Patent Description:
Wireless communications systems are capable of supporting communications with multiple users by sharing portions of a system bandwidth using a multiple-access technology such as code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems (such as a Long Term Evolution (LTE) system or a Fifth Generation (<NUM>) New Radio (NR) system).

These improvements also may be applicable to other multi-access technologies and the telecommunication standards that employ these technologies. <CIT> decribes a method and apparatus for supporting frequency hopping for low cost user equipment in wireless communication system. <CIT> describes communicating over an anchor channel for Unlicensed Internet of Things (U-IoT).

The following description is directed to some particular implementations for the purposes of describing innovative aspects of this disclosure. However, a person having ordinary skill in the art will readily recognize that the teachings herein can be applied in a multitude of different ways. The described implementations can be implemented in any device, system or network that is capable of transmitting and receiving radio frequency (RF) signals according to one or more of the Long Term Evolution (LTE), <NUM>, <NUM> or <NUM> (New Radio (NR)) standards promulgated by the 3rd Generation Partnership Project (3GPP), the Institute of Electrical and Electronics Engineers (IEEE) <NUM> standards, the IEEE <NUM> standards, or the Bluetooth® standards as defined by the Bluetooth Special Interest Group (SIG), among others. The described implementations can be implemented in any device, system or network that is capable of transmitting and receiving RF signals according to one or more of the following technologies or techniques: code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), single-user (SU) multiple-input multiple-output (MIMO) and multi-user (MU) MIMO. The described implementations also can be implemented using other wireless communication protocols or RF signals suitable for use in one or more of a wireless wide area network (WWAN), a wireless personal area network (WPAN), a wireless local area network (WLAN), or an internet of things (IOT) network.

Implementations of the subject matter described in this disclosure may allow user equipments (UEs) and base stations (BSs) operating according to <NUM> NR protocols to exchange data and other information using narrowband communications with frequency hopping in an unlicensed frequency band. In accordance with some aspects of the present disclosure, a base station and a UE may exchange downlink (DL) data using a DL frequency hopping pattern and may exchange uplink (UL) data using an UL frequency hopping pattern. The DL frequency hopping pattern may include a sequence of DL hopping channels, and the UL frequency hopping pattern may include a sequence of UL hopping channels different than the sequence of DL hopping channels. Each DL hopping channel of the sequence of DL hopping channels may be associated with a corresponding DL hopping frame of a sequence of DL hopping frames, and each UL hopping channel of the sequence of UL hopping channels may be associated with a corresponding UL hopping frame of a sequence of UL hopping frames. In some implementations, each DL hopping channel of the sequence of DL hopping channels may be separated from a corresponding UL hopping channel of the sequence of UL hopping channels by a gap frequency configured or selected to reduce interference between DL and UL transmissions.

In some implementations, the base station transmits a discovery reference signal (DRS) including a skipping signal identifying one or more UEs. The UE receives the DRS, and determines whether the skipping signal identifies the UE. In some implementations, the DRS may indicate the DL frequency hopping pattern. The UE may select an uplink (UL) frequency hopping pattern for transmitting UL data to the base station. In some implementations, the UL frequency hopping pattern may be selected in response to the DL frequency hopping pattern and an identifier unique to the UE (such as a UE ID). In some other implementations, the UL frequency hopping pattern may be selected in response to the DL frequency hopping pattern and a cell-specific identifier.

When the skipping signal does not identify the UE, the UE jumps to the first DL hopping channel of the DL frequency hopping pattern. The UE may detect a signal indicating a channel occupancy time (COT) obtained by the base station on the first DL hopping channel of the DL frequency hopping pattern, and receive DL data on the first DL hopping channel of the DL frequency hopping pattern. If the UE detects a presence of buffered UL data, the UE may switch to a first UL hopping channel of the UL frequency hopping pattern, and may transmit the buffered UL data on the first UL hopping channel of the UL frequency hopping pattern.

When the skipping signal identifies the UE, the UE stays on an anchor channel for a time period. The one or more UEs identified by the skipping signal skip frequency hopping between the anchor channel and the DL hopping channels during the time period. If a respective one of the identified UEs detects a presence of buffered UL data during the time period, the respective UE may switch to a first UL hopping channel of the UL frequency hopping pattern, and transmit the buffered UL data on the first UL hopping channel of the UL frequency hopping pattern.

Particular implementations of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. The ability of base stations and UEs to communicate with each other using narrowband communications in an unlicensed frequency band may improve channel access because there may be less contention on relatively small frequency bands (such as the hopping channels associated with the DL and UL frequency hopping patterns) than on relatively large frequency bands (such as primary channels used in wideband communications). Unlicensed frequency bands may be more ubiquitous than licensed portions of the radio frequency (RF) spectrum, and therefore narrowband communications performed in one or more unlicensed frequency bands may provide better coverage for wireless communication devices (such as base stations and UEs) than communications performed solely on licensed portions of the RF spectrum. Further, employing frequency hopping techniques in narrowband communications on one or more unlicensed frequency bands may reduce interference from other wireless communication devices operating on unlicensed frequency bands by exploiting the frequency diversity of the unlicensed frequency bands.

Also, by identifying one or more UEs (or one or more groups of UEs) for which the base station does not have queued DL data during a respective time period and allowing the identified UEs (or groups of UEs) to stay on the anchor channel during the respective time period, implementations of the subject matter disclosed herein may reduce power consumption of the one or more identified UEs (or groups of UEs) associated with switching between the anchor channel and one or more DL channels of the DL frequency hopping pattern. Moreover, by allowing UEs identified by the skipping signal to jump to an UL hopping channel and transmit buffered UL data during the time period, implementations of the subject matter disclosed herein may reduce power consumption of the identified UEs without adversely impacting UL throughput.

Accordingly, in one or more example implementations, the functions described may be implemented in hardware, software, or any combination thereof. By way of example, and not limitation, such computer-readable media can include a random-access memory (RAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the aforementioned types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer.

<FIG> shows a diagram of an example wireless communications system <NUM>. The wireless communications system <NUM> includes base stations <NUM>, UEs <NUM>, an Evolved Packet Core (EPC) <NUM>, and another core network <NUM> (such as a <NUM> Core (5GC)). The base stations <NUM> may include macrocells (high power cellular base station) or small cells (low power cellular base station).

The base stations <NUM> configured for <NUM> LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) may interface with the EPC <NUM> through backhaul links <NUM> (such as the S1 interface). The base stations <NUM> configured for <NUM> NR (collectively referred to as Next Generation RAN (NG-RAN)) may interface with core network <NUM> through backhaul links <NUM>. In addition to other functions, the base stations <NUM> may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (such as handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations <NUM> may communicate directly or indirectly (such as through the EPC <NUM> or core network <NUM>) with each other over backhaul links <NUM> (such as the X2 interface).

