WO2021160039A1

WO2021160039A1 - Method for measuring pathloss reference signal, terminal device, and computer readable medium

Info

Publication number: WO2021160039A1
Application number: PCT/CN2021/075557
Authority: WO
Inventors: Li Guo
Original assignee: Guangdong Oppo Mobile Telecommunications Corp., Ltd.
Priority date: 2020-02-13
Filing date: 2021-02-05
Publication date: 2021-08-19

Abstract

The embodiments of the disclosure provide a method for measuring pathloss reference signal, a terminal device, and a computer readable medium. The method includes: receiving a first activation command, wherein the first activation command activates a first pathloss reference signal for a first uplink transmission; applying a filtered reference signal received power (RSRP) measured from the first pathloss reference signal to obtain a pathloss based on an application time; determining an uplink transmit power for the first uplink transmission based on the pathloss; and performing the uplink transmission with the uplink transmit power.

Description

METHOD FOR MEASURING PATHLOSS REFERENCE SIGNAL, TERMINAL DEVICE, AND COMPUTER READABLE MEDIUM

BACKGROUND

1. Field of the Invention

The present disclosure generally relates to a method for pathloss estimation, in particular, to a method for measuring pathloss reference signal, a terminal device, and a computer readable medium.

2. Description of Related Art

In the current specification of 5G communication system, the user equipment (UE) behavior of measuring an activated pathloss reference signal (RS) and how to apply the filtered reference symbol received power (RSRP) of the activated pathloss RS after the UE receives one medium access control (MAC) control element (CE) activating one pathloss RS is not specified. But such a specification is needed.

The pathloss RS used to estimate the pathloss for transmission of Physical Uplink Shared Channel (PUSCH) or transmission of SRS resources in a sounding reference signal (SRS) set is semi-statically configured through radio resource configuration (RRC) signalling. In real deployment scenario, changing pathloss would require RRC configuration or reconfiguration. The consequence is large configuration latency and great signalling overhead, and even service interruptions could be caused. Therefore, it is crucial to design a mechanism for updating pathloss reference signals for PUSCH and SRS.

SUMMARY

Accordingly, the disclosure is directed to a method for measuring pathloss reference signal, a terminal device, and a computer readable medium, which may be used to solve the above technical problems.

The embodiments of the disclosure provide a method for measuring pathloss reference signal, adapted to a terminal device. The method includes: receiving a first activation command, wherein the first activation command activates a first pathloss reference signal for a first uplink transmission; applying a filtered reference signal received power (RSRP) measured from the first pathloss reference signal to obtain a pathloss based on an application time; determining an uplink transmit power for the first uplink transmission based on the pathloss; and performing the uplink transmission with the uplink transmit power.

The embodiments of the disclosure provide a terminal device including a transceiver and a processor. The processor is coupled with the transceiver and performs: controlling the transceiver to receive a first activation command, wherein the first activation command activates a first pathloss reference signal for a first uplink transmission; applying a filtered reference signal received power (RSRP) measured from the first pathloss reference signal to obtain a pathloss based on an application time; determining an uplink transmit power for the first uplink transmission based on the pathloss; and controlling the transceiver to perform the uplink transmission with the uplink transmit power.

The embodiments of the disclosure provide a non-transitory computer readable medium storing program codes thereon for execution by a processor in a communication device, wherein the program codes comprise instructions for: controlling the transceiver to receive a first activation command, wherein the first activation command activates a first pathloss reference signal for a first uplink transmission; applying a filtered reference signal received power (RSRP) measured from the first pathloss reference signal to obtain a pathloss based on an application time; determining an uplink transmit power for the first uplink transmission based on the pathloss; and controlling the transceiver to perform the uplink transmission with the uplink transmit power.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the disclosure.

FIG. 1 shows the power control parameters for one SRS resource set.

FIG. 2 show the RRC parameters for configuring the pathloss reference signal for PUSCH.

FIG. 3 shows a functional diagram of a terminal device according to an embodiment of the disclosure.

FIG. 4 shows a flow chart of the method for measuring pathloss reference signal according to an embodiment of the disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.

5G (e.g., new radio (NR) ) system supports uplink power control on uplink transmission, including PUSCH transmission, PUCCH transmission and SRS transmission. For an uplink transmission, the UE generally calculates the transmit power as:

P=min {P _CMAX, {P ₀+α×PL+f+10log ₁₀M+Δ} } . (1)

wherein P _CMAX is the maximal allowed transmit power. P ₀ is the target received signal power level of open-loop power control operation. The choice of P ₀ is based on the expected target signal to interference and noise ratio (SINR) and level of interference at the network side. Larger value of P ₀ means higher uplink transmit power and thus greater SINR value at the receiver side, but it could cause more interference to other cells. PL is the estimated pathloss. The pathloss is estimated based on measuring some downlink reference signals. The pathloss is calculated as pathloss = reference signal power –L3-filtered RSRP. f is the power control adjustment state for of closed-loop power control operation. 10log ₁₀M is the power adjustment parameter that takes into account the size of bandwidth of resource allocation of the uplink transmission, and Δ is the power control adjustment parameter related with uplink transmission format, e.g., modulation and coding scheme (MCS) level used by the PUSCH transmission.

