CN113259953A

CN113259953A - Spatial relationship switching method and user equipment

Info

Publication number: CN113259953A
Application number: CN202110143540.5A
Authority: CN
Inventors: 唐治汛; 余仓纬; 林烜立
Original assignee: MediaTek Singapore Pte Ltd
Current assignee: MediaTek Singapore Pte Ltd
Priority date: 2020-02-12
Filing date: 2021-02-02
Publication date: 2021-08-13
Also published as: TW202131736A; WO2021159292A1; TWI815083B

Abstract

The invention provides a spatial relationship switching method and user equipment, wherein one embodiment provides the spatial relationship switching method, which comprises the following steps: receiving, by a user equipment, a spatial relationship configuration in a new radio network to switch an uplink channel to a target spatial relationship, wherein the spatial relationship configuration indicates that a spatial filter of the uplink channel is quasi co-located with a spatial filter of one or more downlink reference signals; determining whether the target spatial relationship is known or unknown according to a predefined list of conditions; and when the target spatial relationship is known, directly switching to the target spatial relationship; performing spatial filter training on co-located downlink reference signals when the target spatial relationship is unknown. By using the invention, the spatial relationship switching can be better carried out.

Description

Spatial relationship switching method and user equipment

Technical Field

The present invention relates to wireless communications, and more particularly, to a method and apparatus for spatial relationship switching (sps) in a New Radio (NR) communication system.

Background

In recent years, wireless communication networks have multiplied. Long Term Evolution (LTE) systems have a simplified network architecture that can provide high peak data rates, low latency, improved system capacity, and lower operating costs. The LTE system (also referred to as a 4G system) also provides seamless integration with existing wireless networks (e.g., GSM, CDMA, UMTS, etc.). In an LTE system, an evolved universal terrestrial radio access network (E-UTRAN) includes a plurality of evolved node bs (enodebs or enbs) to communicate with a plurality of mobile stations. Wherein the mobile station is also referred to as User Equipment (UE). Third generation partnership project (3)^rdgeneration partner project, 3GPP) networks typically comprise a mixture of 2G/3G/4G systems. Next Generation Mobile Networks (NGMN) have a future activity focus on defining end-to-end (end-to-end) requirements of the 5G NR system.

Increasing bandwidth shortages have spurred the exploration of the millimeter wave (mmWave) spectrum underutilized between 3G and 300G Hz for next generation broadband cellular communication networks. The available spectrum in the millimeter wave band is 200 times that of a conventional cellular system. Millimeter-wave wireless networks use directional communication of narrow beams and can support data rates of several gigabits. In principle, a beam training mechanism including initial beam alignment and subsequent beam tracking may ensure that a Base Station (BS) beam and a UE beam are aligned for data communication. In Downlink (DL) based Beam Management (BM), the BS side provides the UE with an opportunity to measure beamforming channels for different combinations of BS and UE beams. Similarly, in Uplink (UL) based BM, the UE side provides the BS with an opportunity to measure the beamformed channels for different combinations of UE beams and BS beams.

Two signals transmitted from the same antenna and the same beam experience the same radio channel. Two signals transmitted from different antennas or beams are said to be spatially co-located (QCLed) if they encounter a radio channel with common performance. In 5G NR, each BS beam broadcasts a minimum number of cell-specific (cell-specific) and beam-specific (beam-specific) information via a Synchronization Signal (SS) block (SSB). In addition, the network signals a spatial relationship between the SSB and other Reference Signals (RSs) to the UE to indicate the QCL type for the uplink channel. The network may indicate a target spatial relationship to the UE to change the QCL type through Radio Resource Control (RRC) configuration, Medium Access Control (MAC) Control Element (CE) activation, Downlink Control Information (DCI) indication.

Therefore, solutions are sought to enhance spatial relationship switching, e.g., how to efficiently switch an active spatial relationship to a new spatial relationship.

