Method for early time domain channel attribute (TDCP) feedback via 4-step random access channel (RACH) procedure

Abstract

A method, system, and apparatus for early time domain channel attribute (TDCP) feedback via a 4-step random access channel (RACH) procedure are disclosed. According to one aspect, a method in a user equipment, UE, configured to communicate with a network node comprises: receiving assistance information from the network node to assist the UE in obtaining a time domain channel attribute, TDCP; receiving a trigger signal from the network node in a message 2 of the 4-step random access procedure; performing a TDCP measurement based at least in part on the received assistance information; and transmitting a TDCP report to the network node in a message 3 of the 4-step random access procedure in response to the trigger signal.

Description

Technical Field

[0001] This disclosure relates to wireless communication, and more particularly to a method for early time-domain channel attribute (TDCP) feedback via a 4-step random access channel (RACH) process. Background Technology

[0002] The 3rd Generation Partnership Project (3GPP) has developed and is developing standards for fourth-generation (4G) (also known as Long Term Evolution (LTE)) and fifth-generation (5G) (also known as New Radio (NR)) wireless communication systems. Among other features, such systems provide broadband communication between network nodes (e.g., base stations) and mobile user equipment (UE) or radio equipment (WD), as well as communication between network nodes and between UEs. 3GPP is also developing standards for sixth-generation (6G) wireless communication networks.

[0003] Synchronization signal block In NR, the UE obtains time and frequency synchronization with the cell based on two synchronization signals (SS): the primary synchronization signal (PSS) and the secondary synchronization signal (SSS). The UE also uses the PSS and SSS to detect the cell's physical layer cell ID. The PSS, SSS, and physical broadcast channel (PBCH) are transmitted together in consecutive symbols, forming an SS / PBCH block or SSB.

[0004] In the time domain, the SS / PBCH block has four Orthogonal Frequency Division Multiplexing (OFDM) symbols, numbered in ascending order from 0 to 3. In the frequency domain, the SS / PBCH block consists of 240 consecutive subcarriers, numbered in ascending order from 0 to 239. This... Figure 1 As shown in the figure. More details about the SS / PBCH block can be found in 3GPP Technical Standard (TS) 38.211.

[0005] SS / PBCH blocks are transmitted periodically at possible intervals of 5 milliseconds, 10 milliseconds, 20 milliseconds, 40 milliseconds, 80 milliseconds, or 160 milliseconds. One or more SS / PBCH blocks can be transmitted within the serving cell, each block having a Synchronization Signal Block (SSB) index. One or more SS / PBCH blocks within a 5-millisecond time window form an SSB burst set. The default SS burst set period value for the initial cell selection is 20 milliseconds. The maximum number of SS blocks within an SS burst set depends on the frequency range, with a maximum of 4 at 3 GHz and 8 between 3 GHz and 6 GHz. More details regarding the possible time positions of SS / PBCH blocks can be found in 3GPP TS 38.213.

[0006] Channel State Information Reference Signal (CSI-RS) For CSI measurement and feedback, a CSI-RS is defined. The CSI-RS is transmitted on each antenna port and used by the UE to measure the downlink channel between each transmit antenna port and each receive antenna port. The transmit antenna port is also called the CSI-RS port. The number of antenna ports supported in NR is {1, 2, 4, 8, 12, 16, 24, 32}. By measuring the received CSI-RS, the UE can estimate the channel that the CSI-RS is traversing, including the radio propagation channel and antenna gain. The CSI-RS used for the above purposes is also known as Non-Zero Power (NZP) CSI-RS.

[0007] CSI-RS can be configured to be transmitted in some REs and some time slots. Figure 2 This is an example of a CSI-RS RE with 12 antenna ports, showing one RE per RB per port.

[0008] In addition, Interference Measurement Resources (IMR) are defined in NR for UEs to measure interference. An IMR resource consists of four REs, either four frequency-adjacent REs within the same OFDM symbol, or two-by-two time- and frequency-adjacent REs within a time slot. By measuring both the channel based on Non-Zero Power (NZP) CSI-RS and the interference based on IMR, the UE can estimate the effective channel and noise-plus-interference to determine the CSI, i.e., rank, precoding matrix, and channel quality.

[0009] In addition, UEs in NR can be configured to measure interference based on one or more NZP CSI-RS resources.

[0010] TRS Due to oscillator limitations, transmission and reception can become asynchronous in time and / or frequency, leading to inter-symbol interference and intra-symbol interference. In NR, a tracking reference signal (TRS) is introduced, which can be used by the UE for fine-grained time / frequency synchronization.

[0011] In the NR 3GPP specification, TRS can be configured when CSI reporting settings are not configured, or when the higher-level parameter "reportQuantity" associated with all reporting settings in the CSI-ReportConfig information element (IE) linked to the CSI-RS resource set containing one or more TRSs is set to "none". This means that NR does not support CSI reporting based on measurements on TRS.

[0012] For example, a TRS can be configured via “trs-Info” in the NZP-CSI-RS-ResourceSet IE of 3GPP TS 38.331 V17.5.0. This “TRS-Info” is associated with a CSI-RS resource set for which the UE can assume that the antenna ports with the same port index of the NZP CSI-RS resources configured in the resource set are identical. From the perspective of the 3GPP specification, a TRS is designated as a special type of NZP CSI-RS that contains one or more TRSs. The corresponding NZP CSI-RS resource set has a higher-level parameter “trs-info” set to true.

[0013] TRS is not a true CSI-RS, but rather a resource set consisting of multiple periodic NZP CSI-RS. More specifically, TRS has four one-port, density-3 CSI-RS located within two consecutive time slots. The CSI-RS in this resource set can be configured with periods of 10, 20, 40, or 80 ms. Note that the exact RE set used for TRS CSI-RS can vary. There is always a four-symbol time-domain interval between two CSI-RS within a time slot. Figure 3 This is an example of a periodic TRS, showing the TRS locations within two consecutive time slots. The TRS in these two time slots is also referred to as a TRS burst.

[0014] NR also supports aperiodic TRS.

[0015] CSI framework in NR In NR, a UE can be configured with multiple CSI reporting settings and multiple CSI-RS resource settings. Each resource setting can contain multiple resource sets, and each resource set can contain up to 8 CSI-RS resources. For each CSI reporting setting, the UE feeds back a CSI report.

[0016] Each CSI report setting can include at least the following information: CSI-RS resource set for channel measurements; IMR resource set for interference measurement; Optionally, a CSI-RS resource set for interference measurement; Temporal behavior, i.e., periodic, semi-persistent, or aperiodic reporting; Frequency granularity, i.e., broadband or subband; When there are multiple CSI-RS resources in the resource set, the CSI parameters to be reported include, for example, Rank Indicator (RI), Precoder Matrix Indicator (PMI), Channel Quality Indicator (CQI), and CSI-RS Resource Indicator (CRI). Codebook type, i.e., type I or II, and codebook subset restrictions; Measurement limitations; and Subband size. Indicates one of two possible subband sizes, with the value depending on the bandwidth of the bandwidth portion (BWP). Each subband provides a CQI / PMI (if configured for subband reporting).

[0017] In NR, CSI-AperiodicTriggerState is configured to trigger aperiodic CSI reports. In 3GPPTS 38.331 V17.2.0, the CSI-AperiodicTriggerList IE is defined as follows: There is a list of trigger states, which can include up to 128 CSI-AperiodicTriggerStates. Each trigger state can include up to 16 CSI-AssociatedReportConfigInfos. Each CSI-AssociatedReportConfigInfo contains a reportconfig id that associates it with a CSI-Reportconfig. The UE can configure up to 48 different reportconfigs. Each reportconfig contains a codebookConfig field.

[0018] Rel-18 TRS-based TDCP report It has been taken into consideration that TRS-based TDCP (Time Domain Channel Attributes) reporting will be supported in NR Technology Release 18 (3GPP Rel-18).

[0019] There are several use cases for network nodes to know TDCP (Time Domain Channel Attributes) based on TRS measurements. One use case for TDCP reporting is to enable network nodes to select a transmission scheme that is more robust to channel aging when the channel changes rapidly. For example, based on TRS-based TDCP reported by the UE to the network node, the network node may need to decide whether the UE's precoder should be based on CSI obtained from uplink measurements or on CSI feedback obtained from the UE. Another example is that the network node may need to decide whether to schedule the UE's precoder based on Type I CSI feedback obtained from the UE (as specified in 3GPP TS 38.214) or Type II CSI feedback obtained from the UE (as specified in 3GPP TS 38.214).

