parent node about necessary PRB gaps to minimize interference.

Alternatively, to reduce interference from DL link/transmission, different DL power may be used in PRBs depending on how close they are to UL portion. For example, PRBs near to UL portion may use power level P1, PRBs are not very near but have impacts to UL portion may use power level P2, and PRBs which are far apart from UL portion may use power level P3, where P1 < P2 < P3. In this case, power level may mean average RE power. In this case, in-band emission between PRBs using different power level may be another issue. To address this, a gap may be placed between different power levels. At least within output power dynamics, the IAB node may place lower RE power channels near UL portion to minimize interference. If the gap of PRBs is used to suppress in-band emission, the gap may be placed between DL and UL when DL uses the similar PSD over the bandwidth or between different power levels (e.g., between PRBs with low PSD regardless of DL or UL and PRBs with high PSD).

(4) Case 2-2

The similar approach mentioned in Case 2-1 may be used 1. However, as the target is the child node, power may be relatively easily increased.

When UL power is increased for Case 2-1 and 2-2, interference to other neighboring IAB nodes sharing the same PRBs may also be increased. Thus, power adaptation and controlling gap between UL and DL may need to be used adaptively depending on the situations.

Another issue is to partition power between DL link/transmission and UL link/transmission. The following options may be considered.

(1) Option 1: UL maximum power may be the maximum power of UE, and the maximum configured by parent node by P_EMAX (i.e., min {maximum power of UE, P_EMAX}), then remaining power may be used for DL. UL power may be limited by schemes specified in Rel-15 power control except for PRBs requiring special handling as mentioned above for suppressing/minimizing interferences.

(2) Option 2: IAB node may define its maximum power on UL based on pathloss information. Alternatively, IAB node may report pathloss information to the parent node then the parent node may determine maximum UL power, and remaining power may be used for DL.

(3) Option 3: IAB node may define its maximum power on DL based on coverage requirements. Alternatively, the IAB node may report coverage requirements/maximum DL power to the parent node, then parent node may determine maximum DL power and maximum UL power based on the reported total power capability from the IAB node.

(4) Option 4: Parent node may configure UL portion (PRBs used for UL link/transmission), maximum MCS and other power-control parameters, based on that the IAB node determines maximum possible UL power allocatable by the parent node. Then the remaining power may be used to DL link/transmission.

Each of four options mentioned above has pros and cons if IAB node does not have sufficient power to support both full DL coverage and UL coverage. As semi-static partitioning has some drawbacks in terms of potential coverage loss, the following option may be considered.

(5) Option 5: Parent node may configure UL portion, and then the IAB node may report maximum UL power based on the average RE power computation. Average RE power may be computed as IAB node maximum power / the whole bandwidth including UL/DL portions. In other words, UL power may be determined proportionally based on the number of PRBs allocated to UL portions. This may be considered as maximum UL power by the parent node. In this case, at least for FDM, there is not necessarily DL coverage loss as the same power is used compared to the full PRB case.

In this example, the fist node may be an IAB node which performs relaying operation between the second node and the wireless device. The second node may be a parent node of the first node. The second node may be a donor node. A link between the first node and the second node may be a wireless backhaul link, and a link between the first node and the wireless device may be a wireless access link. However, the first node/second node/wireless device are merely exemplary, and the first node/second node/wireless device may be replaced with various devices mentioned in FIG. 1, FIG. 2 and FIG. 4.

In step S1700, the first node receives, from the second node, a configuration of a DL resource for a DL transmission from the first node to the wireless device. In step S1710, the first node receives, from the second node, a configuration of a UL resource for a UL transmission from the first node to the second node. In step S1720, the first node performs the DL transmission to the wireless device based on the DL resource and the UL transmission to the second node based on the UL resource at a same time interval.

The DL resource and the UL resource are separated by at least one guard PRB in a frequency domain. At least one guard PRBs may be PRBs impacted by the UL transmission. A number of the at least one guard PRBs may be based on the UL resource and/or a power for the UL transmission. A number of the at least one guard PRBs may be configured by the second node.