In the RRC configuration of PUSCH and SRS, a downlink reference signal (e.g., a periodic CSI-RS (channel state information reference signal) resource or SS/PBCH (synchronization signals and physical broadcast channel) block) is configured as pathloss reference signal that is used to estimate the pathloss for uplink power control.

For SRS power control, the power control parameters including pathloss reference signal are configured per SRS resource set. In one SRS resource set, the UE can be configured with one or more SRS resources. For one transmission of each SRS resource in the set, the UE may use the power control parameters including pathloss reference signal to determine the transmit power for that SRS resource.

See FIG. 1, which shows the power control parameters for one SRS resource set. In FIG. 1, the RRC parameter pathlossReferenceRS configures one periodic CSI-RS resource index or SS/PBCH block index that provides the downlink reference signal resource index for estimating the pathloss.

For a semi-persistent SRS or aperiodic SRS, MAC CE can be used to update the pathloss RS configuration to accommodate the MAC CE-based beam switch. In particular, a MAC CE message can provide a corresponding RS resource (an SS/PBCH block or a periodic CSI-RS resource) index through a parameter SRS-PathlossReferenceRS-Id.

For a PUSCH transmission scheduled by DCI format 0_1, the power parameters including pathloss reference signals are configured through RRC parameter PUSCH-PowerControl. The parameter PUSCH-PowerControl includes multiple entries of SRI-PUSCH-PowerControls, in each of which a set of power control parameters including a pathloss reference signal are configured. Each entry of SRI-PUSCH-PowerControls corresponds to one codepoint of SRS resource indicator (SRI) field in DCI format 0_1.

For one PUSCH transmission scheduled by DCI format 1_0, the UE can derive the pathloss reference signal according the codepoint of SRI field in the scheduling DCI format 0_1 and the mapping between SRI codepoint and PUSCH pathloss reference signals configured by RRC parameters. Then the UE can estimate the pathloss based on the determined pathloss reference signal and then determine the transmit power.

See FIG. 2, which show the RRC parameters for configuring the pathloss reference signal for PUSCH. In FIG. 2, each SRI-PUSCH-PowerControl configures one sri-PUSCH-PathlossReferenceRS-Id that is mapped with one codepoint of SRI field in the DCI format scheduling PUSCH transmission.

The pathloss RS for PUSCH transmission can be updated through a MAC CE. The MAC CE can update the mapping between sri-PUSCH-PowerControlId and PUSCH-PathlossReferenceRS-Id. Thus, for each SRI bit filed in DCI 0_1, the corresponding pathloss RS is updated.

In the embodiments of the disclosure, a method for measuring pathloss reference signal and a terminal device are provided for solving the technical problem mentioned in the background, and detailed discussions would be provided in the following.

See FIG. 3, which shows a functional diagram of a terminal device according to an embodiment of the disclosure. In various embodiments, the terminal device 300 may be any type of communication devices or user equipment (UE) , such as smart phones, notebook, tablet computer, or the like. In FIG. 3, the terminal device 300 includes a transceiver 302 and a processor 304. The transceiver 302 may include at least a transmitter circuit, a receiver circuit, an analog-to-digital (A/D) converter, and a digital-to-analog (D/A) converter, low noise amplifier (LNA) , mixer, filter, matching circuit, transmission line, power amplifier (PA) , one or more antenna units and local storage media components to provide wireless transmission functions for the terminal device 300, but the disclosure is not limited thereto.

The processor 304 is coupled to the transceiver 302, and may be, for example, a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP) , a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs) , Field Programmable Gate Array (FPGAs) circuits, any other type of integrated circuit (IC) , a state machine, and the like.

In the embodiments of the disclosure, the processor 304 may access modules or program codes stored in storage circuits (e.g., memory, disks, etc. ) to implement the method for measuring pathloss reference signal provided in the disclosure, which would be further discussed in the following.

See FIG. 4, which shows a flow chart of the method for measuring pathloss reference signal according to an embodiment of the disclosure. The method of this embodiment may be executed by the terminal device 300 in FIG. 3, and the details of each step in FIG. 4 will be described below with the components shown in FIG. 3.

Firstly, in step S410, the processor 304 may control the transceiver 302 to receive a first activation command, wherein the first activation command may activate a first pathloss reference signal for a first uplink transmission. In the embodiments of the disclosure, the first activation command may be assumed to be a medium access control (MAC) control element (CE) command carried on a physical downlink shared channel (PDSCH) and sent by a serving base station of the terminal device 300, but the disclosure is not limited thereto.

In various embodiments of the disclosure, the first uplink transmission may be a PUSCH transmission, an SRS transmission, or a PUCCH transmission, but the disclosure is not limited thereto. In addition, the first pathloss reference signal may be a periodic CSI-RS resource or an SS/PBCH block, but the disclosure is not limited thereto.

