Patent Description:
With the developments of wireless communication, the utilization of wideband frequency resources and spatial domain resources is further enhanced. In order to achieve wireless communication with high efficiency, more flexible measurement/report is needed to enable a gNB (next generation node B) with "intelligent" scheduling. However, for supporting such flexible measurement, more signaling and measurement efforts are needed at the user equipment (UE) -side according to existing mechanisms (e.g., gNB triggered measurement). Furthermore, for supporting the adaptation among different frequency resources (e.g. different bandwidth parts (BWPs)), measurements across a large scale of resources are needed and the impact caused by radio frequency (RF) tuning may need to be considered during the resource configuration for such measurements.

Moreover, the above issues may become more serious in a non-terrestrial network with services from satellite (e.g. High-Altitude Pseudo-Satellites (HAPS)) or in air-to-ground (ATG) cases. More specifically, an instantaneous service area for one cell may be covered by plenty of beams, which sweep across a target region with a movement of the satellite along the orbit of the satellite. To alleviate occurring interference, resource reuse among beams may be adopted. For example, the beams are mapped to different frequency regions and/or different polarization modes. <FIG> show examples of resource reuse modes among beams B1 to B7 covering adjacent service areas. In <FIG>, the beams B1 to B2 are configured to the same frequency region and the same polarization mode. In <FIG>, the beams B1 and B2 are configured to the same frequency region and different polarization modes. In <FIG>, the beams B1 to B7 are configured to different frequency regions and the same polarization mode. In <FIG>, the beams B1 to B7 are configured to different frequency regions and different polarization modes. When the resource reuse among beams is adopted, the resource configuration and/or triggering condition should be carefully considered.

In addition, a footprint diameter of a single satellite beam could be hundreds of kilometers or even larger. In such large coverage, the number of user equipments (UEs) would be huge. If the network informs the UEs one by one about serving frequency changes, signaling overhead would be high because of the huge number of UEs.

<CIT> relates to improving resource switching by using polarization information of beams within a network.

<CIT> relates to an Unmanned Aerial Vehicle (UAV) communication technology based on Long Term Evolution (LTE).

"<NPL> relates to a forecast based handover.

The exemplary embodiments disclosed herein are directed to providing features that will become readily apparent by reference to the following description when taken in conjunction with the accompany drawings. In accordance with various embodiments, exemplary systems, methods, devices and computer program products are disclosed herein. It is understood, however, that these embodiments are presented by way of example and not limitation, and it will be apparent to those of ordinary skill in the art who read the present disclosure that various modifications to the disclosed embodiments can be made while remaining within the scope of the present disclosure.

<FIG> relates to a schematic diagram of a wireless terminal <NUM> according to an embodiment of the present disclosure. The wireless terminal <NUM> may be a user equipment (UE), a mobile phone, a laptop, a tablet computer, an electronic book or a portable computer system and is not limited herein. The wireless terminal <NUM> may include a processor <NUM> such as a microprocessor or Application Specific Integrated Circuit (ASIC), a storage unit <NUM> and a communication unit <NUM>. The storage unit <NUM> may be any data storage device that stores a program code <NUM>, which is accessed and executed by the processor <NUM>. Embodiments of the storage unit <NUM> include but are not limited to a subscriber identity module (SIM), read-only memory (ROM), flash memory, random-access memory (RAM), hard-disk, and optical data storage device. The communication unit <NUM> may a transceiver and is used to transmit and receive signals (e.g. messages or packets) according to processing results of the processor <NUM>. In an embodiment, the communication unit <NUM> transmits and receives the signals via at least one antenna <NUM> shown in <FIG>.

In an embodiment, the storage unit <NUM> and the program code <NUM> may be omitted and the processor <NUM> may include a storage unit with stored program code.

The processor <NUM> may implement any one of the steps in exemplified embodiments on the wireless terminal <NUM>, e.g., by executing the program code <NUM>.

The communication unit <NUM> may be a transceiver. The communication unit <NUM> may as an alternative or in addition be combining a transmitting unit and a receiving unit configured to transmit and to receive, respectively, signals to and from a wireless network node (e.g. a base station).