A heterogeneous network also may include Home Evolved Node Bs (eNBs) (HeNBs), which may provide service to a restricted group known as a closed subscriber group (CSG). The communication links <NUM> between the base stations <NUM> and the UEs <NUM> may include uplink (UL) (also referred to as reverse link) transmissions from a UE <NUM> to a base station <NUM> or downlink (DL) (also referred to as forward link) transmissions from a base station <NUM> to a UE <NUM>. The communication links <NUM> may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, or transmit diversity. The base stations <NUM> / UEs <NUM> may use spectrum up to Y MHz (such as <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, etc.) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction. Allocation of carriers may be asymmetric with respect to DL and UL (such as more or fewer carriers may be allocated for DL than for UL).

Some UEs <NUM> may communicate with each other using device-to-device (D2D) communication link <NUM>.

The small cell <NUM>' may operate in a licensed or an unlicensed frequency spectrum. The small cell <NUM>', employing NR in an unlicensed frequency spectrum, may boost coverage to or increase capacity of the access network.

A base station <NUM>, whether a small cell <NUM>' or a large cell (such as a macro base station), may include an eNB, gNodeB (gNB), or another type of base station. Some base stations, such as gNB <NUM>, may operate in a traditional sub <NUM> spectrum, in millimeter wave (mmW) frequencies, or near mmW frequencies in communication with the UE <NUM>. When the gNB <NUM> operates in mmW or near mmW frequencies, the gNB <NUM> may be referred to as a millimeter wave or mmW base station. Communications using the mmW / near mmW radio frequency band (such as between <NUM> - <NUM>) has extremely high path loss and a short range.

The UE <NUM> may receive the beamformed signal from the base station <NUM> in one or more receive directions <NUM>''. The UE <NUM> also may transmit a beamformed signal to the base station <NUM> in one or more transmit directions. The base station <NUM> and UE <NUM> may perform beam training to determine the best receive and transmit directions for each of the base station <NUM> and UE <NUM>.

The IP Services <NUM> may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service, or other IP services. The MBMS Gateway <NUM> may be used to distribute MBMS traffic to the base stations <NUM> belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting MBMS related charging information.

The IP Services <NUM> may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service, or other IP services.

The base station also may be referred to as a gNB, Node B, evolved Node B (eNB), an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a transmit reception point (TRP), or some other suitable terminology. Examples of UEs <NUM> include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (such as an MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor/actuator, a display, or any other similar functioning device. Some of the UEs <NUM> may be referred to as IoT devices (such as a parking meter, gas pump, toaster, vehicles, heart monitor, etc.). The UE <NUM> also may be referred to as a station, a mobile station, 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, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

For example, the wireless system <NUM> may employ LTE License Assisted Access (LTE-LAA), LTE Unlicensed (LTE U) radio access technology, or <NUM> NR technology in an unlicensed radio band (such as the <NUM> Industrial, Scientific, and Medical (ISM) band or the <NUM> UNII bands). When operating in unlicensed radio bands, wireless communication devices (such as the base stations <NUM> and UEs <NUM>) may employ listen-before-talk (LBT) channel access mechanisms to ensure the channel is clear before transmitting data. In some instances, operations in unlicensed radio bands may be based on a carrier aggregation (CA) configuration in conjunction with component carriers (CCs) operating in a licensed band. Operations in unlicensed radio bands may include downlink transmissions, uplink transmissions, or both. Duplexing in unlicensed radio bands may be based on frequency division duplexing (FDD), time division duplexing (TDD) or a combination of both.

<FIG> shows an example of a first slot <NUM> within a <NUM>/NR frame structure. <FIG> shows an example of DL channels <NUM> within a <NUM>/NR slot. <FIG> shows an example of a second slot <NUM> within a <NUM>/NR frame structure. <FIG> shows an example of UL channels <NUM> within a <NUM>/NR slot. In some cases, the <NUM>/NR frame structure may be FDD in which, for a particular set of subcarriers (carrier system bandwidth), slots within the set of subcarriers are dedicated for either DL or UL transmissions. In other cases, the <NUM>/NR frame structure may be TDD in which, for a particular set of subcarriers (carrier system bandwidth), slots within the set of subcarriers are dedicated for both DL and UL transmissions. In the examples shown in <FIG>, the <NUM>/NR frame structure is based on TDD, with slot <NUM> configured with slot format <NUM> (with mostly DL), where D indicates DL, U indicates UL, and X indicates that the slot is flexible for use between DL and UL, and with slot <NUM> configured with slot format <NUM> (with mostly UL). While slots <NUM> and <NUM> are shown with slot formats <NUM> and <NUM>, respectively, any particular slot may be configured with any of the various available slot formats <NUM>-<NUM>. Slot formats <NUM> and <NUM> are all DL and all UL, respectively. UEs may be configured with the slot format, either dynamically through downlink control information (DCI) or semi-statically through radio resource control (RRC) signaling by a slot format indicator (SFI). The configured slot format also may apply to a <NUM>/NR frame structure that is based on FDD.

Other wireless communication technologies may have a different frame structure or different channels. A frame may be divided into a number of equally sized subframes. For example, a frame having a duration of <NUM> microseconds (µs) may be divided into <NUM> equally sized subframes each having a duration of <NUM>. Subframes also may include mini-slots, which may include <NUM>, <NUM>, or <NUM> symbols. The symbols on UL may be CP-OFDM symbols (such as for high throughput scenarios) or discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (also referred to as single carrier frequency-division multiple access (SC-FDMA) symbols) (such as for power limited scenarios).

For slot configuration <NUM>, different numerologies (µ) <NUM> to <NUM> allow for <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> slots, respectively, per subframe. Accordingly, for slot configuration <NUM> and numerology µ, there are <NUM> symbols per slot and 2µ slots per subframe. The subcarrier spacing may be equal to <NUM>^µ*<NUM>, where µ is the numerology <NUM> to <NUM>. As such, the numerology µ=<NUM> has a subcarrier spacing of <NUM>, and the numerology µ=<NUM> has a subcarrier spacing of <NUM>. The subcarrier spacing is <NUM> and symbol duration is approximately <NUM> microseconds (µs).

Each time slot includes a resource block (RB) (also referred to as a physical RB (PRB)) that extends across <NUM> consecutive subcarriers and across a number of symbols. The intersections of subcarriers and across <NUM> symbols. The intersections of subcarriers and of the RB define multiple resource elements (REs).