In one embodiment, the processor 304 may control the transceiver 302 to send an acknowledgement signal for first activation command, wherein the acknowledgement signal may be a HARQ-ACK (Hybrid Automatic Repeat Request acknowledgement) for the PDSCH carrying the MAC CE command (i.e., the first activation command) , but the disclosure is not limited thereto.

In step S420, the processor 304 may apply a filtered RSRP measured from the first pathloss reference signal to obtain a pathloss based on an application time. In the embodiments of the disclosure, the application time may be determined to be X ₁ after a reported time length after X ₂ after sending the acknowledge signal, wherein X ₁ is a first time duration (which may be in terms of several milliseconds) , X ₂ is a second time duration (which may be in terms of several milliseconds) , and the reported time length is reported in a terminal device capability report.

In various embodiments the reported time may be implemented in different ways. In one embodiment, the reported time length may be characterized by a predetermined number of measurement samples for the first reference signal, and the application time is determined to be X ₁ after p-th measurement samples of the first pathloss RS after X ₂ after sending the acknowledge signal, wherein p is the predetermined number.

In one embodiment, in response to determining that the first reference signal is already activated for other uplink transmission (e.g., the uplink transmissions previous to the first uplink transmission and correspond to the same channel as the first uplink transmission) , the processor 304 may neglect X ₁ and the reported time length and define X ₂ to be non-negative. For example, the processor 304 may determine the application time to be 3ms (i.e., X ₂) after the terminal device 300 sending the HARQ-ACK for the PDSCH carrying the MAC CE, but the disclosure is not limited thereto.

On the other hand, in response to determining that the first reference signal is not already activated for other uplink transmission, the processor 304 may define X ₁ and p to be positive and defining X ₂ to be non-negative. For example, X ₁ may be 2ms, p may be 5, and X ₂ may be 3ms or 0ms, but the disclosure is not limited thereto. In one example, the processor 304 may determine the application time to be 2ms (i.e., X ₁) after 5-th (i.e., p-th) measurement samples of the first pathloss reference signal after 3ms (i.e., X ₂) after the terminal device 300 sending the HARQ-ACK for the PDSCH carrying the MAC CE. In another example, the processor 304 may determine the application time to be 2ms (i.e., X ₁) after 5-th (i.e., p-th) measurement samples of the first pathloss reference signal after 0ms (i.e., X ₂) after the terminal device 300 sending the HARQ-ACK for the PDSCH carrying the MAC CE.

In step S430, the processor 304 may determine an uplink transmit power for the first uplink transmission based on the pathloss. For example, the processor 304 may determine the uplink transmit power based on the pathloss obtained in step S420 by using the formula (1) provided in the above or other similar formulas for determining uplink transmit power, but the disclosure is not limited thereto.

In step S440, the processor 304 may control the transceiver 302 to perform the uplink transmission with the uplink transmit power.

In one embodiment, in response to determining that the first pathloss reference signal is also activated by one previous activation command, the processor 304 may apply the first pathloss reference signal for the first uplink transmission starting from a later one of a first time point and a second time point, wherein the first time point is the application time of the previous activation command, and the second time point is X ₃ after sending an acknowledgement signal for first activation command, wherein X ₃ is a third time duration, which may be 3ms, 0ms, or other time length preferred by the designer.

In one embodiment, in response to determining that the first pathloss reference signal is activated, the processor 304 may apply the first pathloss reference for the first uplink transmission starting from a later one of a third time point and a fourth time point, wherein the third time point is when the filtered RSRP of the first pathloss reference signal is available, and X ₃ after sending an acknowledgement signal for first activation command.

In addition, as mentioned in the above, the first uplink transmission may be a PUSCH transmission, an SRS transmission, or a PUCCH transmission, and how the first reference signal is indicated in the first activation command may be different in these cases.

In a first embodiment where the first uplink transmission is assumed to be a PUSCH transmission, if the terminal device 300 is provided with enablePLRSupdateForPUSCHSRS, a mapping between sri-PUSCH-PowerControlId and PUSCH-PathlossReferenceRS-Id values can be updated by a MAC CE (i.e., the first activation command) as described in the 3GPP specification TS 38.321.

In this case, the first pathloss reference signal may be identified by PUSCH-PathlossReferenceRS-Id indicated in the MAC CE command (i.e., the first activation command) , and the terminal device 300 may accordingly determine the application time and perform step S420 to obtain the pathloss.

In one example, the terminal device 300 may apply the first pathloss reference signal identified by PUSCH-PathlossReferenceRS-Id indicated in the MAC CE command for pathloss measurement after 2ms after the terminal device 300 measures the 5-th measurement samples of the indicated first pathloss reference signal after 3ms after the terminal device 300 transmits the HARQ-ACK corresponding to the PDSCH carrying the MAC CE command (i.e., the first activation command) . In this case, X ₁ may be regarded as 2ms, p may be 5, and X ₂ may be 3ms.

In one example, the terminal device may apply the first pathloss reference signal identified by PUSCH-PathlossReferenceRS-Id indicated in the MAC CE command for pathloss measurement after 2ms (i.e., X ₁) after the terminal device 300 measures the 5-th (i.e., p-th) measurement samples of the indicated first pathloss reference signal after the terminal device 300 transmits the HARQ-ACK corresponding to the PDSCH carrying the MAC CE command (i.e., the first activation command) . In this example, X ₂ may be understood as being 0.

