Patent Description:
Fifth-generation (<NUM>) New Radio (NR) is a telecommunication standard promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with Internet of Things (IoT)), and other requirements. Some aspects of <NUM> NR may be based on the fourth-generation (<NUM>) Long Term Evolution (LTE) standard and resources. There exists a need for further improvements in <NUM> NR technology such that <NUM> NR is more scalable and deployable in a more efficient and cost-effective way.

US patent application <CIT> discloses spectrum sharing mechanisms between LTE and NR in the same frequency. US patent application <CIT> discloses configuring NR reserved resources for supporting NR co-carrier co-existence with LTE/NB-IoT.

The following presents a summary of one or more aspects of the present disclosure, in order to provide a basic understanding of such aspects. Its sole purpose is to present some concepts of one or more aspects of the disclosure as a prelude to the more detailed description that is presented later.

The present disclosure provides a method for spectrum sharing in wireless communication according to claim <NUM>, an apparatus for wireless communication according to claim <NUM>, and a non-transitory computer-readable medium according to claim <NUM>. Specific embodiments are subject of the dependent claims.

Other aspects, features, and embodiments will become apparent to those of ordinary skill in the art, upon reviewing the following description of specific, exemplary embodiments in conjunction with the accompanying figures. While features may be discussed relative to certain embodiments and figures below, all embodiments can include one or more of the advantageous features discussed herein. In other words, while one or more embodiments may be discussed as having certain advantageous features, one or more of such features may also be used in accordance with the various embodiments discussed herein.

The electromagnetic spectrum is often subdivided, based on frequency/wavelength, into various classes, bands, channels, etc. In <NUM> NR two initial operating bands have been identified as frequency range designations FR1 (<NUM> - <NUM>) and FR2 (<NUM> - <NUM>). It should be understood that although a portion of FR1 is greater than <NUM>, FR1 is often referred to (interchangeably) as a "Sub-<NUM>" band in various documents and articles.

For example, three higher operating bands have been identified as frequency range designations FR4-a or FR4-<NUM> (<NUM> - <NUM>), FR4 (<NUM> - <NUM>), and FR5 (<NUM> - <NUM>).

While aspects and embodiments are described in this application by illustration to some examples, those skilled in the art will understand that additional implementations and use cases may come about in many different arrangements and scenarios. Innovations described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, packaging arrangements. For example, embodiments and/or uses may come about via integrated chip embodiments and other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, AI-enabled devices, etc.). While some examples may or may not be specifically directed to use cases or applications, a wide assortment of applicability of described innovations may occur. Implementations may range a spectrum from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregate, distributed, or OEM devices or systems incorporating one or more aspects of the described innovations. In some practical settings, devices incorporating described aspects and features may also necessarily include additional components and features for implementation and practice of claimed and described embodiments. For example, transmission and reception of wireless signals necessarily includes a number of components for analog and digital purposes (e.g., hardware components including antenna, RF-chains, power amplifiers, modulators, buffer, processor(s), interleaver, adders/summers, etc.). It is intended that innovations described herein may be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, end-user devices, etc. of varying sizes, shapes and constitution.

Aspects of the present disclosure provide various devices, methods, and systems for dynamic spectrum sharing between different radio access technologies. Dynamic spectrum sharing (DSS) is a technology that allows wireless network operators to share a spectrum between different radio access technologies (RATs). In some examples, DSS allows an operator to dynamically allocate or share some existing <NUM> (e.g., LTE) spectrum with a <NUM> network (e.g., New Radio (NR)) to deliver <NUM> services using the shared spectrum.

The wireless communication system <NUM> includes three interacting domains: core networks <NUM> and <NUM>, a radio access network (RAN) <NUM>, and a user equipment (UE) <NUM>. By virtue of the wireless communication system <NUM>, the UE <NUM> may be enabled to carry out data communication with external data networks <NUM> and <NUM>, such as (but not limited to) the Internet.

In different technologies, standards, or contexts, a base station may variously be referred to by those skilled in the art as a base transceiver station (BTS), a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), an access point (AP), a Node B (NB), an eNode B (eNB), a gNode B (gNB), a transmission and reception point (TRP), or some other suitable terminology. In some examples, a base station may include two or more TRPs that may be collocated or non-collocated. Each TRP may communicate on the same or different carrier frequency within the same or different frequency band.

The radio access network <NUM> is further illustrated supporting wireless communication for multiple mobile apparatuses. A mobile apparatus may be referred to as user equipment (UE) in 3GPP standards, but may also be referred to by those skilled in the art as a mobile station (MS), a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal (AT), a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, or some other suitable terminology. A UE may be an apparatus (e.g., a mobile apparatus) that provides a user with access to network services.

Within the present document, a "mobile" apparatus need not necessarily have a capability to move, and may be stationary. The term mobile apparatus or mobile device broadly refers to a diverse array of devices and technologies. UEs may include a number of hardware structural components sized, shaped, and arranged to help in communication; such components can include antennas, antenna arrays, RF chains, amplifiers, one or more processors, etc. electrically coupled to each other. For example, some non-limiting examples of a mobile apparatus include a mobile, a cellular (cell) phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal computer (PC), a notebook, a netbook, a smartbook, a tablet, a personal digital assistant (PDA), and a broad array of embedded systems, e.g., corresponding to an "Internet of things" (IoT). A mobile apparatus may additionally be an automotive or other transportation vehicle, a remote sensor or actuator, a robot or robotics device, a satellite radio, a global positioning system (GPS) device, an object tracking device, a drone, a multi-copter, a quad-copter, a remote control device, a consumer and/or wearable device, such as eyewear, a wearable camera, a virtual reality device, a smart watch, a health or fitness tracker, a digital audio player (e.g., MP3 player), a camera, a game console, etc. A mobile apparatus may additionally be a digital home or smart home device such as a home audio, video, and/or multimedia device, an appliance, a vending machine, intelligent lighting, a home security system, a smart meter, etc. A mobile apparatus may additionally be a smart energy device, a security device, a solar panel or solar array, a municipal infrastructure device controlling electric power (e.g., a smart grid), lighting, water, etc.; an industrial automation and enterprise device; a logistics controller; agricultural equipment, etc. Still further, a mobile apparatus may provide for connected medicine or telemedicine support, e.g., health care at a distance. Telehealth devices may include telehealth monitoring devices and telehealth administration devices, whose communication may be given preferential treatment or prioritized access over other types of information, e.g., in terms of prioritized access for transport of critical service data, and/or relevant QoS for transport of critical service data.