Disclosure of Invention

An embodiment of the present invention provides a spatial relationship switching method, including: receiving, by a user equipment, a spatial relationship configuration in a new radio network to switch an uplink channel to a target spatial relationship, wherein the spatial relationship configuration indicates that a spatial filter of the uplink channel is quasi co-located with a spatial filter of one or more downlink reference signals; determining whether the target spatial relationship is known or unknown according to a predefined list of conditions; and when the target spatial relationship is known, directly switching to the target spatial relationship; performing spatial filter training on co-located downlink reference signals when the target spatial relationship is unknown.

An embodiment of the present invention provides a user equipment, including a circuit configured to: receiving a spatial relationship configuration in a new radio network to switch an uplink channel to a target spatial relationship, wherein the spatial relationship configuration indicates that spatial filters of the uplink channel are quasi co-located with spatial filters of one or more downlink reference signals; determining whether the target spatial relationship is known or unknown according to a predefined list of conditions; and when the target spatial relationship is known, directly switching to the target spatial relationship; performing spatial filter training on co-located downlink reference signals when the target spatial relationship is unknown.

Another embodiment of the present invention provides a non-transitory computer readable medium storing instructions that, when executed by a processor, cause the processor to perform the steps of the proposed sidelink delivery method.

By using the invention, the spatial relationship switching can be better carried out.

Drawings

Various embodiments of the present invention, which are set forth by way of example, will be described in detail with reference to the following drawings, wherein like reference numerals refer to like elements, and wherein:

fig. 1 is a system diagram of an NR beamforming wireless system with spatial relationship switching in accordance with an embodiment of the present invention.

Fig. 2 is a simplified block diagram of a base station and user equipment according to an embodiment of the present invention.

Fig. 3 is a diagram illustrating an example of the definition of the spatial relationship quasi-co-location source RS.

Fig. 4 is a schematic diagram of a spatial relationship switching process when configured uplink target spatial relationship is quasi co-located to DL RS according to an embodiment of the present invention.

Fig. 5 is an exemplary diagram of a spatial relationship switching process when a configured uplink spatial relationship is quasi co-located to an SRS according to an embodiment of the invention.

Fig. 6 is an exemplary diagram of PUCCH spatial relationship switching according to an embodiment of the present invention.

Fig. 7 is an exemplary diagram of PUSCH spatial relationship switching according to an embodiment of the present invention.

Fig. 8 is an exemplary diagram of SRS spatial relationship switching according to an embodiment of the present invention.

Fig. 9 is a flowchart of a method of performing spatial relationship switching according to an embodiment of the present invention.

Detailed Description

Certain terms are used throughout the description and following claims to refer to particular components. As one skilled in the art will appreciate, manufacturers may refer to components by different names. This document does not intend to distinguish between components that differ in name but not function. In the following description and claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. Likewise, the term "coupled" is intended to mean either an indirect or direct electrical connection. Thus, if a device couples to another device, that connection may be through a direct electrical connection or through an indirect electrical connection via other devices and connections. The making and using of embodiments of the present invention are discussed in detail below. However, it should be understood that embodiments may be practiced in a variety of specific environments. The specific embodiments discussed are merely illustrative and do not limit the invention. The invention also describes some variants of the embodiments. Like reference numerals are used to indicate like elements in the various figures and illustrative embodiments.

The following description is of the preferred implementation of the present invention and is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. Note that the 3GPP specifications described herein are used to teach the spirit of the present invention, but the present invention is not limited thereto. Reference will now be made in detail to some embodiments of the invention, examples of which are illustrated in the accompanying drawings