In one example, if the first pathloss reference signal identified by PUSCH-PathlossReferenceRS-Id indicated in the MAC CE is already activated for other PUSCH transmissions, the terminal device 300 may apply the first pathloss reference signal identified by PUSCH-PathlossReferenceRS-Id indicated in the MAC CE command for pathloss measurement after 3ms (i.e., X ₂) after the terminal device 300 transmits the HARQ-ACK corresponding to the PDSCH carrying the MAC CE command (i.e., the first activation command) . In this example, the reported time length may be regarded as being neglected.

On the other hand, if the first pathloss reference signal identified by PUSCH-PathlossReferenceRS-Id indicated in the MAC CE is not already activated for other PUSCH uplink transmissions, the terminal device 300 may apply the first pathloss reference signal identified by PUSCH-PathlossReferenceRS-Id indicated in the MAC CE command for pathloss measurement after 2ms (i.e., X ₁) after the terminal device 300 measures the 5-th (i.e., p-th) measurement samples of the indicated first pathloss reference signal after 3ms or 0ms (i.e., X ₂) after the terminal device 300 transmits the HARQ-ACK corresponding to the PDSCH carrying the MAC CE command (i.e., the first activation command) . For another example, the terminal device 300 may apply the first pathloss reference signal identified by PUSCH-PathlossReferenceRS-Id indicated in the MAC CE command for pathloss measurement after 2ms after the terminal device 300 measures the p-th measurement samples of the indicated first pathloss reference signal after 3ms (another example 0ms) after the terminal device 300 transmits the HARQ-ACK corresponding to the PDSCH carrying the MAC CE command (i.e., the first activation command) , where the value of p is reported in UE capability report.

In one example, the terminal device 300 may apply the first pathloss reference signal identified by PUSCH-PathlossReferenceRS-Id indicated in the MAC CE command for pathloss measurement after 2ms after the terminal device 300 measures the p-th measurement samples of the indicated first pathloss reference signal after 3ms after the terminal device 300 transmits the HARQ-ACK corresponding to the PDSCH carrying the MAC CE command (or called activation command) , where the value of p is reported in UE capability report.

In one example, the terminal device 300 may apply the first pathloss reference signal identified by PUSCH-PathlossReferenceRS-Id indicated in the MAC CE command for pathloss measurement after 2ms after the terminal device 300 measures the p-th measurement samples of the indicated first pathloss reference signal after the terminal device 300 transmits the HARQ-ACK corresponding to the PDSCH carrying the MAC CE command (i.e., the first activation command) , where the value of p is reported in UE capability report.

In some embodiments, the pathloss reference signal for PUSCH scheduled by DCI format 0_0 can be activated/updated implicitly by the MAC CE that is used to activate/update spatial relation info for PUCCH resource, and the mechanism taught in the first embodiment can be used as well.

Specifically, in response to determining that the first uplink transmission is scheduled by a downlink control information (DCI) format 0_0, the terminal device is not provided with a spatial setting for PUCCH resources on an active uplink bandwidth part (BWP) of a primary cell (described in 3GPP specification TS 38.321) , and the terminal device is provided with enableDefaultBeamPlForPUSCH0_0, the processor 304 may determine a reference signal resource index providing a reference signal resource with ‘QCL (quasi co-location) -TypeD’ in a transmission configuration indicator (TCI) state or a QCL assumption of a control resource set (CORESET) with a lowest index in an active downlink BWP of a scheduling cell for a serving cell. Next, the processor 304 may determine the first pathloss reference signal based on the reference signal resource index.

With the first pathloss reference signal, the processor 304 may accordingly perform steps S420-S440, but the disclosure is not limited thereto.

In a second embodiment where the first uplink transmission is assumed to be an SRS transmission, if the terminal device 300 is provided with enablePLRSupdateForPUSCHSRS, a MAC CE described in the 3GPP specification TS 38.321 can provide by SRS-PathlossReferenceRS-Id a corresponding RS resource index q _d for aperiodic or semi-persistent SRS resource set q _s. In this case, the first pathloss reference signal may be identified by SRS-PathlossReferenceRS-Id indicated in the MAC CE command (i.e., the first activation command) , and the terminal device 300 may accordingly determine the application time and perform step S420 to obtain the pathloss.

In one example, the terminal device 300 may apply the first pathloss reference signal identified by SRS-PathlossReferenceRS-Id indicated in the MAC CE command for pathloss measurement after 2ms after the terminal device 300 measures the 5-th measurement samples of the indicated first pathloss reference signal after 3ms after the terminal device 300 transmits the HARQ-ACK corresponding to the PDSCH carrying the MAC CE command (i.e., the first activation command) . In this case, X ₁ may be regarded as 2ms, p may be 5, and X ₂ may be 3ms.