[0020] Figure 4 and Figure 5 An example of average user throughput for a specific scheme relative to the average throughput (baseline) of feedback-based single-user multiple-input multiple-output (SU-MIMO) precoding is shown. Throughput is calculated for the baseline case corresponding to 70% resource utilization at each UE speed. Figure 4 and Figure 5 Results for both SU-MIMO and multi-user (MU)-MIMO are presented. The scenario is a UMa network with a site-to-site distance of 500 meters. The carrier frequency is 2 GHz, and the subcarrier spacing is 15 kHz. The CSI period is 20 ms for both feedback-based and reciprocity-based CSI. The results show that for both SU-MIMO and MU-MIMO, reciprocity-based precoding performs better at 3 km / h. However, at UE speeds of approximately 10 km / h, feedback-based precoding performs better. Therefore, feedback-based precoding is more robust to rapidly changing channels. A speed of 10 km / h corresponds to a channel coherence time longer than two time slots.

[0021] These results demonstrate that it can be beneficial to select a precoding scheme based on a parameter related to UE velocity. It should be noted that, in this context, UE velocity itself is not a fundamental parameter. Instead, how rapidly the channel changes depends on the UE velocity and the angle between the UE velocity vector and the propagation path as seen from the UE. Therefore, selecting a precoding scheme based on parameters such as coherence time or autocorrelation in TDCP is more appropriate.

[0022] UE measurement and reporting time-domain correlation based on TRS samples across different time delays is an effective way to report TDCP based on TRS.

[0023] To define the time-domain correlation measurement across TRS samples, let... These are the received frequency domain TRS samples after matched filtering and after removing the reference signal sequence. Index This indicates different OFDM symbols carrying the TRS used for correlation estimation. Note that the TRS used for correlation estimation can be located in the same or different time slots. OFDM Symbols The start time is determined by Give (to be precise, Indicates the start of the non-CP portion of the OFDM symbol. Index n represents the TRS sample index (assuming it is proportional to the subcarrier index).

[0024] set up It is used for delay Related estimates a pair of symbols - Index. Assumption The symbols are spaced equidistant in time.

[0025] In one example, delay The normalized time-domain correlation low-complexity estimate is computed in the frequency domain as follows: , In another example, for each OFDM symbol Calculate the inverse discrete Fourier transform (DFT): Time delay The normalized correlation estimate is calculated as follows: , The sum of the time samples exceeds a set defined, for example, by using a noise threshold to suppress noise. For example: in It is a noise estimation.

[0026] Note that at low speeds, changes in the channel are small, and correlation changes at different delays within a TRS burst (i.e., within two time slots) are very small. Within a TRS burst, correlation can be measured for delays of 4, 10, 14, and 18 symbols, such as... Figure 6 and 7 As shown in the example.

[0027] Because the correlation changes between different delays within a TRS pulse are very small for low speeds, measurements within a TRS pulse are insufficient to distinguish different speeds within the low-speed region. Therefore, 3GPP Rel-18 will also support the measurement and reporting of correlations corresponding to time delays across multiple TRS bursts. See also Figure 8 .

[0028] When the UE is in RRC connection mode, after Radio Resource Control (RRC) configuration, the TDCP report supported in 3GPP (NR) Rel-18 is executed.

[0029] Random access procedures in LTE and NR The random access procedures in LTE and NR are similar. In existing random access designs, the random access procedure serves multiple purposes, such as initial access when establishing a radio link and scheduling requests. One of the purposes of the random access procedure is to achieve uplink synchronization, which is to maintain uplink orthogonality in LTE and NR. To maintain the orthogonality of uplink signals from different UEs in an OFDM-based access (OFDMA) system, the arrival time of each UE's signal must be within the cyclic prefix (CP) of the OFDM signal at the network node. In the remainder of this document, Figure 9 Steps 2, 3, and 4 shown will be referred to as message 2, message 3, and message 4, respectively.

[0030] LTE and NR random access can be contention-based or contention-free. Contention-based random access involves four steps, such as... Figure 9 As shown: 1) Message 1: UE transmits random access preamble; 2) Message 2: The network node (e.g., gNB / eNB) transmits a random access response containing a timing advance (TA) command and scheduling of uplink resources for the UE to use in the third step. Note that the random access response is a PDCCH / PDSCH transmission, where the PDCCH is transmitted in the common search space; 3) Message 3: The UE uses the scheduled resources to transmit its identity to the network; and 4) Message 4: The network node transmits a contention resolution message to resolve any contention caused by multiple UEs transmitting the same random access preamble in the first step.

[0031] For contention-free random access, the UE uses a reserved preamble assigned by the network node (e.g., gNB / eNB). In this case, no contention resolution is required, and therefore only steps 1 and 2 are needed.

[0032] In NR, message 3 is scheduled via a Random Access Response (RAR) uplink grant. The contents of the RAR uplink grant are shown in Table 1 below. It should be noted that in 3GPP (NR) Rel-15, the CSI request bit in the RAR uplink grant is reserved.

[0033] Table 1: Size of Random Access Response License Content Field (from Table 8.2-1 of 3GPP TS 38.213 V17.6.0) The “PUSCH Time Resource Allocation” field in the RAR license is used to indicate the timing offset and the start / length of the resource allocated for message 3. This four-bit field is used to indicate a row in Table 2, which provides the time offset value K2 (note that K2 is given in timeslot), the start symbol S, and the length L of the allocated resource. The value j used to define K2 depends on the Physical Uplink Shared Channel (PUSCH) (denoted as µ). PUSCH The subcarrier spacing (SCS) is given in Table 3.

[0034] Table 2: Temporal Resource Allocation A for Default Physical Uplink Shared Channel (PUSCH) for Normal Cyclic Prefix (CP) (from Table 6.1.2.1.1-2 of 3GPP TS 38.214, V17.6.0) Table 3: Definition of value j (from Table 6.1.2.1.1-4 of 3GPP TS 38.214 V17.6.0) exist Figure 10 The example describes the timing offset of message 3 relative to message 2. For a Physical Downlink Shared Channel (PDSCH) with a RAR message ending in slot n, the UE in slot n+K2+ Δ Message 3 PUSCH is transmitted in the middle, where Δ The results are given in Table 4.

[0035] SSB and SS sudden outbreak In NR, NR-PSS (NR - Primary Synchronization Signal), NR-SSS (NR - Secondary Synchronization Signal), and NR-PBCH (NR - Physical Broadcast Channel) are transmitted within an SS block (also known as an SS / PBCH block or SSB). The SSB spans four OFDM symbols, where: NR-PSS is transmitted in 127 subcarriers in the first OFDM symbol of SSB; NR-SSS is transmitted in 127 subcarriers within the third OFDM symbol of the SSB; and NR-PBCH is transmitted in 240 subcarriers in the second and fourth OFDM symbols of the SSB, and in 96 subcarriers in the third OFDM symbol of the SSB.

[0036] It should be noted that the Narrowband Physical Broadcast Channel (NB-PBCH) consumes 576 REs, and it also contains the PBCH Demodulation Reference Signal (DMRS) used for demodulating the NR-PBCH.

[0037] An SS burst consists of one or more SSBs. The default period of an SS burst is 20ms, and the transmission of SSBs within an SS burst is limited to a 5ms window, regardless of the SS burst period. The maximum number L of SSBs within an SS burst for different frequency ranges is defined as follows: For frequencies up to 3 GHz, L is 4; For the frequency range from 3 GHz to 6 GHz, L is 8; and For the frequency range from 6 GHz to 52.6 GHz, L is 64.

[0038] QCL Several signals can be transmitted from the same network node antenna from different antenna ports. These signals may have the same large-scale characteristics, such as in terms of Doppler frequency shift / spread, average delay spread, or average delay. These antenna ports are referred to as quasi-cooperative localization (QCL).