Fig. 1 is a system diagram of an NR beamforming wireless system 100 with spatial relationship switching in accordance with an embodiment of the present invention. Beamformed millimeter-wave mobile communication network 100 includes a BS 101 and a UE 102. Millimeter-wave cellular networks employ directional communication with beamformed transmissions, which can support data rates up to several gigabits. Directional communication is achieved through digital and/or analog beamforming, wherein multiple sets of beamforming weights are applied to multiple antenna elements to form multiple beams. In the example shown in fig. 1, the BS 101 is directionally configured with multiple cells, and each cell is covered by a set of TX/RX beams. For example, for uplink transmission, cell 103 is covered by a set of five BS RX beams RX #1, RX #2, RX #3, RX #4, and RX # 5. The set of BS RX beams RX #1-RX #5 covers the entire service area of cell 103. Similarly, the UE 102 may also apply beamforming to form multiple UE TX beams, e.g., TX #1-TX # 5. For beamformed access, both ends of the link need to know which beamformers (beamformers) to use, e.g., the serving Beam Pair Link (BPL) 130 for uplink communications between the BS 101 (using RX #3) and the UE 102 (using TX # 1). BS 101 may also be referred to as an Access Point (AP), access terminal, nodeb, eNodeB, eNB, gnnodeb, gNB, or other terminology used in the art. The UE 102 may be a mobile phone, a laptop, a device carried in a vehicle, an Internet of Things (IoT) device, and so on.

In 5G NR, each BS control beam broadcasts a minimum amount of cell-specific and beam-specific information through SSBs. In addition, the network transmits the spatial relationship to the UE to indicate a QCL Type (QCL-Type) between the uplink channel resources and the reference signals. The uplink channel includes a Physical Uplink Control Channel (PUCCH) and a Physical Uplink Shared Channel (PUSCH). Two spatial relationships may be defined. The first { QCL-TypeA, QCL-TypeB, QCL-TypeC } relates to channel statistics. The second { QCL-type } relates to spatial TX parameters, which relate only to FR 2. The spatial relationship information indicates a spatial filter (e.g., TX beam) that the UE will use for a corresponding PUCCH, PUSCH, or Sounding Reference Signal (SRS) transmission. The network may indicate the target spatial relationship to the UE to change the QCL type through RRC configuration, MAC-CE activation, and DCI indication.

As shown in fig. 1, the spatial relationship information, e.g., the spatial relationship between the spatial TX filter of the dedicated uplink resource and the spatial filter of the reference signal resource, may be indicated through RRC signaling or RRC + MAC CE. In an example, a spatial relationship list (spatialiationlnfolist) is configured in the dedicated PUCCH resource configuration through RRC signaling, and includes one or more PUCCH-spatialiationlnfo Information Elements (IEs). Each PUCCH-spatial relationship info IE may include an SSB resource indicator (SSBRI), a channel state information reference signal (CSI-RS) resource indicator (CRI), or an SRS Resource Indicator (SRI) to indicate a spatial filter (e.g., a UE TX beam) to be used by a UE associated with a corresponding PUCCH transmission. When the number of PUCCH-SpatialRelationInfo IEs in the spatialrelationsnfisti list is greater than one, the MAC CE is used to point to one of the PUCCH-spatialrelationsinfo IEs to indicate spatial relationship information for the dedicated PUCCH resource. In the example shown in fig. 1, spatialrelationlnfolist 110 contains up to four PUCCH-spatialrelationlnfo IEs, including SSB #1, CSI #3, CSI #5, and SRS # 4. The MAC CE 120 includes a four-bit bitmap and a PUCCH resource ID for PUCCH spatial relationship activation, the second bit of the bitmap having a value of 1 indicating that the UE 102 can infer the spatial relationship between the spatial filter for CSI #3 and the spatial filter for the UE PUCCH transmission on the dedicated PUCCH resource indicated by the PUCCH resource ID.

Fig. 1 further illustrates an exemplary spatial relationship switching when the spatial relationship is configured to be quasi co-located with a DL RS or UL SRS. The term "quasi co-location" may also be referred to herein as association. First, the network configures the current spatial relationship, requesting the UE to transmit a signal using TX #1 (active spatial filter). The network receives the transmission signal (e.g., BPL 130) using RX # 3. After some time, the network detects that the UE using TX #3 is better than the UE using TX # 1. The network then configures a new spatial relationship to request the UE to switch its TX beam to TX #3 (target spatial filter). The network may receive signals (e.g., BPL 140) from the UE using its RX # 1. The new target spatial relationship is configured to be quasi co-located with the DL RS or UL SRS. The network may provide the spatial relationship information through RRC signaling, MAC CE activation, or DCI indication.