As illustrated in <FIG>, some of the REs carry a reference signal (RS) for the UE. In some configurations, one or more REs may carry a demodulation reference signal (DM-RS) (indicated as Rx for one particular configuration, where 100x is the port number, but other DM-RS configurations are possible). In some configurations, one or more REs may carry a channel state information reference signal (CSI-RS) for channel measurement at the UE. The REs also may include a beam measurement reference signal (BRS), a beam refinement reference signal (BRRS), and a phase tracking reference signal (PT-RS).

The PSS is used by a UE <NUM> to determine subframe or symbol timing and a physical layer identity.

The PUSCH carries data, and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), or UCI.

<FIG> shows a block diagram of an example base station <NUM> and UE <NUM> in an access network. In the DL, IP packets from the EPC <NUM> may be provided to a controller/processor <NUM> of the base station <NUM>. The controller/processor <NUM> may implement layer <NUM> and layer <NUM> functionality. The controller/processor <NUM> also may provide RRC layer functionality associated with broadcasting of system information (such as the MIB and SIBs), RRC connection control (such as RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting. The controller/processor <NUM> also may provide PDCP layer functionality associated with header compression / decompression, security (such as ciphering, deciphering, integrity protection, integrity verification), and handover support functions. The controller/processor <NUM> also may provide RLC layer functionality associated with the transfer of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs. The controller/processor <NUM> also may provide MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

In some implementations, controller/processor <NUM> may be a component of a processing system. A processing system may generally refer to a system or series of machines or components that receives inputs and processes the inputs to produce a set of outputs (which may be passed to other systems or components of, for example, the base station <NUM>). For example, a processing system of the base station <NUM> may refer to a system including the various other components or subcomponents of the base station <NUM>.

The processing system of the base station <NUM> may interface with other components of the base station <NUM>, and may process information received from other components (such as inputs or signals), output information to other components, and the like. For example, a chip or modem of the base station <NUM> may include a processing system, a first interface to receive or obtain information, and a second interface to output, transmit or provide information. In some instances, the first interface may refer to an interface between the processing system of the chip or modem and a receiver, such that the base station <NUM> may receive information or signal inputs, and the information may be passed to the processing system. In some instances, the second interface may refer to an interface between the processing system of the chip or modem and a transmitter, such that the base station <NUM> may transmit information output from the chip or modem. A person having ordinary skill in the art will readily recognize that the second interface also may obtain or receive information or signal inputs, and the first interface also may output, transmit or provide information.

The TX processor <NUM> handles mapping to signal constellations based on various modulation schemes (such as binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols may be split into parallel streams. Each stream may be mapped to an OFDM subcarrier, multiplexed with a reference signal (such as a pilot signal) in the time or frequency domain, and combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially pre-coded to produce multiple spatial streams. The channel estimate may be derived from a reference signal or channel condition feedback transmitted by the UE <NUM>. Each spatial stream may be provided to a different antenna <NUM> via a separate transmitter 318TX.

The RX processor <NUM> converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT). The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The soft decisions are decoded and deinterleaved to recover the data and control signals that were originally transmitted by the base station <NUM> on the physical channel. The data and control signals are provided to the controller/processor <NUM>, which implements layer <NUM> and layer <NUM> functionality.

The controller/processor <NUM> is also responsible for error detection using an ACK or NACK protocol to support HARQ operations.

Similar to the functionality described in connection with the DL transmission by the base station <NUM>, the controller/processor <NUM> of the UE <NUM> provides RRC layer functionality associated with system information (such as the MIB and SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression / decompression, and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

In some implementations, the controller/processor <NUM> may be a component of a processing system. A processing system may generally refer to a system or series of machines or components that receives inputs and processes the inputs to produce a set of outputs (which may be passed to other systems or components of the UE <NUM>). For example, a processing system of the UE <NUM> may refer to a system including the various other components or subcomponents of the UE <NUM>.

The processing system of the UE <NUM> may interface with other components of the UE <NUM>, and may process information received from other components (such as inputs or signals), output information to other components, and the like. For example, a chip or modem of the UE <NUM> may include a processing system, a first interface to receive or obtain information, and a second interface to output or transmit information. In some instances, the first interface may refer to an interface between the processing system of the chip or modem and a receiver, such that the UE <NUM> may receive information or signal inputs, and the information may be passed to the processing system. In some instances, the second interface may refer to an interface between the processing system of the chip or modem and a transmitter, such that the UE <NUM> may transmit information output from the chip or modem. A person having ordinary skill in the art will readily recognize that the second interface also may obtain or receive information or signal inputs, and the first interface also may output, transmit or provide information.

The controller/processor <NUM> is also responsible for error detection using an ACK or NACK protocol to support HARQ operations. Information to be wirelessly communicated (such as for LTE or NR based communications) is encoded and mapped, at the PHY layer, to one or more wireless channels for transmission.

In the example of <FIG>, each antenna <NUM> of the UE <NUM> is coupled to a respective transmitter 354TX. In some other implementations, some UEs may have fewer transmitters (or transmit chains) than receive (RX) antennas. Although not shown for simplicity, each transmitter may be coupled to a respective power amplifier (PA) which amplifies the signal to be transmitted. The combination of a transmitter with a PA may be referred to herein as a "transmit chain" or "TX chain. " To save on cost or die area, the same PA may be reused to transmit signals over multiple RX antennas. In other words, one or more TX chains of a UE may be switchably coupled to multiple RX antennas ports.

Narrowband communications involve communicating with a limited frequency bandwidth (such as compared to wideband communications typically used by cellular and Wi-Fi devices), and may be implemented in an unlicensed frequency band. An unlicensed frequency band may refer to a radio-frequency (RF) band that is open for shared use by any device that complies with regulatory agency rules for communicating via the RF band. In some implementations, the unlicensed frequency band may include one or more radio frequencies in the <NUM> band (such as the UNII frequency bands between approximately <NUM> and approximately <NUM>). In some other implementations, the unlicensed frequency band may include one or more radio frequencies in the <NUM> band (such as radio frequencies between approximately <NUM> and <NUM> typically used by Wi-Fi devices and wireless networks). In some other implementations, the unlicensed frequency band may include one or more radio frequencies in the <NUM> band.

