Physical downlink control channel (PDCCH) monitoring adaptation method and user equipment thereof

Abstract

A method of physical downlink control channel (PDCCH) monitoring adaptation based on downlink control information (DCI) is proposed. A user equipment (UE) performs a discontinuous reception (DRX) operation. The UE detects a UE-specific DCI format during the DRX operation, wherein the UE-specific DCI format includes a bit field indicating an adaptation of PDCCH monitoring. The UE adjusts a PDCCH monitoring periodicity value for a DRX active time of the DRX operation in accordance with the bit field.

Description

[0001] Related citations

[0002] This application claims priority under 35 USC §119 to the following applications: U.S. Provisional Application No. 62 / 990,490, filed March 17, 2020, entitled “Efficient Adaptation Triggering for PDCCH monitoring reduction in Connected-mode”; and U.S. Provisional Application No. 62 / 990,493, filed March 17, 2020, entitled “Efficient Adaptation Triggering for UE Power Saving in M-DCIbased M-TRP with Non-ideal Backhaul”, the subject of which is incorporated herein by reference. Technical Field

[0003] The disclosed embodiments generally relate to wireless communication, and more specifically, to a method for monitoring and adapting the Physical Downlink Control Channel (PDCCH) in 5G New Radio (NR). Background Technology

[0004] Wireless communication networks have grown exponentially over the years. Long-Term Evolution (LTE) systems offer high peak data rates, low latency, improved system capacity, and lower operating costs due to simplified network architecture. LTE systems, also known as 4G systems, also provide seamless integration with legacy wireless networks such as GSM, CDMA, and the Universal Mobile Telecommunication System (UMTS). In LTE systems, the Evolved Universal Terrestrial Radio Access Network (E-UTRAN) comprises multiple evolved Node-Bs (eNodeBs or eNBs), which communicate with multiple mobile stations called User Equipment (UEs). The 3rd Generation Partnership Project (3GPP)... rdGeneration Parter Project (3GPP) networks typically include a mix of 2G / 3G / 4G systems. With optimizations in network design and the evolution of various standards, many improvements have been developed. The Next Generation Mobile Network (NGMN) committee has decided to focus future NGMN activities on defining the end-to-end requirements for 5G New Radio (NR) systems.

[0005] Some wireless communication technologies, including 4G / LTE and 5G / NR, employ a technique called Discontinuous Reception (DRX) to conserve system resources. In DRX operation, the UE typically receives radio signals during DRX ON and switches to a power-saving mode during DRX OFF, as the network does not transmit any data to the UE during the OFF period. Specifically, the UE needs to monitor the Physical Downlink Control Channel (PDCCH) during DRX ON to see if the network is transmitting any data to the UE. Through DRX operation, the UE is allowed to enter a sleep state during the DRX OFF period of each DRX cycle, thereby reducing the UE's power consumption.

[0006] However, analysis of 5G / NR Daily Use (DoU) revealed that PDCCH monitoring was performed most of the time without any further data. In other words, the UE always monitors the PDCCH during DRX ON, but the network may not have any data to send to the UE. This PDCCH monitoring without further data can consume a significant portion of the UE's battery power, especially when data is configured to have short inter-packet arrival times.

[0007] A solution was sought. Summary of the Invention

[0008] A method for Physical Downlink Control Channel (PDCCH) monitoring and adaptation based on Downlink Control Information (DCI) is proposed. The User Equipment (UE) performs Discontinuous Reception (DRX) operation. During DRX operation, the UE detects a UE-specific DCI format, which includes a bit field indicating adaptation for PDCCH monitoring. The UE adjusts the PDCCH monitoring period value based on this bit field during the DRX activity period of the DRX operation.

[0009] In some examples, the UE-specific DCI format is a scheduled DCI using DCI formats 0_1, 1_1, 0_2, or 1_2. Adjustments to the PDCCH monitoring period value can be made for all types of SSS, or for type 3 common SSS and UE-specific SSS, or only for UE-specific SSS. In one embodiment, in response to a bit field indicating an SSS switch, the UE can switch from a first SSS to a second SSS (e.g., a dormant SSS), where the second SSS is configured to have no PDCCH monitoring, a longer period, or fewer PDCCH candidates compared to the first SSS. For example, in response to switching to a dormant SSS, the UE can stop monitoring DCIs scrambled by any of the following: Cell-Radio Network Temporary Identifier (C-RNTI), Configured Scheduling-RNTI (CS-RNTI), and Modulation Coding Scheme-Cell-RNTI (MCS-C-RNTI). In another embodiment, the bit field may indicate the rate at which the PDCCH monitoring period value decreases. In yet another embodiment, in response to the bit field indicating SSS disablement, the UE may disable the configured SSS, and in response to disabling the configured SSS, not perform PDCCH monitoring. In yet another embodiment, for an M-TRP transmission scenario based on M-DCI, the bit field may indicate adaptation for PDCCH monitoring of a first SSS having the same CORESET pool index value as the second SSS, wherein a UE-specific DCI format is detected in the second SSS. In yet another embodiment, the UE may receive a Radio Resource Control (RRC) message including a timer value, and in response to a UE-specific DCI format, start a timer, wherein when the time expires, an adjustment to the PDCCH monitoring period value is performed.

[0010] A method for timer-based PDCCH monitoring adaptation is proposed. The UE receives a first timer value from the radio network, where the first timer value is less than a BWP inactivity timer value. The UE starts the BWP inactivity timer at the start of the DRX active period. The UE applies the PDCCH monitoring period value during the DRX active period before the BWP inactivity timer reaches its first timer value. In response to the BWP inactivity timer reaching its first timer value, the UE adjusts the PDCCH monitoring period value during the DRX active period.