In an exemplary embodiment, a method of performing spatial relationship switching in an NR system is provided as shown at 140. In one embodiment, the configured spatial relationship is quasi-co-located with the source of the DL RS (e.g., SSB or CSI-RS) (step 1). In such a quasi co-located relationship, the active spatial relationship switching condition should distinguish between the known case and the unknown case (step 2). In a known case, when the UE receives the spatial relationship configuration, the UE parses the configuration and performs fine (fine) timing tracking on the quasi co-located RS of the new configuration. Thereafter, the UE switches its spatial relationship to the new configuration. In the unknown case, in addition to the above procedure, the UE may perform layer 1(layer 1, L1) RSRP measurements after the UE resolves the spatial relationship configuration and before the fine timing tracking. In another embodiment, the configured spatial relationship may be quasi co-located with the root source (root source) of the UL SRS (step 1). In this quasi co-located relationship, the active spatial relationship switching condition does not need to distinguish between the known case and the unknown case (step 2). When the UE receives the spatial relationship configuration, the UE parses the configuration and switches the spatial relationship based on the configured SRS index.

The above spatial relationship switching may be applied to PUSCH, PUCCH and SRS transmissions (step 3). In PUCCH, MAC based spatial relationship switching should be defined. In PUSCH, spatial relationship activation should only follow the relevant PUCCH or SRS spatial relationship switching process. In periodic SRS, RRC-based spatial relationship switching should be defined. In semi-static SRS, MAC based spatial relationship switching should be defined. In aperiodic SRS, DCI-based spatial relationship switches should be defined. The aperiodic SRS should always be associated with a known spatial relationship.

Fig. 2 is a simplified block diagram of a base station and user equipment according to an embodiment of the present invention. The BS 201 has an antenna array 211, the antenna array 211 having a plurality of antenna elements for transmitting and receiving radio signals. One or more RF transceiver modules 212 are coupled to the antenna array, receive RF signals from the antennas 211, convert them to baseband signals, and send them to the processor 213. The RF transceiver 212 also converts a baseband signal from the processor 213 into an RF signal and transmits to the antenna 211. Processor 213 processes the received baseband signals and invokes different functional modules to perform functions in BS 201. Memory 214 stores program instructions and data 215 to control the operation of BS 201. The BS 201 also includes a number of functional blocks and circuits to perform various tasks according to embodiments of the present invention.

Similarly, the UE 202 has an antenna 231 that transmits and receives radio signals. An RF transceiver module 232 coupled to the antenna receives RF signals from the antenna 231, converts them to baseband signals, and sends them to the processor 233. The RF transceiver 232 also converts a baseband signal received from the processor 233 into an RF signal and transmits to the antenna 231. The processor 233 processes the received baseband signal and invokes different functional modules to perform functions in the UE 202. The memory 234 stores program instructions and data 235 to control the operation of the UE 202. The UE 202 also includes a number of functional modules and circuitry to perform various tasks according to embodiments of the present invention.

Functional blocks and circuits may be implemented and configured by hardware, firmware, software, or any combination thereof. For example, the BS 201 includes a beam management module 220, the beam management module 220 further including beam forming circuitry 221, a beam monitor 222, configuration and scheduling circuitry 223, and beam configuration and handover processing circuitry 224. The beamforming circuitry 221, which may be part of an RF chain, applies various beamforming weights to the multiple antenna elements of the antenna 211 to form various beams. The beam monitor 222 monitors the received radio signals and performs measurements of the radio signals on the respective beams. The configuration and scheduling circuitry 223 schedules uplink transmissions for the UE and configures radio resources for the UE including spatial relationship information and handover for uplink transmissions. Beam configuration and switch processing circuitry 224 handles the spatial relationship switching process.