<FIG> relates to a schematic diagram of a wireless network node <NUM> according to an embodiment of the present disclosure. The wireless network node <NUM> may be a satellite, a base station (BS), a network entity, a Mobility Management Entity (MME), Serving Gateway (S-GW), Packet Data Network (PDN) Gateway (P-GW), a radio access network (RAN), a next generation RAN (NG-RAN), a data network, a core network or a Radio Network Controller (RNC), and is not limited herein. In addition, the wireless network node <NUM> may comprise (perform) at least one network function such as an access and mobility management function (AMF), a session management function (SMF), a user place function (UPF), a policy control function (PCF), an application function (AF), etc. The wireless network node <NUM> may include a processor <NUM> such as a microprocessor or ASIC, a storage unit <NUM> and a communication unit <NUM>. The storage unit <NUM> may be any data storage device that stores a program code <NUM>, which is accessed and executed by the processor <NUM>. Examples of the storage unit <NUM> include but are not limited to a SIM, ROM, flash memory, RAM, hard-disk, and optical data storage device. The communication unit <NUM> may be a transceiver and is used to transmit and receive signals (e.g. messages or packets) according to processing results of the processor <NUM>. In an example, the communication unit <NUM> transmits and receives the signals via at least one antenna <NUM> shown in <FIG>.

In an embodiment, the storage unit <NUM> and the program code <NUM> may be omitted. The processor <NUM> may include a storage unit with stored program code.

The processor <NUM> may implement any steps described in exemplified embodiments on the wireless network node <NUM>, e.g., via executing the program code <NUM>.

The communication unit <NUM> may be a transceiver. The communication unit <NUM> may as an alternative or in addition be combining a transmitting unit and a receiving unit configured to transmit and to receive, respectively, signals to and from a wireless terminal (e.g. a user equipment).

In this disclosure, a frequency region may be a frequency region, a bandwidth part (BWP), a carrier, a component carrier (CC), an anchor carrier or a non-anchor carrier.

In this disclosure, a reference signal may be equated to a reference resource.

In this disclosure, a reference signal (RS) may be a channel state information (CSI) RS, a synchronization signal block (SSB), synchronization signal (SS) or a cell specific RS (CRS).

In this disclosure, a group of reference signals can refer to the resource set (e.g. resource group) and multiple resource groups can be further organized into different resource settings. That is, the resource setting may comprise one or more resource groups.

In an embodiment, the BS configures resources of RS(s) to the UE, to acknowledge channel conditions. For example, the BS may transmit a configuration to the UE, wherein the configuration indicates resources of RS(s).

In an embodiment, the configuration indicates resource reuse mode(s) of the RS(s). The resource reuse mode refers to resources where the associated RS (or channel) is transmitted/received. For example, the resource reuse mode indicates (e.g. refers to or is determined as) at least one of:.

Note that the frequency region and/or the polarization mode can be described (e.g. indicated) by either the index of resource or indicator only. For example, the frequency region may be indicated by a BWP Id or a carrier frequency ID. In an embodiment, the polarization mode may be indicated by the indicator (e.g., <NUM> refers to polarization mode <NUM>, <NUM> refers to polarization mode <NUM>, and so on).

In an embodiment, the polarization mode may refer to the following exemplified polarization: right-hand circular polarization, left-hand circular polarization, liner polarization, or cross-polarization.

In an embodiment, the spatial resource may refer to resource for different antenna ports, resource for different antennas, resource with different Quasi Co-Location (QCL) reference signal for QCL type (e.g., Type-D) in the associated QCL indication.

After receiving the configuration, the UE transmits report(s) to the BS based on the configuration. For example, the UE may perform measurements based on the configuration and transmits the report(s) with measurement results to the BS based on the configuration.

The resources configuration of the RSs (i.e. measurements), condition(s) of triggering the measurement and behaviors of reporting are discussed in the following.

In this embodiment, configurations of resource are exemplified for elaborating:.

Case-<NUM>: At least one RS is configured within a resource group (e.g. a resource set) to the UE, wherein each RS has its own resources. In an embodiment, the number of RSs configured within single resource group is a positive integer N.

