CN117377118A - Method executed by user equipment and user equipment - Google Patents

Abstract

The invention provides a method executed by user equipment and the user equipment, wherein the method comprises the following steps: the User Equipment (UE) receives a Physical Downlink Control Channel (PDCCH) command from a base station and triggers a random access process; when a PDCCH command is received, under the condition that a service cell in which the UE is positioned is configured with a plurality of transmitting and receiving nodes TRPs and a time advance TA value corresponding to each TRP is independent, the UE determines the TRP corresponding to the PDCCH command; and the UE performs random access resource selection according to the determined TRP.

Description

Method executed by user equipment and user equipment

Technical field

The present invention relates to the field of wireless communication technology, and more specifically, the present invention relates to a method executed by user equipment and corresponding user equipment.

Background technique

In order to further enhance the performance of uplink transmission and reception in NR technology, the 3rd Generation Partnership Project (3GPP) plans to study uplink transmission under multiple transmitting and receiving nodes (TRP). In a serving cell, more than one sending and receiving node TRP can be arranged, and each TRP provides services to the same UE, as shown in Figure 1. Due to the different physical distances between different TRPs and the UE, the propagation delays are different, so that the values of the timing advance (TimingAdvance) used by the UE when sending different TRPs are different. In the existing technology, the UE can trigger a random access process by receiving a PDCCH order (PDCCHorder) from the network layer, and obtain a valid TA value in the process, thereby updating the time advance it maintains. In the existing technology, the UE only interacts with one TRP on a serving cell and maintains one TA value; with the introduction of multiple TRPs, how the UE maintains multiple TA values is a problem that needs to be solved.

Contents of the invention

In order to solve the above problems, the present invention provides a user equipment that can effectively maintain multiple TA values to reliably perform uplink transmission under multiple TRPs even when the UE is configured with multiple TRPs on a serving cell. The method of execution and the corresponding user device.

According to an aspect of the present invention, a method performed by user equipment is provided, including the following steps:

The user equipment UE receives the physical downlink control channel PDCCH command from the base station and triggers the random access process;

When receiving the PDCCH command, when the serving cell where the UE is located is configured with multiple transmitting and receiving nodes TRP and the time advance TA value corresponding to each TRP is independent, the UE determines the TRP corresponding to the PDCCH command;

The UE selects random access resources based on the determined TRP.

In the above method executed by user equipment, preferably, the following steps are also included:

According to the determined TRP, a dedicated random access resource associated with the determined TRP is selected for the triggered random access process.

In the above method executed by user equipment, preferably, the following steps are also included:

According to the determined TRP, select the SSB or CSI-RS associated with the determined TRP for the triggered random access process, and set the random access parameter preamble sequence number PREAMBLE_INDEX to the value equal to the selected SSB or CSI-RS The corresponding preamble sequence number.

In the above method performed by user equipment, preferably,

The UE selects random access resources based on the determined TRP only when the determined TRP is the secondary TRP.

In the above method executed by user equipment, preferably, the following steps are also included:

During the random access process initiated by the UE, when the number of times the preamble sequence is sent is equal to the value of the maximum number of times the preamble sequence is allowed to be sent plus 1, that is, when the variable PREAMBLE_TRANSMISSION_COUNTER is equal to the value of the parameter preambleTransMax plus 1,

If the random access process is triggered by a PDCCH command, and the triggered PDCCH command is associated with a certain TRP, then the UE indicates the random access problem to the upper layer and indicates that the random access is initiated by a certain TRP. Triggered by PDCCH command;

If the random access procedure is triggered for TRP, or is associated with a determined TRP, then the UE indicates the random access problem to the upper layer, and indicates that the random access is triggered for TRP, or indicates that it is associated with TRP. associated;

When the upper layer of the UE receives a random access problem indication from the lower layer, if the random access is not triggered by a PDCCH command from TRP or is not triggered for TRP, then the UE determines that a radio link failure RLF is detected.

In the above method executed by user equipment, preferably, the following steps are also included:

During the random access process initiated by the UE, when the number of times the preamble sequence is sent is equal to the value of the maximum number of times the preamble sequence is allowed to be sent plus 1, that is, when the variable PREAMBLE_TRANSMISSION_COUNTER is equal to the value of the parameter preambleTransMax plus 1,

If the random access process is triggered by a PDCCH command, and the triggered PDCCH command is associated with the determined TRP, then the UE does not indicate the random access problem to the upper layer;

If the random access procedure is triggered for TRP, or is associated with TRP, then the UE does not indicate the random access problem to the upper layer;

When the upper layer of the UE receives a random access problem indication from the lower layer, the UE determines that a radio link failure RLF is detected.

In the above method executed by user equipment, preferably, the following steps are also included:

For a random access process that is not successfully completed, if the random access process is triggered by a PDCCH command, and the triggered PDCCH command is associated with a determined TRP, or if the random access process is triggered for a TRP , or is associated with a TRP, then the UE generates a MAC CE, in which the information of the TRP associated with the random access is indicated, and the information indicating that a random access failure occurs.

In the above method executed by user equipment, preferably, the following steps are also included:

The TRP corresponding to the PDCCH command is determined by transmitting the configuration indication TCI status.

According to another aspect of the present invention, a user equipment is provided, including:

processor; and

memory, which stores instructions,

Wherein, the above instructions execute the method described above when executed by the above processor.

According to the method executed by user equipment and the corresponding user equipment involved in the present invention, even if the UE is configured with multiple TRPs on a serving cell, multiple TA values can be effectively maintained, thereby reliably performing Uplink transmission under multiple TRPs.