Similarly, the UE 202 includes a beam management module 240, the beam management module 240 further including control and configuration circuitry 241, beamforming circuitry 242, beam measurement circuitry 243, measurement reporting circuitry 244, and spatial relationship switching processing circuitry 245. The control and configuration circuitry 241 receives configuration information from the serving BS via RRC signaling and/or MAC CE and/or PDCCH DCI. The configuration information may include uplink resources and spatial relationship information. The beamforming circuit 242, which may be part of an RF chain, applies various beamforming weights to the multiple antenna elements of the antenna 231 to form various beams based on the network's UL control beam indication. The beam measurement circuit 243 performs L1 RSRP measurement on the configured measurement object. The measurement reporting circuit 244 reports the measurement results. Spatial relationship switch processing circuitry 245 processes the spatial relationship switch process and determines whether to perform beam scanning and L1 measurements based on whether the configured spatial relationship is known or unknown.

Fig. 3 is a diagram illustrating an example of the definition of the spatial relationship quasi-co-location source RS. In fig. 3 (a), the PUSCH channel 310 is configured in a spatial relationship that is quasi co-located with SRS index # 0320, and the SRS # 0320 is configured to be quasi co-located with DL SSB # 0330. As such, the source of the quasi-co-located spatial relationship for the PUSCH channel 310 is the DL RS, e.g., SSB # 0330. Wherein the DL RS can be SRS or CSI-RS. In fig. 3 (b), the PUSCH channel 340 is configured with a spatial relationship quasi-co-located with the SRS index # 0350, and the SRS # 0350 is not configured with another quasi-co-located relationship. In general, such SRS may be configured as "beam management". As such, the source of the quasi-co-located spatial relationship for the PUSCH channel 340 is the UL SRS, such as SRS # 0350.

Fig. 4 is a schematic diagram of a spatial relationship switching process when configured uplink target spatial relationship is quasi co-located to DL RS according to an embodiment of the present invention. When the quasi-co-located source is a DL RS (e.g., SSB or CSI-RS), known or unknown conditions of the configured target spatial relationship for spatial relationship switching need to be defined. The configured target spatial relationship is known if the following condition is satisfied: 1) spatial relationship switching is within [ X ] s of the last transmission of a beam report or beam measurement for an RS that is quasi co-located with the target spatial relationship, e.g., X ═ 1.28 s; 2) the UE sends at least one measurement report aiming at the RS quasi co-located in the target spatial relationship in advance; 3) during spatial relationship switching, the spatial relationship remains detectable, e.g., the SNR of the quasi co-located RS and the source quasi co-located SSB/CSI-RS is greater than a threshold (e.g., -3dB) throughout spatial relationship switching; 4) the target spatial relationship is configured such that the signal quality of the quasi co-located RS is better than a threshold, e.g., SNR is greater than a threshold, e.g., -3 dB. Otherwise, the configured target spatial relationship is unknown.

In the example of fig. 4, the UE receives SpatialRelationInfoList and an optional Measurement Object (MO) from the serving BS in the NR network in step 410. In step 420, the UE performs L1-RSRP measurement and reporting based on the MO. If the configured spatial relationship is known, when the network receives a measurement report of the UE, it may configure the UE to switch to the new spatial relationship. When the UE receives the spatial relationship switch command, the UE need only decode the command and optionally perform a single fine timing tracking. The UE will then complete the active spatial relationship switch, e.g., using the new spatial relationship for uplink channel transmission. Otherwise, if the configured spatial relationship is unknown, the network may configure the UE to switch to the new spatial relationship without any measurement information. When the UE receives the spatial relationship switching command, it needs to decode the command. Thereafter, the UE performs RX beam scanning and performs L1-RSRP measurements to find the best RX beam, and then performs one fine timing tracking. The UE will then complete the active spatial relationship switch, e.g., using the new spatial relationship for uplink channel transmission.