In an embodiment, the BS configures the resources (e.g. a resource reuse mode) per RS. In other words, the BS explicitly indicates the resources for each RS via the configuration.

In an embodiment, each RS is transmitted in a single frequency region. In this embodiment, the frequency region corresponding to each RS may be configured to the UE. For example, an index of the frequency region may be configured per RS.

In an embodiment, each RS may have its own polarization mode. Under such a condition, the polarization mode corresponding to each RS may be configured to the UE.

In an embodiment, each RS may have its own frequency region and polarization mode. In this embodiment, the index of the frequency region and the polarization mode corresponding to each RS are configured to the UE.

In an embodiment, the BS may configure an identification (ID) per RS, wherein each ID is associated to a specific resource reused mode.

In an embodiment, the ID is derived from other sources. For example, the ID may be derived in a similar way as a cell-ID, which is obtained based on detection of secondary synchronization signal (SSS). In another example, the ID may be derived in similar way as a synchronization signal block (SSB) index, which is derived via decoding corresponding information within the SSB.

In an embodiment, the ID may be determined by at least one of:.

In an embodiment, the configured parameter indicates which kind of resource-reuse mode is supported. In an example, the configured parameter may indicate whether polarization-reuse is enabled. In another example, the configured parameter may indicate whether frequency-reuse is enabled. In still another example, the configured parameter may indicate enabled resource-reuse mode among beams (e.g. those shown in <FIG>).

In an embodiment, the ID is associated to one resource reuse mode (e.g. a polarization mode and/or a frequency region).

<FIG> shows a schematic diagram of the ID according to an embodiment of the present application. In <FIG>, each of the IDs L0, L1, L2 and L3 is associated with its own frequency region and polarization mode. The L0 is associated with frequency region ID F1 and polarization mode ID P1, the L1 is associated with frequency region ID F2 and polarization mode ID P2, and so on.

In an embodiment, the resource reuse mode for the ID is determined based on the maximum number of supported resource reuse modes (e.g. the maximum number of indexes for the resource reuse modes) and the ID.

In an embodiment, the resource reuse mode for each ID may be determined by: <MAT> wherein l is the ID, mod(X, Y) is a function of modulo operation of dividing X by Y and N refers to the maximum number of indexes for the resource reuse mode.

<FIG> shows a schematic diagram of the ID and corresponding beam IDs according to an embodiment of the present application. In <FIG>, the ID implicitly refers to the beam IDs B0 to B11. In addition, the resource reuse mode indicates the frequency region ID and <NUM> frequency region IDs F1, F2 and F3 are supported. In this embodiment, the resource reuse mode for each ID may be determined by mod(l, N + <NUM>) + <NUM>. Note that the index of the resource reuse ID starts from <NUM> in this embodiment. Thus, N =<NUM> in this embodiment.

For example, B0 is corresponding to F1 because mod(<NUM>,<NUM>) + <NUM> = <NUM>. Similarly, B3, B6 and B9 are corresponding to F1; B1, B4, B7 and B10 are corresponding to F2; and B2, B5, B8 and B11 are corresponding to F3.

In an embodiment, the resource reuse mode for each ID may be determined by: <MAT> wherein mod(X, Y) is a function of modulo operation of dividing X by Y, l is the ID and M refers to the maximum number of supported resource reuse modes.

In an embodiment, the resource reuse mode for each ID may be determined by: <MAT> wherein <MAT> is a function (e.g. bottom function) of acquiring the maximum integer smaller than or equal to X, l is the ID and N refers to the maximum number of indexes for the resource reuse mode.

In an embodiment, the resource reuse mode for each ID may be determined by: <MAT> wherein <MAT> is a function of acquiring the maximum integer smaller than or equal to X, l is the ID and M refers to the maximum number of supported the resource reuse mode.

In an embodiment, the resource reuse mode indicates only one of frequency region and polarization mode. In this embodiment, the ID is determined by considering only one factor.

According to the invention, the resource reuse mode configured per RS is indicated by a QCL relationship. Further according to the invention, the resource reuse mode of each RS is implicitly indicated by the configured QCL relationship. The RS for measurement is assumed to share a frequency region and/or a polarization mode as the associated reference signal for QCL indication.