In contrast to most licensed RF bands, users of unlicensed frequency bands typically do not have regulatory protection against radio interference from devices of other users, and may be subject to radio interference caused by other devices that use the unlicensed frequency band. Because unlicensed frequency bands may be shared by devices operating according to different communication protocols (such as the 3GPP standards for LTE and <NUM> NR devices and the IEEE <NUM> standards for Wi-Fi devices), a device operating in an unlicensed frequency band typically contends with other nearby devices for medium access before transmitting data on the unlicensed frequency band.

When communicating in an unlicensed frequency band, a UE or base station may need to coexist or share the unlicensed frequency band with other devices. One way to promote coexistence with other devices is to use a listen-before-talk or listen-before-transmit (LBT) procedure to determine that the shared wireless medium has been idle for a duration before attempting transmissions on the shared wireless medium. In some implementations, LBT procedures may be used with frequency hopping techniques to increase the likelihood of finding a clear channel for communication.

<FIG> shows a sequence diagram depicting communications <NUM> between a base station (BS) <NUM> and a UE <NUM> in a radio access network (RAN). The BS <NUM> may be one example of the BS <NUM> of <FIG> or the BS <NUM> of <FIG>, the UE <NUM> may be one example of the UE <NUM> of <FIG> or the UE <NUM> of <FIG>, and the radio access network may be any suitable RAN including, for example, a <NUM> NR access network. In some implementations, the communications <NUM> may be narrowband communications in an unlicensed frequency band. Although described herein with reference to unlicensed portions of the <NUM> frequency band, the communications <NUM> may be performed on one or more other unlicensed frequency bands (such as one or more of the UNII bands in the <NUM> frequency band, unlicensed portions of the <NUM> frequency band, or other unlicensed frequency bands).

The BS <NUM> and UE <NUM> may use frequency hopping to exploit the frequency diversity in the unlicensed frequency band. The BS <NUM> may transmit DL data to the UE <NUM> according to a DL frequency hopping pattern that includes a sequence of DL hopping channels, and the UE <NUM> may transmit UL data to the BS <NUM> according to an UL frequency hopping pattern that includes a sequence of UL hopping channels different than the sequence of DL hopping channels. In some implementations, each DL hopping channel of the sequence of DL hopping channels may be associated with a corresponding DL hopping frame of a sequence of DL hopping frames, and each UL hopping channel of the sequence of UL hopping channels may be associated with a corresponding UL hopping frame of a sequence of UL hopping frames. The DL hopping frames may be used to transmit DL data on corresponding DL hopping channels of the DL frequency hopping pattern, and the UL hopping frames may be used to transmit UL data on corresponding UL hopping channels of the UL frequency hopping pattern. In some implementations, the DL hopping channels may be separated from corresponding UL hopping channels by a frequency gap configured or selected to reduce interference between DL and UL transmissions associated with the communications <NUM>.

The BS <NUM> may transmit a discovery reference signal (DRS) to the UE <NUM> on an anchor channel of a shared wireless medium. The DRS may indicate at least one of the DL frequency hopping pattern or the UL frequency hopping pattern. In some implementations, the DRS may indicate locations of the DL hopping channels and the UL hopping channels, an order in which the UE <NUM> is to hop between the DL and UL hopping channels, the dwell time on each hopping channel, a duration of the DL and UL hopping channels, the gap frequency, or any combination thereof. In some other implementations, the DRS may indicate locations of the DL hopping channels, and the UE <NUM> may derive the UL frequency hopping pattern based on the DL frequency hopping pattern and an identifier unique to the UE <NUM> (such as a UEID).

The DRS also may include one or more of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), a system information block (SIB), or a slot format indicator (SFI). In some implementations, the DRS also may include a remaining minimum system information (RMSI) field containing information indicative of the DL frequency hopping pattern.

The DRS also includes a skipping signal that indicates a duration for which one or more UEs or groups of UEs are to skip frequency hopping between the anchor channel and the DL hopping channels of the DL frequency hopping pattern. In some implementations, the skipping signal may indicate (or may be based on) an absence of queued DL data for the one or more identified UEs or groups of UEs.

The skipping duration may be indicated or expressed using any suitable technique. In some implementations, the skipping signal may indicate the skipping duration as a number (N) of DL hopping channels, where N is an integer greater than or equal to <NUM>. For example, if the skipping signal indicates that the UE <NUM> is to skip N = <NUM> DL hopping channels, the UE <NUM> may stay on the anchor channel for a duration corresponding to the dwell times on the first and second DL hopping channels (or at least avoid frequency hopping between the anchor channel and the first and second DL hopping channels). In some other implementations, the skipping signal may indicate the skipping duration as a number (M) of DRS periods, where M may be an integer or a non-integer greater than <NUM>. For one example, if the skipping signal indicates that the UE <NUM> is to skip frequency hopping between the anchor channel and the DL hopping channels for M = <NUM> DRS period, the UE <NUM> may stay on the anchor channel for a duration corresponding to the first DRS period, and jump to the second DL hopping channel during the second DRS period. For another example, if the skipping signal indicates that the UE <NUM> is to skip frequency hopping between the anchor channel and the DL hopping channels for M = <NUM>/<NUM> DRS period, the UE <NUM> may stay on the anchor channel for a duration corresponding to one-half of the first DRS period, and jump to the first DL hopping channel at a mid-point of the dwell time on the first DL hopping channel.

In some implementations, the skipping signal may be encoded in a bitmap contained in a reduced RMSI field of the DRS. The bitmap may identify the one or more UEs that are to skip frequency hopping between the anchor channel and the DL hopping channels, or may identify one or more groups of UEs that are to skip frequency hopping between the anchor channel and the DL hopping channels. In some other implementations, the skipping signal may be contained in the frequency domain resource assignment (FDRA) field (or any other suitable field) of a downlink control information (DCI) message. In some other implementations, the skipping signal may be included in a slot format indicator (SFI) carried by the DRS. For example, the skipping signal may be contained in a reserved slotFormat ID of the SFI, or may be indicated by an SFI format index.

After transmission of the DRS, the BS <NUM> may jump to the first DL hopping channel. The UE <NUM> may receive the DRS, and use information contained therein to determine the locations of the DL hopping channels, to determine the locations of the UL hopping channels, and to determine whether the skipping signal identifies the UE <NUM>. The UE <NUM> may either jump to the first DL hopping channel or stay on the anchor channel based on information contained in the skipping signal.

When the UE <NUM> is not identified by the skipping signal, the UE <NUM> jumps to the first DL hopping channel and monitor the first DL hopping channel for DL data, one or more reference signals, configured grants, and other information transmitted by the BS <NUM>, as indicated by arrow <NUM> in <FIG>. In some implementations, the BS <NUM> may contend for medium access to the first DL hopping channel using a CCA-based medium access contention operation, and may obtain access to the first DL hopping channel for a channel occupancy time (COT) based on winning the contention operation. The BS <NUM> may transmit a signal informing the UE <NUM> of the obtained COT on the first DL hopping channel. The signal may be one or more of system information channel occupancy time (SI-COT), a group-common physical downlink control channel (GC-PDCCH), or a common transmit preamble.