Accordingly, in step 430, the UE receives a spatial relationship configuration from the network to switch to a new spatial relationship. In step 440, the UE decodes the spatial relationship configuration. If the spatial relationship is known, the UE skips step 450 and optionally performs a single timing tracking in step 460. In step 470, the UE completes the spatial relationship switching process and switches to the new spatial relationship. Otherwise, if the spatial relationship is unknown, the UE performs L1-RSRP measurement in step 450. In step 460, the UE optionally performs a single timing tracking. In step 470, the UE completes the spatial relationship switching process and switches to the new spatial relationship. Note that when the spatial relationship is unknown, the UE should perform L1-RSRP measurement (RX beam sweep) to train the downlink spatial filter before transmitting uplink signals using the same spatial transmit filter. According to an embodiment, spatial filter training may select the best spatial filter for the configured quasi co-located DL RS. In the training phase, the UE has only previous spatial relationship information (the spatial relationship information the UE employed before receiving the handover command), and this information is also known to the network. Therefore, the UE should be allowed to transmit signals using the previous spatial transmission filter, but the signal quality cannot be guaranteed until the UE completes the effective spatial relationship switching procedure.

Fig. 5 is an exemplary diagram of a spatial relationship switching process when a configured uplink spatial relationship is quasi co-located to an SRS according to an embodiment of the invention. After certain quasi co-located links are made, the uplink spatial relationship may be quasi co-located to the SRS, which may be configured as "beam management" in general. In this case, the UE does not need any additional beam scanning procedure. Thus, when the uplink spatial relationship is quasi co-located to the SRS, the process does not distinguish between known conditions and unknown conditions. In step 510, the network configures a list of spatial relationships with the UE. In step 520, the network configures the UE directly with a new spatial relationship with SRS index. In step 530, the UE resolves the spatial relationship configuration, e.g., quasi co-sited to the uplink SRS index. In step 540, the UE employs the same beam as the uplink SRS.

Fig. 6 is an exemplary diagram of PUCCH spatial relationship switching according to an embodiment of the present invention. In step 610, the UE receives (e.g. by RRC signaling) a spatial relationship configuration for the uplink control channel PUCCH, which includes up to 8 spatial relationships. In step 620, one spatial relationship is activated for PUCCH via MAC CE, which is based on the MAC's active spatial relationship configuration. In step 630, the UE transmits the PUCCH using the same spatial filter as the reception beam of the DL RS (SSB or CSI-RS) (if the UE supports beamcorepressance capability, as configured to 1) or the transmission beam of the UL SRS. As previously shown in fig. 4, when the active spatial relationship is configured to switch to DL RS, the UE requirements will be different for the known and unknown spatial relationships. On the other hand, when configuring the active spatial relationship to switch to UL SRS, the only consideration is the MAC CE parsing time.

Fig. 7 is an exemplary diagram of PUSCH spatial relationship switching according to an embodiment of the present invention. From the received DCI command (DCI format 0_0 or 0_1), it can be clear that the PUSCH spatial relationship follows the PUCCH or SRS spatial relationship. As shown in fig. 7 (a), when DCI format 0_0 is received, the PUSCH always follows the same spatial transmission filter as the PUCCH. In step 710, the UE receives DCI format 0_0 activation of PUSCH with the smallest ID within the active UL BWP of the cell, which is based on the active spatial relationship configuration of the DCI. In step 720, the UE transmits the PUCCH using the same spatial filter as the reception beam of the DL RS (SSB or CSI-RS) (if the UE supports the beamcorepressance capability, as configured to 1) or the transmission beam of the UL SRS, as activated by DCI format 0_ 0.

As shown in fig. 7 (b), when DCI format 0_1 is configured, the UE will transmit PUSCH using the same antenna port as the SRS port in the SRS resource indicated by the SRI. In step 730, the UE receives a DCI format 0_1 activation for PUSCH, where the indicated SRS in slot n is associated with the latest transmission of SRS resources identified by the SRI, which are configured based on the active spatial relationship of the DCI. In step 740, the UE transmits the PUSCH using the same antenna port as the SRS port in the SRS resource indicated by the SRI, as activated by DCI format 0_ 1. PUSCH spatial relationship activation follows a related PUCCH or SRS spatial relationship switching process.