[0011] In some examples, the first timer value is received in the RRC message. In one embodiment, the UE can perform PDCCH monitoring in the first SSS using the PDCCH monitoring period value starting from the DRX active time; in response to the BWP inactivity timer reaching the first timer value, the UE switches from the first SSS to the second SSS, and before the BWP inactivity timer expires, the UE applies the adjusted PDCCH monitoring period value in the second SSS. In another embodiment, the UE can perform PDCCH monitoring in the SSS using the PDCCH monitoring period value before the BWP inactivity timer reaches the first timer value, and in response to the BWP inactivity timer reaching the first timer value, apply the adjusted PDCCH monitoring period value in the SSS. In yet another embodiment, in response to the BWP inactivity timer reaching the first timer value, the UE can apply the adjusted PDCCH monitoring period value, and in response to the BWP inactivity timer being reset, the UE switches back to the PDCCH monitoring period value. In yet another embodiment, for M-TRP transmission based on M-DCI, the SSS corresponding to the first timer value and the adjusted PDCCH monitoring period value are associated with the same CORESET pool index value.

[0012] A method for UE-initiated PDCCH monitoring adaptation is proposed. The UE performs DRX operation with the radio network. During the DRX operation, the UE receives data scheduling information from the radio network, wherein the data scheduling information indicates the data scheduling of the last TB. In response to the data scheduling information, the UE adjusts the PDCCH monitoring period value during the DRX activity time of the DRX operation.

[0013] In some examples, data scheduling information is included in a bit field of a UE-specific DCI format that uses DCI formats 0_1, 1_1, 0_2, or 1_2 for scheduling DCI. In one embodiment, the UE can perform PDCCH monitoring in a first SSS using the PDCCH monitoring period value, starting from the DRX activity time; in response to the bit field, the UE switches from the first SSS to a second SSS, and applies the adjusted PDCCH monitoring period value in the second SSS. Specifically, for M-TRP transmissions based on M-DCI, the first and second SSSs are associated with the same CORESET pool index value. In another embodiment, the UE can receive an RRC message including a timer value and start a timer in response to the UE-specific DCI format, wherein the adjustment of the PDCCH monitoring period value is performed when the time expires. In yet another embodiment, the adjustment of the PDCCH monitoring period value is performed after the UE sends an acknowledgment (ACK) for the corresponding scheduled data.

[0014] Other embodiments and advantages are described in the detailed description below. This overview is not intended to define the invention. The invention is defined by the claims. Attached Figure Description

[0015] The accompanying drawings illustrate embodiments of the present invention, wherein the same numbers denote the same elements.

[0016] Figure 1 An exemplary 5G New Radio (NR) network according to aspects of the present invention is shown, which supports Physical Downlink Control Channel (PDCCH) monitoring adaptation.

[0017] Figure 2 An exemplary DRX operation according to an aspect of the present invention is shown.

[0018] Figure 3 A simplified block diagram of a wireless device according to an embodiment of the present invention is shown, such as UE 301 and gNB / TRP 311.

[0019] Figure 4A and 4B An embodiment of a DCI-based PDCCH monitoring adaptation is shown.

[0020] Figure 5 An embodiment of a DCI-based PDCCH monitoring adaptation for a scenario of M-TRP transmission based on M-DCI is shown, according to a novel aspect.

[0021] Figure 6A and 6B Another embodiment of a DCI-based PDCCH monitoring adaptation is shown, based on a novel aspect.

[0022] Figure 7A and 7B Another embodiment of a DCI-based PDCCH monitoring adaptation is shown, based on a novel aspect.

[0023] Figure 8A and 8B Another embodiment of a DCI-based PDCCH monitoring adaptation is shown, based on a novel aspect.

[0024] Figure 9 An example of a DCI indication using the existing bit field "Minimum Applicable Scheduling Offset Indicator" is shown, based on a novel aspect.

[0025] Figure 10 An embodiment of a timer-based PDCCH monitoring adaptation according to a novel aspect is shown.

[0026] Figure 11 An embodiment of UE autonomous PDCCH monitoring adaptation based on a novel aspect is shown.

[0027] Figure 12 A flowchart is shown for a method for DCI-based PDCCH monitoring adaptation according to a novel aspect.

[0028] Figure 13 A flowchart is shown illustrating a method for adapting a timer-based PDCCH monitoring system according to a novel aspect.

[0029] Figure 14 A flowchart illustrating a novel approach to UE autonomous PDCCH monitoring adaptation is shown. Detailed Implementation

[0030] Reference will now be made in detail to some embodiments of the invention, examples of which are shown in the accompanying drawings.

[0031] Figure 1 An exemplary 5G New Radio (NR) network 100 supporting Physical Downlink Control Channel (PDCCH) monitoring adaptation according to aspects of the present invention is illustrated. The 5G NR network 100 includes a User Equipment (UE) 110 communicatively connected to one or more gNBs or Transmit / Receive Points (TRPs), including gNB / TRPs 121 and 122 operating in a licensed frequency band (e.g., 30 GHz to 300 GHz for millimeter waves) of an access network 120, which provides radio access using Radio Access Technology (RAT) (e.g., 5G NR technology). The access network 120 is connected to a 5G core network 130 via an NG interface, more specifically, to a User Plane Function (UPF) via an NG User Plane Part (NG-u), and to a Mobility Management Function (AMF) via an NG Control Plane Part (NG-c). A gNB can connect to multiple UPFs / AMFs for load sharing and redundancy. UE 110 can be a smartphone, wearable device, Internet of Things (IoT) device, or tablet computer, etc. Alternatively, UE 110 can be a laptop (NB) or personal computer (PC) with a data card inserted or installed, which includes a modem and radio frequency transceiver to provide wireless communication capabilities.