In an embodiment, a reference signal REF-A is configured with a QCL relationship consisting of reference signal REF-X as a reference for a QCL-type D and/or Type-D. That is, the reference signals REF-A and REF-X share the same resource reuse mode.

In an embodiment, the definition of the QCL types is defined as:.

In an embodiment, the RSs configured within the same resource set (e.g. resource group) may have at least one of the following limitations:.

In an embodiment, the time gap may be determined with consideration of the UE capability and specified with the time unit as symbol(s) or slot(s). In case the RSs are within different resource reuse modes, there is a requirement on timing duration for RF tuning or "synchronization". If the RSs across different resources are transmitted in contiguous symbols without the time gap, inaccurate measurement results may be acquired.

In an embodiment, the time gap is specified as a minimum value.

In an embodiment of the UE supporting simultaneously reception of RSs over different resource reuse modes, the time gap may not be needed (e.g. the time gap is set to <NUM>).

In an embodiment, the UE does not have scheduling during the measurement with involving the switching across resources (e.g. during the time gap). That is, the UE is not expected to receive any scheduled channel/RS within this frequency region.

<FIG> shows a schematic diagram of resource allocation for RSs according to an embodiment of the present disclosure. In <FIG>, three RSs, RS1, RS2 and RS3 are transmitted in adjacent symbols, wherein RS1 is corresponding to a polarization mode P0 and a frequency region F1, RS2 is corresponding to a polarization mode P1 and the frequency region F1 and RS3 is corresponding to the polarization mode P0 and a frequency region F0. Because RS1 and RS2 have different resources (i.e. polarization mode P0 and P1), a time gap TG1 is kept between RS1 and RS2. Similarly, a time gap TG2 is kept between RS2 and RS3. Note that TG1 is smaller than TG2 since RS1 and RS2 are different at only the polarization mode and RS2 and RS3 are different at both the polarization mode and the frequency region.

In an embodiment, the time gap may be set to <NUM> for certain resource switching between RSs transmitted in adjacent symbols.

Case <NUM> - In this case, up to K resource sets (e.g. resource groups) are configured to UE within single or multiple resource settings, wherein K is a positive integer. In an embodiment, each of resource sets has its own resources (e.g. resource reuse mode) for measurements. For example, the resource reuse mode may be configured per resource set (e.g. per resource group).

In an embodiment, the configuration transmitted from the BS explicitly indicates the resource reuse mode per resource set.

In an embodiment, each RS set is transmitted in its own frequency region. Under such a condition, the index of a corresponding frequency region is configured per RS set.

In an embodiment, each RS set is transmitted with its own polarization mode. In this embodiment, the corresponding polarization mode is configured per RS set.

In an embodiment, each RS set is transmitted with its own polarization mode and frequency region. In this embodiment, the resource reuse mode may be defined as including parameters for both the polarization mode and the frequency region and the resource reuse mode is configured per RS set. As an alternative or in addition, corresponding indexes of frequency region and polarization mode are configured per RS set.

In an embodiment, the BS may configure an ID per RS set, wherein each ID is associated to a specific resource reused mode. The details of ID can be referred to <FIG> and corresponding descriptions and are not described herein for brevity.

In an embodiment, the RS configuration may have at least one of the following limitations:.

In an embodiment, the time gap may be determined with consideration of UE capability and specified with time unit as symbol or slots. In case of RSs within different resource reuse modes, the time gap may be inserted for timing durations used for RF tuning or "synchronization". If the RSs across different resources are transmitted in contiguous symbols without the time gap, inaccurate measurement results may be acquired.

In an embodiment, the time gap may be <NUM>.

In an embodiment, the UE does not have scheduling during the measurement with involving the switching cross resources (e.g. during the time gap). That is, the UE is not expected to receive any scheduled channel/RS within this frequency region.

Case-<NUM>: In this case, up to K resource sets are configured to UE within multiple resource settings. In this embodiment, the resource reuse mode may be configured per resource setting (i.e. per resource sets).

In an embodiment, within each resource setting, the same frequency region is shared by the RSs within resource sets included in this resource setting.

