Patent Description:
These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform-spread-OFDM (DFT-S-OFDM).

In some wireless communications systems, wireless devices (e.g., base stations, UEs, etc.) may communicate using directional signal transmission and reception (e.g., beams), in which beamforming techniques may be applied using one or more antenna elements to form a beam in a particular direction. For a beamformed transmission, the amplitude and phase of each antenna in an array of antennas may be precoded, or controlled to create a desired (e.g., directional) pattern of constructive and destructive interference in the wavefront. In such systems, a base station may schedule downlink or uplink transmissions for a UE on a set of resources, and the base station may then send and receive transmissions in a direction of the UE's scheduled transmission, for example, by forming a transmit beam in that direction.

The use of beamforming techniques is particularly useful in communication systems that operate over higher millimeter wave (mmWave) frequencies since mmWave communications are more vulnerable to adverse atmospheric conditions and physical propagation impediments. However, beamforming by itself may not be sufficient to fully compensate for the losses attributable to physical impediments such as walls and other common objects. Range extension of beams in the past has been focused on optimized antenna array geometries that adjust beam amplitudes. However, such solutions are not designed with the computational and power constraints of modern telecommunication devices in mind.

US patent application <CIT> discloses a method and system for avoiding degradation of system performance where a moving object, such as a train, including a plurality of user terminals passes through a cell boundary.

The techniques described herein relate to methods, systems, devices and apparatus that extend the effective communication range of mm Wave communication systems.

The present disclosure provides a method for range extension of highly directional beams from a serving cell to a user equipment in a communication system according to claim <NUM>, an apparatus for performing range extension of highly directional beams in a communication system according to claim <NUM>, a method for using information from a network node to aid reception of mmWave communications from a serving cell according to claim <NUM>, and an apparatus for using information from a network node to aid reception of mmWave communications from a serving cell according to claim <NUM>. Specific embodiments are subject of the dependent claims.

The following description and the appended drawings set forth in detail certain illustrative features of one or more aspects.

Some wireless communication systems may operate in millimeter wave (mmWave) frequency ranges, e.g., <NUM> gigahertz (GHz), <NUM>, <NUM>, <NUM>. It should be noted that though certain aspects are described with respect to mmWave frequency ranges, they may be applicable to wireless communication systems that use other frequency ranges. Wireless communication at these frequencies may be associated with increased signal attenuation (e.g., path loss), which may be influenced by various factors, such as temperature, barometric pressure, diffraction, etc. As a result, transmissions may be beamformed to overcome the path loss experienced at these frequencies. Wireless devices within such systems may accordingly communicate via these directional beams (e.g., beamformed for transmission and reception using one or more antenna arrays at the wireless device). For example, a base station and a UE may communicate via beam pair links (BPLs), each BPL including a transmit beam of one wireless node (e.g. a base station) and a receive beam of a second wireless node (e.g., a UE). For this disclosure, a "wireless node" or "network node" may be referring generically to either a UE, a base station, or a cell of a base station depending upon context and interactions. More specific descriptions such as "UE" and "serving cell" may be used along with generic descriptions to clarify interactions between separate entities.

For mmWave systems that are susceptible to high path loss and penetration loss, the gains attributable to directional beamforming has been vital for supporting links between wireless devices. However, beamforming by itself may not be sufficient to fully compensate for the losses attributable to physical impediments such as walls and other objects. Range extension of beams in the past has been focused on optimized antenna array geometries that adjust beam amplitudes.

Range extension of uplink and downlink communications is possible through signal repetition techniques. Contents of a signal can be sent repetitively so that if portions of one signal are not received in their entirety, portions of a repeated version of the signal may be used to supplement the original signal and thereby reconstruct the transmitted signal contents. However, the use of beamforming in mmWave systems introduces technical hurdles for repetition procedures, namely, the presence of multiple beams corresponds to the presence of multiple decoding candidates. For a UE that is physically constrained to a limited number of antennas/antenna arrays and by power constraints, using blind decoding on an original signal received on one beam and repetitions of the original signal on the same or other beams would be time inefficient and power consuming due to the computational complexity of the various training and weighting algorithms involved in beamforming.

<NUM> introduces a further level of complexity by envisioning wireless devices, both base stations and UEs, that support a large multiplicity of antennas and antenna arrays. For example, <NUM> is currently promulgating operational support for up to <NUM> antenna arrays at one wireless device, e.g., a base station, that may be used to communicate with another wireless device, e.g. a UE, that may be mobile. To support such communications, a base station may configure multiple sets of resources that are specific to one or more base station receive beams. These sets of beam-specific resources may be configured to be associated (e.g., quasi co-located (QCL)) with a reference signal, such as a channel state information reference signal (CSI-RS), a synchronization signal block (SSB), or the like.

A QCL association between a set of resources and a reference signal may correspond to the same or similar base station transmit beam(s) for transmitting the reference signal and corresponding base station receive beams for receiving uplink transmissions. Accordingly, a QCL association may also refer to a QCL relationship between antenna ports. Two antenna ports (or two sets of antenna ports) may be said to be QCL, spatially QCL, or have a QCL relationship if properties of the channel over which a symbol on one antenna port is conveyed can be inferred from the channel over which a symbol on the other antenna port is conveyed. For example, if a measured value for a parameter (e.g., delay spread, Doppler spread, Doppler shift, average delay, spatial parameters, etc.) of the channel for a first antenna port (or set of antenna ports) is within a threshold value of a measured value for the parameter of the channel for a second antenna port (or set of antenna ports), then the two antenna ports (or two sets of antenna ports) may be considered QCL. That is, if a first signal is transmitted with a first antenna port that is QCL with a second antenna port used to transmit a second signal, then the first signal and the second signal may be communicated via the same transmit beam and receive beam (e.g., the same beam pair link).

This disclosure provides methods, systems, and apparatus to support range extension in communication systems that utilize highly directional beams. Range extension is enabled by using novel repetition procedures. Repetition procedures are described that account for information that would help a receiver determine at least the repetition number, time/frequency location per repetition, or QCL information across repetitions.