[0039] The network can then signal to the UE that both antenna ports are QCL. If the UE knows that both antenna ports are QCL relative to a certain parameter (e.g., Doppler spread), the UE can estimate that parameter based on one of the antenna ports and use that estimate when receiving from the other antenna ports. Typically, the first antenna port is represented by a measurement reference signal (called the source RS) such as CSI-RS (Channel State Information RS), and the second antenna port is a demodulation reference signal (DMRS) (called the target RS). This is useful for demodulation because the UE can know the channel properties in advance when using DMRS for channel estimation.

[0040] The network signals to the UE about what assumptions can be made regarding QCL. In NR, four types of QCL relationships are defined between the source RS and the destination RS: Type A: {Doppler frequency shift, Doppler spread, average delay, delay spread}; Type B: {Doppler frequency shift, Doppler spread}; Type C: {Average Delay, Doppler Shift}; and Type D: {Space Rx parameter}.

[0041] QCL Type D was introduced to facilitate beam management for analog beamforming and is referred to as Spatial QCL. There is currently no strict definition of Spatial QCL, but it is understood that if two transmit antenna ports are Spatial QCL, the UE can use the same Rx beam to receive them.

[0042] Because the 3GPP Rel-18 TDCP report is executed after RRC configuration when the UE is in RRC connected mode, decisions made on the network side based on the TDCP report (e.g., configuring the UE for reciprocity-based CSI versus feedback-based CSI) can only be executed after the network receives the TDCP report, which occurs after the UE moves to RRC connected mode and after RRC configuration. This means that after the UE is in RRC connected mode, the network can first configure the UE for RRC with the TDCP report, then receive the configured TDCP report from the UE, and subsequently perform other configurations based on TDCP feedback (e.g., for reciprocity-based CSI versus feedback-based CSI). This will result in significant latency because configurations dependent on TDCP feedback may only be executed after the TDCP report is received. Therefore, reducing TDCP acquisition latency is an unresolved issue. Summary of the Invention

[0043] Some embodiments advantageously provide methods, systems, and apparatus for early time-domain channel attribute (TDCP) feedback via a 4-step random access channel (RACH) process.

[0044] This document discloses a method for obtaining a TDCP report early during the 4-step RACH process. Some embodiments include one or more of the following: Determine how the UE receives information about one or more RSs to be used for TDCP measurement and reporting via the System Information Block (SIB); Trigger an aperiodic TDCP report request in message 2 of the 4-step RACH process, and / or Provide a TDCP report as part of Information 3 of the 4-step RACH process.

[0045] In some embodiments, the network can obtain an early TDCP report as part of message 3 of the 4-step RACH procedure. When the UE moves to the RRC connected state, the network node can use the early TDCP report to properly configure the UE with RRC parameter configuration. This reduces the configuration latency associated with the 3GPP Rel-18-based TDCP reporting solution, where the TDCP report is only available after the UE has received the RRC configuration, once the UE has moved to the RRC connected state.

[0046] According to one aspect, a network node configured to communicate with a UE is provided. The network node is configured to transmit information to the UE to assist the UE in acquiring the Time Domain Channel Attribute (TDCP). The network node is also configured to configure the UE via a trigger signal in message 2 of the four-step random access procedure, which causes the UE to transmit a TDCP report. The network node is further configured to receive the TDCP report in message 3 of the four-step random access procedure.

[0047] According to this aspect, in some embodiments, a network node is configured to receive a TDCP report from a UE during a scheduled Physical Uplink Shared Channel (PUSCH) transmission. In some embodiments, the network node is configured to transmit at least one tracking reference signal to the UE, which will be used by the UE for TDCP measurements relative to previously received signals within predefined time-frequency resources. In some embodiments, the network node is configured to indicate at least one aperiodic tracking reference signal to be used by the UE for TDCP measurements. In some embodiments, the at least one aperiodic tracking reference signal to be used for TDCP measurements is indicated in message 2 of the 4-step random access procedure. In some embodiments, at least one aperiodic tracking reference signal is received in the same time slot of the Physical Downlink Control Channel (PDCCH) that triggers message 2 of the 4-step random access procedure. In some embodiments, at least one aperiodic tracking reference signal is received in a time slot following the time slot of receiving message 2 of the 4-step random access procedure. In some embodiments, the TDCP report is an aperiodic TDCP report. In some embodiments, the transmitted information includes sample-related correlation values ​​of the tracking reference signal TRS. In some embodiments, the method includes transmitting at least one periodic reference signal to the UE in predefined time-frequency resources, the reference signal being used by the UE for TDCP measurements.

[0048] According to another aspect, a method is provided implemented in a network node configured to communicate with a user equipment (UE). The method includes transmitting information to the UE to assist the UE in acquiring the Time Domain Channel Attribute (TDCP). The method also includes configuring the UE via a trigger signal in message 2 of a four-step random access procedure, the trigger signal causing the UE to transmit a TDCP report. The method further includes receiving the TDCP report in message 3 of the four-step random access procedure.

[0049] According to this aspect, in some embodiments, the method includes receiving a TDCP report from the UE in message 3 of the 4-step random access procedure. In some embodiments, the method includes receiving a TDCP report from the UE in a scheduled Physical Uplink Shared Channel (PUSCH) transmission. In some embodiments, the method includes transmitting at least one tracking reference signal to the UE, which will be used by the UE for TDCP measurements relative to previously received signals in predefined time-frequency resources. In some embodiments, the method includes indicating at least one aperiodic tracking reference signal to be used by the UE for TDCP measurements. In some embodiments, at least one aperiodic tracking reference signal to be used for TDCP measurements is indicated in message 2 of the 4-step random access procedure. In some embodiments, the method includes receiving at least one aperiodic tracking reference signal in the same time slot of the Physical Downlink Control Channel (PDCCH) that triggers message 2 of the 4-step random access procedure. In some embodiments, the method includes receiving at least one aperiodic tracking reference signal in a time slot following the time slot of receiving the PDCCH of message 2 of the 4-step random access procedure. In some embodiments, the TDCP report is an aperiodic TDCP report. In some embodiments, the transmitted information includes sample-related correlation values ​​of the tracking reference signal TRS. In some embodiments, the method includes transmitting at least one periodic reference signal to the UE in predefined time-frequency resources, the reference signal being used by the UE for TDCP measurements.

[0050] According to another aspect, a user equipment (UE) configured to communicate with a network node is provided. The UE is configured to receive auxiliary information from the network node to assist the UE in acquiring the Time-Domain Channel Attribute (TDCP). The UE is configured to receive a trigger signal from the network node on message 2 of a four-step random access procedure. The UE is also configured to perform TDCP measurements at least in part based on the received auxiliary information. The UE is further configured to transmit a TDCP report to the network node in message 3 of the four-step random access procedure in response to the trigger signal.

[0051] According to this aspect, in some embodiments, the UE is configured to transmit a TDCP report to a network node in a scheduled Physical Uplink Shared Channel (PUSCH) transmission. In some embodiments, the UE is configured to receive at least one tracking reference signal from the network node, which the UE will use for TDCP measurements relative to previously received signals in predefined time-frequency resources. In some embodiments, the UE is configured to receive an indication of at least one aperiodic tracking reference signal to be used by the UE for TDCP measurements. In some embodiments, the at least one aperiodic tracking reference signal to be used for TDCP measurements is indicated in message 2 of the 4-step random access procedure. In some embodiments, at least one aperiodic tracking reference signal is transmitted in a second time slot corresponding to the first time slot, in which the Physical Downlink Control Channel (PDCCH) for message 2 of the 4-step random access procedure is triggered in the first time slot. In some embodiments, at least one aperiodic tracking reference signal is transmitted in a second time slot following the first time slot, in which the Physical Downlink Control Channel (PDCCH) for message 2 of the 4-step random access procedure is received in the first time slot. In some embodiments, the UE is configured to receive at least one periodic reference signal from a network node, which will be used by the UE for TDCP measurements in predefined time-frequency resources. In some embodiments, the TDCP report is an aperiodic TDCP report. In some embodiments, the received auxiliary information includes sample-related correlation values ​​of the tracking reference signal (TRS).

[0052] According to another aspect, a method is provided implemented in a user equipment (UE) configured to communicate with a network node. The method includes receiving auxiliary information from the network node to assist the UE in acquiring the Time-Domain Channel Attribute (TDCP). The method includes receiving a trigger signal from the network node on message 2 of a four-step random access procedure. The method also includes performing a TDCP measurement based at least in part on the at least one associated delay value. The method further includes transmitting a TDCP report to the network node in response to the trigger signal on message 3 of the four-step random access procedure.