In one example, the terminal device 300 may apply the first pathloss reference signal identified by SRS-PathlossReferenceRS-Id indicated in the MAC CE command for pathloss measurement after 2ms (i.e., X ₁) after the terminal device 300 measures the 5-th (i.e., p-th) measurement samples of the indicated first pathloss reference signal after the terminal device 300 transmits the HARQ-ACK corresponding to the PDSCH carrying the MAC CE command (i.e., the first activation command) . In this example, X ₂ may be understood as being 0.

In one example, if the first pathloss reference signal identified by SRS-PathlossReferenceRS-Id indicated in the MAC CE is already activated for other SRS transmissions, the terminal device 300 may apply the first pathloss reference signal identified by SRS-PathlossReferenceRS-Id indicated in the MAC CE command for pathloss measurement after 3ms or 0ms (i.e., X ₂) after the terminal device 300 transmits the HARQ-ACK corresponding to the PDSCH carrying the MAC CE command (i.e., the first activation command) . In this example, the reported time length may be regarded as being neglected.

On the other hand, if the first pathloss reference signal identified by SRS-PathlossReferenceRS-Id indicated in the MAC CE is not already activated, the terminal device 300 may apply the first pathloss reference signal identified by SRS-PathlossReferenceRS-Id indicated in the MAC CE command for pathloss measurement after 2ms (i.e., X ₁) after UE measures the 5-th (i.e., p-th) samples of the indicated first pathloss reference signal after 3ms or 0ms (i.e., X ₂) after the terminal device 300 transmits the HARQ-ACK corresponding to the PDSCH carrying the MAC CE command (i.e., the first activation command) . For another example, the terminal device 300 may apply the first pathloss reference signal identified by SRS-PathlossReferenceRS-Id indicated in the MAC CE command for pathloss measurement after 2ms (i.e., X ₁) after terminal device 300 measures the p-th measurement samples of the indicated first pathloss reference signal after 3ms or 0ms (i.e., X ₂) after the terminal device 300 transmits the HARQ-ACK corresponding to the PDSCH carrying the MAC CE command (i.e., the first activation command) , where the value of p is reported in UE capability report.

In one example, the terminal device 300 may apply the first pathloss reference signal identified by SRS-PathlossReferenceRS-Id indicated in the MAC CE command for pathloss measurement after 2ms after terminal device 300 measures the p-th measurement samples of the indicated first pathloss reference signal after 3ms after the terminal device 300 transmits the HARQ-ACK corresponding to the PDSCH carrying the MAC CE command (i.e., the first activation command) , where the value of p is reported in the UE capability report.

In one example, The terminal device 300 may apply the first pathloss reference signal identified by SRS-PathlossReferenceRS-Id indicated in the MAC CE command for pathloss measurement after 2ms after terminal device 300 measures the p-th measurement samples of the indicated first pathloss reference signal after the terminal device 300 transmits the HARQ-ACK corresponding to the PDSCH carrying the MAC CE command (i.e., the first activation command) , where the value of p is reported in the UE capability report.

In some embodiments, when the terminal device 300 determines default pathloss RS for an SRS resource set, the pathloss reference signal for the SRS resource set can be updated/activated implicitly by the MAC CE activating TCI-state of PDCCH or PDSCH. In this case, the mechanism of applying pathloss reference signal described in the second embodiment can be used as well.

Specifically, the first uplink transmission may be an SRS transmission for an SRS resource set, and the first activation command may be MAC CE command activating a TCI state of PDCCH or PDSCH. In this case, in responses to determining that the terminal device 300 is not provided with pathlossReferenceRS or SRS-PathlossReferenceRS, is not provided spatialRelationInfo, and is provided enableDefaultBeamPlForSRS, the processor 304 may determine whether a plurality of CORESETs are provided in an active downlink BWP.

In one embodiment, in response to determining that the CORESETs are provided in the active downlink BWP, the processor 304 may determine a reference signal resource index providing a reference signal resource with a first QCL-TypeD in the TCI state or a QCL assumption of a CORESET with the lowest index. On the other hand, in response to determining that the CORESETs are not provided in the active downlink BWP, the processor 304 may determine the reference signal resource index providing the reference signal resource with a second QCL-TypeD in an active PDSCH TCI state with lowest ID. Next, the processor 304 may determine the first pathloss reference signal based on the reference signal resource index.

In a third embodiment where the first uplink transmission is assumed to be a PUCCH transmission, the terminal device 300 may be provided with PUCCH-SpatialRelationInfo for PUCCH transmission, wherein PUCCH-SpatialRelationInfo provides an pucch-PathlossReferenceRS-Id index to identify a pathloss reference signal. The terminal device 300 may receive a MAC CE command to activate one PUCCH-SpatialRelationInfo for PUCCH and a pathloss reference signal is also activated here by the same MAC CE command. If the terminal device 300 is provided with a plurality of values for pucch-SpatialRelationInfoId and the terminal device 300 receives the first activation command (described in 3GPP specification TS 38.321) indicating a specific value of pucch-SpatialRelationInfoId, the processor 304 determines the referenceSignal value in PUCCH-PathlossReferenceRS through the link to a pucch-PathlossReferenceRS-Id index corresponding to the specific value. With the first reference signal identified by the referenceSignal, the terminal device 300 may accordingly determine the application time and perform step S420 to obtain the pathloss.