<FIG> illustrates an example of a wireless communications system <NUM> in accordance with various aspects of the present disclosure. The wireless communications system <NUM> includes base stations <NUM>, UEs <NUM>, and a core network <NUM>. In some examples, the wireless communications system <NUM> may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some cases, wireless communications system <NUM> may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, or communications with low-cost and low-complexity devices.

Base stations <NUM> described herein may include or may be referred to by those skilled in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB) for Long Term Evolution (LTE), a next-generation Node B or giga-nodeB (either of which may be referred to as a gNB) for fifth generation (<NUM>) new radio (NR), a Home NodeB, a Home eNodeB, or some other suitable terminology.

Direct communications between base stations <NUM> may be conducted either wirelessly or through a conventional wired medium.

In some examples, wireless communications system <NUM> may support millimeter wave (mmWave) communications between UEs <NUM> and base stations <NUM>, and EHF antennas of the respective devices may be even smaller and more closely spaced than UHF antennas.

A UE <NUM> attempting to access a wireless network may perform an initial cell search by detecting a primary synchronization signal (PSS) from a base station <NUM>. The PSS may enable synchronization of slot timing and may indicate a physical layer identity value. The UE <NUM> may then receive a secondary synchronization signal (SSS). The SSS may enable radio frame synchronization, and may provide a cell identity value, which may be combined with the physical layer identity value to identify the cell. The SSS may also enable detection of a duplexing mode and a cyclic prefix length. Some systems, such as time division duplexing (TDD) systems, may transmit an SSS but not a PSS. The UE <NUM> may further receive a master information block (MIB), which may be transmitted in the physical broadcast channel (PBCH). The MIB may contain system bandwidth information, a system frame number (SFN), and other system information that will enable decoding of other system channels. After decoding the MIB, the UE <NUM> may receive one or more remaining minimum system information that contain information such as cell access parameters and RRC configuration information related to random access channel (RACH) procedures, paging, PUCCH, physical uplink shared channel (PUSCH), power control, sounding reference signal (SRS), and cell barring. In some cases, a base station <NUM> may transmit synchronization signals (SSs) (e.g., PSS SSS, PBCH, and the like) as a block using multiple beams in a beam-sweeping manner through a cell coverage area.

A base station <NUM> may insert periodic pilot symbols such as a cell-specific reference signal (CRS) to aid UEs <NUM> in channel estimation and coherent demodulation. CRS may include one of <NUM> different cell identities. They may be modulated using quadrature phase shift keying (QPSK) and power boosted (e.g., transmitted at 6dB higher than the surrounding data elements) to make them resilient to noise and interference. CRS may be embedded in <NUM> to <NUM> resource elements in each resource block based on the number of antenna ports or layers (up to <NUM>) of the receiving UEs <NUM>. In addition to CRS, which may be utilized by all UEs <NUM> in the coverage area <NUM> of the base station <NUM>, demodulation reference signal (DMRS) may be directed toward specific UEs <NUM> and may be transmitted only on resource blocks assigned to those UEs <NUM>. DMRS may include signals on <NUM> resource elements in each resource block in which they are transmitted. The DMRS for different antenna ports may each utilize the same <NUM> resource elements, and may be distinguished using different orthogonal cover codes (e.g., masking each signal with a different combination of <NUM> or -<NUM> in different resource elements). In some cases, two sets of DMRS may be transmitted in adjoining resource elements. In some cases, additional reference signals known as channel state information reference signals (CSI-RS) may be included to aid in generating CSI. On the UL, a UE <NUM> may transmit a combination of periodic SRS and uplink DMRS for link adaptation and demodulation, respectively.

Duplexing in unlicensed spectrum may be based on frequency division duplexing (FDD), TDD, or a combination of both. In some cases, a UE <NUM> may perform an LBT procedure prior to performing an AUL transmission.

Within the present disclosure, a frame may refer to a duration of <NUM> for wireless transmissions, with each frame consisting of <NUM> subframes of <NUM> each. Each <NUM> subframe may consist of one or more adjacent slots. 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.

Downlink control information (DCI), including HARQ information, is transmitted in a physical downlink control channel (PDCCH) carries DCI in at least one control channel elements CCE, which may consist of nine logically contiguous resource element groups (REGs), where each REG contains <NUM> resource elements. DCI includes information regarding downlink scheduling assignments, uplink resource grants, transmission scheme, uplink power control, HARQ information, modulation and coding scheme (MCS), and other information. The size and format of the DCI messages can differ depending on the type and amount of information that is carried by the DCI. For example, if spatial multiplexing is supported, the size of the DCI message is large compared to contiguous frequency allocations. Similarly, for a system that employs MIMO, the DCI includes additional signaling information. DCI size and format depend on the amount of information as well as factors such as bandwidth, the number of antenna ports, and duplexing mode.

In other examples, some UEs <NUM> may be configured for operation using a narrowband protocol type that is associated with a predefined portion or range (e.g., set of subcarriers or resource blocks (RBs))) within a carrier (e.g., "in-band" deployment of a narrowband protocol type).

Devices of the wireless communications system <NUM> (e.g., base stations <NUM> or UEs <NUM>) may have a hardware configuration that supports communications over a particular carrier bandwidth, or may be configurable to support communications over one of a set of carrier bandwidths. In some examples, the wireless communications system <NUM> may include base stations <NUM> and/or UEs that can support simultaneous communications via carriers associated with more than one different carrier bandwidth.