[0032] Each of gNB / TRP 121 and gNB / TRP 122 can provide communication coverage for a geographic coverage area where communication with UE 110 is supported by a communication link. The communication link between gNB / TRP 121 / 122 and UE 110 can utilize one or more frequency carriers to form one or more cells (e.g., PCell and one or more SCells). Specifically, each communication link can be used to carry uplink transmissions from UE 110 to the associated gNB (e.g., on the Physical Uplink Control Channel (PUCCH) or Physical Uplink Shared Channel (PUSCH)) or to carry downlink transmissions from the associated gNB to UE 110 (e.g., on the Physical Downlink Control Channel (PDCCH) or Physical Downlink Shared Channel (PDSCH)). For example, UE 110 can be configured to perform discontinuous reception (DRX) operation, wherein UE 110 monitors PDCCH during DRX activity time (e.g., configured by gNB / TRP 121 / 122).

[0033] M-TRP transmissions based on M-DCI for UE 110 can be configured RRC as follows. If UE 110 is configured by a higher-layer parameter “PDCCH-Config” containing two different values ​​of CORESETPoolIndex in ControlResourceSet, UE 110 can expect to receive multiple PDCCHs that schedule all / partial / non-overlapping PDSCHs in the time and frequency domains. Data scheduling from two TRPs (e.g., gNB / TRP 121 and gNB / TRP 122) should be scheduled using the same active BWP and the same Sub-Carrier Spacing (SCS). That is, when UE 110 is scheduled with all / partial / non-overlapping PDSCHs in the time and frequency domains, all scheduling information for receiving PDSCHs is indicated and carried only by the corresponding PDCCH, and UE 110 expects to schedule using the same active BWP and the same SCS. In particular, power-saving techniques based on BWP handover (including SCell hibernation, if M-DCI is supported in the SCell) may be useless if the backhaul is not ideal. For example, even without traffic for UE 110, it is almost impossible for TRP#1 (e.g., gNB / TRP 121) to handover the BWP because TRP#1 is unaware of the scheduling status of TRP#2 (e.g., gNB / TRP 122).

[0034] According to a novel aspect, UE 110 can adjust the PDCCH monitoring period value during DRX activity time based on an indication of PDCCH monitoring adaptation provided by 5G NR network 100 to save power. In one embodiment, PDCCH monitoring adaptation can be DCI-based adaptation, and the indication of PDCCH monitoring adaptation can be included in the bit field of a UE-specific DCI, such as a scheduling DCI using DCI formats 0_1, 1_1, 0_2, or 1_2. For example, UE 110 can be configured with multiple SSSs configured with different PDCCH monitoring period values, and the bit field can be a Search Space Set (SSS) switching field indicating that UE 110 switches to an SSS (e.g., a dormant SSS) configured to have no PDCCH monitoring or with a longer period or fewer PDCCH candidates. Alternatively, the bit field can indicate the rate at which the PDCCH monitoring period value is reduced, allowing UE 110 to perform longer-period PDCCH monitoring. Alternatively, this bit field can indicate whether the current SSS is disabled or enabled for UE 110, and if the current SSS is disabled, UE 110 may not perform PDCCH monitoring. In other words, UE 110 can adjust (e.g., decrease / decrease or increase) the PDCCH monitoring period value based on the bit field of the UE-specific DCI. In one example, the 5G / NR network can configure a timer via UE-specific RRC signaling, causing the UE to start the timer when it receives an indication of PDCCH monitoring adaptation, and adjust the PDCCH monitoring period value when the timer expires to ensure data latency. Furthermore, in the scenario of M-TRP transmission based on M-DCI, this bit field can indicate adaptation for PDCCH monitoring for SSSs with the same Control Resource Set (CORESET) pool index value as the SSS in which the UE-specific DCI format is detected.

[0035] In another embodiment, PDCCH monitoring adaptation can be timer-based, and the indication of PDCCH monitoring adaptation can be received via UE-specific Radio Resource Control (RRC) signaling. For example, the indication of PDCCH monitoring adaptation may include one or more additional timer values ​​that are less than the Bandwidth Part (BWP) inactivity timer value. The additional timer may start at the beginning of DRX activity, and when the additional timer expires, UE 110 may adjust (e.g., decrease / decrease or increase) the PDCCH monitoring period value. Alternatively, the BWP inactivity timer may start at the beginning of DRX activity, and when the BWP inactivity timer reaches the additional timer value, UE 110 may adjust the PDCCH monitoring period value. Furthermore, in M-TRP transmission scenarios based on M-DCI, different CORESET pool index values ​​are configured with additional timer values, and the reached timer values ​​and SSS corresponding to the adjusted PDCCH monitoring period value are associated with the same CORESET pool index value.

[0036] In another embodiment, PDCCH monitoring adaptation can be UE-initiated, and the indication of PDCCH monitoring adaptation can be conveyed in the data scheduling information. For example, the data scheduling information can be included in the bit field of the UE-specific DCI, such as a scheduling DCI using DCI format 0_1, 1_1, 0_2, or 1_2, and this bit field can indicate the data scheduling of the last transport block (TB). In response to the data scheduling information, UE 110 can adjust (e.g., decrease / decrease or increase) the PDCCH monitoring period value by switching to an SSS with a longer PDCCH monitoring period or reducing the PDCCH monitoring period by a ratio after sending an acknowledgment (ACK) of the corresponding scheduling data. Furthermore, in the scenario of M-TRP transmission based on M-DCI, the SSS before and after the SSS switch can be associated with the same CORESET pool index value.