If the UE <NUM> detects the signal, the UE <NUM> may begin receiving DL data from the BS <NUM> on the first DL hopping channel. In some implementations, the UE <NUM> may be configured for full-duplex operation, and may receive DL data on the first DL hopping channel concurrently with transmitting UL data on the first UL hopping channel. In some other implementations, the UE <NUM> may be configured for half-duplex operation, and may transmit UL data on the first UL hopping channel during portions of the first DRS period when the UE <NUM> is not receiving DL data. If the UE <NUM> does not detect the signal within a time period after transmission of the DRS, the UE <NUM> may jump to the next DL hopping channel, or may transmit UL data to the BS <NUM> using configured grant (CG) resources.

At the end of the first DRS period, the BS <NUM> and the UE <NUM> may return to the anchor channel. The BS <NUM> may transmit another DRS on the anchor channel to indicate the beginning of the second DRS period, and operations between the BS <NUM> and UE <NUM> may continue in a similar manner for a remainder of the DL frequency hopping pattern.

When the UE <NUM> is identified by the skipping signal, the UE <NUM> stays on the anchor channel for a time period indicated by the skipping signal, rather than jumping to the first DL hopping channel, as indicated by arrow <NUM> in <FIG>. In some implementations, the BS <NUM> may generate the skipping signal based on an absence of queued DL data for one or more UEs or groups of UEs (such as the UE <NUM>). For one example, the BS <NUM> may determine an absence of queued DL data for one or more UEs for a time period, and may configure the skipping signal to identify the one or more UEs and to indicate that the one or more identified UEs are to skip frequency hopping between the anchor channel and the DL hopping channels for the time period. For another example, the BS <NUM> may determine an absence of queued DL data for one or more groups of UEs for a time period, and may configure the skipping signal to identify the one or more groups of UEs and to indicate that the one or more identified groups of UEs are to skip frequency hopping between the anchor channel and the DL hopping channels for the time period. In this manner, power consumption associated with frequency hopping may be reduced in UEs identified by the skipping signal.

In some implementations, the UE <NUM> may jump to one or more UL hopping channels during the indicated time period if the UE <NUM> has buffered UL data to transmit, and return to the anchor channel. If the UE <NUM> does not have buffered UL data, the UE <NUM> may stay on the anchor channel for the remainder of the indicated time period. In some implementations, when the UE <NUM> has buffered UL data to transmit using either a configured grant or a physical random access channel (PRACH), the UE <NUM> may jump to the first UL hopping channel, transmit the buffered UL data on the first UL hopping channel, jump to the first DL hopping channel to receive a re-transmission grant or a random access response (RAR), and return to the anchor channel. In some other implementations, when the UE <NUM> is to transmit reference signals (such as a SRS) or control signals on the PUUCH, rather than UL data, the UE <NUM> may jump to the first UL hopping channel, transmit the reference signals or control signals on the first UL hopping channel, and return to the anchor channel.

<FIG> shows an example frequency hopping pattern <NUM> that may be used for narrowband communications between the BS <NUM> and the UE <NUM>. The frequency hopping pattern <NUM> includes a DL frequency hopping pattern <NUM> and an UL frequency hopping pattern <NUM>. The DL frequency hopping pattern <NUM> and the UL frequency hopping pattern <NUM> each may include any suitable number (N) of unique hopping channels. In some implementations, the DL frequency hopping pattern <NUM> and the UL frequency hopping pattern <NUM> each may include N = <NUM> different hopping channels. In some other implementations, the DL frequency hopping pattern <NUM> and the UL frequency hopping pattern <NUM> each may include more than <NUM> different hopping channels. In aspects for which the BS <NUM> and the UE <NUM> exchange data using narrowband communications in the <NUM> frequency spectrum, the anchor channel may have a bandwidth of less than <NUM>, and each of the DL hopping channels and UL hopping channels may have a bandwidth not greater than <NUM>.

The DL frequency hopping pattern <NUM> includes a sequence of DL hopping channels upon which a sequence of DL hopping frames <NUM>-<NUM> to <NUM>-N (only two DL hopping frames <NUM>-<NUM> and <NUM>-<NUM> shown for simplicity) may be used to transmit DL data to one or more UEs. The UL frequency hopping pattern <NUM> includes a sequence of UL hopping channels upon which a sequence of UL hopping frames <NUM>-<NUM> to <NUM>-N (only two UL hopping frames <NUM>-<NUM> and <NUM>-<NUM> shown for simplicity) may be used to transmit UL data to the BS <NUM>. Each of the DL hopping channels of the DL frequency hopping pattern <NUM> may be separated from a corresponding UL hopping channel of the UL frequency hopping pattern <NUM> by at least a gap frequency that is configured or selected to minimize interference between DL and UL transmissions. In some implementations, the DL hopping frames of the DL frequency hopping pattern <NUM> may be separated from corresponding UL hopping frames of the UL frequency hopping pattern <NUM> by a constant frequency offset in modulo.

The BS <NUM> and the UE <NUM> initially tune to the anchor channel, and the BS <NUM> transmits the DRS to indicate a beginning of the first DRS period. The DRS may indicate at least one of the DL frequency hopping pattern <NUM> or the UL frequency hopping pattern <NUM>, and includes a skipping signal that indicates a time period during which one or more UEs (or groups of UEs) are to skip frequency hopping between the anchor channel and DL hopping channels of the DL frequency hopping pattern <NUM>. In some implementations, the indicated time period may be one of a number of the DL hopping channels, a number of DRS periods, or a portion of a DRS period.

The UE <NUM> receives the DRS, identifies the DL hopping channels of the DL frequency hopping pattern <NUM> and the UL hopping channels of the UL frequency hopping pattern <NUM>, and determines whether the skipping signal identifies the UE <NUM>. The skipping signal in the example of <FIG> identifies the UE <NUM> and indicates a time period of N = <NUM> DL hopping channels, thereby allowing the UE <NUM> to stay on the anchor channel, or to at least skip frequency hopping between the anchor channel and the DL hopping channels, for <NUM> DRS periods.