[0053] According to this aspect, in some embodiments, the method includes transmitting a TDCP report to a network node during a scheduled Physical Uplink Shared Channel (PUSCH) transmission. In some embodiments, the method includes receiving from the network node at least one tracking reference signal to be used by the UE for TDCP measurements relative to previously received signals in predefined time-frequency resources. In some embodiments, the method includes receiving an indication of at least one aperiodic tracking reference signal to be used by the UE for TDCP measurements. In some embodiments, the at least one aperiodic tracking reference signal to be used for TDCP measurements is indicated in message 2 of a 4-step random access procedure. In some embodiments, at least one aperiodic tracking reference signal is transmitted in a second time slot corresponding to a first time slot, in which the Physical Downlink Control Channel (PDCCH) for message 2 of the 4-step random access procedure is triggered in the first time slot. In some embodiments, at least one aperiodic tracking reference signal is transmitted in a second time slot following the first time slot, in which the Physical Downlink Control Channel (PDCCH) for message 2 of the 4-step random access procedure is received in the first time slot. In some embodiments, the method includes receiving from the network node at least one periodic reference signal to be used by the UE for TDCP measurements in predefined time-frequency resources. In some embodiments, the TDCP report is a non-periodic TDCP report. In some embodiments, the received auxiliary information includes sample-related correlation values ​​of the tracking reference signal TRS. Attached Figure Description

[0054] A more complete understanding of this embodiment and its accompanying advantages and features will be more readily understood when considered in conjunction with the accompanying drawings, by referring to the following detailed description, wherein: Figure 1 The time-frequency structure of the Synchronization Signal / Physical Broadcast (SS / PBCH) block is shown; Figure 2 This is an example of the allocation of resource elements (REs) for the 12-port channel state information reference signal in the New Radio (NR) interface; Figure 3 This is an example of periodic trace reference signaling (TRS); Figure 4 It is a graph of the relative average user input speed relative to the user equipment (UE) speed based on reciprocal channel state information (CSI) and feedback-based CSI for the antenna ports of 16 network nodes; Figure 5 It is a graph showing the relative average user input versus UE speed for the antenna ports of 32 network nodes, based on reciprocal channel state information (CSI) and feedback-based CSI. Figure 6This is a graph showing the relative average user input versus UE speed for Type II CSI antenna ports of 16 network nodes; Figure 7 This is a graph showing the relative average user input versus UE speed for Type II CSI antenna ports of 32 network nodes; Figure 8 This demonstrates how the associated delay can be estimated using TRS signals based on burst measurements within the TRS signal; Figure 9 This illustrates a contention-based random access procedure; Figure 10 The timing offset of message 3 is shown; Figure 11 This is a schematic diagram illustrating an example network architecture of a communication system based on the principles disclosed herein; Figure 12 This is an example of configuring user equipment and network nodes for early time-domain channel attribute (TDCP) feedback via a 4-step random access channel (RACH) procedure; Figure 13 This is a flowchart of an example process for an early time-domain channel attribute (TDCP) feedback method in a network node via a 4-step random access channel (RACH) procedure.

[0055] Figure 14 This is a flowchart of an example process for the early time-domain channel attribute (TDCP) feedback method in a network node via the 4-step random access channel (RACH) procedure; Figure 15 This is a flowchart of an example process for obtaining early TDCP reports via a 4-step Random Access Channel (RACH) procedure; Figure 16 This is an example of triggering TDCP by scheduling downlink control information (DCI) in the random access response; and Figure 17 This is an example of using message 2 to trigger an aperiodic reference signal to be used for TDCP measurements. Detailed Implementation

[0056] Before describing the exemplary embodiments in detail, it should be noted that the embodiments primarily consist of combinations of apparatus components and processing steps related to the method of early time-domain channel attribute (TDCP) feedback via a 4-step random access channel (RACH) process. Therefore, in the accompanying drawings, components are indicated by conventional symbols where appropriate, and only those specific details relevant to understanding the embodiments are shown so as not to obscure this disclosure with details obvious to those skilled in the art who benefit from the description herein. Throughout the specification, the same reference numerals refer to the same elements.

[0057] As used herein, relational terms such as “first” and “second,” “top” and “bottom,” etc., may be used only to distinguish one entity or element from another, and do not necessarily require or imply any physical or logical relationship or order between these entities or elements. The terminology used herein is solely for describing particular embodiments and not for limiting the concepts described herein. As used herein, the singular forms “a” and “the” are intended to also include the plural forms, unless the context clearly indicates otherwise. It will also be understood that the terms “comprise” and / or “comprising” as used herein specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof.

[0058] In the embodiments described herein, connection terms such as "communicating with" can be used to indicate electrical or data communication, which can be achieved, for example, through physical contact, induction, electromagnetic radiation, radio signaling, infrared signaling, or optical signaling. Those skilled in the art will understand that multiple components can interoperate, and modifications and variations are possible to achieve electrical and data communication.

[0059] In some embodiments described herein, the terms “coupled,” “connected,” etc., may be used herein to indicate a connection, although not necessarily a direct connection, and may include wired and / or wireless connections.

[0060] As used herein, the term "network node" can refer to any type of network node included in a radio network, which may also include base stations (BS), radio base stations, base transceiver stations (BTS), base station controllers (BSC), radio network controllers (RNC), gNode B (gNB), evolved Node B (eNB or eNodeB), Node B, multi-standard radio (MSR) radio nodes (e.g., MSR BS), multi-cell / multicast coordination entities (MCE), integrated access and backhaul (IAB) nodes, relay nodes, donor nodes of control relays, radio access points (AP), transmission points, transmission nodes, remote radio units (RRU), remote radio heads (RRH), core network nodes (e.g., mobility management entities (MME), ad hoc network (SON) nodes, coordination nodes, location nodes, MDT nodes, etc.), external nodes (e.g., third-party nodes, nodes outside the current network), nodes in distributed antenna systems (DAS), spectrum access systems (SAS) nodes, element management systems (EMS), etc. Network nodes may also include test equipment. The term “radio node” used in this article can also be used to refer to a wireless device (WD) or a user equipment (UE).

[0061] In some embodiments, the non-limiting terms wireless device (WD) or user equipment (UE) are used interchangeably. The UE herein can be any type of wireless device, such as a wireless device (WD), capable of communicating with a network node or another UE via radio signals. A UE can also be a radio communication device, a target device, a device-to-device (D2D) UE, a machine-type UE or a UE capable of machine-to-machine communication (M2M), a low-cost and / or low-complexity UE, a sensor equipped with a UE, a tablet computer, a mobile terminal, a smartphone, a laptop embedded device (LEE), a laptop mounted device (LME), a USB dongle, a client device (CPE), an Internet of Things (IoT) device, or a narrowband IoT (NB-IoT) device, etc.

[0062] Furthermore, in some embodiments, the generic term "radio network node" is used. It can be any kind of radio network node, which may include any of the following: base station, radio base station, base transceiver station, base station controller, network controller, RNC, evolved Node B (eNB), Node B, gNB, multi-cell / multicast coordination entity (MCE), IAB node, relay node, access point, radio access point, remote radio unit (RRU), and remote radio headend (RRH).

[0063] Note that although terms from a particular wireless system, such as, for example, 3GPP LTE and / or New Radio (NR), may be used in this disclosure, this should not be construed as limiting the scope of this disclosure to the aforementioned systems. Other wireless systems, including but not limited to Wideband Code Division Multiple Access (WCDMA), Microwave Access Global Interoperability (WiMax), Ultra Mobile Broadband (UMB), and Global System for Mobile Communications (GSM), may also benefit from utilizing the ideas covered in this disclosure.

[0064] It should also be noted that the functions performed by wireless devices or network nodes as described herein can be distributed across multiple wireless devices and / or network nodes. In other words, the functions of the network nodes and wireless devices described herein are not expected to be limited to the performance of a single physical device, and in fact, can be distributed across several physical devices.

[0065] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will be further understood that the terms used herein should be interpreted as having the same meaning as they have in the context of this specification and the relevant field, and will not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0066] Some embodiments provide a method for early time-domain channel attribute (TDCP) feedback via a 4-step random access channel (RACH) process.