In an embodiment, within each resource setting, the same polarization mode is shared by RSs within resource sets included in this resource setting.

Based on the configuration received from the BS, the UE may perform measurements and transmit at least one report with measurement results to the BS.

In an embodiment, the measurement/report is triggered by the BS.

In an embodiment, the measurement/report is triggered by the UE when at least one of following criteria is satisfied:.

In an embodiment, the serving resource/beams refers to the resource where the data (e.g., PDSCH), configuration and scheduling information is transmitted.

In an embodiment, the measurement/report is triggered by the UE when the criteria for distance and RSRP/RSRQ/SINR is satisfied.

In an embodiment, the measurement/report is triggered by the UE when the criteria for elevation angle and RSRP/RSRQ/SINR is satisfied.

In an embodiment, the criteria of triggering the measurement/report may be configured by the BS.

In an embodiment, the criteria, e.g., defined as trigger condition of the measurement/report, may be configured to be aligned with the report configuration for each UE.

In an embodiment of the reference signals for measurement are configured via multiple resource sets (e.g. as proposed in Case-<NUM> within embodiment-<NUM>), the UE conducts the measurement following an order of resource set ID. Within multiple resource settings, the measurement follows an order of resource setting ID first, then the order of the resource set ID. As an example, it can highlight that such group level indication occurs once the same resource reuse mode is shared among resources within each group.

In an embodiment, the report may comprises at least one of Reference Signal Received Power (RSRP), layer <NUM> signal-to-interference-plus-noise-ratio (L1-SINR), Reference Signal Received Quality (RSRQ), deviation of RSRP, deviation of L1-SINR deviation of RSRQ, resource index, resource set index, or ID.

In an embodiment, the ID may refer to the ID of corresponding RS.

In an embodiment, the ID may refer to the ID of the RS with the best received quality (e.g. the highest L1-SINR, the best RSRQ and/or the greatest RSRP).

In an embodiment, the ID(s) represents frequency reuse mode(s), which is associated to the corresponding RS(s).

In this case, the measurement/report is triggered by the BS and the report can be carried by either physical uplink control channel (PUCCH) or physical uplink shared channel (PUSCH) according to the scheduling from the BS.

In an embodiment, transmission instants for the scheduling resource carrying the report are Z time unit after corresponding measurement. Because the uplink (UL) resources including polarization mode for report may be different from the resources allocated for the measurements (e.g., the last one RS during one measurement). Thus, after the measurement finishes, the RF module of the UE should have enough time for being tuned to the UL resource for report transmission.

In an embodiment, the number Z may be determined with consideration on at least one of:.

In an embodiment, the number of resources for measurements indicates that how many RSs will be measured and corresponding configuration, e.g., bandwidth.

In an embodiment, the resource switching gap may refer to the gap for switching among resources for measurements (more resources and switches, more time is required before reporting).

In an embodiment, the resource switching gap may refer to the gap between the resources for measurement and report: if the resource for measurement is different as the resource for report, switching after the measurement is needed.

In an embodiment, the Duplex mode refers to frequency division duplex FDD and/or time division duplex (TDD). In an embodiment, the Duplex mode may also refer to full-duplex mode, half-duplex mode and/or the following two half-duplex mode:.

In an embodiment, the timing advanced (TA) refers to the TA adjustment for UL transmission. That is, an offset between receiving of scheduling and the UL transmission of report may be larger than value of the TA. In addition, measurement within the TA adjustment region for the UL transmission may not be performed.

In case-<NUM>, the measurement/report is triggered by UE once the pre-defined rule(s) is satisfied (e.g. case-<NUM> of embodiment <NUM>). In this case, the measurement report may be carried by a pre-configured resource. For example, the pre-configured resource may be configured-grant PUSCH via radio resource control (RRC), which is periodic with certain periodicity.

It should be noticed that, the measurement results are only carried on the configured resource which satisfy the timing restriction as highlighted in Case-<NUM>.

In case-<NUM>, the measurement/report is triggered by the UE once the pre-defined rule(s) is satisfied. In an embodiment, there is not available resource for carrying the corresponding measurement results. Under such a condition, the UE may send a scheduling request and/or buffer status report to the BS.