After transmitting the first DRS, the BS <NUM> jumps to the first DL hopping channel CH-<NUM> and transmits DL data to UE1 using a first portion of the first DL hopping frame <NUM>-<NUM>. The UE <NUM> has buffered UL data, jumps to the first UL hopping channel CH-<NUM>, and transmits UL data on a configured grant using a portion of the first UL hopping frame <NUM>-<NUM>. The UE <NUM> jumps to the first DL hopping channel CH-<NUM>, and receives a re-transmission grant from the BS <NUM> using a second portion of the first DL hopping frame <NUM>-<NUM>.

The UE <NUM> returns to the first UL hopping channel CH-<NUM> to transmit additional UL data using a second portion of the first UL hopping frame <NUM>-<NUM>, and fails to obtain access to the first UL hopping channel <NUM>-<NUM> using a CCA-based medium access contention operation. In response thereto, the UE <NUM> may jump to the second UL hopping frame <NUM>-<NUM>, and transmit the additional UL data using a portion of the second UL hopping frame <NUM>-<NUM>.

<FIG> shows a flowchart depicting an example operation <NUM> for wireless communication that supports frequency hopping between a BS and a UE. The operation <NUM> may be performed by an apparatus of a wireless communication device such as the UE <NUM> of <FIG>, the UE <NUM> of <FIG>, or the UE <NUM> of <FIG>. At block <NUM>, the UE receives a discovery reference signal (DRS) including a skipping signal identifying one or more UEs. At block <NUM>, the UE stays on an anchor channel when the skipping signal identifies the UE. At block <NUM>, the UE switches from the anchor channel to a first DL hopping channel of a DL frequency hopping pattern when the signal does not identify the UE. In some implementations, the one or more UEs identified by the skipping signal may be permitted to enter a low-power state for one or more DRS periods (or other periods of time indicated by the DRS). In some other implementations, the skipping signal may indicate an absence of queued DL data during one or more DRS periods for each of the one or more identified UEs.

In some implementations, the DRS may include one or more of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), or a system information block (SIB). In some instances, the DRS may be received on an anchor channel of an unlicensed frequency band. In some other instances, the DRS may indicate the DL frequency hopping pattern.

In some implementations, the skipping signal may be received in a reduced remaining minimum system information (RMSI) field of the DRS. In some instances, the RMSI field may include a bitmap identifying one or more UEs that are to stay on the anchor channel for at least a time period. For example, each bit of the bitmap may be used to indicate that a corresponding UE of the one or more identified UEs is to remain on the anchor channel for the time period. In some other instances, the RMSI field may include a bitmap identifying one or more groups of UEs that are to remain on the anchor channel for the time period. In some implementations, the one or more identified groups of UEs may be mapped to corresponding bits of the bitmap via a radio resource control (RRC) configuration.

In some other implementations, the skipping signal may be included in a frequency domain resource assignment (FDRA) field of a downlink control information (DCI) message. In some other instances, the skipping signal may be indicated by a slot format indicator (SFI) format index carried by the DRS.

<FIG> shows a flowchart depicting an example operation <NUM> for wireless communication that supports frequency hopping between a BS and a UE. The operation <NUM> may be performed by an apparatus of a wireless communication device such as the UE <NUM> of <FIG>, the UE <NUM> of <FIG>, or the UE <NUM> of <FIG>. In some implementations, the operation <NUM> may be performed after selectively switching to the first DL hopping channel in block <NUM> of <FIG>. For example, at block <NUM>, the UE detects a presence of uplink (UL) data buffered in the UE. At block <NUM>, the UE selects an UL frequency hopping pattern based at least in part on the DL frequency hopping pattern and an identifier unique to the UE. At block <NUM>, the UE switches to a first UL hopping channel of the UL frequency hopping pattern based on detecting the presence of the buffered UL data. At block <NUM>, the UE transmits the buffered UL data on the first UL hopping channel of the UL frequency hopping pattern. In some implementations, the first UL hopping channel of the UL frequency hopping pattern corresponds to one of a configured grant (CG) configuration or a physical random access channel (PRACH).

<FIG> shows a flowchart depicting an example operation <NUM> for wireless communication that supports frequency hopping between a BS and a UE. The operation <NUM> may be performed by an apparatus of a wireless communication device such as the UE <NUM> of <FIG>, the UE <NUM> of <FIG>, or the UE <NUM> of <FIG>. In some implementations, the operation <NUM> may be performed after transmitting the buffered UL data on the first UL hopping channel in block <NUM> of <FIG>. For example, at block <NUM>, the UE returns to the first DL hopping channel of the DL frequency hopping pattern. At block <NUM>, the UE monitors the first DL hopping channel of the DL frequency hopping pattern for one of an UL re-transmission grant or a random access response (RAR). In some implementations, the UE may return to the first DL hopping channel after transmitting buffered UL data on the first UL hopping channel and receive a re-transmission grant that allows the UE to transmit additional buffered UL data. In some other implementations, the UE may return to the first DL hopping channel after transmitting buffered UL data on the first UL hopping channel and receive a message (such as an RAR) indicating which portions of the transmitted UL data were received and correctly decoded by the BS.

<FIG> shows a flowchart depicting an example operation <NUM> for wireless communication that supports frequency hopping between a BS and a UE. The operation <NUM> may be performed by an apparatus of a wireless communication device such as the UE <NUM> of <FIG>, the UE <NUM> of <FIG>, or the UE <NUM> of <FIG>. In some implementations, the operation <NUM> may be one example of selectively switching to the first DL hopping channel in block <NUM> of <FIG>. For example, at block <NUM>, the UE detects a signal indicating a channel occupancy time (COT) obtained by a BS on the first DL hopping channel of the DL frequency hopping pattern. At block <NUM>, the UE receives DL data on the first DL hopping channel of the DL frequency hopping pattern.

As discussed, in some instances, the BS may contend for channel access to the first DL hopping channel using a CCA-based channel access contention operation. After obtaining a COT on the first DL hopping channel, the BS may transmit a signal informing one or more UEs <NUM> of the COT obtained on a respective DL hopping channel. In some instances, signal may be one or more of system information channel occupancy time (SI-COT), a group-common physical downlink control channel (GC-PDCCH), or a common transmit preamble.

<FIG> shows a flowchart depicting an example operation <NUM> for wireless communication that supports frequency hopping between a BS and a UE. The operation <NUM> may be performed by an apparatus of a wireless communication device such as the UE <NUM> of <FIG>, the UE <NUM> of <FIG>, or the UE <NUM> of <FIG>. In some implementations, the operation <NUM> may be one example of selectively switching to the first DL hopping channel in block <NUM> of <FIG>. For example, at block <NUM>, the UE stays on the anchor channel for a period of time in response to determining that the skipping signal identifies the UE. In some implementations, UEs identified by the skipping signal may not have any queued DL data in the BS <NUM>, and therefore can saver power by remaining on the anchor channel rather than jumping to a DL hopping channel (such as when the BS does not have any DL data to transmit to the UE). In some instances, the UE may return to a low-power state or sleep state in response to determining that the skipping signal identifies the UE.