In one example, the terminal device 300 may apply the first pathloss reference signal identified by referenceSignal for pathloss measurement after 2ms after the terminal device 300 measures the 5-th measurement samples of the indicated first pathloss reference signal after 3ms after the terminal device 300 transmits the HARQ-ACK corresponding to the PDSCH carrying the MAC CE command (i.e., the first activation command) . In this case, X ₁ may be regarded as 2ms, p may be 5, and X ₂ may be 3ms.

In one example, the terminal device 300 may apply the first pathloss reference signal identified by referenceSignal for pathloss measurement after 2ms (i.e., X ₁) after the terminal device 300 measures the 5-th measurement samples of the indicated first pathloss reference signal after the terminal device 300 transmits the HARQ-ACK corresponding to the PDSCH carrying the MAC CE command (i.e., the first activation command) . In this example, X ₂ may be understood as being 0.

In one example, if the first pathloss reference signal identified by referenceSignal is already activated for other PUCCH transmissions, the terminal device 300 may apply the first pathloss reference signal identified by referenceSignal for pathloss measurement after 3ms (another example 0ms) after the terminal device 300 transmits the HARQ-ACK corresponding to the PDSCH carrying the MAC CE command (i.e., the first activation command) .

On the other hand, if the first pathloss reference signal identified by referenceSignal is not already activated, the terminal device 300 may apply the first pathloss reference signal identified by referenceSignal for pathloss measurement after 2ms after UE measures the 5-th measurement samples of the indicated first pathloss reference signal after 3ms (another example 0ms) after the terminal device 300 transmits the HARQ-ACK corresponding to the PDSCH carrying the MAC CE command (i.e., the first activation command) . For another example, the terminal device 300 may apply the first pathloss reference signal identified by referenceSignal for pathloss measurement after 2ms after the terminal device 300 measures the p-th measurement samples of the indicated first pathloss reference signal after 3ms (another example 0ms) after the terminal device 300 transmits the HARQ-ACK corresponding to the PDSCH carrying the MAC CE command (i.e., the first activation command) , where the value of p is reported in the UE capability report.

In one example, the terminal device 300 may apply the pathloss reference signal identified by referenceSignal for pathloss measurement after 2ms after the terminal device 300 measures the p-th samples of the indicated pathloss reference signal after 3ms after the terminal device 300 transmits the HARQ-ACK corresponding to the PDSCH carrying the MAC CE command (i.e., the first activation command) , where the value of p is reported in the UE capability report.

In one example, the terminal device 300 may apply the pathloss reference signal identified by referenceSignal for pathloss measurement after 2ms after the terminal device 300 measures the p-th samples of the indicated pathloss reference signal after the terminal device 300 transmits the HARQ-ACK corresponding to the PDSCH carrying the MAC CE command (i.e., the first activation command) , where the value of p is reported in the UE capability report.

In some embodiments, the terminal device 300 may determine default spatial relation info and default pathloss reference signal for PUCCH. The default pathloss reference signal for PUCCH is the RS configured as QCL-TypeD in the TCI-state or QCL assumption of the CORESET with lowest index in the active DL BWP. The TCI-state of that CORESET can be updated through MAC CE. Thus, when the terminal device 300 receives one MAC CE command updating the TCI-state of that CORESET, the pathloss reference signal for the PUCCH is also updated. In this case, the mechanism of applying pathloss reference signal described in the third embodiment can be used as well.

Specifically, in response to determining that the terminal device is not provided with pathlossReferenceRSs, PUCCH-SpatialRelationInfo and provided with enableDefaultBeamPlForPUCCH, the processor 304 may determine a reference signal resource index providing a reference signal resource with QCL-TypeD in a TCI state or a QCL assumption of a CORESET with a lowest index in an active downlink BWP of a primary cell. Next, the processor 304 may determine the first pathloss reference signal based on the reference signal resource index.

In some embodiments, the terminal device 300 may expect a time gap between the first activation command and a second activation command is not less than a predefined time length (referred to as T) , wherein the second activation command activates a second pathloss reference signal for a second uplink transmission, and the first uplink transmission and the second uplink transmission correspond to the same channel. In the embodiment, the second activation command may be the MAC CE command next to the first activation command, but the disclosure is not limited thereto.

In one example, the predefined time length T may be given as a length of time, for instance in terms of milliseconds. In other examples, the predefined time length T may be given as a number of samples of pathloss reference signal resource. In this case, the terminal device 300 may expect that the time gap between the first activation command and the second activation command may be not less than N samples of transmission instances of the first pathloss reference signal, but the disclosure is not limited thereto.

In various embodiments, the reported time length may be determined and reported in the following ways. In one embodiment, the processor 304 may determine different reported time length for different types of reference signals. For example, in response to determining that the first reference signal is a first type reference signal (e.g., the SS/PBCH block) , the processor 304 may determine the reported time length to be a first value. On the other hand, in response to determining that the first reference signal is a second type reference signal (e.g., the periodic CSI-RS resource) , the processor 304 may determine the reported time length to be a second value. In some embodiments, the first value may be equal to the second value, but the disclosure is not limited thereto.