Description of the drawings

Figure 1 is a schematic diagram showing uplink transmission under multiple transmitting and receiving nodes (TRP).

FIG. 2 is a schematic diagram showing the timing advance amount.

Figure 3 is a flow chart showing a four-step random access process.

Figure 4 is a flow chart showing a two-step random access process.

FIG. 5 is a flowchart showing a method executed by user equipment according to an embodiment of the present invention.

Figure 6 is a schematic structural block diagram of the user equipment involved in the present invention.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the present invention should not be limited to the specific embodiments described below. In addition, for the sake of simplicity, detailed descriptions of well-known technologies that are not directly related to the present invention are omitted to prevent confusion in the understanding of the present invention.

Before the detailed description, several terms mentioned in the present invention will be explained as follows. Unless otherwise indicated, the terms used in the present invention have the following meanings.

UE: User Equipment, user equipment;

NR: New Radio, a new generation of wireless technology;

LTE: Long Term Evolution, long-term evolution technology;

eLTE: Enhanced Long Term Evolution, enhanced long-term evolution technology;

RRC: Radio Resource Control, radio resource control (layer);

MAC: Medium Access Control, media access control (layer);

MAC CE: MAC Control Element, MAC control element;

PHY: physical layer, physical layer;

RB: radio bearer, wireless bearer;

DRB: Data Radio Bearer, data wireless bearer;

SRB: Signalling Radio Bearer, signaling wireless bearer;

TCI: Transmission Configuration Indicator, transmission configuration indication;

DCI: Downlink Control Information downlink control information

RSRP: Reference Signal Received Power, reference signal received power;

PRACH: Physical Random Access Channel, physical random access channel;

PDCCH: Physical Downlink Control Channel, physical downlink control channel;

RA: Random Access, random access;

RAR: Random Access Response, random access response;

TRP: Transmit/Receive Point, sending and receiving node;

SS: Synchronization Signal, synchronization signal;

PBCH: Physical Broadcast Channel, physical broadcast channel;

SSB: SS/PBCH block, synchronous broadcast block;

CSI-RS: Channel State Information-Reference Signal channel state information reference signal.

Below, a description will be given of the technology related to the present invention.

Random Access procedure Random Access procedure

The random access process includes a four-step random access process and a two-step random access process.

Four-step random access process

In the following, the four-step random access process in the prior art will first be described. When the UE performs the 4-step random access process, it generally includes the following steps.

Step 0: The UE selects random access resources for random access. in this process

- The UE selects the preamble sequence (preamble) for transmission, and sets the sequence number corresponding to the selected preamble to the value of the parameter PREAMBLE_INDEX; and

-determine the next available PRACH occasion from the PRACH occasions.

Step 1: The UE sends the selected preamble on the determined PRACH opportunity.

Step 2: The UE receives a random access response (Random Access Response, RAR) sent from the base station.

If this RAR carries the sequence number (preamble index id) corresponding to the preamble sent by the UE in step 1, then the UE can determine that the RAR is sent to itself.

Such a RAR will carry an uplink grant (UL grant) and a timing advance command (TimingAdvance Command).

The UL grant indicates the PUSCH resources used to transmit message 3. The Timing Advance Command indicates the index value T A used to control the amount of timing adjustment (the index value T _A used to control the amount of timing adjustment).

After receiving the above RAR, the UE will apply the Timing Advance Command to obtain a valid TA value. If this random access process is a random access process based on non-contention conflict, for example, a dedicated preamble is provided in the PDCCH order, then at this step, the random access process is considered to be successfully completed. If not, the UE will continue to perform the following steps, including processing the UL grant carried in the RAR and indicating it to the lower layer. If this is the first time that the UE successfully receives the above RAR, then the UE obtains the MAC PDU for transmission from the multiplexing and assembly entity (Multiplexing and assembly entity) and saves it in the buffer area of message 3 (MSG3 buffer).

Step 3: The UE sends message 3 on the PUSCH resource indicated by the UL grant.

In this message 3, the UE will carry identification information used for contention conflict resolution.

Step 4: The UE receives message 4 sent from the base station.

If message 4 carries the identification information carried by the UE in message 3, then the UE considers that the contention conflict is resolved and the random access process is successfully completed.

Since the UE has gone through the message delivery process of steps 1-4 in the above random access process, it is called a "four-step random access" (4-step RA) process.

Two-step random access process

Next, the "two-step random access process" involved in the present invention is described in detail. The "two-step random access process" in the present invention generally includes the following steps.

Step 0: The UE selects random access resources for random access. in this process

- The UE selects the preamble sequence (preamble) for transmission, and sets the sequence number corresponding to the selected preamble to the value of the parameter PREAMBLE_INDEX;

- determine the next available PRACH occasion from the PRACH occasions (determine the next available PRACH occasion from the PRACH occasions); and

- Determine the PUSCH resource corresponding to the preamble sequence.

Step 1: The UE sends message A (MSG A) to the base station.

Among them, message A contains the preamble and the payload of message A.

Among them, the preamble is sent on PRACH, and the payload of message A is sent on PUSCH. The payload of message A is packaged into MAC PDU and transmitted on PUSCH. The payload of message A can carry RRC messages, such as RRC connection establishment request messages, and can also carry user data packets.

Step 2: The UE receives message B (MSG B) sent by the base station.

Among them, message B carries information for contention conflict resolution.