In general, base stations <NUM> may include a backhaul interface for communication with a backhaul portion (e.g., backhauls <NUM> and <NUM>) of the wireless communication system. A first backhaul <NUM> may provide a link between a base station <NUM> and a <NUM> NR core network <NUM>. A second backhaul <NUM> may provide a link between a base station <NUM> and a <NUM> core network <NUM> (e.g., LTE core network). Further, in some examples, a backhaul network (e.g., backhaul <NUM> in <FIG>) may provide interconnection between the respective base stations <NUM>.

<FIG> is an exemplary illustration of an example of a radio access network according to some aspects. Referring now to <FIG>, by way of example and without limitation, a schematic illustration of a RAN <NUM> is provided. In some examples, the RAN <NUM> may be the same as the RAN <NUM> described above and illustrated in <FIG>. In one example, the RAN <NUM> may be a RAN that supports both <NUM> RAT and <NUM> RAT (e.g., hybrid RAN or NG-RAN). The geographic area covered by the RAN <NUM> may be divided into cellular regions (cells) that can be uniquely identified by a user equipment (UE) based on an identification broadcasted from one access point or base station. <FIG> illustrates macrocells <NUM>, <NUM>, and <NUM>, and a small cell <NUM>, each of which may include one or more sectors (not shown). A sector is a sub-area of a cell. All sectors within one cell are served by the same base station. A radio link within a sector can be identified by a single logical identification belonging to that sector. In a cell that is divided into sectors, the multiple sectors within a cell can be formed by groups of antennas with each antenna responsible for communication with UEs in a portion of the cell.

In some examples, the base stations may support multiple radio access technologies (e.g., LTE and/or NR communication), and two base stations may communicate with each other through a backhaul link (e.g., backhaul <NUM>) to coordinate resources allocation and scheduling in different RATs. For example, an LTE base station (e.g., base station <NUM>) and a <NUM> NR base station (e.g., base station <NUM>) may communicate to each other through a wired or wireless backhaul link <NUM> to coordinate communication resource allocation and scheduling to facilitate dynamic spectrum sharing (DSS) as described in this disclosure.

Within the RAN <NUM>, the cells may include UEs that may be in communication with one or more sectors of each cell. Further, each base station <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> may be configured to provide an access point to a core network <NUM> (see <FIG>) for all the UEs in the respective cells. For example, UEs <NUM> and <NUM> may be in communication with base station <NUM>; UEs <NUM> and <NUM> may be in communication with base station <NUM>; UEs <NUM> and <NUM> may be in communication with base station <NUM> by way of RRH <NUM>; UE <NUM> may be in communication with base station <NUM>; and UE <NUM> may be in communication with mobile base station <NUM>. In some examples, the UEs <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and/or <NUM> may be the same as the UE/scheduled entity <NUM> described above and illustrated in <FIG>. In some aspects, the UEs may communicate with the RAN <NUM> using different RATs (e.g., <NUM> RAT (e.g., LTE) and/or <NUM> RAT (e.g., NR Light)).

In a further aspect of the RAN <NUM>, sidelink signals may be used between UEs without necessarily relying on scheduling or control information from a base station. For example, two or more UEs (e.g., UEs <NUM> and <NUM>) may communicate with each other using peer to peer (P2P) or sidelink signals <NUM> without relaying that communication through a base station (e.g., base station <NUM>). In a further example, UE <NUM> is illustrated communicating with UEs <NUM> and <NUM>. Here, the UE <NUM> may function as a scheduling entity or a primary sidelink device, and UEs <NUM> and <NUM> may function as a scheduled entity or a non-primary (e.g., secondary) sidelink device. In still another example, a UE may function as a scheduling entity in a device-to-device (D2D), peer-to-peer (P2P), or vehicle-to-vehicle (V2V) network, and/or in a mesh network. In a mesh network example, UEs <NUM> and <NUM> may optionally communicate directly with one another in addition to communicating with the scheduling entity <NUM>. Thus, in a wireless communication system with scheduled access to time-frequency resources and having a cellular configuration, a P2P configuration, or a mesh configuration, a scheduling entity and one or more scheduled entities may communicate utilizing the scheduled resources.

The air interface in the radio access network <NUM> may utilize one or more duplexing algorithms. Duplex refers to a point-to-point communication link where both endpoints can communicate with one another in both directions. Full duplex (FD) means both endpoints can simultaneously communicate with one another. Half duplex (HD) means only one endpoint can send information to the other at a time. In a wireless link, a full duplex channel generally relies on physical isolation of a transmitter and receiver, and suitable interference cancellation technologies. Full duplex emulation is frequently implemented for wireless links by utilizing frequency division duplex (FDD) or time division duplex (TDD). In FDD, transmissions in different directions operate at different carrier frequencies. In TDD, transmissions in different directions on a given channel are separated from one another using time-division multiplexing. That is, at some times the channel is dedicated for transmissions in one direction, while at other times the channel is dedicated for transmissions in the other direction, where the direction may change very rapidly, e.g., several times per slot.

In some aspects of the disclosure, the radio access network <NUM> may use half-duplex (HD) frequency division duplex (FDD) (HD-FDD) for the communication between a base station (e.g., base station <NUM>) and a UE (e.g., NR Light UE). A HD-FDD type UE may be implemented with less complexity and cost because the duplexer may be replaced by a switch, and only a single phase-locked loop (PLL) is needed. A HD-FDD UE may be compatible with an FD-FDD network and may coexist with regular FDD UEs. HD-FDD can use different frequencies or bands for uplink and downlink communications, and the uplink and downlink communications are not only on distinct frequencies but are also separated in the time domain.

The air interface in the radio access network <NUM> may utilize one or more multiplexing and multiple access algorithms to enable simultaneous communication of the various devices. For example, <NUM> NR specifications provide multiple access for UL transmissions from UEs <NUM> and <NUM> to base station <NUM>, and for multiplexing for DL transmissions from base station <NUM> to one or more UEs <NUM> and <NUM>, utilizing orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP). In addition, for UL transmissions, <NUM> NR specifications provide support for discrete Fourier transform-spread-OFDM (DFT-s-OFDM) with a CP (also referred to as single-carrier FDMA (SC-FDMA)). However, within the scope of the present disclosure, multiplexing and multiple access are not limited to the above schemes, and may be provided utilizing time division multiple access (TDMA), code division multiple access (CDMA), frequency division multiple access (FDMA), sparse code multiple access (SCMA), resource spread multiple access (RSMA), or other suitable multiple access schemes. Further, multiplexing DL transmissions from the base station <NUM> to UEs <NUM> and <NUM> may be provided utilizing time division multiplexing (TDM), code division multiplexing (CDM), frequency division multiplexing (FDM), orthogonal frequency division multiplexing (OFDM), sparse code multiplexing (SCM), or other suitable multiplexing schemes.