[0037] Figure 2Exemplary DRX operation according to aspects of the present invention is illustrated. DRX activity time refers to the period during which the UE is awake, and the DRX activity time can be determined according to parameters configured by gNB / TRP 121 / 122 (e.g., DRX ON duration timer, DRX inactivity timer, DRX retransmission timer, etc.). As shown, the UE wakes up at the beginning of the DRX ON duration of each DRX cycle and remains awake to monitor the PDCCH and receive downlink data packets, including PDCCH packets and PDSCH packets. Intra-packet cycles are typically caused by scheduling gaps or beam scanning modes in fair scheduling between UEs, and are generally shorter than inter-packet cycles. Inter-packet cycles are typically caused by the UE having no data (i.e., data transmission has ended), and are generally longer than intra-packet cycles.

[0038] Figure 3 A simplified block diagram of a wireless device (e.g., UE 301 and gNB / TRP 311) according to an embodiment of the present invention is shown. gNB / TRP 311 has an antenna 315 that transmits and receives radio signals. A radio frequency (RF) transceiver module 314 coupled to the antenna 315 receives RF signals from the antenna 315, converts them into baseband signals, and sends them to a processor 313. The RF transceiver 314 also converts baseband signals received from the processor 313 into RF signals and sends them to the antenna 315. The processor 313 processes the received baseband signals and invokes different functional modules to perform functions in the gNB / TRP 311. A memory 312 stores program instructions and data 320 to control the operation of the gNB / TRP 311. Figure 3In the example, gNB / TRP 311 also includes a protocol stack 380 and a set of control function modules and circuits 390. The protocol stack 380 may include a Non-Access-Stratum (NAS) layer (for communicating with AMF / SMF / MME entities connected to the core network), a Radio Resource Control (RRC) layer (for higher-layer configuration and control), a Packet Data Convergence Protocol / Radio Link Control (PDCP / RLC) layer, a Media Access Control (MAC) layer, and a Physical (PHY) layer. In one example, the control function modules and circuits 390 include a DRX configuration circuit 391 and a DCI generation circuit 392. The DRX configuration circuit 391 configures DRX parameters for the UE 301, and the DCI generation circuit 392 generates a DCI with or without an indication of PDCCH monitoring adaptation.

[0039] Similarly, UE 301 has a memory 302, a processor 303, and an RF transceiver module 304. The RF transceiver 304 is coupled to an antenna 305, receives RF signals from the antenna 305, converts them into baseband signals, and sends them to the processor 303. The RF transceiver 304 also converts the received baseband signals from the processor 303 into RF signals and sends them to the antenna 305. The processor 303 processes the received baseband signals and invokes different functional modules and circuits to execute features in UE 301. The memory 302 stores data and program instructions 310 to be executed by the processor 303 to control the operation of UE 301. Suitable processors include, for example, dedicated processors, digital signal processors (DSPs), multiple microprocessors, one or more microprocessors associated with a DSP core, controllers, microcontrollers, application-specific integrated circuits (ASICs), file programmable gate arrays (FPGAs), and other types of integrated circuits (ICs) and / or state machines. The processor associated with the software can be used to implement and configure the features of UE 301.

[0040] UE 301 also includes a protocol stack 360 and a set of control function modules and circuits 370. Protocol stack 360 may include a NAS layer (for communication with AMF / SMF / MME entities connected to the core network), an RRC layer (for higher-level configuration and control), a PDCP / RLC layer, a MAC layer, and a PHY layer. Control function modules and circuits 370 may be implemented and configured through software, firmware, hardware, and / or combinations thereof. When executed by processor 303 via program instructions contained in memory 302, the control function modules and circuits 370 cooperate to allow UE 301 to perform implementations and functional tasks and features within the network.

[0041] In one example, the control function module and circuit 370 includes a DRX operation circuit 371, a DCI detection circuit 372, a timer control circuit 373, and a PDCCH monitoring control circuit 374. The DRX operation circuit 371 performs DRX operation based on DRX parameters configured by gNB / TRP 311. The DCI detection circuit 372 detects the DCI format with or without an indication of PDCCH monitoring adaptation. The timer control circuit 373 controls the operation of one or more timers. The PDCCH monitoring control circuit 374 applies a PDCCH monitoring period value configured by gNB / TRP 311 and adjusts the PDCCH monitoring period value based on the PDCCH monitoring adaptation indication during the DRX activity period.

[0042] Figure 4A and 4B An embodiment of DCI-based PDCCH monitoring adaptation according to a novel aspect is illustrated. The 5G / NR network can configure SSS groups for the UE, with each SSS group associated with a different PDCCH monitoring period value. For example... Figure 4A As shown, the UE first performs PDCCH monitoring in SSS group #1, which is associated with shorter PDCCH monitoring periods (i.e., smaller PDCCH monitoring period values). During PDCCH monitoring in SSS group #1, the UE receives DCI format 0_1 / 1_1 / 0_2 / 1_2, which contains an SSS handover field (e.g., a value of 0) indicating that the UE should switch to SSS group #0. In response to DCI format 0_1 / 1_1 / 0_2 / 1_2 with the SSS handover field = 0, the UE switches to SSS group #0, which is associated with longer PDCCH monitoring periods (i.e., larger PDCCH monitoring period values). Figure 4BAs shown, the UE first performs PDCCH monitoring in SSS group #0, which is associated with a longer PDCCH monitoring period (i.e., a larger PDCCH monitoring period value). During PDCCH monitoring in SSS group #0, the UE receives a DCI format 0_1 / 1_1 / 0_2 / 1_2, which contains an SSS handover field (e.g., a value of 1) indicating that the UE should switch to SSS group #1. In response to a DCI format 0_1 / 1_1 / 0_2 / 1_2 with the SSS handover field = 1, the UE switches to SSS group #1, which is associated with a shorter PDCCH monitoring period (i.e., a smaller PDCCH monitoring period value).