<FIG> shows a flowchart depicting an example operation <NUM> for wireless communication that supports frequency hopping between a BS and a UE. The operation <NUM> may be performed by an apparatus of a wireless communication device such as the BS <NUM> of <FIG>, the BS <NUM> of <FIG>, or the BS <NUM> of <FIG>. At block <NUM>, the BS transmits a discovery reference signal (DRS) including a skipping signal identifying one or more user equipment (UEs). At block <NUM>, the BS transmits a signal indicating a channel occupancy time (COT) obtained on a first downlink (DL) hopping channel of a DL frequency hopping pattern. At block <NUM>, the BS transmits DL data on the first DL hopping channel of the DL frequency hopping pattern. In some implementations, the one or more UEs identified by the skipping signal may be permitted to enter a low-power state for one or more DRS periods (or other periods of time indicated by the DRS). In some other implementations, the skipping signal may indicate an absence of queued DL data during one or more DRS periods for each of the one or more identified UEs.

<FIG> shows a flowchart depicting an example operation <NUM> for wireless communication that supports frequency hopping between a BS and a UE. The operation <NUM> may be performed by an apparatus of a wireless communication device such as the UE <NUM> of <FIG>, the UE <NUM> of <FIG>, or the UE <NUM> of <FIG>. At block <NUM>, the UE receives a discovery reference signal (DRS) indicating a downlink (DL) frequency hopping pattern and including a skipping signal indicating a time period during which one or more UEs are to skip frequency hopping between an anchor channel and DL hopping channels of the DL frequency hopping pattern. At block <NUM>, the UE determines whether the skipping signal identifies the UE. At block <NUM>, the UE selectively switches to a first DL hopping channel of the DL frequency hopping pattern based on the determination.

The DL frequency hopping pattern may include a sequence of DL hopping channels upon which the BS may transmit DL data. Each of the DL hopping channels may be associated with a corresponding DL hopping frame of a sequence of DL hopping frames. In some implementations, the BS may transmit DL data to one or more UEs in each of the DL hopping frames.

In some implementations, the DRS in block <NUM> may include one or more of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), a system information block (SIB), a slot format indicator (SFI), or remaining minimum system information (RMSI). The DRS may be transmitted on an anchor channel of a frequency spectrum (such as one or more unlicensed frequency bands). In some implementations, the frequency spectrum may be an unlicensed frequency band in the <NUM> frequency spectrum, and each of the DL hopping channels may have a bandwidth not greater than <NUM>. In some other implementations, the frequency spectrum may be an unlicensed frequency band in another frequency spectrum (such as the <NUM> frequency spectrum or the <NUM> frequency spectrum), and one or both of the DL hopping channels and the UL hopping channels may have other suitable bandwidths.

In some implementations, the skipping signal in block <NUM> also may indicate an absence of DL data for the one or more UEs during a time period. The time period indicated by the skipping signal may be one of a number of the DL hopping channels, a number of DRS periods, or a portion of a DRS period.

In some implementations, the skipping signal in block <NUM> may be included in a reduced remaining minimum system information (RMSI) field of the DRS. The RMSI field may include a bitmap identifying the one or more UEs that are to skip frequency hopping between the anchor channel and the DL hopping channels. Each bit of the bitmap may be used to indicate that a corresponding UE of the one or more identified UEs is to skip frequency hopping between the anchor channel and the DL hopping channels. In some other implementations, the RMSI field may include a bitmap identifying one or more groups of UEs that are to skip frequency hopping between the anchor channel and the DL hopping channels. Each bit of the bitmap may be used to indicate that a corresponding group of UEs of the one or more identified groups of UEs are to skip frequency hopping between the anchor channel and the DL hopping channels. In some implementations, the one or more identified groups of UEs may be mapped to corresponding bits of the bitmap via a radio resource control (RRC) configuration.

In some other implementations, the skipping signal in block <NUM> may be carried in a downlink control information (DCI) message received from the BS. The skipping signal may be contained in a frequency domain resource assignment (FDRA) field of the DCI message, and the DCI message may be configured in a Type3 common search space. In some other implementations, the skipping signal in block <NUM> may be included in a slot format indicator (SFI) carried by the DRS. In some aspects, the skipping signal may be contained in a reserved slotFormat ID of the SFI. In other aspects, the skipping signal may be indicated by an SFI format index.

<FIG> shows a flowchart depicting an example operation <NUM> for wireless communication that supports frequency hopping between a BS and a UE. The operation <NUM> may be performed by an apparatus of a wireless communication device such as the UE <NUM> of <FIG>, the UE <NUM> of <FIG>, or the UE <NUM> of <FIG>. In some implementations, the operation <NUM> may be one example of selectively switching to the first DL hopping channel in block <NUM> of <FIG>. For example, in block <NUM>, the UE determines whether the skipping signal identifies the UE. At block <NUM>, the UE stays on the anchor channel for a duration in response to determining that the skipping signal identifies the UE. At block <NUM>, the UE jumps to the first DL hopping channel of the DL frequency hopping pattern in response to determining that the skipping signal does not identify the UE.

<FIG> shows a flowchart depicting an example operation <NUM> for wireless communication that supports frequency hopping between a BS and a UE. The operation <NUM> may be performed by an apparatus of a wireless communication device such as the UE <NUM> of <FIG>, the UE <NUM> of <FIG>, or the UE <NUM> of <FIG>. In some implementations, the operation <NUM> may begin after staying on the anchor channel in block <NUM> of <FIG>. For example, in block <NUM>, the UE detects a presence of UL data buffered in the UE. At block <NUM>, the UE determines an uplink (UL) frequency hopping pattern based at least in part on the DL frequency hopping pattern and an identifier unique to the UE. At block <NUM>, the UE switches to a first UL hopping channel of the UL frequency hopping pattern based on the detection of the buffered UL data. At block <NUM>, the UE transmits the buffered UL data on the first UL hopping channel of the UL frequency hopping pattern.

The UL frequency hopping pattern may include one or more unique sequences of UL hopping channels upon which one or more corresponding UEs may concurrently transmit UL data. Each sequence of UL hopping channels may be associated with a unique sequence of UL hopping frames upon which a respective UE may transmit UL data. In some implementations, each sequence of UL hopping channels may be allocated or assigned to a different UE, for example, so that a plurality of UEs may concurrently transmit UL data using their respective sequences of UL hopping channels.