In some embodiments, if the first reference signal is a periodic CSI-RS resource, the processor 304 may determine the reported time length based on whether the first reference signal is configured with the TCI state. For example, in response to determining that the first reference signal is configured with the TCI state, the processor 304 may determine the reported time length to be a third value. On the other hand, in response to determining that the first reference signal is not configured with the TCI state, the processor 304 may determine the reported time length to be a fourth value, wherein the third value is smaller than the fourth value.

In some embodiments, if the first reference signal is a periodic CSI-RS resource configured with the TCI state, the processor 304 may determine the reported time length based on whether the TCI state is known or not. For example, in response to determining that the TCI state is known, the processor 304 may determine the reported time length to be a fifth value. On the other hand, in response to determining that the TCI state is not known, the processor 304 may determine the reported time length to be a sixth value, wherein the fifth value is smaller than the sixth value.

In some embodiments, the processor 304 may determine different reported time length for different frequency ranges. For example, in response to determining that the first uplink transmission corresponds to a first frequency range (e.g., FR1) , the processor 304 may determine the reported time length to be a first time length. On the other hand, in response to determining that the first uplink transmission corresponds to a second frequency range (e.g., FR2) , the processor 304 may determine the reported time length to be a second time length, but the disclosure is not limited thereto.

In some embodiments, the reported time length may be characterized by a specific number of time slots, subframes, or symbols, and the specific number may be determined based on a subcarrier spacing value (μ) . For example, the processor 304 may determine values of number of slots for μ=0, 1, 2, 3, and 4, respectively, which corresponds to subcarrier spacing 15KHz, 30KHz, 60KHz, 120 KHz and 240KHz, respectively. For one subcarrier spacing value μ, the processor 304 may determine a first number of slots for FR1 system and a second number of slots for FR2 system.

In summary, the terminal device of the disclosure may expect that the time gap between two MAC CE commands activating pathloss reference signal for PUSCH or SRS is not less than a given time length, for example X ms or N samples of the first pathloss reference signal that is activated by the first MAC CE (i.e., the first activation command) .

For activating pathloss reference signal for one same SRS resource set, the terminal device may expect the time gap between those two MAC CE messages may not be less than a given time length. For activating pathloss reference signal for one same sri-PUSCH-PowerControlId, the terminal device may expect the time gap between those two MAC CE messages may not be less than a given time length.

After receiving a MAC CE command activating one pathloss reference signal for PUSCH or SRS, the terminal device may determine the application time of the activated pathloss via following ways. If the activated pathloss reference signal is already activated (for example for other SRS or SRI bit-field value in DCI 0_1) , the application time may be 3ms after the HARQ-ACK for the PDSCH carrying that MAC CE command is sent. If the activated pathloss reference signal is not already activated, the application time for the filtered RSRP of the activated pathloss reference signal may be 3ms after the HARQ-ACK for the PDSCH carrying that MAC CE command is sent + N samples of the activated pathloss reference signal + 2ms.

In some embodiments, the value of N can be determined based on the type of pathloss reference signal. For example, if the pathloss reference signal is an SS/PBCH block, the value of N may be n ₁. If the pathloss reference signal is a periodic CSI-RS resource, the value of N may be n ₂.

The value of N can be determined based on whether TCI-state is configured for the periodic CSI-RS resource activated as pathloss reference signal. If the activated CSI-RS resource is configured with the TCI-state, the value of N may be n ₃. If the activated CSI-RS resource is not configured with the TCI-state, the value of N may be n ₄.

The value of N can be determined based on whether the TCI state configured to the CSI-RS resource activated as pathloss reference signal is known or not. If the TCI state is known, the value of N may be n ₅. If the configured TCI state is not known, the value of N may be n ₆.

The terminal device of the disclosure can report the number of measurement samples of one activated pathloss reference signal, which is needed for application time of the filter RSRP. The terminal device of the disclosure can determine different reported time length for FR1 and FR2. The terminal device of the disclosure can determine different reported time length for SS/PBCH block and periodic CSI-RS resource.

The reported time length can be a length of time, for instance, in terms of milliseconds, for instance, in terms of slot, in terms of subframe, in terms of symbols. The reported time length can be the number of measurement sample of reference signal resource.

Accordingly, based on the embodiments of the disclosure, the terminal device behavior of measuring an activated pathloss reference signal and how to apply the filtered RSRP of the activated pathloss RS after the terminal device receives one MAC CE command activating one pathloss reference is provided.

It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the present disclosure cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.