In one example, a base station <NUM> may use multiple antennas or antenna arrays to conduct beamforming operations for directional communications with a UE <NUM>. For instance, some signals (e.g. synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a base station <NUM> multiple times in different directions, which may include a signal being transmitted according to different beamforming weight sets associated with different directions of transmission. Transmissions in different beam directions may be used to identify (e.g., by the base station <NUM> or a receiving device, such as a UE <NUM>) a beam direction for subsequent transmission and/or reception by the base station <NUM>. Some signals, such as data signals associated with a particular receiving device, may be transmitted by a base station <NUM> in a single beam direction (e.g., a direction associated with the receiving device, such as a UE <NUM>). In some examples, the beam direction associated with transmissions along a single beam direction may be determined based at least in in part on a signal that was transmitted in different beam directions. For example, a UE <NUM> may receive one or more of the signals transmitted by the base station <NUM> in different directions, and the UE <NUM> may report to the base station <NUM> an indication of the signal it received with a highest signal quality, or an otherwise acceptable signal quality. Although these techniques are described with reference to signals transmitted in one or more directions by a base station <NUM>, a UE <NUM> may employ similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE <NUM>), or transmitting a signal in a single direction (e.g., for transmitting data to a receiving device).

A receiving device (e.g., a UE <NUM>, which may be an example of a mmWave receiving device) may try multiple receive beams when receiving various signals from the base station <NUM>, such as synchronization signals, reference signals, beam selection signals, or other control signals.

<FIG> is a block diagram of a design of a base station <NUM> (e.g., a serving cell and/or network node) and UE <NUM> of <FIG>, according to certain aspects of the disclosure. Base station <NUM> may be equipped with T antennas 234a through 234t, and UE <NUM> may be equipped with R antennas 252a through 252r. For the purposes of clarity, the term "antenna" is used to be representative of either a singular antenna structure or an antenna array structure, and that the plural form of antenna may be representative of a plurality of singular antennas, a plurality of singular antennas and antenna arrays, or a plurality of antenna array structures without departing the scope of this disclosure.

At base station <NUM>, a transmit processor <NUM> may receive data from a data source <NUM> for one or more UEs, select one or more modulation and coding schemes (MCSs) for each UE based on channel quality indicators (CQIs) received from the UE, process (e.g., encode and modulate) the data for each UE based on the MCS(s) selected for the UE, and provide data symbols for all UEs. Transmit processor <NUM> may also process system information (e.g., for semi-static resource partitioning information (SRPI), etc.) and control information (e.g., CQI requests, grants, upper layer signaling, etc.) and provide overhead symbols and control symbols. Processor <NUM> may also generate reference symbols for reference signals (e.g., the common reference signal (CRS)) and synchronization signals (e.g., the primary synchronization signal (PSS) and secondary synchronization signal (SSS)). Each MOD <NUM> may process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each MOD <NUM> may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. Transmission via T antennas 234a through 234t may be sent on transmit beams or omni-directionally.

At UE <NUM>, antennas 252a through 252r may receive the downlink signals from base station <NUM> and/or other BSs and may provide received signals to demodulators (DEMODs) 254a through 254r, respectively. Antennas 252a through 252r may be configured to receive beamformed or omni-directional downlink signals. Each DEMOD <NUM> may condition (e.g., filter, amplify, down-convert, and digitize) its received signal to obtain input samples. Each DEMOD <NUM> may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A channel processor may determine reference signal received power (RSRP), received signal strength indicator (RSSI), reference signal received quality (RSRQ), CQI, etc..

On the uplink, at UE <NUM>, a transmit processor <NUM> may receive and process data from a data source <NUM> and control information (e.g., for reports comprising RSRP, RSSI, RSRQ, CQI, etc.) from controller/processor <NUM>. Processor <NUM> may also generate reference symbols for one or more reference signals. The symbols from transmit processor <NUM> may be precoded by a TX MIMO processor <NUM> if applicable, further processed by MODs 254a through 254r (e.g., for SC-FDM, OFDM, etc.), and transmitted to base station <NUM>. At base station <NUM>, the uplink signals from UE <NUM> and other UEs may be received by antennas <NUM>, processed by DEMODs <NUM>, detected by a MIMO detector <NUM> if applicable, and further processed by a receive processor <NUM> to obtain decoded data and control information sent by UE <NUM>. Processor <NUM> may provide the decoded data to a data sink <NUM> and the decoded control information to controller/processor <NUM>.

Controllers/processors <NUM> and <NUM> may direct the operation at base station <NUM> and UE <NUM>, respectively. For example, controller/processor <NUM> and/or other processors and modules at base station <NUM> may perform or direct operations and/or processes for techniques described herein. Similarly, controller/processor <NUM> and/or other processors and modules at UE <NUM> may perform or direct operations and/or processes for the techniques described herein (e.g., those illustrated in <FIG>). Memories <NUM> and <NUM> may store data and program codes for base station <NUM> and UE <NUM>, respectively.

In some aspects of the disclosure, the controller/processor <NUM> may include beam management circuitry <NUM> configured for various functions, including, for example, for processing at least one repetition configuration information message received from a base station <NUM>. For example, the beam management circuitry <NUM> may be configured to implement one or more of the functions described below in relation to <FIG>. In some configurations, the beam management circuitry <NUM> may be separate from the controller/processor <NUM>.

In some aspects of the disclosure, the controller/processor <NUM> may include beam management circuitry <NUM> configured for various functions, including, for example, for determining a configuration for performing repetition procedures, and for communicating configuration information that will be used by the UE <NUM> to configure the at least one antenna array for receiving (e.g., mmWave) communications from the serving cell. For example, the beam management circuitry <NUM> may be configured to implement one or more of the functions described below in relation to <FIG> and/or <NUM>.

<FIG> illustrates an example of a wireless communications system <NUM> that supports beamforming with multiple beams in accordance with various aspects of the present disclosure. In some examples, wireless communications system <NUM> may implement aspects of wireless communications system <NUM>. For example, wireless communications system <NUM> includes a base station <NUM>, and multiple UEs, including UE 115a and UE 115b, which may be examples of UE <NUM> devices described with reference to <FIG>.