From a chronological perspective, the UE first sends MSG A, including the preamble and the payload of message A; then the UE receives message B sent by the base station. Message B is the response information from the network side/base station to MSG A sent by the UE.

In addition, when the UE determines the transmission opportunity that can be used for message A, the UE obtains the MAC PDU for transmission from the multiplexing and assembly entity (Multiplexing and assembly entity), and saves the obtained MAC PDU in the buffer area.

Since message A contains the preamble sequence transmitted on PRACH and the load information of message A transmitted on PUSCH, the following situations can be used as the transmission opportunities for message A, including: UE determines A PUSCH opportunity that can be used to transmit the payload of message A is determined; or the UE determines the next available PRACH opportunity, which is used to transmit the above-mentioned preamble sequence; or the UE selects a preamble sequence and the selected preamble sequence It is used for this random access process; or the preamble sequence selected by the UE is associated with PUSCH or associated with PUSCH timing.

Time advance N _TA

The timing advance N _TA can be used to calculate the timing advance between downlink and uplink (Timing advance between downlink and uplink).

As shown in Figure 2, in order to maintain uplink synchronization, the UE needs to start transmitting the i-th uplink frame (Uplink Frame i) some time before the starting position of the i-th downlink frame (Downlink Frame i). This period of time can be characterized by a time advance value T _TA , T _TA = (N _TA +N _{TA, offset} )*T _c , where T _c is a time parameter related to the carrier frequency.

The Timing advance command contains an index value, which is recorded as T _A and is used to calculate N _TA . When receiving the Timing advance command included in the random access response, the UE can calculate the value of N _TA based on the _TA in it. In other words, T _A indirectly indicates the value of N _TA .

Timing Advance Group

In the prior art, in order to maintain uplink time alignment (UL time alignment), each serving cell is divided into a TAG, and serving cells with the same time advance belong to the same TAG. In order to manage the validity of the TA value, each TAG can have its own timer timeAlignmentTimer, which is used to control the effective time of uplink synchronization of the serving cells (ServingCells) belonging to the TAG. When the TA value is updated, the timeAlignmentTimer of the corresponding TAG will be started or restarted; when the timeAlignmentTimer of a TAG times out, it means that the uplink of the serving cell belonging to the TAG is no longer synchronized.

In a multi-TRP scenario, one serving cell may contain more than one TRP, and each TRP has its own corresponding timing advance. Then an implementation method may be that one serving cell may belong to more than one TAG, for example There are two TAGs, each TAG corresponds to a TRP, or each TRP has its own associated TAG. Similarly, each TAG can have its own timeAlignmentTimer.

Another implementation is that a serving cell belongs to a TAG, but this TAG has more than one TA value. For example, a TAG can have at least two TA values, and each TA value corresponds to or is associated with a TRP. Similarly, each TA can have its own timeAlignmentTimer, and then the TAG can have multiple timeAlignmentTimers.

In this article, any of the above methods can be used to manage TA.

In this article, since TRP and TAG/TA correspond to each other, the two terms can be interchanged. For example, the TRP corresponding to the PDCCH order that triggers random access is determined, and the TAG corresponding to the PDCCH order that triggers random access is also determined. .

PDCCH order (PDCCH order)

A proprietary DCI format is used to characterize the PDCCH order. Such DCI is carried in the PDCCH and used to trigger the random access process. In such a DCI format, the random access preamble sequence number (Randomaccess preamble index) can be clearly indicated, and the SS/PBCH sequence number can also be clearly indicated.

Synchronous Broadcast Block SSB

When the NR system operates in a high frequency band, the base station often cannot send multiple beams covering the entire cell at the same time. Therefore, beam scanning technology is introduced in the NR system to solve the cell coverage problem.

The so-called beam scanning means that the base station only sends one or several beam directions at a certain time, and sends different beams at multiple times to cover all directions required for the entire cell. The synchronization broadcast block set is designed for beam scanning and is used to send the primary synchronization signal, secondary synchronization signal and physical broadcast channel required by the UE to search for the cell in each beam direction, and these signals form a synchronization broadcast block (SSB). ). A synchronous broadcast block set is a collection of multiple synchronous broadcast blocks within a certain time period. In the same period, each synchronous broadcast block corresponds to a beam direction, and the beam direction of each synchronous broadcast block in a synchronous broadcast block set covers the entire cell.

In a multiple TRP scenario, it can be considered that one TRP corresponds to some SSBs in the synchronous broadcast block set, and another TRP corresponds to some SSBs in the set. The SSBs corresponding to the two constitute the complete set of synchronous broadcast block sets, that is, coverage the entire community. Therefore, during the random access process, when selecting random access resources, the UE needs to first determine the beam direction of the random access, that is, determine the SSB.

In the scenario of multiple TRPs (multiple TRPs), there can also be a primary TRP (primary TRP) corresponding to all SSBs of the synchronized broadcast block set, achieving coverage of the entire cell, and there are one or more secondary TRPs (Secondary TRP) at the same time. Their corresponding beam directions can be partial SSBs, or can be more subdivided and can be characterized by CSI-RS, that is, the beam directions corresponding to CSI-RS.

Therefore, it can be considered that TRP and SSB or CSI-RS have a corresponding relationship or are related to each other.