Fig. 8 is an exemplary diagram of SRS spatial relationship switching according to an embodiment of the present invention. The SRS resources may be periodic, semi-static, or aperiodic. As shown in fig. 8 (a), in step 810, a spatial relationship list for the periodic SRS may be configured (e.g., through RRC signaling). In step 820, the UE transmits a periodic SRS with a target spatial relationship. If the SRS is associated with another uplink SRS, the UE will use the same beam directly for this uplink SRS without requiring additional RX beam scan time. If the SRS is associated with the DL RS, then the active spatial relationship switching should distinguish between known and unknown conditions.

As shown in fig. 8 (b), in step 830, a spatial relationship list for the semi-static SRS may be configured (e.g., through RRC signaling). In step 840, the semi-static SRS is activated by the MAC-CE. If the SRS is associated with another UL SRS, the UE will directly use the same beam for this uplink SRS. The UE does not need additional Rx beam scanning time. When the network configures semi-static SRS transmission, active spatial relationship switching should distinguish between known and unknown conditions if SRS is associated with DL RS. In step 850, the UE transmits the static SRS through the target spatial relationship.

As shown in fig. 8 (c), in step 860, a spatial relationship list for aperiodic SRS may be configured (e.g., through RRC signaling). In step 870, triggered/activated by DCI command. For aperiodic SRS, it can be generally considered to be an emergency probe behavior. This means that the network does not need extra beam training time and needs to obtain the sounding information as soon as possible. The time interval between the DCI command and the aperiodic SRS transmission is very short. Therefore, the aperiodic SRS should always be associated with a known spatial relationship. In step 880, the UE transmits the aperiodic SRS through the target spatial relationship.

Fig. 9 is a flowchart of a method of performing spatial relationship switching according to an embodiment of the present invention. In step 901, the UE receives a spatial relationship configuration in the NR network to switch an uplink channel to a target spatial relationship. For example, the spatial relationship configuration may be sent via RRC or MAC or DCI signaling. The spatial relationship configuration indicates that the spatial filter of the uplink channel is quasi co-located with one or more spatial filters of the one or more DL RSs. In step 902, the UE determines whether the target spatial relationship is known or unknown based on a predefined list of conditions. In step 903, when the target spatial relationship is known, the UE switches to the target spatial relationship, otherwise, when the target spatial relationship is unknown, the UE performs spatial filter training on the co-located DL RS.

The UE may be configured to implement various embodiments of the present invention. The UE may include a processor, memory, and an RF module as shown in fig. 2. The UE may optionally include other components, such as input and output devices, additional CPU or signal processing circuitry, and so forth. Accordingly, the UE may be capable of performing other additional functions, such as executing applications, processing other communication protocols, and so forth.

The procedures and functions described herein may be implemented as a computer program that, when executed by one or more processors, causes the one or more processors to perform the respective procedures and functions. A computer program may be stored or distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware. The computer program may also be distributed in other forms, for example via the internet or other wired or wireless telecommunication systems. The computer program may be obtained and loaded into the apparatus, for example, by means of a physical medium or by a distributed system, for example including from a server connected to the internet.

The computer program can be accessed from a computer-readable (storage) medium that provides program instructions for use by or in connection with a computer or any instruction execution system. A computer readable medium may include any means that can store, communicate, propagate, or transport a computer program for use by or in connection with an instruction execution system, apparatus, or device. The computer readable medium can be a magnetic, optical, electronic, electromagnetic, infrared, or semiconductor system (or apparatus or device) or a propagation medium. The computer-readable medium may include a computer-readable non-transitory storage medium such as a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a Read Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk and an optical disk. The computer-readable non-transitory storage medium may include all types of computer-readable media, including magnetic storage media, optical storage media, flash memory media, and solid state storage media.

While the invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Various modifications, adaptations and combinations of the various features of the embodiments described herein may be practiced without departing from the scope of the invention as set forth in the claims.