Wireless communications system <NUM> may operate in frequency ranges that are associated with beamformed transmissions between base station <NUM> and UE 115a and/or UE 115b. For example, wireless communications system <NUM> may operate using mmWave frequency ranges. As a result, signal processing techniques, such as beamforming, may be used to coherently combine energy and overcome path losses. For example, base station <NUM> and the UEs (115a and/or 115b) may communicate via beam pair links BPLs, each BPL including, for example, a transmit beam (205a and 205b) of a UE <NUM> and a receive beam <NUM> of a base station <NUM>. It is understood that the respective devices are capable of forming directional beams for transmission and reception, where base station <NUM> may also form one or more transmit beams for transmitting on the downlink, and the UEs <NUM> may form corresponding receive beams to receive signals from base station <NUM>. In some cases, base station <NUM> may only have the capacity to utilize a single receive beam <NUM> at a time (e.g., during a TTI), and base station <NUM> may receive directional transmissions from UE 115a and UE 115b when monitoring the path of a transmit beam <NUM> (e.g., in a particular direction).

One or both of UE 115a and UE 115b may be capable of uplink transmissions to base station <NUM>. Thus, the UEs <NUM> in wireless communications system <NUM> may perform uplink transmissions <NUM> to base station <NUM> via a transmit beam <NUM>, which may be received using a corresponding receive beam <NUM> at base station <NUM>. Corresponding receive beams may be defined as a receive beam <NUM> that is used to receive signals from a certain direction, where there may be a corresponding transmit beam (205a and/or 205b) used to transmit in that direction. Additionally, or alternatively, corresponding beams may refer to a transmit beam <NUM> and receive beam <NUM> using the same beamforming weights. There may also be correspondence between transmit beams and receive beams at the same device. For instance, base station <NUM> may receive a transmission (i.e., in a first direction) on a particular receive beam <NUM>, and base station <NUM> may use the same beam path as the receive beam <NUM> to send downlink transmissions (i.e., in the first direction) on a corresponding transmit beam. The beamforming weights in such a scenario may be the same for both a receive beam <NUM> and a transmit beam at base station <NUM>. The same correspondence may take place for transmit beams <NUM> and receive beams formed at UE 115a and UE 115b. In any case, an uplink transmission <NUM> may be sent on a set of uplink resources by UE 115a. Base station <NUM> may accordingly transmit downlink communications to the UEs <NUM> via downlink beams, which may include an uplink configuration, where the uplink configuration indicates the set of uplink resources for use by a UE <NUM>.

<FIG> is a wireless communication system <NUM> in accordance with aspects of the present disclosure comprising a first node, a second node, and a third node. The first node is a serving cell <NUM>, the second node is a UE <NUM>, and the third node is a network node <NUM>. The serving cell <NUM> operates at a higher mmWave frequency than the network node <NUM>, which operates at a sub-<NUM> frequency. Serving cell 401and network node <NUM> may be the same node with the same identifier, or may be co-located cells, i.e., serving cell <NUM> is physically part of network node <NUM> but has a different cell identifier, or may be geographically separated cells. Serving cell <NUM> and network node <NUM> may be a small cell gNB and macro gNB, respectively, or alternatively, both may be small cell gNBs. In one embodiment, serving cell <NUM> and network node <NUM> may be communicating with each other directly, either through a wireless interface or a wired interface. In an alternative embodiment, serving cell <NUM> and network node <NUM> communicate with each other indirectly through another network node (not shown) or other core network component.

UE <NUM> can receive and decode transmissions from both the serving cell <NUM> and the network node <NUM> contemporaneously. UE <NUM> is configured with at least one antenna array for receiving mmWave communications and at least one omni-directional for receiving sub-<NUM> communications. Serving cell <NUM> broadcasts synchronization information in synchronization signal block (SSB) bursts in multiple beams in multiple directions. As part of the SSB transmissions, serving cell <NUM> transmits repetition versions 410a-410j of PBCH to UE <NUM> over at least one transmit beam. More transmit beams are possible depending upon implementation choice. For descriptive purposes, the PBCH will be used as an exemplar in this disclosure, but the repetition configurations and procedures described in conjunction with PBCH are applicable for other control and data channels (e.g., physical downlink shared channel (PDSCH), physical multicast channel (PMCH), etc.), and the embodiments described herein should not be limited to PBCH.

Network node <NUM> transmits repetition configuration information <NUM> to the UE <NUM> prior to or while the UE <NUM> is receiving repetition versions 410a-410j of PBCH from serving cell <NUM>. Repetition configuration information <NUM> is sent at a sub-<NUM> frequency to the UE <NUM>. Since the repetition configuration information <NUM> is sent at a lower frequency, network node <NUM> may transmit repetition configuration information <NUM> in an omni-directional transmission. Since network node <NUM> is communicating with serving cell <NUM>, any adjustments made to the repetition configuration by the serving cell <NUM> can be communicated to the network node <NUM>, which can then update repetition configuration information <NUM> to the UE <NUM>.

Accordingly, serving cell <NUM> repeatedly transmits contents of an original SSB signal to UE <NUM> so that UE <NUM> can use portions of the repeated content to supplement the original signal in the event UE <NUM> does not receive the original signal in its entirety. Moreover, UE <NUM> is provided at least one of: (i) a repetition number (e.g., a number of instances a portion of the original signal will be repeatedly transmitted), (ii) a time/frequency location per repetition, or (iii) QCL information across repetitions, prior to or during receiving repetition versions 410a-410j of PBCH from serving cell <NUM>. Thus, UE <NUM> is no longer required to use blind decoding to receive and decode the original signal received on one beam and repetitions of the original signal on the same or another beam. This reduces processing time and power consumption that would otherwise be required to accommodate the computational complexity of various training and weighting algorithms involved in blind decoding.

In <NUM>, beam management of mmWave signals is envisioned to occur constantly during communications between a mmWave UE and the network. A portion of the beam management information may be passed from the serving cell <NUM> to the network node <NUM> to support a decision by the network node <NUM> to update the repetition configuration information <NUM>. The network node <NUM> may determine to update and convey the repetition configuration information <NUM> whenever a first threshold value has been reached, which would be part of a dynamic updating process that is based on changing conditions at the serving cell <NUM>. Or alternatively, the network node <NUM> may be configured to convey the repetition configuration information <NUM> periodically or at specific predetermined time instances that may be aperiodic.