A power scaling may be applied to the UL transmission. The power scaling may be applied to the UL transmission on PRBs from the UL resources adjacent to the DL resource. Or, the power scaling may be applied to the UL transmission on entire PRBs from the UL resources. A power scaling may also be applied to the DL transmission.

In addition, an additional tolerance level may be configured by the second node. The additional tolerance level may be used to determine whether to drop the UL transmission or not.

The steps of S1700 to S1720 described above may be implemented by one of the wireless device 100x of FIG. 1, the first wireless device 100 of FIG. 2, or the wireless device 100 of FIG. 4. For example, referring to FIG. 2, the processor 102 may control the transceiver 106 to perform steps of S1700 to S1720.

According to the embodiment of the present disclosure shown in FIG. 17, when a node (e.g. IAB node) perform UL transmission to another node (e.g., parent node) and DL transmission to wireless device (e.g., UE) simultaneously, guard PRB can be placed between UL portion and DL portion. Therefore, in-band emission or out-of-band emission can be minimized.

In view of the exemplary systems described herein, methodologies that may be implemented in accordance with the disclosed subject matter have been described with reference to several flow diagrams. While for purposed of simplicity, the methodologies are shown and described as a series of steps or blocks, it is to be understood and appreciated that the claimed subject matter is not limited by the order of the steps or blocks, as some steps may occur in different orders or concurrently with other steps from what is depicted and described herein. Moreover, one skilled in the art would understand that the steps illustrated in the flow diagram are not exclusive and other steps may be included or one or more of the steps in the example flow diagram may be deleted without affecting the scope of the present disclosure.

Claims in the present description can be combined in a various way. For instance, technical features in method claims of the present description can be combined to be implemented or performed in an apparatus, and technical features in apparatus claims can be combined to be implemented or performed in a method. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in an apparatus. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in a method. Other implementations are within the scope of the following claims.

Claims

A method performed by a first node in a wireless communication system, the method comprising:

receiving, from a second node, a configuration of a downlink (DL) resource for a DL transmission from the first node to a wireless device;

receiving, from the second node, a configuration of an uplink (UL) resource for a UL transmission from the first node to the second node; and

perform the DL transmission to the wireless device based on the DL resource and the UL transmission to the second node based on the UL resource at a same time interval,

wherein the DL resource and the UL resource are separated by at least one guard physical resource block (PRB) in a frequency domain.
The method of claim 1, wherein the at least one guard PRBs is PRBs impacted by the UL transmission.
The method of claim 1, wherein a number of the at least one guard PRBs is based on the UL resource and/or a power for the UL transmission.
The method of claim 1, wherein a number of the at least one guard PRBs is configured by the second node.
The method of claim 1, wherein a power scaling is applied to the UL transmission.
The method of claim 5, wherein the power scaling is applied to the UL transmission on PRBs from the UL resources adjacent to the DL resource.
The method of claim 5, wherein the power scaling is applied to the UL transmission on entire PRBs from the UL resources.
The method of claim 1, wherein an additional tolerance level is configured by the second node, and

wherein the additional tolerance level is used to determine whether to drop the UL transmission or not.
The method of claim 1, wherein a power scaling is applied to the DL transmission.
The method of claim 1, wherein the first node is an integrated access and backhaul (IAB) node which performs relaying operation between the second node and the wireless device.
The method of claim 1, wherein a link between the first node and the second node is a wireless backhaul link, and

wherein a link between the first node and the wireless device is a wireless access link.
The method of claim 1, wherein the second node is a parent node of the first node.
The method of claim 1, wherein the second node is a donor node.
The method of claim 1, wherein the wireless device is in communication with at least one of a mobile device, a network, and/or autonomous vehicles other than the wireless device.
A first node in a wireless communication system, the method comprising:

a memory;

a transceiver; and

a processor, coupled to the memory and the transceiver,

wherein the first node is configured to:

receive, from a second node, a configuration of a downlink (DL) resource for a DL transmission from the first node to a wireless device;

receive, from the second node, a configuration of an uplink (UL) resource for a UL transmission from the first node to the second node; and

perform the DL transmission to the wireless device based on the DL resource and the UL transmission to the second node based on the UL resource at a same time interval,

wherein the DL resource and the UL resource are separated by at least one guard physical resource block (PRB) in a frequency domain.