[0043] Please note that, although Figure 4A and 4B In one embodiment, the SSS switching field is a 1-bit field, but in other embodiments, the SSS switching field can be an N-bit field, where N equals Where x is the number of configured SSS groups.

[0044] Figure 5 An embodiment of a DCI-based PDCCH monitoring adaptation for a scenario of M-TRP transmission based on M-DCI is illustrated, according to a novel aspect. Figure 5 As shown, only SSSs with the same CORESETPoolIndex value as the SSS that sent the DCI instruction are switched.

[0045] Figure 6A and 6B Another embodiment of DCI-based PDCCH monitoring adaptation according to a novel aspect is illustrated. The 5G / NR network can configure multiple SSSs for the UE, each SSS associated with a different PDCCH monitoring period value. Of the configured SSSs, at least one SSS can be further configured as a dormant SSS, while another SSS can be configured as a non-dormant SSS. Specifically, the dormant SSS can be associated with PDCCH monitoring that does not have PDCCH monitoring or has a longer period or fewer PDCCH candidates. Figure 6AAs shown, the UE first performs PDCCH monitoring in a non-dormant SSS (e.g., SSS#3), which is associated with a shorter PDCCH monitoring period (i.e., a smaller PDCCH monitoring period value). During PDCCH monitoring in SSS#3, the UE receives a DCI format 0_1 / 1_1 / 0_2 / 1_2, which contains a bit field (e.g., a value of 0) indicating that the UE should switch to a dormant SSS. Responding with a DCI format 0_1 / 1_1 / 0_2 / 1_2 having a bit field = 0, the UE switches to a dormant SSS (e.g., SSS#2), which is associated with a longer PDCCH monitoring period (i.e., a larger PDCCH monitoring period value). Figure 6B As shown, the UE first performs PDCCH monitoring in a dormant SSS (e.g., SSS#2), which is associated with a longer PDCCH monitoring period (i.e., a larger PDCCH monitoring period value). During PDCCH monitoring in SSS#2, the UE receives a DCI format 0_1 / 1_1 / 0_2 / 1_2, which contains a bit field (e.g., a value of 1) indicating that the UE switches to a non-dormant SSS. In response to a DCI format 0_1 / 1_1 / 0_2 / 1_2 with a bit field = 1, the UE switches to a non-dormant SSS (e.g., SSS#3), which is associated with a shorter PDCCH monitoring period (i.e., a smaller PDCCH detection period value).

[0046] Please note that, although in Figure 6A and 6B The example is not shown, but the bit fields in DCI format 0_1 / 1_1 / 0_2 / 1_2 can be used to instruct the UE to switch all types of SSSs to dormant SSSs. In another example, the bit fields in DCI format 0_1 / 1_1 / 0_2 / 1_2 can be used to instruct the UE to switch only Type 3 common SSSs and UE-specific SSSs to dormant SSSs. That is, the UE can continue monitoring non-Type 3 common SSSs (if configured) after switching to dormant SSSs. In yet another example, the bit fields in DCI format 0_1 / 1_1 / 0_2 / 1_2 can be used to instruct the UE to switch only UE-specific SSSs to dormant SSSs. That is, the UE can continue monitoring common SSSs (if configured) after switching to dormant SSSs. Alternatively, in response to switching to dormant SSSs, the UE can stop monitoring DCIs scrambled by any of the Cell Radio Network Temporary Identifier (C-RNTI), Configuration Scheduling-RNTI (CS-RNTI), and Modulation Codec Scheme-Cell-RNTI (MCS-C-RNTI).

[0047] Figure 7A and 7BAnother embodiment of a DCI-based PDCCH monitoring adaptation is shown, based on a novel aspect. (See example...) Figure 7A As shown, the UE first performs PDCCH monitoring for each time slot. During each time slot's PDCCH monitoring, the UE receives a DCI format 0_1 / 1_1 / 0_2 / 1_2, which includes a bit field (e.g., with a value of 1 / 2) indicating the rate at which the PDCCH monitoring period is reduced. In response to the DCI format 0_1 / 1_1 / 0_2 / 1_2 with the bit field = 1 / 2, the UE monitors the PDCCH every two time slots. That is, the UE extends the PDCCH monitoring period (i.e., increases the PDCCH monitoring period value). Figure 7B As shown, the UE first performs PDCCH monitoring every two time slots. During each two-slot PDCCH monitoring period, the UE receives a DCI format 0_1 / 1_1 / 0_2 / 1_2, which includes a bit field (e.g., with a value of 2) indicating the rate at which the PDCCH monitoring period is reduced. In response to the DCI format 0_1 / 1_1 / 0_2 / 1_2 with a bit field of 2, the UE monitors the PDCCH for each time slot. That is, the UE shortens the PDCCH monitoring period (i.e., reduces the PDCCH monitoring period value).

[0048] Please note that, although in Figure 7A and 7B The example is not shown, but the bit fields in DCI format 0_1 / 1_1 / 0_2 / 1_2 can be used to indicate the rate of reduction of PDCCH monitoring cycle values ​​for all types of SSS. In another example, the bit fields in DCI format 0_1 / 1_1 / 0_2 / 1_2 can be used to indicate the rate of reduction of PDCCH monitoring cycle values ​​only for type 3 common SSS and UE-specific SSS. In yet another example, the bit fields in DCI format 0_1 / 1_1 / 0_2 / 1_2 can be used to indicate the rate of reduction of PDCCH monitoring cycle values ​​only for UE-specific SSS. Alternatively, the 5G / NR network can pre-configure a set of PDCCH monitoring cycle value reduction rates to the UE via higher-layer signaling, or this set of PDCCH monitoring cycle reduction rates can be predefined in the 3GPP specification, and the bit fields in DCI format 0_1 / 1_1 / 0_2 / 1_2 can be used to indicate one of the pre-configured / predefined rates of reduction of PDCCH monitoring cycle values.