Alternatively, the serving cell <NUM> may be configured to pass the repetition configuration information that it decides is appropriate to have conveyed to the UE <NUM> by the network node <NUM> at a predetermined point in time. As described herein, the repetition configuration information <NUM> sent to the UE <NUM> can be updated dynamically, periodically, or at certain predetermined times. The serving cell <NUM> and/or the network node <NUM> can be configured to take into account UE mobility and system resources (including UE resources such as time and frequency resources) to select an appropriate updating process.

In the embodiment of <FIG>, the repetition configuration information may be generated by the serving cell <NUM> when the serving cell <NUM> determines to extend the range of transmit beams to the UE <NUM>, or the serving cell <NUM> may have predetermined repetition configuration information that the serving cell <NUM> retrieves from a memory. Predetermined repetition configuration information may be generated by another node in the wireless communication system, such as a core network component (not shown) or network node <NUM>, or generated by the UE <NUM> and communicated by the UE <NUM> whilst establishing communications with the serving cell <NUM> or during beam management message exchanges with the serving cell <NUM>.

<FIG> shows possible repetition patterns that can be used by a serving cell to transmit five (<NUM>) repeated versions of an original PBCH to a UE. The serving cell may inform a network node as to the repetition pattern identifier that is associated with a repetition pattern at a predetermined point of time and the network node may convey this repetition pattern identifier to the UE. Although alternative versions of five PBCH repetitions are shown in <FIG>, it is envisioned that other multiples of repetitions may be used without departing from the scope of this disclosure.

Patterns <NUM>, <NUM>, <NUM>, and <NUM> show a slot configuration that carries fourteen (<NUM>) symbols. In Pattern <NUM>, the original SSB which contains the original PBCH is conveyed by symbols <NUM>, <NUM>, <NUM>, and <NUM>. A first repetition of PBCH is located at symbols <NUM> and <NUM>. A second repetition of PBCH is located at symbols <NUM> and <NUM>. A third repetition of PBCH is located at symbols <NUM> and <NUM>. A fourth repetition of PBCH is located at symbols <NUM> and <NUM>. A fifth repetition of PBCH is located at symbols <NUM> and <NUM>.

In Pattern <NUM>, the original SSB which contains the original PBCH is conveyed by symbols <NUM>, <NUM>, <NUM>, and <NUM>. A first repetition of PBCH is located at symbols <NUM> and <NUM>. A second repetition of PBCH is located at symbols <NUM> and <NUM>. A third repetition of PBCH is located at symbols <NUM> and <NUM>. A fourth repetition of PBCH is located at symbols <NUM> and <NUM>. A fifth repetition of PBCH is located at symbols <NUM> and <NUM>.

In the repetition patterns of <FIG>, the common rule for the patterns was to place repetitions on the two (<NUM>) symbols immediately before the SSB and two (<NUM>) symbols immediately after the SSB. Other repetition patterns and rules are possible depending on the selected number of repetitions supported by the serving cell.

The number of repetitions and the locations of the symbols that carry the repetitions may be directly communicated to a UE by a repetition pattern identifier as part of the repetition configuration information from a network node. However, alternative embodiments may be directed towards a repetition pattern identifier that identifies a repetition location offset to the SSB symbols being broadcast by the serving cell. In another alternative embodiment, the repetition pattern identifier may convey an indexed mapping, e.g., bitmap, indicating all symbol locations of all repetition patterns for which the serving cell may support. In another alternative embodiment, the repetition pattern identifier may provide a set of possible symbol locations per number of repetitions so that a UE will be performing a constrained number of blind decodings on the set of possible symbol locations rather than blind decoding of all possible symbol locations.

<FIG> illustrates an example of a frequency offset for a repetition version of a serving cell PBCH that can be part of the repetition configuration information transmitted to a UE from a network node. For each repetition that is identified by the repetition configuration information, repetition configuration information can also carry the frequency location of each repetition. The frequency location per repetition can be varied in order to introduce more frequency diversity to the signals from the network node. In <FIG>, an original SSB burst <NUM> carrying a PSS, PBCH, SSS and PBCH over four (<NUM>) symbols are sent in one frequency location. A subsequent PBCH repetition <NUM> are sent over two (<NUM>) symbols in a higher frequency range. The frequency location of the PBCH repetition <NUM> can be represented by an offset from the original signal and bandwidth, e.g., the PBCH repetition may be <NUM>-tones above the original SSB with a <NUM>-tone bandwidth.

In an alternative embodiment, the network node may provide a fixed mapping, e.g., bitmap, indicating the frequency locations of all repetition patterns for which the serving cell may support rather than providing repetition configuration information on a per update basis. In yet another embodiment, the network node may provide a mapping that indicates the frequency locations of subsets of the repetitions patterns for which the serving cell may support.

One type of payload information that could be useful to an UE is whether the payload is identical across repetition versions. Whether the payload is identical or not may trigger different soft combining behavior at the UE. Most incremental redundancy techniques involve soft combining, where copies of incorrectly received data are stored and are subsequently combined with other copies of the same received data to recreate a correct copy of the transmitted data. Principles of incremental redundancy are known in the art and a detailed discussion on incremental redundancy techniques will not be included in this disclosure.

<FIG> and <FIG> illustrate a series of paired transmit and receive beams at different repetition instances in accordance with different aspects of the present disclosure. As noted previously, <NUM> is envisioned to support multiple device types, including wireless devices that use multiple antennas or antenna arrays. <FIG> and <FIG> show how QCL information may be used if it is included as part of the repetition configuration information transmitted to a UE. A network node can inform a UE that the repetitions to be sent by the serving cell are spatially quasi co-located with the original signal. In the embodiment illustrated by <FIG>, the UE can decide that due to the QCL nature of the repetitions, the UE does not need to adjust the receive beam that has a dominant arrival angle based on the original signal propagation path.