Various aspects of the present disclosure will be described with reference to an OFDM waveform, schematically illustrated in <FIG>. It should be understood by those of ordinary skill in the art that the various aspects of the present disclosure may be applied to a DFT-s-OFDMA waveform in substantially the same way as described herein below. That is, while some examples of the present disclosure may focus on an OFDM link for clarity, it should be understood that the same principles may be applied as well to DFT-s-OFDMA waveforms as well as other waveforms.

Within the present disclosure, a frame refers to a duration of <NUM> for wireless transmissions, with each frame consisting of <NUM> subframes of <NUM> each. Referring now to <FIG>, an expanded view of an exemplary DL subframe <NUM> is illustrated, showing an OFDM resource grid <NUM>. However, as those skilled in the art will readily appreciate, the PHY transmission structure for any particular application may vary from the example described here, depending on any number of factors. Here, time is in the horizontal direction with units of OFDM symbols; and frequency is in the vertical direction with units of subcarriers or tones.

The resource grid <NUM> may be used to schematically represent time-frequency resources for a given antenna port. That is, in a MIMO implementation with multiple antenna ports available, a corresponding multiple number of resource grids <NUM> may be available for communication. The resource grid <NUM> is divided into multiple resource elements (REs) <NUM>. An RE, which is <NUM> subcarrier × <NUM> symbol, is the smallest discrete part of the time-frequency grid, and contains a single complex value representing data from a physical channel or signal. Depending on the modulation utilized in a particular implementation, each RE may represent one or more bits of information. In some examples, a block of REs may be referred to as a physical resource block (PRB) or more simply a resource block (RB) <NUM>, which contains any suitable number of consecutive subcarriers in the frequency domain. In one example, an RB may include <NUM> subcarriers, a number independent of the numerology used. In some examples, depending on the numerology, an RB may include any suitable number of consecutive OFDM symbols in the time domain. Within the present disclosure, it is assumed that a single RB such as the RB <NUM> entirely corresponds to a single direction of communication (either transmission or reception for a given device).

Scheduling of scheduled entities (e.g., UEs) for downlink, uplink, or sidelink transmissions typically involves scheduling one or more resource elements <NUM> within one or more sub-bands or bandwidth parts (BWPs). Thus, a UE generally utilizes only a subset of the resource grid <NUM>. In some examples, an RB may be the smallest unit of resources that can be allocated to a UE. Thus, the more RBs scheduled for a UE, and the higher the modulation scheme chosen for the air interface, the higher the data rate for the UE. The RBs may be scheduled by a base station (e.g., gNB, eNB, etc.) or may be self-scheduled by a UE implementing D2D sidelink communication.

Each subframe <NUM> (e.g., a <NUM> subframe) may consist of one or multiple adjacent slots. In the example shown in <FIG>, one subframe <NUM> includes four slots <NUM>, as an illustrative example. In some examples, a slot may be defined according to a specified number of OFDM symbols with a given cyclic prefix (CP) length. For example, a slot may include <NUM> or <NUM> OFDM symbols with a nominal CP. Additional examples may include mini-slots, sometimes referred to as shortened transmission time intervals (TTIs), having a shorter duration (e.g., one to three OFDM symbols). These mini-slots may in some cases be transmitted occupying resources scheduled for ongoing slot transmissions for the same or for different UEs. Any number of resource blocks may be utilized within a subframe or slot.

An expanded view of one of the slots <NUM> illustrates the slot <NUM> including a control region <NUM> and a data region <NUM>. In general, the control region <NUM> may carry control channels (e.g., physical downlink control channel (PDCCH)), and the data region <NUM> may carry data channels (e.g., physical downlink shared channel (PDSCH) or PUSCH). Of course, a slot may contain all DL, all UL, or at least one DL portion and at least one UL portion. The structure illustrated in <FIG> is merely exemplary in nature, and different slot structures may be utilized, and may include one or more of each of the control region(s) and data region(s).

Although not illustrated in <FIG>, the various REs <NUM> within an RB <NUM> may be scheduled to carry one or more physical channels, including control channels, shared channels, data channels, etc. Other REs <NUM> within the RB <NUM> may also carry pilots or reference signals. These pilots or reference signals may provide for a receiving device to perform channel estimation of the corresponding channel, which may enable coherent demodulation/detection of the control and/or data channels within the RB <NUM>.

In some examples, the slot <NUM> may be utilized for broadcast, multicast, groupcast, or unicast communication. For example, a broadcast, multicast, or groupcast communication may refer to a point-to-multipoint transmission by one device (e.g., a base station, UE, or other similar device) to other devices. Here, a broadcast communication is delivered to all devices, whereas a multicast communication is delivered to multiple intended recipient devices and a groupcast communication is delivered to a group of intended recipient devices. A unicast communication may refer to a point-to-point transmission by a one device to a single other device.

In an example of cellular communication over a cellular carrier via a Uu interface, for a DL transmission, the scheduling entity (e.g., a base station) may allocate one or more REs <NUM> (e.g., within the control region <NUM>) to carry DL control information including one or more DL control channels, such as a PDCCH, to one or more scheduled entities (e.g., UEs). The PDCCH carries downlink control information (DCI) including but not limited to power control commands (e.g., one or more open loop power control parameters and/or one or more closed loop power control parameters), scheduling information, a grant, and/or an assignment of REs for DL and UL transmissions. The PDCCH may further carry HARQ feedback transmissions such as an acknowledgment (ACK) or negative acknowledgment (NACK). HARQ is a technique well-known to those of ordinary skill in the art, wherein the integrity of packet transmissions may be checked at the receiving side for accuracy, e.g., utilizing any suitable integrity checking mechanism, such as a checksum or a cyclic redundancy check (CRC). If the integrity of the transmission confirmed, an ACK may be transmitted, whereas if not confirmed, a NACK may be transmitted. In response to a NACK, the transmitting device may send a HARQ retransmission, which may implement chase combining, incremental redundancy, etc..

The base station may further allocate one or more REs <NUM> (e.g., in the control region <NUM> or the data region <NUM>) to carry other DL signals, such as a demodulation reference signal (DMRS); a phase-tracking reference signal (PT-RS); a channel state information (CSI) reference signal (CSI-RS); and a synchronization signal block (SSB). SSBs may be broadcast at regular intervals based on a periodicity (e.g., <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>). An SSB includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast control channel (PBCH). A UE may utilize the PSS and SSS to achieve radio frame, subframe, slot, and symbol synchronization in the time domain, identify the center of the channel (system) bandwidth in the frequency domain, and identify the physical cell identity (PCI) of the cell.