[0067] Now returning to the accompanying drawings, the same elements are indicated by the same reference numerals. Figure 11The diagram illustrates a communication system 10 according to an embodiment, such as a 3GPP-type cellular network that can support standards such as LTE and / or NR (5G), comprising an access network 12 (e.g., a radio access network) and a core network 14. The access network 12 includes multiple network nodes 16a, 16b, 16c (collectively referred to as network nodes 16), such as NBs, eNBs, gNBs, or other types of radio access points, each defining a corresponding coverage area 18a, 18b, 18c (collectively referred to as coverage area 18). Each network node 16a, 16b, 16c can be connected to the core network 14 via a wired or wireless connection 20. A first user equipment (UE) 22a located in coverage area 18a is configured to wirelessly connect to or be paged by the corresponding network node 16a. A second UE 22b in coverage area 18b can wirelessly connect to the corresponding network node 16b. Although multiple UEs 22a, 22b (collectively referred to as wireless devices 22) are shown in this example, the disclosed embodiments are equally applicable to situations where a single UE is in a coverage area or a single UE is connected to a corresponding network node 16. Note that although only two UEs 22 and three network nodes 16 are shown for convenience, the communication system may include more UEs 22 and network nodes 16.

[0068] Furthermore, it is anticipated that UE 22 can communicate simultaneously with more than one network node 16 and more than one type of network node 16, and / or be configured to communicate with them separately. For example, UE 22 may have dual connectivity with LTE-enabled network nodes 16 and the same or different NR-enabled network nodes 16. For example, UE 22 may communicate with an eNB for LTE / E-UTRAN and a gNB for NR / NG-RAN.

[0069] Network node 16 is configured to include RACH unit 32, which can be configured to configure the UE via a trigger signal in message 2 of the 4-step random access procedure, the trigger signal causing the UE to transmit a TDCP report. Radio device 22 is configured to include TDCP unit 34, which can be configured to perform TDCP measurements in response to the trigger signal, at least in part based on received auxiliary information.

[0070] According to the embodiments, reference will now be made to Figure 12 Describe the example implementation of UE 22 and network node 16 discussed in the preceding paragraphs.

[0071] The communication system 10 includes a network node 16 provided within the communication system 10, and includes hardware 28 enabling it to communicate with the UE 22. The hardware 28 may include a radio interface 30 for establishing and maintaining at least one wireless connection 32 with the UE 22 located within a coverage area 18 served by the network node 16. The radio interface 30 may be configured as or may include, for example, one or more RF transmitters, one or more RF receivers, and / or one or more RF transceivers. The radio interface 30 includes an antenna array 34 for radiating and receiving signals(s) carrying electromagnetic waves.

[0072] In the illustrated embodiment, the hardware 28 of network node 16 further includes processing circuitry 36. Processing circuitry 36 may include processor 38 and memory 40. Specifically, in addition to or in lieu of processors (e.g., central processing units) and memory, processing circuitry 36 may include integrated circuits for processing and / or control, such as one or more processors and / or processor cores and / or FPGAs (Field-Programmable Gate Arrays) and / or ASICs (Application-Specific Integrated Circuits), adapted to execute instructions. Processor 38 may be configured to access (e.g., write to and / or read from) memory 40, which may include any kind of volatile and / or non-volatile memory, such as cache and / or buffer memory and / or RAM (Random Access Memory) and / or ROM (Read-Only Memory) and / or optical memory and / or EPROM (Erasable Programmable Read-Only Memory).

[0073] Therefore, network node 16 also has software 42 internally stored, for example, in memory 40, or stored in external memory (e.g., a database, storage array, network storage device, etc.), which can be accessed by network node 16 via an external connection. Software 42 can be executed by processing circuitry 36. Processing circuitry 36 can be configured to control any methods and / or processes described herein, and / or cause such methods and / or processes to be executed, for example, by network node 16. Processor 38 corresponds to one or more processors 38 for performing the functions of network node 16 described herein. Memory 40 is configured to store data, programming software code, and / or other information described herein. In some embodiments, software 42 may include instructions that, when executed by processor 38 and / or processing circuitry 36, cause processor 38 and / or processing circuitry 36 to perform the processes described herein for network node 16. For example, processing circuitry 68 of network node 16 may include RACH unit 32, which can be configured to configure the UE via a trigger signal in message 2 of the 4-step random access procedure, causing the UE to transmit an aperiodic TDCP report.

[0074] The communication system 10 also includes the previously mentioned UE 22. UE 22 may have hardware 44, which may include a radio interface 46 configured to establish and maintain a wireless connection 32 with a network node 16 serving the coverage area 18 where UE 22 is currently located. The radio interface 46 may be configured as or may include, for example, one or more RF transmitters, one or more RF receivers, and / or one or more RF transceivers. The radio interface 46 includes an antenna array 48 for radiating and receiving signals(s) carrying electromagnetic waves.

[0075] The hardware 44 of UE 22 also includes processing circuitry 50. Processing circuitry 50 may include processor 52 and memory 54. Specifically, in addition to or in lieu of processors (e.g., central processing units) and memory, processing circuitry 50 may include integrated circuits for processing and / or control, such as one or more processors and / or processor cores and / or FPGAs (Field-Programmable Gate Arrays) and / or ASICs (Application-Specific Integrated Circuits), adapted to execute instructions. Processor 52 may be configured to access (e.g., write to and / or read from) memory 54, which may include any kind of volatile and / or non-volatile memory, such as cache and / or buffer memory and / or RAM (Random Access Memory) and / or ROM (Read-Only Memory) and / or optical memory and / or EPROM (Erasable Programmable Read-Only Memory).

[0076] Therefore, UE 22 may further include software 56, which is stored, for example, in memory 54 at UE 22, or in external memory (e.g., a database, storage array, network storage device, etc.) accessible by UE 22. Software 56 may be executed by processing circuitry 50. Software 56 may include a client application 58. Client application 58 may be operable to provide services to human or non-human users via UE 22.

[0077] Processing circuitry 50 may be configured to control any methods and / or processes described herein, and / or cause such methods and / or processes to be performed, for example, by UE 22. Processor 52 corresponds to one or more processors 52 for performing the functions of UE 22 described herein. UE 22 includes memory 54 configured to store data, programming software code, and / or other information described herein. In some embodiments, software 56 and / or client application 58 may include instructions that, when executed by processor 52 and / or processing circuitry 50, cause processor 52 and / or processing circuitry 50 to perform the processes described herein for UE 22. For example, processing circuitry 50 of UE 22 may include TDCP unit 34, which may be configured to perform TDCP measurements in response to a trigger signal, at least in part based on received auxiliary information.

[0078] In some embodiments, the internal operations of network node 16 and UE 22 can be as follows: Figure 12 As shown, and independently, the surrounding network topology can be Figure 11 The network topology.

[0079] The wireless connection 32 between UE 22 and network node 16 conforms to the teachings of the embodiments described throughout this disclosure. More precisely, some of the teachings in these embodiments can improve data rates, latency, and / or power consumption, thereby providing benefits such as reduced user wait times, relaxed file size limits, better responsiveness, and extended battery life. In some embodiments, a measurement process may be provided to monitor data rates, latency, and other factors that improve upon one or more embodiments.

[0080] although Figure 11 and Figure 12 Various "units," such as RACH unit 24 and TDCP unit 26, are shown as residing within their respective processors; however, it is conceivable that these units could be implemented such that a portion of the unit is stored in a corresponding memory within the processing circuitry. In other words, these units could be implemented in the processing circuitry in hardware or a combination of hardware and software.

[0081] Figure 13This is a flowchart of an example process of the Early Time-Domain Channel Attribute (TDCP) feedback method via the 4-Step Random Access Channel (RACH) procedure in network node 16. One or more blocks described herein can be executed by one or more elements of network node 16, such as processing circuitry 68 (including RACH unit 32), processor 70, radio interface 62, and / or communication interface 60. Network node 16 is configured, for example, via processing circuitry 68 and / or processor 70 and / or radio interface 62 and / or communication interface 60 to transmit information to the UE to assist the UE in obtaining the Time-Domain Channel Attribute (TDCP) (block S10). The process includes configuring UE 22 via a trigger signal in message 2 of the 4-Step Random Access Procedure (block S12). The process also includes receiving a TDCP report in message 3 of the 4-Step Random Access Procedure (block S14).