[0049] Figure 8A and 8B Another embodiment of a DCI-based PDCCH monitoring adaptation is shown, based on a novel aspect. Figure 8AAs shown, the UE first performs PDCCH monitoring in an SSS associated with a specific PDCCH monitoring period value. During PDCCH monitoring, the UE receives a DCI format 0_1 / 1_1 / 0_2 / 1_2, which contains a bit field (e.g., with a value of 0) that indicates the UE has disabled the configured SSS. In response to the DCI format 0_1 / 1_1 / 0_2 / 1_2 with a bit field = 0, the UE disables the SSS and stops PDCCH monitoring in the SSS. Figure 8B As shown, the UE first performs PDCCH monitoring in SSS#1, which is associated with a specific PDCCH monitoring period, but does not perform PDCCH monitoring in the disabled SSS#0. During PDCCH monitoring in SSS#1, the UE receives DCI format 0_1 / 1_1 / 0_2 / 1_2, which contains a bit field (e.g., with a value of 1) that indicates that the UE has enabled the configured SSS. In response to DCI format 0_1 / 1_1 / 0_2 / 1_2 with bit field = 1, the UE enables SSS#0 and performs PDCCH monitoring in SSS#0.

[0050] Please note that, although in Figure 8A and 8B The example is not shown, but the bit fields in DCI format 0_1 / 1_1 / 0_2 / 1_2 can be used to indicate the enabling / disabling of all types of SSS. In another example, the bit fields in DCI format 0_1 / 1_1 / 0_2 / 1_2 can be used to indicate the enabling / disabling of only type 3 public SSS and UE-specific SSS. In yet another example, the bit fields in DCI format 0_1 / 1_1 / 0_2 / 1_2 can be used to indicate the enabling / disabling of only UE-specific SSS. Alternatively, the 5G / NR network can configure a timer for the UE to enable disabled SSS via UE-specific RRC signaling, so that the UE can start the timer when it receives a DCI indication for disabling SSS, and then enable the disabled SSS when the timer expires.

[0051] exist Figures 4A-8BIn the embodiments, the bit fields in DCI format 0_1 / 1_1 / 0_2 / 1_2 can be implemented as newly introduced bit fields to indicate adaptation to PDCCH monitoring. Alternatively, if the bit fields in DCI format 0_1 / 1_1 / 0_2 / 1_2 exist, they can be implemented as reinterpreted bit fields of the "Minimum Applicable Scheduling Offset Indicator" for R16 cross-slot scheduling adaptation. For example, if only cross-slot scheduling adaptation of the R16 feature is configured, this bit field indicates which minimum applicable K0 / K2 is used for the active DL / UL BWP; if PDCCH monitoring adaptation of the R17 feature is configured, this bit field indicates which PDCCH monitoring adaptation is used; if both features are configured, this bit field represents a joint adaptation of cross-slot scheduling and PDCCH monitoring, such as... Figure 9 As shown.

[0052] Figure 10 An embodiment of timer-based PDCCH monitoring adaptation according to a novel aspect is illustrated. Compared to DCI-based adaptation, the advantage of timer-based adaptation is the absence of DCI overhead. In timer-based adaptation, one or more intermediate timer values / points are introduced for the BWP inactivity timer, and the 5G / NR network can configure these intermediate timer values / points and corresponding SSS via UE-specific RRC signaling. Specifically, the intermediate timer values / points are less than the configured BWP inactivity timer value. Figure 10 As shown, the BWP inactivity timer value tN and two intermediate timer values ​​t1 and t2 are configured with different PDCCH monitoring period values, where the intermediate timer values ​​t1 and t2 correspond to the configured SSS#1 and SSS#2, respectively. At the start of the DRX activity time (denoted as t0), the UE starts the BWP inactivity timer (denoted as T). BWPinactivityThe UE then begins PDCCH monitoring in SSS#0, which is associated with a specific PDCCH monitoring period value. When the BWP inactivity timer reaches t1, the UE switches from SSS#0 to SSS#1, which has a reduced / lower PDCCH monitoring period value. For example, when the UE switches to SSS#1, it can skip intra-burst PDCCH monitoring, and setting a shorter value for t1 is beneficial. Subsequently, when the BWP inactivity timer reaches t2, the UE switches from SSS#1 to SSS#2, which has a further reduced / lower PDCCH monitoring period value. For example, when the UE switches to SSS#2, it can skip inter-burst PDCCH monitoring, and setting t1 to a value not less than the Hybrid Automatic Repeat Request (HARQ) feedback time is beneficial for tolerating good UE data latency. Finally, when the BWP inactivity timer expires (i.e., reaches tN), the UE switches from the current BWP to the default BWP.

[0053] Please note that although not in Figure 10 As illustrated in the embodiments, when the BWP inactivity timer is reset, for example, when receiving scheduled DCI and corresponding data, the UE can switch back to the original / initial SSS or the original / initial PDCCH monitoring period value. Alternatively, instead of switching the SSS at each intermediate timer point, when the BWP inactivity timer reaches an intermediate timer point, the UE can adjust (e.g., reduce / lower) the PDCCH monitoring period value in the current SSS simply by using the corresponding scaling value configured by higher-layer signaling.