The PBCH in the SSB may further include a master information block (MIB) that includes various system information, along with parameters for decoding a system information block (SIB). The SIB may be, for example, a SystemInformationType <NUM> (SIB1) that may include various additional system information. Examples of system information transmitted in the MIB may include, but are not limited to, a subcarrier spacing, system frame number, a configuration of a PDCCH control resource set (CORESET) (e.g., PDCCH CORESETO), and a search space for SIB1. Examples of additional system information transmitted in the SIB1 may include, but are not limited to, a random access search space, downlink configuration information, and uplink configuration information. The MIB and SIB1 together provide the minimum system information (SI) for initial access.

In an UL transmission, the scheduled entity (e.g., UE) may utilize one or more REs <NUM> to carry UL control information (UCI) including one or more UL control channels, such as a physical uplink control channel (PUCCH), to the scheduling entity. UCI may include a variety of packet types and categories, including pilots, reference signals, and information configured to enable or assist in decoding uplink data transmissions. In some examples, the UCI may include a scheduling request (SR), i.e., request for the scheduling entity to schedule uplink transmissions. Here, in response to the SR transmitted on the UCI, the scheduling entity may transmit downlink control information (DCI) that may schedule resources for uplink packet transmissions. UCI may also include HARQ feedback, channel state feedback (CSF), such as a CSI report, or any other suitable UCI.

In addition to control information, one or more REs <NUM> (e.g., within the data region <NUM>) may be allocated for data traffic (e.g., user data). Such data traffic may be carried on one or more traffic channels, such as, for a DL transmission, a physical downlink shared channel (PDSCH); or for an UL transmission, a physical uplink shared channel (PUSCH). In some examples, one or more REs <NUM> within the data region <NUM> may be configured to carry other signals, such as one or more SIBs and DMRSs.

In an example of sidelink communication over a sidelink carrier via a PC5 interface, the control region <NUM> of the slot <NUM> may include a physical sidelink control channel (PSCCH) including sidelink control information (SCI) transmitted by an initiating (transmitting) sidelink device (e.g., V2X or other sidelink device) towards a set of one or more other receiving sidelink devices. The data region <NUM> of the slot <NUM> may include a physical sidelink shared channel (PSSCH) including sidelink data traffic transmitted by the initiating (transmitting) sidelink device within resources reserved over the sidelink carrier by the transmitting sidelink device via the SCI. Other information may further be transmitted over various REs <NUM> within slot <NUM>. For example, HARQ feedback information may be transmitted in a physical sidelink feedback channel (PSFCH) within the slot <NUM> from the receiving sidelink device to the transmitting sidelink device. In addition, one or more reference signals, such as a sidelink SSB and/or a sidelink CSI-RS, may be transmitted within the slot <NUM>.

The channels or carriers described above and illustrated in <FIG> are not necessarily all the channels or carriers that may be utilized between a scheduling entity <NUM> and scheduled entities <NUM>, and those of ordinary skill in the art will recognize that other channels or carriers may be utilized in addition to those illustrated, such as other traffic, control, and feedback channels.

In OFDM, to maintain orthogonality of the subcarriers or tones, the subcarrier spacing may be equal to the inverse of the symbol period. A numerology of an OFDM waveform refers to its particular subcarrier spacing and cyclic prefix (CP) overhead. In some aspects, the network (e.g., RAN <NUM>) may use the same or different numerologies for different RATs (e.g., LTE and NR). A scalable numerology refers to the capability of the network to select different subcarrier spacings, and accordingly, with each spacing, to select the corresponding symbol duration, including the CP length. With a scalable numerology, a nominal subcarrier spacing (SCS) may be scaled upward or downward by integer multiples. In this manner, regardless of CP overhead and the selected SCS, symbol boundaries may be aligned at certain common multiples of symbols (e.g., aligned at the boundaries of each <NUM> subframe). The range of SCS may include any suitable SCS. For example, a scalable numerology may support a SCS ranging from <NUM> to <NUM>.

To illustrate this concept of a scalable numerology, <FIG> shows a first RB <NUM> having a nominal numerology, and a second RB <NUM> having a scaled numerology. As one example, the first RB <NUM> may have a 'nominal' subcarrier spacing (SCSn) of <NUM>, and a 'nominal' symbol durationn of <NUM>. Here, in the second RB <NUM>, the scaled numerology includes a scaled SCS of double the nominal SCS, or <NUM> × SCSn = <NUM>. Because this provides twice the bandwidth per symbol, it results in a shortened symbol duration to carry the same information. Thus, in the second RB <NUM>, the scaled numerology includes a scaled symbol duration of half the nominal symbol duration, or (symbol durationn)÷<NUM> = <NUM>.

<FIG> is a block diagram illustrating an example of a hardware implementation for a scheduling entity <NUM> employing a processing system <NUM>. For example, the scheduling entity <NUM> may be a user equipment (UE) as illustrated in any one or more of <FIG>, <FIG>, and/or <NUM>. In another example, the scheduling entity <NUM> may be a base station as illustrated in any one or more of <FIG>, <FIG>, and/or <NUM>.

The scheduling entity <NUM> may be implemented with a processing system <NUM> that includes one or more processors <NUM>. Examples of processors <NUM> include microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. In various examples, the scheduling entity <NUM> may be configured to perform any one or more of the functions described herein. That is, the processor <NUM>, as utilized in a scheduling entity <NUM>, may be used to implement any one or more of the processes and procedures described below and illustrated in <FIG>.

In this example, the processing system <NUM> may be implemented with a bus architecture, represented generally by the bus <NUM>. The bus <NUM> may include any number of interconnecting buses and bridges depending on the specific application of the processing system <NUM> and the overall design constraints. The bus <NUM> communicatively couples together various circuits including one or more processors (represented generally by the processor <NUM>), a memory <NUM>, and computer-readable media (represented generally by the computer-readable medium <NUM>). The bus <NUM> may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further. A bus interface <NUM> provides an interface between the bus <NUM> and a transceiver <NUM>. The transceiver <NUM> provides a communication interface or means for communicating with various other apparatus over a transmission medium. In some examples, the transceiver <NUM> may include one or more transceivers and/or RF chains configured to use different radio access technologies (RATs), for example, LTE, 5GNR, etc. Depending upon the nature of the apparatus, a user interface <NUM> (e.g., keypad, display, speaker, microphone, joystick) may also be provided. Of course, such a user interface <NUM> is optional, and may be omitted in some examples, such as a base station.