[0082] In some embodiments, the method includes receiving a TDCP report from UE 22 in message 3 of a 4-step random access procedure. In some embodiments, the method includes receiving a TDCP report from UE 22 during a scheduled Physical Uplink Shared Channel (PUSCH) transmission. In some embodiments, the method includes transmitting at least one tracking reference signal to UE 22, which will be used by UE 22 for TDCP measurements relative to previously received signals in predefined time-frequency resources. In some embodiments, the method includes indicating at least one aperiodic tracking reference signal to be used by UE 22 for TDCP measurements. In some embodiments, the at least one aperiodic tracking reference signal to be used for TDCP measurements is indicated in message 2 of the 4-step random access procedure. In some embodiments, the method includes receiving at least one aperiodic tracking reference signal in the same time slot of the Physical Downlink Control Channel (PDCCH) that triggers message 2 of the 4-step random access procedure. In some embodiments, the method includes receiving at least one aperiodic tracking reference signal in a time slot following the time slot of receiving message 2 of the 4-step random access procedure. In some embodiments, the TDCP report is an aperiodic TDCP report. In some embodiments, the transmitted information includes sample-related correlation values ​​of the tracking reference signal TRS. In some embodiments, the method includes transmitting at least one periodic reference signal to the UE in predefined time-frequency resources, the reference signal being used by the UE for TDCP measurements.

[0083] Figure 14This is a flowchart of an example process in a wireless device 22 according to some embodiments of the present disclosure. One or more blocks described herein can be performed by one or more elements of the wireless device 22, such as one or more of processing circuitry 84 (including TDCP unit 34), processor 86, radio interface 82, and / or communication interface 60. The wireless device 22 is configured, for example, via processing circuitry 84 and / or processor 86 and / or radio interface 82, to receive auxiliary information from network node 16 to assist UE 22 in acquiring the Time Domain Channel Attribute (TDCP) (block S16). The process also includes receiving a trigger signal from network node 16 on message 2 of the 4-step random access procedure (block S18). The process also includes performing TDCP measurements at least in part based on the received auxiliary information (block S20). The process also includes transmitting a TDCP report to the network node in message 3 of the 4-step random access procedure in response to the trigger signal (block S22).

[0084] In some embodiments, the method includes transmitting a TDCP report to network node 16 in message 3 of the 4-step random access procedure. In some embodiments, the method includes transmitting a TDCP report to network node 16 in a scheduled Physical Uplink Shared Channel (PUSCH) transmission. In some embodiments, the method includes receiving at least one tracking reference signal from the network node, which will be used by UE 22 for TDCP measurement relative to a previously received signal in a predefined time-frequency resource. In some embodiments, the method includes receiving an indication of at least one aperiodic tracking reference signal to be used by UE 22 for TDCP measurement. In some embodiments, at least one aperiodic tracking reference signal to be used for TDCP measurement is indicated in message 2 of the 4-step random access procedure. In some embodiments, at least one aperiodic tracking reference signal is transmitted in a second time slot corresponding to a first time slot, in which the Physical Downlink Control Channel (PDCCH) for message 2 of the 4-step random access procedure is triggered in the first time slot. In some embodiments, at least one aperiodic tracking reference signal is transmitted in a second time slot following the first time slot, in which the Physical Downlink Control Channel (PDCCH) for message 2 of the 4-step random access procedure is received in the first time slot. In some embodiments, the method includes receiving at least one periodic reference signal from a network node, the periodic reference signal to be used by the UE for TDCP measurements in predefined time-frequency resources. In some embodiments, the TDCP report is an aperiodic TDCP report. In some embodiments, the received auxiliary information includes sample-related correlation values ​​of the tracking reference signal (TRS).

[0085] The general process flow of the arrangements of this disclosure has been described, and examples of hardware and software arrangements for implementing the processes and functions of this disclosure have been provided. The following sections provide details and examples of the arrangements for a method of early time-domain channel attribute (TDCP) feedback via a 4-step random access channel (RACH) process.

[0086] Some embodiments can be summarized as follows: Figure 15 As shown. This document discloses further details of each step in the flowchart. Note that in some embodiments, Figure 15 The order of the second and third steps in the process can be reversed; that is, UE 22 can measure TDCP based on periodic downlink (DL) RS before being triggered for TDCP reporting.

[0087] Some embodiments obtain early TDCP based on the principles disclosed herein. Although embodiments may be written in NR terminology, they are non-limiting and equally applicable to future wireless standards such as 6G and higher.

[0088] During initial access, UE 22 searches for and locates a cell via the associated SSB, obtaining the cell's Physical Cell Identifier (PCI) and some cell information from the associated Master Information Block (MIB). Second, UE 22 receives SIB1 and obtains Residual System Information (RMSI) containing information about how to access the cell.

[0089] Step 1: In some embodiments, UE 22 receives information related to one or more reference signal (RS) resources to be used for acquiring early TDCP. In some embodiments, the information received by UE 22 may be received via a System Information Block (SIB): In some embodiments, the information received by UE 22 may be time and frequency resource allocations of one or more RS resources, correlation delays between samples of two RS resources or one RS resource to be used for TDCP measurement, and / or scrambling sequences, etc. In some embodiments, the information received by UE 22 may enable UE 22 to perform early time-domain channel attribute (TDCP) measurement and reporting for a single correlation delay (i.e., only a single correlation delay value is indicated in the information received by UE 22). In some embodiments, the information received by UE 22 may enable UE 22 to perform early TDCP measurement and reporting for more than one correlation delay (i.e., more than one correlation delay value is indicated in the information received by UE 22). In some embodiments, the information received by UE 22 may enable UE 22 to perform early TDCP measurement and then report information indicating whether UE 22 is experiencing rapid channel changes. In this embodiment, the RS type may be any one of SSB, DM-RS associated with SSB, DMRS associated with PDCCH, DM-RS associated with PDSCH, CSI-RS, or TRS. In some embodiments, these RSs are available to UE 22 before UE 22 enters RRC connection mode. In some embodiments, if UE 22 is in an idle state, these RSs are configured for TDCP measurements; and / or In some embodiments, this information can be configured to use the existing CSI framework in the NR, and thus, UE 22 can receive (one or more) default CSI reporting settings and (one or more) associated CSI resource settings from network node 16 via SIB (e.g., SIB1) for the purpose of obtaining early TDCP. The RS type of the RS resource can be indicated as part of (one or more) associated CSI resource settings and can be one of SSB, DM-RS, CSI-RS, or TRS.

[0090] Note that in some embodiments of the first alternative described above, the RS used to measure TDCP can be configured as a separate RS, i.e., outside the normal CSI framework defined in the NR. The CSI-RS sequence can be initialized, for example, as a function of the PCI value. In the second alternative, the existing CSI framework is reused, thus gaining greater flexibility at the cost of greater SIB overhead.

[0091] Step 2: In some embodiments, UE 22 receives a trigger for TDCP measurement and reporting via message 2 (e.g., normalized correlation magnitude and / or phase for one or more indicated correlation delays, or information indicating whether UE 22 is experiencing rapid channel changes): In some embodiments, the trigger from network node 16 uses message 2 of the four-step random access procedure to indicate to UE 22 one or more aperiodic RSs to be used for TDCP measurements. In this case, the trigger can be triggered by the CSI request field in message 2 or by the RAR in the physical downlink shared channel (PDSCH) of Msg2. The one or more aperiodic RSs can be CSI-RS, TRS, or DM-RS associated with the physical downlink control channel (PDCCH) and / or PDSCH. The one or more aperiodic RSs can be received in the same time slot of the PDCCH that triggers message 2, or in a time slot after the time slot of the PDCCH that receives message 2; In some embodiments, the RS(s) ... In some embodiments, when an SSB is used for TDCP measurement, the UE 22 selects an SSB from among multiple SSBs, each SSB having an SSB index. The selected SSB can be one of multiple SSBs with the strongest received signal power, or an SSB for which the UE 22 derives its corresponding Physical Random Access Channel (PRACH). TDCP can be measured within an SS / PBCH block (i.e., correlation between different symbols within an SS / PBCH block), between SSB blocks (i.e., correlation between different SS / PBCH blocks with the same SSB index at different time locations), or within an SS / PBCH block and between SS / PBCH blocks with the same SSB index.