[0054] Figure 11 An embodiment of UE-autonomous PDCCH monitoring adaptation according to a novel aspect is illustrated. UE-autonomous adaptation is particularly beneficial for the UE to reduce / lower the PDCCH monitoring period value used for inter-burst PDCCH monitoring. When the UE knows that the current scheduling is for the last TB, the UE can switch to an SSS with a longer PDCCH period, or proportionally reduce / lower the PDCCH monitoring period value after sending an ACK for the corresponding scheduling data (unless the PUSCH does not require ACK transmission). Figure 11As shown, the UE receives a DCI in the format 0_1 / 1_1 / 0_2 / 1_2, whose bit field includes data scheduling information indicating the data scheduling of the last TB. When the UE receives the last TB on the PDSCH and successfully decodes it, the UE enters a power-saving duration, during which the UE switches to an SSS with a longer PDCCH period or reduces / lowers the PDCCH monitoring period value. In one example, the 5G / NR network can configure a timer via UE-specific RRC signaling to enable the UE to start a timer when it receives a DCI indication and enter a power-saving duration when the timer expires to ensure data latency. During the power-saving period, the UE receives a DCI indicating a new data scheduling. In response to the DCI indicating a new data scheduling, the UE leaves the power-saving duration (by switching back to the original SSS with a shorter PDCCH period or increasing the PDCCH monitoring period value) to receive new data on the PDSCH.

[0055] Figure 12 A flowchart illustrating a method for DCI-based PDCCH monitoring adaptation according to a novel aspect is shown. In step 1201, the UE performs a DRX operation. In step 1202, the UE detects a UE-specific DCI format during the DRX operation, wherein the UE-specific DCI format includes a bit field indicating adaptation for PDCCH monitoring. In some examples, the UE-specific DCI format is a scheduling DCI using DCI formats 0_1, 1_1, 0_2, or 1_2. In step 1203, the UE adjusts the PDCCH monitoring period value based on this bit field during the DRX activity period of the DRX operation. For example, the adjustment of the PDCCH monitoring period value can be for all types of SSS, or for type 3 common SSS and UE-specific SSS, or only for UE-specific SSS.

[0056] In one embodiment, in response to a bit field indicating an SSS switch, the UE can switch from a first SSS to a second SSS (e.g., a dormant SSS), wherein the second SSS is configured to have no PDCCH monitoring, a longer PDCCH monitoring period, or a smaller number of PDCCH candidates compared to the first SSS. In another embodiment, the bit field may indicate the rate at which the PDCCH monitoring period value is reduced. In yet another embodiment, in response to a bit field indicating an SSS disable, the UE can disable the configured SSS, and in response to disabling the configured SSS, not perform PDCCH monitoring. In yet another embodiment, for an M-TRP transmission scenario based on M-DCI, the bit field may indicate adaptation to PDCCH monitoring of the first SSS, wherein the first SSS has the same CORESET pool index value as the second SSS, and a UE-specific DCI format is detected in the second SSS.

[0057] Figure 13 A flowchart illustrating a method for timer-based PDCCH monitoring adaptation according to a novel aspect is shown. In step 1301, the UE receives a first timer value from the radio network, wherein the first timer value is less than a BWP inactivity timer value. For example, the first timer value is received in an RRC message. In step 1302, the UE starts a BWP inactivity timer at the start of the DRX active period. In step 1303, the UE applies a PDCCH monitoring period value during the DRX active period before the BWP inactivity timer reaches the first timer value. In step 1304, in response to the BWP inactivity timer reaching the first timer value, the UE adjusts the PDCCH monitoring period value during the DRX active period.

[0058] In one embodiment, the UE can perform PDCCH monitoring in a first SSS using the PDCCH monitoring period value starting from the DRX active time. Upon the BWP inactivity timer reaching a first timer value, the UE switches from the first SSS to a second SSS, and the UE applies the adjusted PDCCH monitoring period value in the second SSS before the BWP inactivity timer expires. In another embodiment, the UE can perform PDCCH monitoring in an SSS using the PDCCH monitoring period value before the BWP inactivity timer reaches the first timer value, and the UE applies the adjusted PDCCH monitoring period value in the SSS upon the BWP inactivity timer reaching the first timer value. In yet another embodiment, the UE can apply the adjusted PDCCH monitoring period value upon the BWP inactivity timer reaching the first timer value, and the UE switches back to the PDCCH monitoring period value upon the BWP inactivity timer being reset. In yet another embodiment, for M-TRP transmission based on M-DCI, the first timer value and the SSS corresponding to the adjusted PDCCH monitoring period value are associated with the same CORESET pool index value.

[0059] Figure 14 A flowchart illustrating a method for UE-autonomous PDCCH monitoring adaptation according to a novel aspect is shown. In step 1401, the UE performs DRX operation using the radio network. In step 1402, the UE receives data scheduling information from the radio network during the DRX operation, wherein the data scheduling information indicates the data scheduling of the last TB. For example, the data scheduling information is contained in a bit field of a UE-specific DCI format, which is a scheduling DCI using DCI format 0_1, 1_1, 0_2, or 1_2. In step 1403, in response to the data scheduling information, the UE adjusts the PDCCH monitoring period value during the DRX activity time of the DRX operation.

[0060] In one embodiment, the UE can perform PDCCH monitoring in the first SSS using the PDCCH monitoring period value starting from the DRX activity time, in response to a switch of the bit field from the first SSS to the second SSS, and apply the adjusted PDCCH monitoring period value in the second SSS. Specifically, for M-TRP transmissions based on M-DCI, the first SSS and the second SSS are associated with the same CORESET pool index value. In another embodiment, the UE can receive an RRC message including a timer value, and start a timer in response to a UE-specific DCI format, wherein the adjustment of the PDCCH monitoring period value is performed when the time expires.

[0061] While the invention has been described with reference to certain specific embodiments for illustrative purposes, it is not limited thereto. Therefore, various modifications, alterations, and combinations of features of the described embodiments can be made without departing from the scope of the claims.