Claims

1. A spatial relationship switching method, comprising:

receiving, by a user equipment, a spatial relationship configuration in a new radio network to switch an uplink channel to a target spatial relationship, wherein the spatial relationship configuration indicates that a spatial filter of the uplink channel is quasi co-located with a spatial filter of one or more downlink reference signals;

determining whether the target spatial relationship is known or unknown according to a predefined list of conditions; and

when the target spatial relationship is known, directly switching to the target spatial relationship; performing spatial filter training on co-located downlink reference signals when the target spatial relationship is unknown.

2. The spatial relationship switching method according to claim 1, wherein the list of predefined conditions comprises: the spatial relationship configuration is whether received within a predetermined period of time of a previous transmission of a beam report or beam measurement for a downlink reference signal quasi co-located with the target spatial relationship.

3. The spatial relationship switching method according to claim 1, wherein the list of predefined conditions comprises: whether the user equipment has sent at least one measurement report for downlink reference signals quasi co-located with the target spatial relationship.

4. The spatial relationship switching method according to claim 1, wherein the list of predefined conditions comprises: whether the target spatial relationship is still detectable during a spatial relationship switching period.

5. The spatial relationship switching method according to claim 1, wherein the list of predefined conditions comprises: whether the signal quality of a downlink reference signal quasi co-located with the target spatial relationship is better than a predetermined threshold.

6. The spatial relationship switching method according to claim 1, wherein the user equipment performs layer 1 measurement and reporting based on the configured measurement object such that the target spatial relationship is known prior to receiving the spatial relationship configuration.

7. The spatial relationship switching method according to claim 1, wherein in performing the spatial filter training phase, the user equipment transmits uplink signals using a previously selected spatial filter.

8. The spatial relationship switching method according to claim 1, wherein the spatial relationship configuration is provided via activation based on medium access control, downlink control information or radio resource control signaling.

9. The spatial relationship switching method according to claim 1, wherein said uplink channel is used for physical uplink control channel transmission.

10. The spatial relationship switching method according to claim 1, wherein said uplink channel is used for physical uplink shared channel transmission.

11. The spatial relationship switching method according to claim 1, wherein said uplink channel is used for uplink sounding reference signal transmission.

12. A user equipment comprising circuitry to:

receiving a spatial relationship configuration in a new radio network to switch an uplink channel to a target spatial relationship, wherein the spatial relationship configuration indicates that spatial filters of the uplink channel are quasi co-located with spatial filters of one or more downlink reference signals;

13. The user equipment of claim 12, wherein the list of predefined conditions comprises: the spatial relationship configuration is whether received within a predetermined period of time of a previous transmission of a beam report or beam measurement for a downlink reference signal quasi co-located with the target spatial relationship.

14. The user equipment of claim 12, wherein the list of predefined conditions comprises: whether the user equipment has sent at least one measurement report for downlink reference signals quasi co-located with the target spatial relationship.

15. The user equipment of claim 12, wherein the list of predefined conditions comprises: whether the target spatial relationship is still detectable during a spatial relationship switching period.

16. The user equipment of claim 12, wherein the list of predefined conditions comprises: whether the signal quality of a downlink reference signal quasi co-located with the target spatial relationship is better than a predetermined threshold.

17. The UE of claim 12, wherein the UE performs layer 1 measurement and reporting based on the configured measurement objects such that the target spatial relationship is known prior to receiving the spatial relationship configuration.

18. The UE of claim 12, wherein in performing the spatial filter training phase, the UE transmits an uplink signal using a previously selected spatial filter.

19. The user equipment of claim 12, wherein the spatial relationship configuration is provided via activation based on media access control, downlink control information, or radio resource control signaling.

20. The user equipment as recited in claim 12 wherein the uplink channel is used for physical uplink control channel transmission, uplink shared channel transmission, or uplink sounding reference signal transmission.

21. A non-transitory computer readable medium storing instructions which, when executed by a processor, cause the processor to perform the steps of the spatial relationship switching method according to any one of claims 1-11.