In <FIG>, a serving cell <NUM> and UE <NUM>, as described in <FIG>, has performed beam management procedures so that the serving cell <NUM> can send control and/or data signaling (i.e., an original signal) using transmit beam <NUM> to a UE <NUM> that receives the control and/or data signaling using receive beam <NUM>. The orientation and strength of transmit and receive beams <NUM>, <NUM> are determined by beam management procedures between the serving cell <NUM> and the UE <NUM>. To a network node, the serving cell sends or has sent information indicative of the configurations that the serving cell will subsequently use for repetition transmissions to the UE. As a part of this information, the serving cell conveys QCL information that indicates that the repetitions will be spatially QCL to the original signal. The network node transmits this QCL information to the UE in a repetition configuration information message, which can be conveyed as an RRC message, MAC-CE, or L1 signaling, as examples. When the UE <NUM> receives this message, the UE <NUM> may decide to refrain from changing the current configuration of the receive beam <NUM> even though the serving cell may be changing the configuration of the transmit beam <NUM>. Examples are shown for repetition <NUM> and <NUM>.

For repetition <NUM>, the transmit beam <NUM> from the serving cell is reconfigured to have a narrower and longer lobe than the original transmit beam <NUM> but whose dominant transmission angle is different from that of the original transmit beam <NUM>. However, transmit beam <NUM> is still spatially QCL with the original transmit beam <NUM> since the dominant arrival angles of the transmit beams are within a tolerable range whereby they can be received by the same receive beam. Hence, the UE need not reconfigure the receive beam <NUM> to cover a different intended angular zone.

For repetition <NUM>, the transmit beam <NUM> from the serving cell <NUM> is again reconfigured to have a narrower and longer lobe than the original transmit beam <NUM> but whose dominant transmission angle is different from that of the original transmit beam <NUM> and transmit beam <NUM>. However, transmit beam <NUM> is still spatially QCL with the original transmit beam <NUM> since the dominant arrival angles are within a tolerable range where they can be received by the same receive beam. Hence, the UE need not reconfigure the receive beam <NUM>. As shown by the other transmit/receive beams in <FIG>, if the transmit beams carrying the repetitions are QCL with the original signal, the computational burden of performing beam sweeping at the UE is lifted if the UE has notice as to the QCL nature of the repetitions.

<FIG> is an example of a UE <NUM> performing beam sweeping due to QCL information conveyed in a repetition configuration information message indicating that the repetition transmissions will not be QCL with the original signal. Serving cell sends control and/or data signaling using transmit beam <NUM> to a UE that receives the control and/or data signaling using receive beam <NUM>. To a network node, the serving cell sends or has sent information indicative of the configurations that the serving cell will subsequently use for repetition transmissions to the UE. As a part of this information, the serving cell conveys QCL information that indicates that the repetitions will not be spatially QCL to the original signal. The network node transmits this QCL information to the UE in a repetition configuration information message, which can be conveyed as an RRC message, MAC-CE, or L1 signaling for example.

For repetition <NUM>, the transmit beam <NUM> from the serving cell is reconfigured to have a dominant transmission angle different from that of the original transmit beam <NUM>. The dominant arrival angles of transmit beam <NUM> and the original transmit beam <NUM> are not within a range to be received by the same receive beam. Hence, the UE should reconfigure the receive beam <NUM> to change the directional orientation of the receive beam <NUM> to one that is more likely to pair with transmit beam <NUM>.

For repetition <NUM>, the transmit beam <NUM> from the serving cell is reconfigured again to have a dominant transmission angle different from that of the original transmit beam <NUM> and the transmit beam <NUM>. The dominant arrival angles of beams <NUM> and <NUM> are not within a tolerable range to be received by the same receive beam. Hence, the UE should reconfigure the receive beam <NUM> to change its directional orientation to one that is more likely to pair with transmit beam <NUM>. As shown by the other transmit/receive beams in <FIG>, if the transmit beams carrying the repetitions are not QCL with the original signal or each other, the UE will be performing a beam sweeping operation with the receive beam.

In the example of <FIG>, the original signal and the repetition versions were conveyed by transmit beams that were formed with a mix of wide and narrow beam widths. The use of narrow transmit beams that are transmitted at different transmit angles provides for better Signal to Noise Ratio (SNR) properties that would enable faster decoding at the UE. In the contrasting example of <FIG>, the original signal and the repetitions were conveyed by wide transmit beams. Repetitions using wide transmit beams may permit more multiplexing of users per symbol in the case where the serving cell is performing analog beamforming. Moreover, if the repetitions have identical contents and channels, then the UE can use the phase differential between the transmit beams to estimate a carrier frequency offset that can be used to correct phase errors that arise over time from frequency errors. The serving cell has the ability to select a repetition configuration that may involve many factors such as the transmit beam shape, angle of arrival, the antenna ports used for the transmit beams, whether the transmit beams are spatially QCL or not, the number of repetitions, the symbol locations of the repetitions, the tones at which the repetitions are sent, the number of transmit beams, etc. Indeed, many different combinations of selections may be possible due to the mechanism of using a repetition configuration information message conveyed by a network node in support of a serving cell.

Alternatively, a selection by the serving cell may be conveyed in separate messages, for example, the QCL status of the repetitions may be conveyed by a QCL indicator separately from the number of repetitions or the repetition patterns. The QCL indicator may be applied to all repetitions or multiple QCL indicators may be generated, each applied to different subsets of repetition versions. Using different messaging to address different serving cell configurations may be efficient depending on whether a lower layer process or an upper layer process is involved. For example, use RRC messaging if an upper layer process is to be invoked to support a change to the repetition configuration or use L1 signaling if a lower layer process is to be invoked to support a change to the repetition configuration.

<FIG> is a flowchart illustrating an exemplary method <NUM> for updating repetition configuration information at a UE. Although the description of <FIG> is in the context of a UE, the method can be performed at any type of node that can support wireless communications, such as at both mmWave and sub-<NUM> frequencies contemporaneously or simultaneously. The method <NUM> presumes that the UE has already established communication sessions with a serving cell and a network node.