This corresponding relationship can be directly reflected in the RRC configuration information. For example, if one or more SSB serial numbers are configured for a TRP, then these SSBs are associated with the TRP; another example is if one or more CSI-SIs are configured for a TRP. RS, then these CSI-RS are associated with the TRP. Such correspondence can also be characterized in an indirect manner, for example, by TCI states. The UE detects the PDCCH on the configured search space. The configuration information of each search space includes information about the control resource set (ControlResource Set, CORESET) used by the search space. The control resource set provides resource blocks in frequency domain and time domain. Each control resource set is associated with a series of TCI states. Each TCI state contains at least one SSB or CSI-RS information. The set of control resources used in the same search space can be numbered by coresetPoolIndex, where the number value 0 can correspond to the first TRP or primary TRP, and the number value 1 can correspond to the second TRP or secondary TRP. And so on. Therefore, the configuration of the TCI state of the resource set can correspond to the TRP corresponding to the resource set, thereby forming a corresponding relationship between the TRP and SSB or CSI-RS.

In this article, since TRP and TCI state or coresetPoolIndex correspond to each other, the two terms can be replaced with each other. For example, the TRP corresponding to the PDCCH order that triggers random access is determined, and correspondingly, the TRP corresponding to the PDCCH order that triggers random access is also determined. TCI state or coresetPoolIndex.

4-step Random Access procedure (4-step RA)

The following is explained with reference to the accompanying drawings. Specifically, as shown in Figure 3, the UE performs a 4-step random access process including the following steps:

Step S300: The UE selects random access resources for random access. in this process

- The UE selects the preamble sequence (preamble) for transmission, and sets the sequence number corresponding to the selected preamble to the value of the parameter PREAMBLE_INDEX; and

-determine the next available PRACH occasion from the PRACH occasions.

Step S301: The UE sends the selected preamble on the determined PRACH opportunity.

Step S302: The UE receives a random access response (Random Access Response, RAR) sent from the base station.

If this RAR carries the sequence number (preamble index id) corresponding to the preamble sent by the UE in step S301, then the UE can determine that the RAR is sent to itself.

Such RAR will carry UL grant, indicating the PUSCH resources used to transmit message 3.

The RAR also carries the Timing Advance Command, which contains the index value _T A used to control the amount of timing adjustment. The index may correspond to a valid upstream synchronization time advance TA. When the UE receives such a Timing Advance Command, it will apply the timing advance indicated therein for the subsequent uplink transmission.

After receiving the above RAR, the UE will apply the Timing Advance Command to obtain a valid TA value. If this random access process is a random access process based on non-contention conflict, for example, a dedicated preamble is provided in the PDCCH order, then at this step, the random access process is considered to be successfully completed. If not, the UE will continue to perform the following steps.

After receiving the above RAR, the UE will process the UL grant carried in the RAR and indicate it to the lower layer. If this is the first time that the UE successfully receives the above RAR, then the UE obtains the MAC PDU for transmission from the multiplexing and assembly entity (Multiplexing and assembly entity) and saves it in the buffer area of message 3 ( MSG3 buffer).

If the UE does not receive the above RAR within the predetermined time, the UE will increase the value of the variable PREAMBLE_TRANSMISSION_COUNTER by 1, and the initial value of this variable is 0. If PREAMBLE_TRANSMISSION_COUNTER=preambleTransMax+1, then the UE believes that the random access process has not been successfully completed and can indicate the random access problem to the upper layer. The variable PREAMBLE_TRANSMISSION_COUNTER is used to record the number of times the preamble is sent, and the parameter preambleTransMax is a preconfigured value, whose value indicates the maximum number of times the preamble is allowed to be sent.

Step S303: The UE sends message 3 on the PUSCH resource indicated by the UL grant.

In this message 3, the UE will carry identification information used for contention conflict resolution.

Step S304: The UE receives message 4 sent from the base station.

If message 4 carries the identification information carried by the UE in message 3, then the UE considers that the contention conflict is resolved and the random access process is successfully completed.

If the UE does not receive the above message 4 within the predetermined time, the UE will increase the value of the variable PREAMBLE_TRANSMISSION_COUNTER by 1, and the initial value of this variable is 0. If PREAMBLE_TRANSMISSION_COUNTER=preambleTransMax+1, then the UE believes that the random access process has not been successfully completed and can indicate the random access problem to the upper layer.

Since the UE has gone through the message delivery process of steps S301 to S304 during the above random access process, it is called a "four-step random access" (4-step RA) process.

The above four-step random access procedure may also be called a first type of layer 1 random access (Type-1 layer 1 Random Access Procedure, type 1 L1 RA). From the perspective of the physical layer (also known as layer 1, layer 1), the type 1 L1 RA process at least includes the transmission of the random access preamble sequence (or transmission of message one) on the PRACH, and the random access response Transmission/reception of the message (Random Access Response Message). The transmission of this random access response message is scheduled by the PDCCH and is transmitted on the PDSCH; in addition, the random access response can also be included in the type 1L1 RA process. The PUSCH scheduled by the carried uplink grant, and the subsequent PDSCH used for contention resolution.

2-step Random Access procedure (2-step RA)

The following is explained with reference to the accompanying drawings. Specifically, as shown in Figure 4, the two-step random access process includes the following steps:

Step S400: The UE selects random access resources for random access. in this process

- The UE selects the preamble sequence (preamble) for transmission, and sets the sequence number corresponding to the selected preamble to the value of the parameter PREAMBLE_INDEX;

- determine the next available PRACH occasion from the PRACH occasions (determine the next available PRACH occasion from the PRACH occasions); and

- Determine the PUSCH resource corresponding to the preamble sequence.

Step S401: The UE sends message A (MSG A) to the base station.

Among them, message A contains the preamble and the payload of message A.