In an embodiment, before reporting measured results (after sending the SR/BSR), the UE does not perform any measurement.

In an embodiment, the signaling is conducted in the UE group level. For example, J (a positive integer) components are included within the signaling and each component includes at least one of:.

Specifically, when the grouping of UE is conducted by the BS and corresponding grouping information is configured to UE, only the target resource ID for switching the serving resources is sufficient.

In an embodiment, the signaling including the J components may be an RRC signaling, media access control control element (MAC CE) or DCI.

In an embodiment, the serving resource may refer to the frequency resource, time domain resource, etc., which carry the corresponding data/control/RS transmitted from the BS to the UE.

In an embodiment, the BS sends the DCI to UE(s) to indicate the serving resource. In this embodiment, target resource ID (e.g., frequency resource ID such as BWP ID or CC ID), resource reuse mode (e.g., only the polarization mode ID) is included within the DCI.

In an embodiment, the resource reuse mode may not be transmitted for indicating switching for serving resources, e.g. , when the same resource reuse mode is applied for both serving and target resource and/or when the BS only schedules the resource with same properties for certain UE based on the report UE capability.

Note that definitions of the resource reuse mode in Embodiment <NUM> are the same as those shown in Embodiment <NUM> and are not described herein for brevity.

In an embodiment, the UE selects the corresponding target resource ID corresponding to the grouping criteria (i.e. the reference point for grouping and/or the elevation threshold for grouping).

In an embodiment, the UE decodes the signaling of switching the serving resources and starts to monitor physical downlink control channel (PDCCH) and/or RSs in the target resources after K time unit(s).

In an embodiment, the UE fails to decode the signaling of switching the serving resources. In this embodiment, the UE may send a feedback to inform the BS and such feedback can be a scheduling request or a physical random access channel (PRACH).

A skilled person would further appreciate that any of the various illustrative logical blocks, units, processors, means, circuits, methods and functions described in connection with the aspects disclosed herein can be implemented by electronic hardware (e.g., a digital implementation, an analog implementation, or a combination of the two), firmware, various forms of program or design code incorporating instructions (which can be referred to herein, for convenience, as "software" or a "software unit"), or any combination of these techniques.

To clearly illustrate this interchangeability of hardware, firmware and software, various illustrative components, blocks, units, circuits, and steps have been described above generally in terms of their functionality. In accordance with various embodiments, a processor, device, component, circuit, structure, machine, unit, etc. can be configured to perform one or more of the functions described herein. The term "configured to" or "configured for" as used herein with respect to a specified operation or function refers to a processor, device, component, circuit, structure, machine, unit, etc. that is physically constructed, programmed and/or arranged to perform the specified operation or function.

Furthermore, a skilled person would understand that various illustrative logical blocks, units, devices, components and circuits described herein can be implemented within or performed by an integrated circuit (IC) that can include a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, or any combination thereof. The logical blocks, units, and circuits can further include antennas and/or transceivers to communicate with various components within the network or within the device.

In this document, the term "unit" as used herein, refers to software, firmware, hardware, and any combination of these elements for performing the associated functions described herein. Additionally, for purpose of discussion, the various units are described as discrete units; however, as would be apparent to one of ordinary skill in the art, two or more units may be combined to form a single unit that performs the associated functions according embodiments of the present disclosure.

Claim 1:
A wireless communication method performed by a wireless terminal, the wireless communication method comprising:
receiving, from a wireless network node, a configuration indicating resources of at least one reference signal, and
transmitting, to the wireless network node, at least one report based on the configuration, wherein the at least one report comprises measurement results of at least one measurement performed based on the resources of the at least one reference signal,
wherein the configuration indicates a resource reuse mode per reference signal, per group of reference signals or per groups of reference signals,
wherein the resource reuse mode indicates the resources where reference signals associated with the resource reuse mode are transmitted, wherein the resources are a frequency region and/or a polarization mode, wherein the resource reuse mode is indicated by a Quasi Co-Location, QCL, relationship between each of the one ore more reference signals and an associated reference signal for QCL indication.