At step <NUM>, a UE processor controls internal processing of communications supporting the exchange of messages with a serving cell. The messages are for supporting beam management procedures. The UE processor may be a transmit processor, a receive processor, or a processor that is configured for both transmit and receive processing.

At step <NUM>, the UE processor controls the internal processing of the transmissions supporting the exchange of messages with a network node. At least one of the messages is a repetition configuration information message from the network node. At optional step (not shown), the UE processor may control feedback transmissions such as an acknowledgement (ACK) or negative acknowledgment (NACK) to the network node. Communication of an ACK/NACK is a technique well-known to those of ordinary skill in the art, wherein the integrity of signal communication 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 signal is confirmed, an ACK may be transmitted, whereas if not confirmed, a NACK may be transmitted.

At step <NUM>, within the UE processes and stores the contents of at least one repetition configuration information message in a memory. The contents of the repetition configuration information message will be used by the beam management circuitry to configure one or more antenna arrays to receive a transmit beam from the serving cell, such as at a mmWave frequency. The beam management circuitry may also be configured to support beam management procedures.

At step <NUM>, the UE receives a first transmission instance of an original signal on a transmit beam from the serving cell. An example of the original signal is an SSB signal comprising a PBCH signal. Other types of signals such as data signals and control signals may also benefit from the embodiments described herein.

At step <NUM>, the beam management circuitry accesses the stored contents of the repetition configuration information message from the memory and determines whether to reconfigure one or more antenna arrays to change a receive beam direction to maintain a pairing with the transmit beam from the serving cell.

At step <NUM>, beam management circuitry determines whether to reconfigure or not reconfigure one or more of the antenna arrays in accordance to the received repetition configuration information message. In an alternative embodiment, the UE determines all reconfiguration actions before the first transmission instance of the signal.

At step <NUM>, the UE processor receives repetition versions of the original signal through the receive beam and performs incremental redundancy techniques to recover information that was previously transmitted by the serving cell (e.g., information in the original signal).

At step <NUM>, the UE continues to monitor for updates to the repetition configuration information message. In one aspect of this embodiment, steps <NUM> and <NUM> may occur contemporaneously.

<FIG> is a flowchart illustrating an exemplary method <NUM> for receiving repetition configuration information at a network node and transmitting the repetition configuration information to a wireless node, (e.g., a UE). Although the description of <FIG> is in the context of a network node, the method <NUM> can be performed at any type of node that can support wireless communications, such as at sub-<NUM> frequencies, and communications with another node in a wireless communication network, contemporaneously or simultaneously.

At step <NUM>, a network node processor controls the internal processing of the transmissions supporting the exchange of network messages with a serving cell. The network messages are for supporting beam configuration updates to a UE that is being served by the serving cell. The exchange of network messages may be communicated wirelessly or over a wired medium.

At step <NUM>, the network node processor determines whether to send a repetition configuration information message to the UE based on the contents of the exchanged network messages. The network node processor may be configured to assess the contents of the exchanged network messages to determine whether to generate and send a repetition configuration information message to the UE or the processor may be configured to not assess the contents of the exchanged network messages and to send the contents of the exchanged message in a repetition configuration information message without further determinations. The processor may be further configured to assess the contents of the exchanged network messages and select parameters indicative of the assessed contents. The selected parameters indicative of the assessed contents may be included as a portion of a repetition configuration information message to the UE.

At step <NUM>, the network node processor generates at least one repetition configuration information message to the UE based at least in part on a portion of the repetition configuration information from the serving cell. The network node processor generates at least one repetition configuration information message in accordance with predetermined rules. One example of predetermined rule is to provide a fixed mapping format, e.g., bitmap, indicating the frequency locations of all repetition patterns for which the serving cell may be supporting. An alternative example is to provide a fixed mapping format indicating the frequency locations of subsets of the repetitions patterns for which the serving cell may be supporting. Another example of a predetermined rule is to provide the contents of the exchanged network message that are relevant to a particular instance in time. Another example of a predetermined rule is that some types of content, for example QCL information, is sent in a different type of messaging than other types of content, for example, the number of repetitions.

At step <NUM>, the network node processor transmits at least one repetition configuration information message to the UE. The repetition configuration message comprises at least one of or a combination of: an indicator for a number of repetition versions in a slot; an indicator for symbol locations carrying a repetition version from the set of repetition versions; a payload indication; an indicator for frequency locations carrying a repetition version from the set of repetition versions; or at least one quasi co-located (QCL) information indicator.

At step <NUM>, the network node processor may determine to forward a received acknowledgement from the UE or to inform the serving cell that the UE has acknowledged reception of the repetition configuration information message.

<FIG> is a flowchart illustrating an exemplary method <NUM> for managing repetition transmissions at a serving cell. Although the description of <FIG> is in the context of a serving cell, the method <NUM> can be performed at any type of node that can support wireless communications, such as at mm Wave frequencies, and communications with another node in a wireless communication network, contemporaneously or simultaneously.

At step <NUM>, a serving cell processor controls the internal processing of the transmissions supporting the exchange of messages with a UE. The messages are for supporting beam management procedures, such as at a mmWave frequency. The serving cell processor may be a transmit processor, a receive processor or a processor that is configured for both transmit and receive processing.

At step <NUM>, the serving cell processor controls the internal processing of the transmissions supporting the exchange of network messages with a network node. The exchange of network messages may be communicated wirelessly or over a wired medium. In one embodiment, steps <NUM> and <NUM> may occur contemporaneously.

At step <NUM>, beam management circuitry determines whether range extension techniques should be implemented to support communications with the UE. The determination can be based upon measured channel conditions, received channel condition reports, the receipt of information indicating that data is not being received at the UE, or other such parameters indicating a loss of channel quality. The beam management circuitry may be co-located within the serving cell processor or may be separate from the serving cell processor.