Among them, the preamble is sent on PRACH, and the payload of message A is sent on PUSCH. The payload of message A is packaged into MAC PDU and transmitted on PUSCH. When the UE determines the opportunity to send message A, if this is the first time that the UE sends MSG A, then the UE obtains the MAC PDU for sending from the multiplexing and assembly entity (Multiplexing and assembly entity), And save it in the buffer area of message A (MSGA buffer).

Step S402: The UE receives the message B (MSG B) sent by the base station.

Among them, message B carries information for contention conflict resolution.

In the present invention, the network, base station and RAN can be used interchangeably. The network can be a Long Term Evolution LTE network, a New Radio Access Technology (New RAT, NR) network, an enhanced Long Term Evolution eLTE network, or a subsequent evolved version of 3GPP. other networks defined in .

Specific examples will be listed below to illustrate the processing method of the present invention.

Example 1

This embodiment provides a method executed by user equipment, as shown in Figure 5, including the following steps.

Step S501: The UE receives the PDCCH order from the base station and triggers the random access process.

Step S502: Upon receiving the PDCCH order, when the serving cell where the UE is located is configured with multiple transmitting and receiving nodes TRP and the TA value corresponding to each TRP is independent, the UE determines the TRP corresponding to the PDCCH order.

Step S503: The UE selects random access resources based on the determined TRP.

Among them, when receiving the PDCCH order, the UE can determine whether the PDCCH order comes from a specific TRP.

In one case, the UE is configured with multiple TRPs in the serving cell, and the TA value corresponding to each TRP is independent (it can also be understood that the UE is configured with multiple TA values in the serving cell, or Multiple TAGs are configured (in the following, these terms are interchangeable), then when the UE receives the PDCCH order, it needs to determine which TRP the PDCCH order is associated with, or which TA value/TAG it is associated with.

As a supplement, in another case, the UE does not have the aforementioned multiple TRPs configured in the serving cell, then the UE does not need to make the above judgment.

After the above determination, the UE can determine the TRP corresponding to the PDCCH order, and it can be considered that the random access process triggered by the PDCCH order also corresponds to the TRP, or is associated with the determined TRP.

Then the UE performs random access resource selection (Random Access Resource selection).

If the sequence number of the RA preamble sequence is clearly indicated in the PDCCH used for the PDCCH order indication, then the UE selects the SSB indicated by the PDCCH order. If the sequence number of the RA preamble sequence is not clearly indicated in the PDCCH used for the PDCCH order indication, the UE further determines Whether dedicated random access resources are configured. specifically,

1. In one case, the PDCCH used for PDCCH order indication clearly indicates the sequence number of the RA preamble sequence (ra-PreambleIndex), and the value of this clearly indicated ra-PreambleIndex is not equal to 0b000000, then the UE can set The value of the parameter PREAMBLE_INDEX in the random access process is the indicated ra-PreambleIndex, and the SSB indicated in the PDCCH is selected.

2. In one case, the PDCCH used for PDCCH order indication does not clearly indicate the sequence number of the RA preamble sequence, or the indicated RA preamble sequence number value is 0b000000, then the UE needs to use other methods to select the RA. resource.

For example, the UE further determines whether it is configured with dedicated random access resources. The dedicated random access resources at least include configuration information of contention-free Random Access Resources based on contention-free random access resources, and the The configured random access resources are associated with SSB or CSI-RS.

2.1 In one case, the configured dedicated RACH resources are associated with TRP. Then based on the previously determined TRP, the UE first needs to select the dedicated random access resources associated with the determined TRP for resource selection of the triggered random access process. If the configured dedicated random access resources are associated with other TRPs, they should not be used for resource selection for this random access, because the triggered random access procedure is associated with a certain TRP. of. Then, in the dedicated random resource associated with the determined TRP, if there is an SSB (or CSI-RS) that meets the level condition, then one of the SSBs (or CSI-RS) that meets the condition is selected, and set The value of the parameter PREAMBLE_INDEX is the ra-PreambleIndex corresponding to the SSB (or CSI-RS).

2.2 In another case, the configured dedicated random access resources are not associated with the TRP. Then when selecting resources for the random access process in the dedicated random access resources, in addition to meeting the aforementioned level requirements, the selected SSB (or CSI-RS) also needs to meet another condition, which is this SSB (or CSI-RS) needs to be associated with a certain TRP. Then select one of the SSBs (or CSI-RS) that meets the conditions, and set the value of the parameter PREAMBLE_INDEX to the ra-PreambleIndex corresponding to the SSB (or CSI-RS).

3. In another case, the UE is not configured with the aforementioned dedicated random access resources, or no SSB or CSI-RS that meets the conditions is found in the aforementioned configured dedicated random access resources. , then the UE needs to use other methods to select random access resources.

3.1 For example, if the UE is configured with multiple TRPs in the serving cell, the UE can select a suitable SSB on the SSB associated with the previously determined TRP. The so-called suitable means that the SSB at least meets the requirements of the level value; if If there is no SSB that meets the level value requirements, the UE can select any SSB from the SSB associated with the previously determined TRP. Correspondingly, the UE can always select the preamble in Random Access Preambles group A and set the value of the parameter PREAMBLE_INDEX to the sequence number (index) of the selected preamble. Or select a preamble from the random access preamble sequence group associated with the previously determined TRP, and set the value of the parameter PREAMBLE_INDEX to the sequence number (index) of the selected preamble.