Claims

1. A physical downlink control channel monitoring and adaptation method, comprising: Discontinuous reception is performed by the user equipment. The user equipment detects a user equipment-specific downlink control information format during the discontinuous reception operation, wherein the user equipment-specific downlink control information format includes a bit field indicating adaptation to physical downlink control channel monitoring; as well as The user equipment adjusts the physical downlink control channel monitoring period value according to the bit field during the discontinuous reception activity time of the discontinuous reception operation. In response to the bit field indicating a search space set switch, the user equipment switches from a first search space set to a second search space set. During the discontinuous reception activity time of the discontinuous reception operation, the bit field is used simultaneously to indicate the switch of the search space set and the adaptation of physical downlink control channel monitoring. In this search space set, compared to the first search space set, the second search space set is configured to have no physical downlink control channel monitoring, or physical downlink control channel monitoring with a longer period, or physical downlink control channel monitoring with a smaller number of physical downlink control channel candidates.

2. The physical downlink control channel monitoring and adaptation method as described in claim 1, characterized in that, The user equipment-specific downlink control information format is a scheduling downlink control information using downlink control information formats 0_1, 1_1, 0_2, or 1_2.

3. The physical downlink control channel monitoring and adaptation method as described in claim 1, characterized in that, The second search space set is the dormant search space set.

4. The physical downlink control channel monitoring and adaptation method as described in claim 3, characterized in that, In response to switching to the hibernation search space set, monitoring of downlink control information scrambled by any of the cell radio network temporary identifiers, configured scheduling-radio network temporary identifiers, and modulation codec-cell-radio network temporary identifiers is stopped.

5. The physical downlink control channel monitoring and adaptation method as described in claim 1, characterized in that, The bit field indicates the rate at which the physical downlink control channel monitoring period value decreases.

6. The physical downlink control channel monitoring and adaptation method as described in claim 1, characterized in that, Further includes: In response to the bit field indicating the disabling of the search space set, the user equipment disables the configured search space set; as well as In response to disabling the configured search space set, the user equipment stops performing physical downlink control channel monitoring.

7. The physical downlink control channel monitoring and adaptation method as described in claim 1, characterized in that, The adjustment of the physical downlink control channel monitoring period value is performed for all types of search space sets, or for type 3 common search space sets and user equipment specific search space sets, or only for user equipment specific search space sets.

8. The physical downlink control channel monitoring and adaptation method as described in claim 1, characterized in that, The bit field indicates the adaptation to physical downlink control channel monitoring of the first search space set, which has the same control resource set pool index value as the second search space set, and the user equipment-specific downlink control information format detected in the second search space set.

9. The physical downlink control channel monitoring and adaptation method as described in claim 1, characterized in that, Further includes: The user equipment receives a radio resource control message including a timer value; as well as The timer is started by the user equipment in response to the user equipment-specific downlink control information format; Specifically, when the time expires, the monitoring period value of the physical downlink control channel is adjusted.

10. A user equipment for physical downlink control channel monitoring adaptation, comprising: Discontinuous reception operation circuit, used to perform discontinuous reception operation; A downlink control information detection circuit is used to detect a user equipment-specific downlink control information format during the discontinuous reception operation, wherein the user equipment-specific downlink control information format includes a bit field indicating adaptation to physical downlink control channel monitoring; as well as The physical downlink control channel monitoring and control circuit is used to adjust the physical downlink control channel monitoring period value according to the bit field during the discontinuous reception activity time of the discontinuous reception operation. In response to the bit field indicating a switch in the search space set, the user equipment switches from a first search space set to a second search space set. During the discontinuous reception activity time of the discontinuous reception operation, the bit field is used simultaneously to indicate the switch in the search space set and the adaptation of physical downlink control channel monitoring. Compared with the first search space set, the second search space set is configured to have no physical downlink control channel monitoring, or physical downlink control channel monitoring with a longer period, or physical downlink control channel monitoring with a smaller number of physical downlink control channel candidates.

11. The user equipment as claimed in claim 10, characterized in that, The user equipment-specific downlink control information format is a scheduling downlink control information using downlink control information formats 0_1, 1_1, 0_2, or 1_2.

12. The user equipment as claimed in claim 10, characterized in that, The second search space set is the dormant search space set.

13. The user equipment as claimed in claim 12, characterized in that, In response to switching to the hibernation search space set, the user equipment further ceases monitoring downlink control information scrambled by any one of the cell radio network temporary identifier, the configured scheduling-radio network temporary identifier, and the modulation codec-cell-radio network temporary identifier.

14. The user equipment as claimed in claim 10, characterized in that, The bit field indicates the rate at which the physical downlink control channel monitoring period value decreases.

15. The user equipment as claimed in claim 10, characterized in that, In response to the bit field indicating the disabling of the search space set, the user equipment disables the configured search space set, and in response to disabling the configured search space set, the user equipment stops performing physical downlink control channel monitoring.

16. The user equipment as claimed in claim 10, characterized in that, The adjustment of the physical downlink control channel monitoring period value is performed for all types of search space sets, or for type 3 common search space sets and user equipment specific search space sets, or only for user equipment specific search space sets.

17. The user equipment as claimed in claim 10, characterized in that, The bit field indicates the adaptation to physical downlink control channel monitoring of the first search space set, which has the same control resource set pool index value as the second search space set, and the user equipment-specific downlink control information format detected in the second search space set.

18. The user equipment as claimed in claim 10, characterized in that, The user equipment further receives a radio resource control message including a timer value, and in response to a user equipment-specific downlink control information format, the user equipment starts the timer, wherein, when the time expires, the adjustment of the physical downlink control channel monitoring period value is performed.

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