At step <NUM>, the beam management circuitry determines configuration information for performing repetition procedures to support range extension of transmissions from the serving cell. Configuration information may include at least one of the number of repetitions, the symbol locations for the repetitions, SFN information, repetition pattern information, payload information, QCL information (or other beam direction information), etc. for at least one transmit beam In one embodiment, the beam management circuitry may determine that transmissions will be over multiple transmit beams, each having different transmit angles and each transmit beam carrying a subset of the repetition versions.

At step <NUM>, the beam management circuitry transfers the configuration information to the serving cell processor. The configuration information may have been processed by the beam management circuitry in a form that will directly inform the UE as to the appropriate UE receive beam configuration to pair with the transmit beam that will be carrying the repetitions or alternatively, the configuration information may be a reporting of the configuration settings used by the serving cell.

At step <NUM>, the serving cell processor exchanges network messages with the network node wherein at least one of the exchanged network messages conveys at least a portion of the repetition configuration information to the network node. Additionally, one of the exchanged network messages provides an indication that the UE has received the repetition configuration information, e.g., acknowledgment information.

At step <NUM>, the beam management circuitry controls the transmission of repetition versions over a transmit beam to the UE, wherein the transmit beam is configured in accordance to the repetition configuration information for a respective repetition version.

The descriptions in this disclosure provide examples, and is not limiting of the scope, applicability, or examples set forth in the claims. It should be understood that any aspect of the disclosure described herein may be embodied by one or more elements of a claim.

For example, means for transmitting and/or means for receiving may comprise one or more antennas, such as antenna(s) <NUM> of the gNB <NUM> and/or antenna(s) <NUM> of the user equipment <NUM>. Additionally, means for transmitting may comprise one or more processors (e.g., Transmit Processors <NUM>/<NUM> and/or Receive Processors <NUM>/<NUM>) configured to transmit/receive via the one or more antennas. Further, means for determining, means for deciding, means for using, and/or means for performing may comprise one or more processors, such as the Transmit Processor <NUM>, the Receive Processor <NUM>, or the Controller/Processor <NUM> of the gNB <NUM> and/or the Transmit Processor <NUM>, the Receive Processor <NUM>, or the Controller/Processor <NUM> of the user equipment <NUM>.

As used herein, the term receiver may refer to an RF receiver (e.g., of an RF front end) or an interface (e.g., of a processor) of a UE (e.g., UE <NUM>) or BS (e.g., gNB <NUM>) for receiving structures processed by an RF front end (e.g., via a bus). Similarly, the term transmitter may refer to an RF transmitter of an RF front end or an interface (e.g., of a processor) of a UE (e.g., UE <NUM>) or BS (e.g., gNB <NUM>) for outputting structures to an RF front end for transmission (e.g., via a bus). According to certain aspects, a receiver and transmitter may be configured to perform operations described herein.

As an example, "at least one of: a, b, or c" is intended to cover: a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a c c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c).

The steps of a method or algorithm described in connection with the present disclosure may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in any form of storage medium that is known in the art. Some examples of storage media that may be used include random access memory (RAM), read only memory (ROM), flash memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM and so forth. A storage medium may be coupled to a processor such that the processor can read information from, and write information to, the storage medium.

The functions described may be implemented in hardware, software, firmware, or any combination thereof. In the case of a user equipment <NUM> (see <FIG>), a user interface (e.g., keypad, display, mouse, joystick, etc.) may also be connected to the bus.

The processor may be responsible for managing the bus and general processing, including the execution of software stored on the machine-readable media. Machine-readable media may include, by way of example, RAM (Random Access Memory), flash memory, ROM (Read Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable Programmable Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), registers, magnetic disks, optical disks, hard drives, or any other suitable storage medium, or any combination thereof. The computer-program product may comprise packaging materials.

In a hardware implementation, the machine-readable media may be part of the processing system separate from the processor. However, as those skilled in the art will readily appreciate, the machine-readable media, or any portion thereof, may be external to the processing system. By way of example, the machine-readable media may include a transmission line, a carrier wave modulated by data, and/or a computer product separate from the wireless node, all which may be accessed by the processor through the bus interface.

The processing system may be configured as a general-purpose processing system with one or more microprocessors providing the processor functionality and external memory providing at least a portion of the machine-readable media, all linked together with other supporting circuitry through an external bus architecture. Alternatively, the processing system may be implemented with an ASIC (Application Specific Integrated Circuit) with the processor, the bus interface, the user interface in the case of an access terminal), supporting circuitry, and at least a portion of the machine-readable media integrated into a single chip, or with one or more FPGAs (Field Programmable Gate Arrays), PLDs (Programmable Logic Devices), controllers, state machines, gated logic, discrete hardware components, or any other suitable circuitry, or any combination of circuits that can perform the various functionality described throughout this disclosure.

The machine-readable media may comprise a number of software modules. The software modules include instructions that, when executed by the processor, cause the processing system to perform various functions.

A storage medium may be any available medium that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer.

Claim 1:
A method for range extension of highly directional beams from a serving cell (<NUM>; <NUM>) to a user equipment, UE (<NUM>; <NUM>), in a communication system, comprising:
determining to transmit (<NUM>) a set of repetitions (410a-j; <NUM>) of an original signal (<NUM>) from the serving cell (<NUM>; <NUM>) to the UE (<NUM>; <NUM>) by at least one transmit beam (<NUM>, <NUM>; <NUM>, <NUM>) of the serving cell (<NUM>; <NUM>);
determining repetition configuration information (<NUM>) for the at least one transmit beam used by the serving cell for transmissions to the UE;
configuring the at least one transmit beam (<NUM>, <NUM>; <NUM>, <NUM>) in accordance with the repetition configuration information;
passing at least a portion of the repetition configuration information to a network node (<NUM>; <NUM>), the portion suitable for conveyance to the UE by the network node (<NUM>; <NUM>);
receiving, from the network node (<NUM>; <NUM>) an indication that the UE has received the portion of the repetition configuration information; and
transmitting (<NUM>) the set of repetitions (410a-j; <NUM>) over the at least one transmit beam from the serving cell (<NUM>; <NUM>) to the UE (<NUM>; <NUM>).