3.2 For another example, if the UE is configured with multiple TRPs in the serving cell, the UE can select an appropriate CSI-RS on the CSI-RS associated with the previously determined TRP. Suitability means that the CSI-RS can meet the level value requirements. If there is no CSI-RS that meets the level value requirements, the UE can select any CSI-RS from the CSI-RS associated with the previously determined TRP.

- If the selected CSI-RS has corresponding random access resources, then the UE can set the value of the parameter PREAMBLE_INDEX to the corresponding preamble sequence number (index) according to the corresponding random access resources;

- If the selected CSI-RS does not have a corresponding random access resource, the UE may select an SSB that is quasi-colocated with the CSI-RS. Then select the leader sequence according to the method described in 3.1.

Example 2

The difference from Embodiment 1 is that the UE only performs the operations in Embodiment 1 when the determined TRP is the second TRP. The specific implementation is as follows:

The UE receives the PDCCH order and triggers the random access process.

When receiving a PDCCH order, the UE can determine whether the PDCCH order comes from a specific TRP.

In one case, the UE is configured with at least two TRPs in the serving cell, and the TA value corresponding to each TRP is independent (it can also be understood that the UE is configured with multiple TA values in the serving cell, or multiple TAGs are configured (in the following, these terms can be interchanged), then when the UE receives the PDCCH order, it needs to determine which TRP the PDCCH order is associated with, or which TA value/TAG it is associated with. Take two TRPs as an example, one is called primary TRP and the other is called secondary TRP.

When the UE determines that the TRP corresponding to the PDCCH order is the primary TRP, the UE can perform operation 1 in selecting random access resources. As a supplement, in another case, the UE is not configured with the aforementioned multiple TRPs in the serving cell, then the UE does not need to make the above judgment, and the UE can perform operations in random access resource selection. one.

When the UE determines that the TRP corresponding to the PDCCH order is the secondary TRP, the UE can perform operation 2 in selecting random access resources.

Operation one:

In one case, the PDCCH order clearly indicates the sequence number of the RA preamble sequence (ra-PreambleIndex), and the value of this clearly indicated ra-PreambleIndex is not equal to 0b000000, then the UE can set the The value of the parameter PREAMBLE_INDEX is the indicated ra-PreambleIndex, and the SSB indicated in the PDCCH order is selected.

In one case, the PDCCH order does not clearly indicate the sequence number of the RA preamble sequence, or the indicated sequence number of the RA preamble sequence is 0b000000, then the UE needs to use other methods to select RA resources.

For example, the UE further determines whether it is configured with a dedicated random access resource. The dedicated random access resource at least contains configuration information of contention-free random access resources (contention-free Random AccessResources), and the The configured random access resources are associated with SSB or CSI-RS.

In the configured dedicated random resources, if there is an SSB (or CSI-RS) that meets the level conditions, then select one of the SSBs (or CSI-RS) that meets the conditions and set the value of the parameter PREAMBLE_INDEX is the ra-PreambleIndex corresponding to the SSB (or CSI-RS).

If the UE is not configured with the aforementioned dedicated random access resources, or no SSB or CSI-RS that meets the conditions is found in the aforementioned configured dedicated random access resources, then the UE selects the appropriate SSB The so-called appropriate SSB means that the SSB at least meets the level value requirements; if there is no SSB that meets the level value requirements, the UE can select any SSB from all SSBs.

Operation 2: As shown in Embodiment 1, the determined TRP is the secondary TRP.

Example 3

For the random access process initiated by the UE, if the variable PREAMBLE_TRANSMISSION_COUNTER is equal to the value of the parameter preambleTransMax plus 1, (PREAMBLE_TRANSMISSION_COUNTER=preambleTransMax+1), the UE can indicate the random access problem (Random) to the upper layer of the UE's MAC layer (such as the RRC layer) access problem).

If the random access process is triggered by PDCCH order, and the triggered PDCCH order is associated with the determined TRP, then the UE can indicate the random access problem (Random access problem) to the upper layer and indicate that the random access is Triggered by PDCCH order from a certain TRP;

Or if the random access process is triggered for TRP, or is associated with a determined TRP, then the UE indicates the random access problem (Random access problem) to the upper layer and indicates that the random access is triggered for TRP. , or the indication is associated with a TRP;

In other cases, the UE may directly indicate random access issues to upper layers.

The upper layer of the UE, such as the RRC layer, receives a random access problem indication from the lower layer. If the random access is not triggered by the PDCCH order from TRP or is not triggered for TRP, then the UE considers that a radio link failure has been detected (consider radio link failure to be detected); otherwise, the UE does not think that RLF is detected.

In other words, the upper layer of the UE, such as the RRC layer, receives a random access problem indication from the lower layer. Except when the random access is triggered by the PDCCH order from the TRP or is triggered by the TRP, the UE always thinks that the detection The wireless link failed.

Embodiment 3 can be used in combination with Embodiments 1 and 2, or can be used alone to manage random access issues associated with TRP.

In particular, the UE can use different processing for random access triggered by primary TRP and secondary TRP.

For example, for the random access process initiated by the UE, if the variable PREAMBLE_TRANSMISSION_COUNTER is equal to the value of the parameter preambleTransMax plus 1, (PREAMBLE_TRANSMISSION_COUNTER=preambleTransMax+1),

If the random access is triggered by the primary TRP, then the UE directly indicates the random access problem to the upper layer; when the upper layer receives the indication, it considers that a wireless link failure has been detected, which can trigger the RRC connection re-establishment process;

If the random access is triggered by the secondary TRP, the UE indicates to the upper layer the random access problem triggered by the secondary TRP; when the upper layer receives the indication, it does not consider that a wireless link failure has been detected.