In some aspects of the disclosure, the processor <NUM> may include circuitry configured for various functions, including, for example, dynamic spectrum sharing between different RATs (e.g., LTE and <NUM> NR). For example, the circuitry may be configured to implement one or more of the functions described in relation to <FIG>.

In one example, the processor <NUM> may include a first RAT communication circuit <NUM>, a second RAT communication circuit <NUM>, and a scheduling and resource allocation circuit <NUM>. The scheduling entity may use the first RAT communication circuit <NUM> to perform various wireless communication functions via the transceiver <NUM> using a first RAT (e.g., LTE). The first RAT communication circuit <NUM> may perform various communication functions using the first RAT, for example, CRC functions, channel coding / decoding, rate matching, multiplexing / demultiplexing, scrambling / descrambling, modulation / demodulation, layer mapping / demapping, etc. The scheduling entity may use the second RAT communication circuit <NUM> to perform various wireless communication functions via the transceiver <NUM> using a second RAT (e.g., <NUM> NR). The second RAT communication circuit <NUM> may perform various communication functions using the second RAT, for example, CRC functions, channel coding / decoding, rate matching, multiplexing / demultiplexing, scrambling / descrambling, modulation / demodulation, layer mapping / demapping, etc. The processor may use the scheduling and resource allocation circuit <NUM> to perform various communication scheduling and resource allocation functions, for example, identifying resource usage by different RATs of a shared spectrum, scheduling UL and DL communication using a first RAT and a second RAT that share a spectrum, and allocating communication resources for communication using a first RAT and a second RAT that share a spectrum.

One or more processors <NUM> in the processing system may execute software. The software may reside on a computer-readable medium <NUM>. The computer-readable medium <NUM> may be a non-transitory computer-readable medium. A non-transitory computer-readable medium includes, by way of example, a magnetic storage device (e.g., hard disk, floppy disk, magnetic strip), an optical disk (e.g., a compact disc (CD) or a digital versatile disc (DVD)), a smart card, a flash memory device (e.g., a card, a stick, or a key drive), a random access memory (RAM), a read only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), a register, a removable disk, and any other suitable medium for storing software and/or instructions that may be accessed and read by a computer. The computer-readable medium <NUM> may reside in the processing system <NUM>, external to the processing system <NUM>, or distributed across multiple entities including the processing system <NUM>. The computer-readable medium <NUM> may be embodied in a computer program product. By way of example, a computer program product may include a computer-readable medium in packaging materials. Those skilled in the art will recognize how best to implement the described functionality presented throughout this disclosure depending on the particular application and the overall design constraints imposed on the overall system.

In one or more examples, the computer-readable storage medium <NUM> may include software configured for various functions, including, for example, dynamic spectrum sharing for communications using different RATs. For example, the software may be configured to implement one or more of the functions described in relation to <FIG>.

In one example, the software may include first RAT communication instructions <NUM>, second RAT communication instructions <NUM>, and scheduling and resource allocation instructions <NUM>. The scheduling entity may execute the first RAT communication instructions <NUM> to perform the communication functions using the first RAT communication circuit <NUM> as described above. The scheduling entity may execute the second RAT communication instructions <NUM> to perform the communication functions using the second RAT communication circuit <NUM> as described above. The scheduling entity may execute the scheduling and resource allocation instructions <NUM> to perform the functions using the scheduling and resource allocation circuit <NUM> as described above.

<FIG> is a diagram illustrating an exemplary downlink resource allocation using dynamic spectrum sharing (DSS) between LTE and NR bands in a DL carrier of an FDD wireless communication system. An exemplary LTE subframe <NUM> has <NUM> subcarriers in a spectrum that may be shared with an NR DL band using DSS. Dynamic spectrum sharing of FDD bands between NR and LTE provides a useful migration path from LTE to NR by allowing LTE and NR devices to share the same spectrum partially or completely. To facilitate DSS between LTE and NR, an LTE scheduling entity (e.g., eNB) and an NR scheduling entity (e.g., gNB) may coordinate their respective resource allocations and scheduling through backhaul communication.

In some aspects of the disclosure, an NR device (e.g., NR Light UE) may receive NR physical signals and channels using shared resources that are not occupied or used by certain LTE signals or channels, for example, cell-specific reference signals (CRS), CSI-RS, positioning reference signal (PRS), physical HARQ indicator channel (PHICH), physical control format indicator channel (PCFICH), PDSCH, and PDCCH. In some aspects, an NR UE may communicate with a base station using HD-FDD in a spectrum shared with LTE. In some aspects, certain LTE signals/channels (e.g., CRS, PHICH, PCFICH, PDCCH, etc.) are allocated to predetermined resource elements (REs) within an LTE subframe according to the LTE standards and cannot be moved to other resource locations within the LTE subframe. For example, the resources (e.g., time, frequency, and spatial resources) of the first two symbols of an LTE subframe, which may include the PHICH, PCFICH, and/or PDCCH, are not shared with NR DL. In other symbol locations, resources allocated to CRS (e.g., resources denoted as "R" in <FIG>) in the LTE subframe <NUM> are also not shared with the NR DL. Other LTE subframe resources that have more scheduling flexibility may be shared with NR DL signals or channels through the coordination between the LTE base station and NR base station.

Within the LTE subframe <NUM>, the resources that are available for sharing with NR may be classified into mini-slots spanning one or more LTE symbols. In one example, a scheduling entity (e.g., gNB) may schedule a <NUM>-symbol mini-slot (e.g., mini-slot <NUM>) for communicating the PDCCH, channel state information reference signal (CSI-RS), and/or tracking reference signal (TRS) of an NR device (e.g., NR light UE). In another example, a scheduling entity may schedule a <NUM>-symbol mini-slot (e.g., mini-slot <NUM>) or <NUM>-symbol mini-slot (e.g., mini-slot <NUM>) for communicating the synchronization signal block (SSB), PDCCH, PDSCH, CSI-RS, TRS, etc. of an NR device. The mini-slots shown in <FIG> are only for illustration purposes, and other configurations of available LTE resources may be shared with NR traffic to facilitate dynamic spectrum sharing (DSS) between LTE and NR. The numerology of the NR min-slots may be the same or different from the numerology of the LTE subframe <NUM>.

In some aspects of the disclosure, an NR device (e.g., NR Light UE) may have reduced coverage due to, for example, fewer equipped antennas and/or use of less robust modulation and coding scheme than a more capable NR UE. For coverage recovery, the scheduling entity (e.g., gNB) may use signal repetition and/or frequency hopping at the mini-slot level to communicate with the UE. In one example, an NR base station may transmit DL signals (e.g., SSB, PDCCH, PDSCH, CSI-RS, and/or TRS) multiple times (i.e., repetition) in multiple mini-slots scheduled using resources shared with the LTE subframe <NUM>. In another example, the NR base station may transmit DL signals (e.g., SSB, PDCCH, PDSCH, CSI-RS, and/or TRS) using frequency hopping between mini-slots that are located at different carriers or frequencies in a spectrum shared with LTE.