[0092] Step 3: In some embodiments, UE 22 performs TDCP measurements on one or more RSs received by UE 22 in step 1. After completing the TDCP measurements on one or more RSs, UE 22 calculates an aperiodic TDCP report based on the information received by UE 22 in step 1 or the default CSI report settings received by UE 22 in step 1.

[0093] Step 4: In some embodiments, UE 22 sends an aperiodic TDCP report as part of message 3, or alternatively as a separate PUSCH transmission scheduled by PDCCH.

[0094] Note that although autocorrelation-based TDCP reporting is specifically mentioned in this disclosure, UE 22 may also be configured to report other types of information indicating channel changes experienced by UE 22 (e.g., other TDCP quantities, or implicit identifiers such as UE 22’s movement speed, or explicit identifiers such as the number of bits used to indicate the severity of channel changes (e.g., according to a predefined table)).

[0095] Example 1: Detailed signaling of (one or more) RS and TDCP In some embodiments, aperiodic TDCP reporting is triggered via message 2. In NR, message 2 (also known as a random access response or RAR message) is scheduled by a DCI with format 1_0, whose CRC is scrambled by the Random Access Radio Network Temporary Identifier (RA-RNTI). Note that the DCI scrambled by RA-RNTI and format 1_0 has 16 reserved bits. Figure 16 An example is shown where UE 22 measures TDCP based on a periodic DL RS such as SSB, and reports TDCP after receiving a request or trigger carried in a DCI that schedules a RACH response message carried in a PDSCH. In some embodiments, aperiodic TDCP reporting can be triggered, and message 2 can also optionally trigger one or more aperiodic RSs to be used for TDCP measurement.

[0096] In some embodiments, TDCP may be triggered by a DCI that is different from the DCI that schedules PDSCH for RACH response messages, such as an uplink DCI (i.e., DCI format 0_0).

[0097] In some embodiments, information regarding default CSI reporting settings and (one or more) RS resources (e.g., (one or more) CSI resource settings) is indicated from network node 16 to UE 22 via an SIB (e.g., SIB1). The information included in the default CSI reporting settings may include one or more of the following: One or more RS resources used for TDCP measurements; The number of associated delay values ​​(one or more) of the TDCP quantity should be assessed / estimated; One or more correlated delay values, each of which corresponds to a TDCP measurement (i.e., corresponding to the first correlated delay value). The first TDCP measurement corresponds to the second relevant delay value. The second TDCP measurement, etc.); Information indicating whether UE 22 is allowed to report TDCP amounts of a subset of configured RS resources; and / or The amount of TDCP to be assessed and reported (e.g., whether to report only the normalized correlation magnitude, only the normalized correlation phase, or both the normalized correlation magnitude and phase) etc.

[0098] Similarly, information about one or more RSs to be used for TDCP measurements may include one or more of the following: The time and frequency location of one or more RS resources (e.g., time slot, symbol, resource element, time slot / symbol offset between the two RS resources to be measured, subcarrier spacing, frequency offset to point A, etc.); The correlation delay between two RS resources or different samples of one RS resource used for TDCP measurements; Scrambling sequences; and / or (Optional) Power ratio between RSs or between RS and data, etc.

[0099] In some embodiments, a set of default CSI reporting settings for TDCP reporting and one or more corresponding CSI resource settings for TDCP measurement can be predefined in the 3GPP specification.

[0100] In some embodiments, the “CSI Request” field in DCI format 1_0 scrambled with RA-RNTI is used to trigger a non-periodic TDCP report.

[0101] In some embodiments, the “CSI Request” bit in the RAR uplink license is used to jointly trigger the default CSI reporting settings for TDCP reporting and one or more CSI resource settings for TDCP measurement indicated from network node 16 to UE 22 via SIB (e.g., SIB1).

[0102] In some embodiments, the “CSI Request” bit in the RAR uplink license is used to trigger the default CSI report setting for the TDCP report indicated from network node 16 to UE 22 via SIB (e.g., SIB1).

[0103] In some embodiments, when carrying a non-periodic CSI report on message 3, where the PUSCH can carry earlier data and where PUSCH resource allocation may be limited, it may be beneficial to restrict the TDCP report to a wideband report. That is, the normalized correlation amplitude and correlation phase can be wideband measurements spanning the bandwidth of one or more RS(s) used for TDCP measurements.

[0104] In some embodiments, when resources are limited for message 3, UE 22 reports only the TDCP of one of the multiple related delay values ​​configured in the default CSI reporting settings. Furthermore, UE 22 may select the related delay to report TDCP based on the estimated normalized correlation magnitude at each delay. In a specific example, UE 22 selects the related delay whose normalized correlation magnitude is furthest from 1.

[0105] In some embodiments, the TDCP report can be multiplexed with Message 3 data in the physical layer, where a power offset between the TDCP and Message 3 data can be applied. The power offset can be pre-specified or signaled in the SIB (e.g., SIB1). In another embodiment, the TDCP report can be included in the MAC CE as part of the MAC PDU carrying Message 3.

[0106] In some embodiments, a TDCP report can be triggered after message 3; that is, a TDCP response can be requested using UL authorization (e.g., DCI·O-O). The TDCP request can be implicitly indicated by using one or more existing fields in the DCI. For example, when A TDCP request can be indicated when the "New Data Indicator" is set to 0 and / or the "Redundant Version" is set to 0. The default modulation and coding scheme (MCS) can be used for the corresponding PUSCH.

[0107] The default reference signal can be used for CSI measurements, such as CSI-RS, TRS, SSB, or DMRS.

[0108] Therefore, in some embodiments, the “CSI Request” field can be used to trigger a TDCP report. A dedicated field for TDCP requests (e.g., the “TDCP Request” field) can be used instead of the “CSI Request” field.

[0109] In some embodiments, when TDCP is triggered and / or requested, UE 22 may indicate whether to report TDCP to the network or not. In some scenarios, UE 22 may not be able to perform TDCP measurement and reporting, or given the amount of time from the DCI triggering TDCP to the scheduled PUSCH transmission, UE 22 may not have enough time to complete TDCP measurement and reporting.

[0110] Example 2: (one or more) early-triggered non-periodic triggering of RS.

[0111] In some embodiments, in addition to triggering aperiodic TDCP reports, the DCI used for scheduling message 2 may optionally trigger one or more aperiodic RSs to be used for TDCP measurements. Figure 17 An example is shown where triggering occurs due to a delay. The aperiodic RS is transmitted at two separate time locations, and TDCP is reported in message 3. The configuration of the aperiodic RS can be notified by signaling in the SIB.

[0112] In some embodiments, one or more aperiodic RS and TDCP measurement requests can be triggered by DCI-scheduled MSG2, and a separate uplink DCI (e.g., DCI format 0_0) can be later used to trigger a TDCP report in another PUSCH scheduled by DCI. Some embodiments provide additional time to UE22 when UE22 needs to measure TDCP and the existing MSG3 timing is maintained.

[0113] Some embodiments may include one or more of the following: Example A1. A network node is configured to communicate with a user equipment (UE), the network node being configured to: and / or include a radio interface and / or include processing circuitry, the processing circuitry being configured to: Information is transmitted to the UE to assist the UE in acquiring the Time Domain Channel Attribute (TDCP), the information including at least one relevant delay value; and The UE is configured by a trigger signal in message 2 of the 4-step random access procedure, which causes the UE to transmit a TDCP report.

[0114] Example A2. A network node according to Example A1, wherein the network node, radio interface and / or processing circuitry are configured to receive a TDCP report from the UE in message 3 of the 4-step random access procedure.

[0115] Example A3. A network node according to any of Examples A1 and A2, wherein the network node, radio interface and / or processing circuitry are configured to receive TDCP reports from the UE in a scheduled Physical Uplink Shared Channel (PUSCH) transmission.

[0116] Example A4. A network node according to any of the embodiments A1-A3, wherein the network node, radio interface and / or processing circuitry are configured to transmit at least one reference signal to the UE, the at least one reference signal being used by the UE for TDCP measurement relative to a previously received signal in predefined time-frequency resources.

[0117] Example A5. A network node according to any of Examples A1-A3, wherein the network node, radio interface and / or processing circuitry are configured to indicate at least one aperiodic reference signal for TDCP measurement of the UE.