That is, when the upper layer receives a random access problem indication from the lower layer, if the indication is not associated with the secondary TRP, or is not a random access problem triggered by the secondary TRP, then the UE considers that a wireless link failure has been detected.

Or when the upper layer receives a random access problem indication from the lower layer, except for the random access problem triggered by the secondary TRP, the UE always thinks that a wireless link failure has been detected.

Example 4

The difference from Embodiment 3 is that when the UE determines the reason for triggering the random access process, if the random access process is triggered by a PDCCH order, and the triggered PDCCH order is associated with the determined TRP, then the UE does not The layer indicates the random access problem (Random access problem);

Or if the random access procedure is triggered for TRP, or is associated with TRP, then the UE does not indicate the random access problem (Random access problem) to the upper layer;

In other cases, the UE may directly indicate random access issues to upper layers.

As a supplement, the upper layer of the UE, such as the RRC layer, considers that a radio link failure (Radio Link Failure) is detected when receiving a random access problem indication from the lower layer.

Example 5

Based on Embodiment 3 or 4, for the random access process initiated by the UE, if the variable PREAMBLE_TRANSMISSION_COUNTER is equal to the value of the parameter preambleTransMax plus 1, (PREAMBLE_TRANSMISSION_COUNTER=preambleTransMax+1), the UE considers that the random access process has not been successfully completed (Random Access procedure unsuccessfully completed).

For a random access process that is not successfully completed, if the random access process is triggered by a PDCCH order, and the triggered PDCCH order is associated with a determined TRP, or if the random access process is triggered for a TRP , or is associated with the TRP, the UE may generate a MAC CE, in which the information of the TRP associated with the random access may be indicated, and the information of a random access failure may also be indicated. The UE then sends the MAC CE to the base station.

Example 6

In the aforementioned embodiment, how the UE determines the TRP corresponding to the PDCCH order can be accomplished in the following ways:

Method 1 is determined by the CORESETPoolIndex corresponding to the configured ControlResourceSet in the search space used to receive PDCCH.

For example, the PDCCH received by the UE on the ControlResourceSet corresponding to the CORESETPoolIndex value of 0 in the search space can be TRP-1; while the UE receives the PDCCH on the resource corresponding to the CORESETPoolIndex value of 1 in the search space. The corresponding TRP of PDCCH may be TRP-2.

Or the PDCCH received by the UE on the ControlResourceSet corresponding to the CORESETPoolIndex value of 1 in the search space (such a Coreset can be called the second CORSET), and its corresponding TRP can be the secondary TRP or the second TRP; and the UE is in The corresponding TRP of the PDCCH received on the ControlResourceSet corresponding to the CORESETPoolIndex that has not been assigned a value in the search space (such a Coreset can be called the first CORSET) can be the primary TRP or the first TRP.

Method two is determined by TCI state.

For example, if the UE receives the PDCCH on the activated TCI state, then the corresponding TRP is the TRP configured with the TCI state.

The TRP corresponding to the PDCCH order may also be determined based on the received TCI state indicated in the DCI format used for the PDCCH order.

Or all TCI states configured for the UE can be divided into several groups or sets, and each group or set can correspond to a TRP. Then the TRP can be determined based on the TCI state set to which the received TCIstate indicated in the DCI format used for the PDCCH order belongs. Or the TRP is determined based on the activation of the TCI state to which it belongs in the TCI state used to receive the PDCCH.

Method Three: Direct Instruction

The DCI format used for the PDCCH order carries indication information to indicate the TRP corresponding to the PDCCH order. For example, when the value of the TRP field is set to 0, it corresponds to TRP-1, and when the value is 1, it corresponds to TRP-2.

In addition to the above methods, this article does not limit the UE to determine the TRP corresponding to the PDCCH order through other methods.

Figure 6 is a schematic structural block diagram of the user equipment involved in the present invention.

As shown in FIG. 6 , the user equipment 600 at least includes a processor 601 and a memory 602 . The processor 601 may include, for example, a microprocessor, a microcontroller, an embedded processor, or the like. The memory 602 may include, for example, volatile memory (such as random access memory RAM), hard disk drive (HDD), non-volatile memory (such as flash memory), or other memory systems. Memory 602 stores program instructions. When this instruction is executed by the processor 601, it may execute one or several steps in the UE processing method of the present disclosure.

The method and related equipment of the present disclosure have been described above in conjunction with preferred embodiments. Those skilled in the art can understand that the methods shown above are only exemplary, and the embodiments described above can be combined with each other without conflict. The method of the present invention is not limited to the steps and sequence shown above.

The user equipment shown above may include more modules, for example, it may also include modules that may be developed or developed in the future and may be used for base stations, MMEs, or UEs, and so on. The various identifications shown above are only illustrative and not restrictive, and the present disclosure is not limited to the specific information elements as examples of these identifications. Many changes and modifications may be made by those skilled in the art in light of the teachings of the illustrated embodiments.

It should be understood that the above-described embodiments of the present disclosure can be implemented by software, hardware, or a combination of software and hardware. For example, various components inside the base station and user equipment in the above embodiments can be implemented by a variety of devices, including but not limited to: analog circuit devices, digital circuit devices, digital signal processing (DSP) circuits, programmable processing processor, application specific integrated circuit (ASIC), field programmable gate array (FPGA), programmable logic device (CPLD), etc.