In some aspects of the disclosure, the numerology of the NR RAT can be the same or different from that of the LTE RAT. In one example, the LTE RAT may have a subcarrier spacing (SCS) of <NUM>, and the NR RAT may have a subcarrier spacing of <NUM>. For example, referring to <FIG>, LTE resources from the <NUM>th symbol through <NUM>th symbol of the second slot, labeled slot <NUM>, may be used for communicating an NR SSB <NUM>. In this case, the SSB punctures the <NUM>nd transmission occasion of CRS <NUM> from, for example, antenna ports <NUM> and <NUM>, and the SSB rate-matches around the LTE CRS <NUM>. In another example, the LTE RAT may have a subcarrier spacing of <NUM>, and the NR RAT may have a subcarrier spacing of <NUM>. Due to different numerology, two LTE symbols in the time domain can provide sufficient resources to carry the entire NR SSB <NUM> without the need to puncture the SSB around the LTE's CRS <NUM>.

Depending on the maximum supported bandwidth of an NR UE, the scheduling entity may schedule the transmission of SSB and CORESETO using TDM or FDM in resources shared with LTE. A CORESET (control resource set) is a set of physical resources (e.g., RBs) and a set of parameters that are used to carry PDCCH/DCI in an NR DL transmission. In general, a CORESET is configured using RRC signaling. CORESETO is a special CORESET that carries the PDCCH. <FIG> is a diagram illustrating an exemplary scheduling of an NR SSB and a CORESETO using TDM in a shared spectrum <NUM>. The spectrum <NUM> may include one or more RBs shared between LTE and NR. In this case, the combined bandwidth of the NR SSB <NUM> and CORESETO <NUM> is larger than the maximum supported bandwidth of the NR device (e.g., NR Light UE). Therefore, the scheduling entity may schedule the SSB <NUM> and CORESETO <NUM> to different time domain resources using TDM. The SSB and CORESETO may be transmitted in the same or different slots, and the numerology of the slot may be based on the subcarrier spacing (SCS) of the NR band. <FIG> is a diagram illustrating an exemplary scheduling of an NR SSB and a CORESETO using FDM in a shared spectrum <NUM>. In this case, the combined bandwidth of the NR SSB <NUM> and CORESETO <NUM> is not larger than the maximum supported bandwidth of the NR device. Therefore, the scheduling entity may schedule the SSB <NUM> and CORESETO <NUM> to different frequency domain resources using FDM.

In some aspects of the disclosure, the frequency domain mapping for the NR SSB may be based on a set of pre-defined non-zero frequency offsets (e.g., RB or RB group (RBG) level) or slot-level offsets with respect to the PSS, SSS, and PBCH of the LTE band. Using the frequency and/or slot-level offsets can reduce interference between the synchronization and control signals of NR and LTE bands. For example, in <FIG>, the NR SSB <NUM> can be allocated to shared resources (e.g., REs or RBGs) that are frequency and/or slot-level offset (non-overlapping) from the LTE PSS/SSS/PDCH <NUM>.

To support SSB beamforming, an NR SSB burst may be time-multiplexed, frequency-multiplexed, and/or space-multiplexed with LTE resources in the same or adjacent subframes. <FIG> is a diagram illustrating an NR SS burst in resources shared with LTE. In this example, the SS burst may include eight SSBs <NUM> (denoted as SSB <NUM> to SSB <NUM> in <FIG>). Each of the SSBs may be mapped to a different beam index (e.g., beam <NUM> to beam <NUM>) corresponding to a different beam direction. These SSBs with different beam directions may be time-multiplexed with LTE resources <NUM> in the same subframe or different subframes.

Some of the concepts described above in relation to DL resource allocation using DSS may be applied to UL resource allocation. For example, in a spectrum shared with an LTE UL subframe, a scheduling entity may schedule NR UL transmission at certain LTE symbol locations, and the UL resources available for NR communication can be classified into mini-slots spanning one or more LTE symbols.

In one aspect of the disclosure, an NR scheduling entity may apply a predetermined frequency offset (e.g., <NUM>) from the DL band when allocating UL resources in the frequency domain for an NR UE. In some examples, the NR network may share a spectrum with an LTE UL band. The entire NR spectrum may be larger than the LTE UL band. <FIG> is a diagram illustrating an LTE uplink subframe <NUM> that may be allocated to a spectrum that is included in an NR UL band. Referring to <FIG>, when LTE and NR UL bands share a spectrum or UL band, the scheduling entity may schedule the NR UL channels/signals (e.g., PUCCH/PUSCH) to be transmitted on resources corresponding to LTE RBs that are not pre-configured for certain LTE control channels (e.g., PRACH <NUM> and PUCCH <NUM>). In one example, the scheduling entity may schedule some or all resources corresponding to LTE RBs <NUM> (e.g., RBs not allocated to LTE control channels) to NR UL channels/signals (e.g., PRACH, SRS, PUCCH and PUSCH).

In some aspects of the disclosure, the scheduling entity may schedule the random access procedure (RACH) occasions of an NR UE to be time-multiplexed and/or frequency-multiplexed with the LTE RACH occasions. The NR RACH may be a two-step RACH or a four-step RACH. <FIG> illustrates a dynamic spectrum sharing (DSS) example in which an NR physical random access channel (PRACH) <NUM> is time-multiplexed (TDM) with an LTE PRACH <NUM> in a spectrum <NUM> shared between LTE and NR. In <FIG>, the amount of resources respectively allocated to the NR PRACH <NUM> and LTE PRACH <NUM> in a TDM fashion are illustrative examples only. In other examples, the resources used for the NR PRACH <NUM> and LTE PRACH <NUM> may be different from those shown in <FIG>.

<FIG> illustrates another DSS example in which an NR PRACH <NUM> is frequency-multiplexed (FDM) with an LTE PRACH <NUM> in a spectrum <NUM> shared by LTE and NR. Different PRACH formats, numerology, and PRACH-configuration-index can be considered for NR and LTE resource allocations.

For UL coverage recovery, the UE may use signal repetition or frequency hopping at the mini-slot level. In one example, an NR UE may transmit an UL signal multiple times (i.e., repetition) using multiple mini-slots. In another example, an NR UE may transmit an UL signal using frequency hopping between mini-slots that are located at different carriers or frequencies.