Claims

A method for measuring pathloss reference signal, adapted to a terminal device, comprising:

receiving a first activation command, wherein the first activation command activates a first pathloss reference signal for a first uplink transmission;

applying a filtered reference signal received power (RSRP) measured from the first pathloss reference signal to obtain a pathloss based on an application time;

determining an uplink transmit power for the first uplink transmission based on the pathloss; and

performing the uplink transmission with the uplink transmit power.
The method according to claim 1, wherein the first activation command is a medium access control (MAC) control element (CE) command carried on a physical downlink shared channel (PDSCH) .
The method according to claim 1, wherein the first pathloss reference signal is a periodic CSI-RS (channel state information reference signal) resource or an SS/PBCH (synchronization signals and physical broadcast channel) block.
The method according to claim 1, further comprising sending an acknowledgement signal for first activation command, wherein the application time is determined to be X ₁ after a reported time length after X ₂ after sending the acknowledge signal, wherein X ₁ is a first time duration, X ₂ is a second time duration, and the reported time length is reported in a terminal device capability report.
The method according to claim 4, wherein the reported time length is characterized by a predetermined number of measurement samples for the first reference signal, and the application time is determined to be X ₁ after p-th measurement samples of the first pathloss RS after X ₂ after sending the acknowledge signal, wherein p is the predetermined number;

wherein in response to determining that the first reference signal is already activated for other uplink transmission, neglecting X ₁ and the reported time length and defining X ₂ to be non-negative;

in response to determining that the first reference signal is not already activated for other uplink transmission, defining X ₁ and p to be positive and defining X ₂ to be non-negative.
The method according to claim 4, further comprising:

in response to determining that the first reference signal is a first type reference signal, determining the reported time length to be a first value; and

in response to determining that the first reference signal is a second type reference signal, determining the reported time length to be a second value.
The method according to claim 6, wherein the first value is equal to the second value.
The method according to claim 4, wherein in response to determining that the first reference signal is a periodic CSI-RS resource, the method further comprises:

in response to determining that the first reference signal is configured with a TCI state, determining the reported time length to be a third value; and

in response to determining that the first reference signal is not configured with the TCI state, determining the reported time length to be a fourth value, wherein the third value is smaller than the fourth value.
The method according to claim 4, wherein in response to determining that the first reference signal is a periodic CSI-RS resource configured with a TCI state, the method further comprises:

in response to determining that the TCI state is known, determining the reported time length to be a fifth value; and

in response to determining that the TCI state is not known, determining the reported time length to be a sixth value, wherein the fifth value is smaller than the sixth value.
A terminal device, comprising:

a transceiver; and

a processor, coupled with the transceiver and performs:

controlling the transceiver to receive a first activation command, wherein the first activation command activates a first pathloss reference signal for a first uplink transmission;

applying a filtered reference signal received power (RSRP) measured from the first pathloss reference signal to obtain a pathloss based on an application time;

determining an uplink transmit power for the first uplink transmission based on the pathloss; and

controlling the transceiver to perform the uplink transmission with the uplink transmit power.
The terminal device according to claim 10, wherein the first activation command is a medium access control (MAC) control element (CE) command carried on a physical downlink shared channel (PDSCH) .
The terminal device according to claim 10, wherein the first pathloss reference signal is a periodic CSI-RS (channel state information reference signal) resource or an SS/PBCH (synchronization signals and physical broadcast channel) block.
The terminal device according to claim 10, wherein the transceiver, configured to send an acknowledgement signal for first activation command, wherein the application time is determined to be X ₁ after a reported time length after X ₂ after sending the acknowledge signal, wherein X ₁ is a first time duration, X ₂ is a second time duration, and the reported time length is reported in a terminal device capability report.
The terminal device according to claim 13, wherein the reported time length is characterized by a predetermined number of measurement samples for the first reference signal, and the application time is determined to be X ₁ after p-th measurement samples of the first pathloss RS after X ₂ after sending the acknowledge signal, wherein p is the predetermined number;

wherein in response to determining that the first reference signal is already activated for other uplink transmission, neglecting X ₁ and the reported time length and defining X ₂ to be non-negative;

in response to determining that the first reference signal is not already activated for other uplink transmission, defining X ₁ and p to be positive and defining X ₂ to be non-negative.
The terminal device according to claim 13, wherein the processor, further configured to determine the reported time length to be a first value in response to determining that the first reference signal is a first type reference signal; and

determine the reported time length to be a second value in response to determining that the first reference signal is a second type reference signal.
The terminal device according to claim 15, wherein the first value is equal to the second value.
The terminal device according to claim 13, wherein the processor, further configured to determine the reported time length to be a third value in response to determining that the first reference signal is configured with a TCI state; and

determining the reported time length to be a fourth value, wherein the third value is smaller than the fourth value in response to determining that the first reference signal is not configured with the TCI state.
The terminal device according to claim 13, wherein the processor, further configured to determine the reported time length to be a fifth value in response to determining that the TCI state is known; and

determine the reported time length to be a sixth value, wherein the fifth value is smaller than the sixth value in response to determining that the TCI state is not known.
A non-transitory computer readable medium storing program codes thereon for execution by a processor in a communication device, wherein the program codes comprise instructions for:

controlling the transceiver to receive a first activation command, wherein the first activation command activates a first pathloss reference signal for a first uplink transmission;

applying a filtered reference signal received power (RSRP) measured from the first pathloss reference signal to obtain a pathloss based on an application time;

determining an uplink transmit power for the first uplink transmission based on the pathloss; and

controlling the transceiver to perform the uplink transmission with the uplink transmit power.