In addition, the program running on the device according to the present invention may be a program that causes the computer to implement the functions of the embodiments of the present invention by controlling a central processing unit (CPU). The program or information processed by the program may be temporarily stored in volatile memory (such as random access memory RAM), hard disk drive (HDD), non-volatile memory (such as flash memory), or other memory systems.

Programs for realizing the functions of each embodiment of the present invention can be recorded on a computer-readable recording medium. Corresponding functions can be realized by causing the computer system to read programs recorded on the recording medium and execute these programs. The so-called "computer system" here may be a computer system embedded in the device, which may include an operating system or hardware (such as peripheral devices). The "computer-readable recording medium" may be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a short-term dynamic storage program recording medium, or any other recording medium readable by a computer.

Various features or functional modules of the devices used in the above-described embodiments may be implemented or performed by circuits (eg, single-chip or multi-chip integrated circuits). Circuitry designed to perform the functions described in this specification may include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination of the above. A general-purpose processor can be a microprocessor or any existing processor, controller, microcontroller, or state machine. The above circuit may be a digital circuit or an analog circuit. When new integrated circuit technologies emerge to replace existing integrated circuits due to advances in semiconductor technology, one or more embodiments of the present invention may also be implemented using these new integrated circuit technologies.

Furthermore, the present invention is not limited to the above-described embodiment. Although various examples of the embodiments have been described, the invention is not limited thereto. Fixed or non-mobile electronic equipment installed indoors or outdoors can be used as terminal equipment or communication equipment, such as AV equipment, kitchen equipment, cleaning equipment, air conditioners, office equipment, vending machines, and other household appliances.

As above, the embodiments of the present invention have been described in detail with reference to the accompanying drawings. However, the specific structure is not limited to the above-described embodiment, and the present invention also includes any design changes that do not deviate from the gist of the present invention. In addition, various modifications can be made to the present invention within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. Furthermore, components having the same effect described in the above embodiments may be substituted for each other.

Claims (10)

1. A method performed by user equipment, including the following steps: The user equipment UE receives the physical downlink control channel PDCCH command from the base station and triggers the random access process; When receiving the PDCCH command, when the serving cell where the UE is located is configured with multiple transmitting and receiving nodes TRP and the time advance TA value corresponding to each TRP is independent, the UE determines the TRP corresponding to the PDCCH command; The UE selects random access resources based on the determined TRP. 2. The method executed by user equipment according to claim 1, further comprising the following steps: According to the determined TRP, a dedicated random access resource associated with the determined TRP is selected for the triggered random access process. 3. The method executed by user equipment according to claim 1, further comprising the following steps: According to the determined TRP, select the SSB or CSI-RS associated with the determined TRP for the triggered random access process, and set the random access parameter preamble sequence number PREAMBLE_INDEX to the value equal to the selected SSB or CSI-RS The corresponding preamble sequence number. 4. The method performed by user equipment according to any one of claims 1 to 3, wherein, The UE selects random access resources based on the determined TRP only when the determined TRP is the secondary TRP. 5. The method executed by user equipment according to any one of claims 1 to 3, further comprising the following steps: In the random access process initiated by the UE, when the number of times the preamble sequence is sent is equal to the value of the maximum number of times the preamble sequence is sent plus 1, If the random access process is triggered by a PDCCH command, and the triggered PDCCH command is associated with a certain TRP, then the UE indicates the random access problem to the upper layer and indicates that the random access is initiated by a certain TRP. Triggered by PDCCH command; If the random access procedure is triggered for TRP, or is associated with a determined TRP, then the UE indicates the random access problem to the upper layer, and indicates that the random access is triggered for TRP, or indicates that it is associated with TRP. associated; When the upper layer of the UE receives a random access problem indication from the lower layer, if the random access is not triggered by a PDCCH command from TRP or is not triggered for TRP, then the UE determines that a radio link failure RLF is detected. 6. The method executed by user equipment according to any one of claims 1 to 3, further comprising the following steps: In the random access process initiated by the UE, when the number of times the preamble sequence is sent is equal to the value of the maximum number of times the preamble sequence is sent plus 1, If the random access process is triggered by a PDCCH command, and the triggered PDCCH command is associated with the determined TRP, then the UE does not indicate the random access problem to the upper layer; If the random access procedure is triggered for TRP, or is associated with TRP, then the UE does not indicate the random access problem to the upper layer; When the upper layer of the UE receives a random access problem indication from the lower layer, the UE determines that a radio link failure RLF is detected. 7. The method executed by user equipment according to claim 5, further comprising the following steps: For a random access process that is not successfully completed, if the random access process is triggered by a PDCCH command, and the triggered PDCCH command is associated with a determined TRP, or if the random access process is triggered for a TRP , or is associated with a TRP, then the UE generates a MAC CE, in which the information of the TRP associated with the random access is indicated, and the information indicating that a random access failure occurs. 8. The method executed by user equipment according to claim 6, further comprising the following steps: For a random access process that is not successfully completed, if the random access process is triggered by a PDCCH command, and the triggered PDCCH command is associated with a determined TRP, or if the random access process is triggered for a TRP , or is associated with a TRP, then the UE generates a MAC CE, in which the information of the TRP associated with the random access is indicated, and the information indicating that a random access failure occurs. 9. The method executed by user equipment according to any one of claims 1 to 3, further comprising the following steps: The TRP corresponding to the PDCCH command is determined by transmitting the configuration indication TCI status. 10. A user equipment, comprising: processor; and memory, which stores instructions, Wherein, the above instructions execute the method according to any one of claims 1 to 9 when executed by the processor.