Due to the spectrum sharing between LTE and NR, the slot format for an NR device may be subject to certain cell-specific scheduling constraints imposed by LTE resource allocation (e.g., CRS, PCFICH, PHICH, PRACH, etc.) as described above. For example, NR DL transmission opportunities may be punctured by or rate-matched around LTE CRS or other reference signals that are pre-configured to be at certain RBs. In some examples, an NR UE that supports full-duplex FDD (FD-FDD) operation can fall back to using HD-FDD operation and share resources with LTE devices. In that case, an NR UE using HD-FDD does not need to monitor the NR PDCCH and other NR DL channels/signals on the LTE CRS symbol locations. In some examples, the cell-specific scheduling constraints may include an LTE muting pattern (e.g., zero-powered CSI-RS, PRS transmission or interference coordination pattern). In some aspects of the disclosure, an NR device can exploit these scheduling constraints to reduce the processing complexity of the DL while using HD-FDD.

In some aspects, the scheduling entity can configure the NR UEs in the same cell to use a common slot format taking into account the DSS scheduling constraints described above. In some examples, the slot formats for an NR UE using LTE-NR DSS can be hard-coded in the standards or signaled by a scheduling entity (e.g., a base station), for example, via a radio resource control (RRC) configuration message or the like. In one example, a cell-specific slot format for an NR UE may include at least the following fields: DL mini-slot, UL mini-slot, guard period mini-slot, and special mini-slot. A special mini-slot can be used for DL or UL traffic. The DL mini-slot field can specify a common DL mini-slot for NR UEs in the same cell. The UL mini-slot field can specify a common UL mini-slot for NR UEs in the same cell. The guard period mini-slot field can specify resources in which a UE may switch between UL or DL. The UE may also use the guard period for supporting discontinuous reception (DRX) and discontinuous transmission (DTX). For power saving and complexity reduction in an RRC connected state, the UE may suspend monitoring the PDCCH and/or other DL channels during the guard period, which is a DRX interval in the RRC connected mode. On the other hand, the UE may suspend UL transmission during the guard period, which is a DTX interval, to relax the preparation time for UL transmissions such as PUSCH, PUCCH, and SRS.

<FIG> is a diagram illustrating coordination between an LTE base station and an NR base station in sharing communication resources using DSS according to some aspects of the disclosure. An LTE base station <NUM> (e.g., eNB) and an NR base station <NUM> (e.g., gNB) can share communication resources (e.g., time-frequency-space resources) in wireless communication. A time-frequency-space resource can correspond to a certain combination of time (e.g., OFDM symbols), frequency (e.g., subcarriers), and spatial resources. The LTE base station <NUM> can communicate with the NR base station, for example, using a wireless or wired backhaul connection (e.g., backhaul link <NUM>). The base stations can exchange scheduling information <NUM> via the backhaul connection by transmitting and/or receiving signals or messages via the backhaul link. For example, the LTE base station <NUM> can communicate its DL scheduling information (e.g., CRS, PCFICH, PHICH, PRACH, etc.) and UL scheduling information (e.g., PRACH, SRS, PUSCH, and PUCCH) to the NR base station <NUM>. Based on the LTE scheduling information, at block <NUM>, the NR base station <NUM> can determine the scheduling constraints in scheduling and allocating the shared resources to one or more NR devices (e.g., UEs). In some examples, the NR base station can allocate the shared resources to one or more of the NR devices that communicate with the base station using HD-FDD techniques. Thereafter, the base stations can coordinate resources sharing for LTE and NR communications <NUM>, for example, using suitable multiplexing schemes (e.g., FDM and/or TDM). For example, the NR base station <NUM> avoid scheduling NR traffic in resources dedicated to certain LTE signals/channels (e.g., CRS, PCFICH, PHICH, PRACH, PRACH, and PUCCH).

<FIG> is flow chart illustrating an exemplary process <NUM> for determining scheduling constraints according to some aspects. The NR base station <NUM> (e.g., gNB) can use the process <NUM> to determine the scheduling constraints when sharing resources with an LTE network. At block <NUM>, the NR base station <NUM> can determine resources that are dedicated to LTE reference signals. For example, the NR base station <NUM> can receive information from the LTE base station <NUM> about resources that are dedicated, reserved, scheduled, or allocated to LTE DL reference signals (e.g., CRS). At block <NUM>, the NR base station <NUM> can determine resources that are dedicated to LTE channels. For example, the NR base station <NUM> can receive information from the LTE base station <NUM> about resources that are dedicated, reserved, scheduled, or allocated to LTE channels (e.g., PCFICH, PHICH, PRACH, PRACH, PUCCH etc.) At block <NUM>, the NR base station can determine the scheduling constraints including the resources dedicated to LTE reference signals and channels.

<FIG> is a flow chart illustrating an exemplary process <NUM> for sharing a spectrum between different RATs in accordance with the present invention. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for the implementation of all embodiments. In some examples, the process <NUM> may be carried out by the scheduling entity <NUM> illustrated in <FIG>. In some examples, the process <NUM> may be carried out by any suitable apparatus (e.g., base station, gNB, eNB, TRP, etc.) or means for carrying out the functions or algorithm described below.

At block <NUM>, a scheduling entity identifies a resource usage of a first RAT (e.g., LTE) in a resource pool for wireless communication. In one example, the scheduling entity may be a base station of a second RAT (e.g., <NUM> NR) that shares the resource pool with the first RAT. The resource pool may be a spectrum that provides time-frequency-space resources that can be dynamically shared between the first and second RATs. In some aspects, a scheduling entity (e.g., gNB or eNB) can use the dynamically shared resources to communicate with a UE using the first RAT or the second RAT. In one example, the scheduling and resource allocation circuit <NUM> (see <FIG>) can provide the means for identifying time-frequency-space resources scheduled and allocated for the first RAT (e.g., LTE communication). The scheduling entity of the second RAT may exchange scheduling information with a scheduling entity (e.g., eNB) of the first RAT to identify the resource allocation of the resource pool among the first RAT and second RAT. For example, the scheduling entity may identify an uplink resource usage and/or a downlink resource usage of the first RAT (e.g., LTE) using the processes described above in relation to <FIG> and <FIG>.

In some aspects, the downlink resource usage may include a resource of the resource pool dedicated to the first RAT, for example, at least one of CRS, PHICH, PCFICH, or PDCCH. The uplink resource usage may include a resource of the resource pool dedicated to the first RAT, for example, at least one of PRACH or PUCCH. In one example, these "dedicated resources" are reserved for LTE always-on signals, which are treated as scheduling constraints for NR communication. When NR and LTE networks share a spectrum, the scheduling constraint for NR can maintain backward compatibility with LTE and improves the co-existence of multiple RATs sharing the same spectrum on a subframe, slot, or symbol level.