The sequence of DL hopping channels may be different than each of the one or more sequences of UL hopping channels, and the sequence of DL hopping frames may occupy different channels than each of the one or more sequences of UL hopping frames. In some implementations, the DL hopping channels may be separated from each of the UL hopping channels by a gap frequency configured or selected to reduce interference between UL and DL transmissions.

In some implementations, the sequence of DL hopping channels and the one or more sequences of UL hopping channels may be uncoordinated relative to each other, for example, to avoid certain FCC restrictions on communications that employ frequency hopping techniques. In some other implementations, the sequence of DL hopping channels and the one or more sequences of UL hopping channels may be coordinated with each other, for example, to reduce a likelihood that UL hopping channels associated with (or assigned to) different UEs do not overlap in both time and frequency. The one or more sequences of UL hopping channels may be orthogonal to each other, and may be orthogonal to the sequence of DL hopping channels. In some implementations, each of the one or more sequences of UL hopping channels may be based on the sequence of DL hopping channels and an identifier unique to the associated UE (such as a UEID).

<FIG> shows a flowchart depicting an example operation <NUM> for wireless communication that supports frequency hopping between a BS and a UE. The operation <NUM> may be performed by an apparatus of a wireless communication device such as the UE <NUM> of <FIG>, the UE <NUM> of <FIG>, or the UE <NUM> of <FIG>. In some implementations, the operation <NUM> may begin after transmitting the buffered UL data in block <NUM> of <FIG>. For example, in block <NUM>, the UE returns to the first DL hopping channel of the DL frequency hopping pattern. At block <NUM>, the UE monitors the first DL hopping channel of the DL frequency hopping pattern for one of an UL re-transmission grant or a random access response (RAR).

<FIG> shows a flowchart depicting an example operation <NUM> for wireless communication that supports frequency hopping between a BS and a UE. The operation <NUM> may be performed by an apparatus of a wireless communication device such as the UE <NUM> of <FIG>, the UE <NUM> of <FIG>, or the UE <NUM> of <FIG>. In some implementations, the operation <NUM> may begin after monitoring the first DL hopping channel in block <NUM> of <FIG>. For example, in block <NUM>, the UE returns to the first UL hopping channel of the UL frequency hopping pattern based on a presence of additional UL data. At block <NUM>, the UE transmits the additional UL data on the first UL hopping channel of the UL frequency hopping pattern.

<FIG> shows a flowchart depicting an example operation <NUM> for wireless communication that supports frequency hopping between a BS and a UE. The operation <NUM> may be performed by an apparatus of a wireless communication device such as the UE <NUM> of <FIG>, the UE <NUM> of <FIG>, or the UE <NUM> of <FIG>. In some implementations, the operation <NUM> may begin after monitoring the first DL hopping channel in block <NUM> of <FIG>. For example, in block <NUM>, the UE returns to the first UL hopping channel of the UL frequency hopping pattern based on a presence of additional UL data. At block <NUM>, the UE fails to obtain medium access to the first UL hopping channel of the UL frequency hopping pattern. At block <NUM>, the UE switches to a second UL hopping channel of the UL frequency hopping pattern after failing to obtain medium access to the first UL hopping channel of the UL frequency hopping pattern. At block <NUM>, the UE transmits the additional UL data on the second UL hopping channel of the UL frequency hopping pattern.

<FIG> shows a flowchart depicting an example operation <NUM> for wireless communication that supports frequency hopping between a BS and a UE. The operation <NUM> may be performed by an apparatus of a wireless communication device such as the UE <NUM> of <FIG>, the UE <NUM> of <FIG>, or the UE <NUM> of <FIG>. In some implementations, the operation <NUM> may begin after jumping to the first DL hopping channel of the DL frequency hopping pattern in block <NUM> of <FIG>. For example, in block <NUM>, the UE detects a signal indicating a channel occupancy time (COT) obtained by the BS on the first DL hopping channel of the DL frequency hopping pattern. At block <NUM>, the UE receives DL data on the first DL hopping channel of the DL frequency hopping pattern.

In some implementations, the signal indicating the COT in block <NUM> may be one or more of a system information channel occupancy time (SI-COT), a group-common physical downlink control channel (GC-PDCCH), or a common transmit preamble. The COT may be obtained based on a CCA operation performed by the BS on the first DL hopping channel of the DL frequency hopping pattern.

<FIG> shows a flowchart depicting an example operation <NUM> for wireless communication that supports frequency hopping between a BS and a UE. The operation <NUM> may be performed by an apparatus of a wireless communication device such as the UE <NUM> of <FIG>, the UE <NUM> of <FIG>, or the UE <NUM> of <FIG>. In some implementations, the operation <NUM> may begin after receiving the DL data in block <NUM> of <FIG>. For example, in block <NUM>, the UE detects a presence of UL data buffered in the UE. At block <NUM>, the UE determines an uplink (UL) frequency hopping pattern based at least in part on the DL frequency hopping pattern and an identifier unique to the UE. At block <NUM>, the UE switches to a first UL hopping channel of the UL frequency hopping pattern based on the detection of the buffered UL data. At block <NUM>, the UE transmits the buffered UL data on the first UL hopping channel of the UL frequency hopping pattern.

In some implementations, the DL frequency hopping pattern includes a sequence of DL hopping channels, and the UL frequency hopping pattern includes one or more sequences of UL hopping channels different than the sequence of DL hopping channels. Each DL hopping channel may be associated with a corresponding DL hopping frame of a sequence of DL hopping frames, and each UL hopping channel of a respective sequence of the one or more sequences of UL hopping channels may be associated with a corresponding UL hopping frame of a respective sequence of one or more sequences of UL hopping frames.

The hardware and data processing apparatus used to implement the various illustrative logics, logical blocks, modules and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose single- or multi-chip processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. A processor also may be implemented as a combination of computing devices (such as a combination of a DSP and a microprocessor), a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some implementations, particular processes and methods may be performed by circuitry that is specific to a given function.

Claim 1:
A method for wireless communication performed by a user equipment, UE, comprising:
receiving (<NUM>) a discovery reference signal, DRS, including a skipping signal identifying one or more UEs that are to skip frequency hopping for a duration indicated by the skipping signal;
staying (<NUM>) on an anchor channel when the skipping signal identifies the UE; and
switching (<NUM>) from the anchor channel to a first downlink, DL, hopping channel of a DL frequency hopping pattern when the signal does not identify the UE.