At block <NUM>, the scheduling entity determines a scheduling constraint imposed by the resource usage of the first RAT for sharing the resource pool (e.g., time-frequency-space resources) for wireless communication using a second RAT (e.g., <NUM> NR). In one example, the scheduling and resource allocation circuit <NUM> can provide the means for determining the scheduling constraint. In some aspects, the scheduling constraint may include a resource of the resource pool that is not available for wireless communication using the second RAT due to sharing a frequency spectrum between the first RAT and the second RAT. For example, the resource not available for the second RAT may include resources preconfigured or dedicated to carry some control or reference signals of the first RAT, for example, the CRS, PHICH, PCFICH, PDCCH, PRACH, and PUCCH.

At block <NUM>, the scheduling entity (e.g., gNB) allocates, based on the scheduling constraint, a resource (e.g., one or more RB) of the resource pool for wireless communication using the second RAT. In one example, the scheduling and resource allocation circuit <NUM> can provide the means for allocating time-frequency-space resources (e.g., RBs) of a shared spectrum to the second RAT, for example, as described above in relation to <FIG>. For example, scheduling entity can allocate the resource that is not in conflict with the scheduling constraint (e.g., not dedicated to CRS, PHICH, PCFICH, PDCCH, PRACH, and/or PUCCH of the first RAT). In some examples, the time-frequency-space resources allocated to the second RAT may be grouped in one or more mini-slots, and each mini-slot spans a time interval corresponding to one or more time domain symbols of the first RAT. The time domain symbols of the first RAT may be included in a subframe that has a numerology aligned with a numerology of the first RAT. The mini-slots may use a numerology that is aligned with the numerology of the second RAT. The first RAT and second RAT may use the same numerology or different numerologies.

In some aspects, the scheduling entity may allocate the resource to an NR synchronization signal block (SSB) based on a predetermined frequency offset from an LTE synchronization signal (e.g., PSS/SSS/PBCH). A numerology of the frequency offset may be based on a numerology of the first RAT or a numerology of the second RAT. In some examples, the scheduling entity may allocate the resource to the NR SSB based on a predetermined slot offset from the LTE synchronization signal. A numerology of the slot offset may be based on a numerology of the first RAT or a numerology of the second RAT.

At block <NUM>, the scheduling entity communicates with a user equipment (UE) using the resource allocated to the second RAT. The UE communicates with the scheduling entity using HD-FDD that can save power and reduce complexity. Also, the UE can skip monitoring for DL signals/channels in resources that are included in the scheduling constraints. In some aspects, the UE may support FD-HDD and fallback to HD-FDD while using dynamic resource sharing. In one aspect, the second RAT communication circuit <NUM> can provide the means for communicating (e.g., UL and/or DL) with a UE (e.g., NR Light UE) using the resource allocated to the second RAT via the transceiver <NUM>.

In one aspect, for coverage recovery, the scheduling entity may repeat a signal transmission of the second RAT using one or more mini-slots or transmit a signal of the second RAT using frequency hopping using the one or more mini-slots. The mini-slots may be consecutive and/or disjoint in time. When a numerology of the first RAT is different from a numerology of the second RAT, the scheduling entity may transmit a synchronization signal (e.g., SSB) of the second RAT that is not punctured by or rate matched around a reference signal (CRS) of the first RAT while sharing spectrum. In one example, the scheduling entity may transmit a synchronization signal (e.g., SSB) of the second RAT that is punctured by or rate matched around a reference signal (CRS), a cell-specific reference signal, a semi-persistently scheduled data channel (e.g., PDSCH or PUSCH) and/or a control channel of the first RAT while sharing the spectrum, and the first RAT and second RAT may use a same numerology or different numerologies. In one example, the scheduling entity may transmit an NR SS burst including a plurality of SSBs that are time-multiplexed with resources that are allocated to LTE such that the SSB beams may be distributed in the time domain. In some examples, the scheduling entity may transmit an SSB and a CORESET using time-division multiplexing, frequency-division multiplexing, and/or space-division multiplexing (e.g., spatial multiplexing), depending on a maximum supported bandwidth of the UE.

In some aspects, the scheduling entity may determine a cell-specific slot format of the second RAT based on the scheduling constraint and signal the cell-specific slot format to the UE using an RRC message. The cell-specific slot format may include information for configuring a downlink mini-slot, an uplink mini-slot, a guard period mini-slot, and a special mini-slot.

In one configuration, the apparatus <NUM> for wireless communication includes means for identifying a resource usage of a resource pool that is used for wireless communication using a RAT; means for determining a scheduling constraint imposed by the resource usage for sharing the resource pool for wireless communication using a second RAT; means for allocating, based on the scheduling constraint, a resource of the resource pool for wireless communication using the second RAT; and means for communicating with a UE using the resource allocated to the second RAT. In one aspect, the aforementioned means may be the processor <NUM> shown in <FIG> configured to perform the functions recited by the aforementioned means. In another aspect, the aforementioned means may be a circuit or any apparatus configured to perform the functions recited by the aforementioned means.

Of course, in the above examples, the circuitry included in the processor <NUM> is merely provided as an example, and other means for carrying out the described functions may be included within various aspects of the present disclosure, including but not limited to the instructions stored in the computer-readable storage medium <NUM>, or any other suitable apparatus or means described in any one of the <FIG>, <FIG>, and/or <NUM>, and utilizing, for example, the processes and/or algorithms described herein in relation to <FIG>.

Claim 1:
A method for spectrum sharing in wireless communication, the method comprising:
identifying (<NUM>, <NUM>; <NUM>) a resource usage of a first radio access technology, RAT, in a resource pool (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>; <NUM>) for wireless communication;
determining (<NUM>; <NUM>; <NUM>) a scheduling constraint imposed by the resource usage of the first RAT for sharing the resource pool for wireless communication using a second RAT;
allocating (<NUM>), based on the scheduling constraint, a resource of the resource pool for wireless communication using the second RAT; and
communicating (<NUM>) with a user equipment, UE (<NUM>; <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>), using the resource allocated to the second RAT;
characterized in that
the resource comprises a plurality of time-frequency-space resources that are grouped in one or more mini-slots (<NUM>, <NUM>, <NUM>) based on a numerology of the second RAT, each mini-slot spanning a time interval corresponding to one or more time domain symbols based on a numerology of the first RAT or the second RAT; and the communicating (<NUM>) with the UE comprises:
communicating with the UE using half-duplex frequency division duplex, HD-FDD, with the resource allocated to the second RAT; and
repeating a signal transmission of the second RAT using the one or more mini-slots.