[0118] Example A6. A network node according to Example A5, wherein the at least one aperiodic reference signal to be used for TDCP measurement is indicated in message 2 of the 4-step random access procedure.

[0119] Example A7. A network node according to any of Examples A5 and A6, wherein the at least one aperiodic reference signal is received in the same time slot of the Physical Downlink Control Channel (PDCCH) of message 2 that triggers the four-step random access procedure.

[0120] Example A8. A network node according to any of Examples A5 and A6, wherein the at least one aperiodic reference signal is received in a time slot following the time slot of the Physical Downlink Control Channel (PDCCH) of message 2 of the four-step random access procedure.

[0121] Example A9. A network node according to any of Examples A1-A8, wherein the TDCP report is an aperiodic TDCP report.

[0122] Example B1. A method implemented in a network node configured to communicate with a wireless device (UE), the method comprising: Information is transmitted to the UE to assist the UE in acquiring the Time Domain Channel Attribute (TDCP), the information including at least one relevant delay value; and The UE is configured by a trigger signal in message 2 of the 4-step random access procedure, which causes the UE to transmit a TDCP report.

[0123] Example B2. According to the method of Example B1, the method further includes receiving a TDCP report from the UE in message 3 of the 4-step random access procedure.

[0124] Example B3. The method according to any one of Examples B1 and B2, the method further comprising receiving a TDCP report from the UE in a scheduled Physical Uplink Shared Channel (PUSCH) transmission.

[0125] Example B4. The method according to any one of Examples B1-B3, the method further comprising transmitting at least one reference signal to the UE, the reference signal being used by the UE for TDCP measurement relative to a previously received signal in predefined time-frequency resources.

[0126] Example B5. The method according to any one of Examples B1-B3, the method further comprising indicating at least one aperiodic reference signal for TDCP measurement of the UE.

[0127] Example B6. The method according to Example B5, wherein the at least one aperiodic reference signal to be used for TDCP measurement is indicated in message 2 of the 4-step random access procedure.

[0128] Example B7. The method according to any of Examples B5 and B6, the method further comprising receiving the at least one aperiodic reference signal in the same time slot of the Physical Downlink Control Channel (PDCCH) of message 2 that triggers the four-step random access procedure.

[0129] Example B8. The method according to any of Examples B5 and B6, the method further comprising receiving the at least one aperiodic reference signal in a time slot following the time slot of receiving message 2 of the four-step random access procedure's physical downlink control channel (PDCCH).

[0130] Example B9. The method according to any one of Examples B1-B8, wherein the TDCP report is a non-periodic TDCP report.

[0131] Example C1. A user equipment (UE) configured to communicate with a network node, the UE being configured to: and / or include a radio interface and / or processing circuitry, the radio interface and / or processing circuitry being configured to: The network node receives auxiliary information to assist the UE in obtaining the Time Domain Channel Attribute (TDCP), the auxiliary information including at least one relevant delay value; On message 2 of the 4-step random access procedure, a trigger signal is received from the network node, which causes the UE to transmit a TDCP report; and In response to the trigger signal, a TDCP measurement is performed at least in part based on the at least one associated delay value.

[0132] Example C2. The UE according to Example C1, wherein the UE, radio interface and / or processing circuitry are configured to transmit a TDCP report to the network node in message 3 of the 4-step random access procedure.

[0133] Example C3. A UE according to any of Examples C1 and C2, wherein the UE, radio interface and / or processing circuitry are configured to transmit a TDCP report to the network node in a scheduled Physical Uplink Shared Channel (PUSCH) transmission.

[0134] Example C4. A UE according to any of Examples C1-C3, wherein the UE, radio interface and / or processing circuitry are configured to receive at least one reference signal from the network node, the reference signal being used by the UE for TDCP measurement relative to a previously received signal in predefined time-frequency resources.

[0135] Example C5. A UE according to any one of Examples C1-C3, wherein the UE, radio interface and / or processing circuitry are configured to receive an indication of at least one aperiodic reference signal to be used by the UE for TDCP measurements.

[0136] Example C6. The UE according to Example C5, wherein the at least one aperiodic reference signal to be used for TDCP measurement is indicated in message 2 of the 4-step random access procedure.

[0137] Example C7. A UE according to any of Examples C5 and C6, wherein the at least one aperiodic reference signal is transmitted in a second time slot corresponding to the first time slot, and in the first time slot, the physical downlink control channel (PDCCH) of message 2 for the four-step random access procedure is triggered.

[0138] Example C8. A UE according to any of Examples C5 and C6, wherein the at least one aperiodic reference signal is transmitted in a second time slot following the first time slot, and in the first time slot, the physical downlink control channel (PDCCH) for message 2 of the four-step random access procedure is received.

[0139] Example C9. The UE according to any one of Examples C1-C8, wherein the TDCP report is a non-periodic TDCP report.

[0140] Example D1. A method implemented in a wireless device (UE) configured to communicate with a network node, the method comprising: The network node receives auxiliary information to assist the UE in obtaining the Time Domain Channel Attribute (TDCP), the auxiliary information including at least one relevant delay value; On message 2 of the 4-step random access procedure, a trigger signal is received from the network node, which causes the UE to transmit a TDCP report; and In response to the trigger signal, a TDCP measurement is performed at least in part based on the at least one associated delay value.

[0141] Example D2. According to the method of Example D1, the method further includes transmitting a TDCP report to the network node in message 3 of the four-step random access procedure.

[0142] Example D3. The method according to any one of Examples D1 and D2, the method further comprising transmitting a TDCP report to the network node in a scheduled Physical Uplink Shared Channel (PUSCH) transmission.

[0143] Example D4. The method according to any one of Examples D1-D3, the method further comprising receiving at least one reference signal from the network node, the reference signal being used by the UE in a predefined time-frequency resource for TDCP measurement relative to a previously received signal.

[0144] Example D5. The method according to any one of Examples D1-D3, the method further comprising receiving an indication of at least one aperiodic reference signal to be used by the UE for TDCP measurement.

[0145] Example D6. The method according to Example D5, wherein the at least one aperiodic reference signal to be used for TDCP measurement is indicated in message 2 of the 4-step random access procedure.

[0146] Example D7. The method according to any of Examples D5 and D6, wherein the at least one aperiodic reference signal is transmitted in a second time slot corresponding to the first time slot, in which the physical downlink control channel (PDCCH) of message 2 for the four-step random access procedure is triggered in the first time slot.

[0147] Example D8. The method according to any of Examples D5 and D6, wherein the at least one aperiodic reference signal is transmitted in a second time slot following the first time slot, and in the first time slot, the physical downlink control channel (PDCCH) for message 2 of the four-step random access procedure is received.

[0148] Example D9. The method according to any one of Examples D1-D8, wherein the TDCP report is a non-periodic TDCP report.

[0149] As those skilled in the art will understand, the concepts described herein can be embodied as methods, data processing systems, computer program products, and / or computer storage media storing executable computer programs. Therefore, the concepts described herein can take the form of entirely hardware embodiments, entirely software embodiments, or embodiments combining software and hardware aspects, all collectively referred to herein as “circuit” or “module.” Any process, step, action, and / or function described herein can be performed by and / or associated with a corresponding module, which can be implemented using software and / or firmware and / or hardware. Furthermore, this disclosure can take the form of a computer program product on a tangible computer-readable storage medium having computer-executable computer program code contained within the medium. Any suitable tangible computer-readable medium can be utilized, including hard disks, CD-ROMs, electronic storage devices, optical storage devices, or magnetic storage devices.

[0150] This document describes several embodiments with reference to flowchart illustrations and / or block diagrams of methods, systems, and computer program products. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer (thus creating a special-purpose computer), a special-purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create components for implementing the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams.

[0151] These computer program instructions may also be stored in a computer-readable storage medium or storage medium that can instruct a computer or other programmable data processing apparatus to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of art including instruction components that implement the functions / actions specified in one or more blocks of a flowchart and / or block diagram.

[0152] Computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus, thereby producing a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide steps for implementing the functions / actions specified in one or more boxes of a flowchart and / or block diagram.

[0153] It should be understood that the functions / actions marked in the boxes may not occur in the order indicated in the operating instructions. For example, two boxes shown consecutively may actually be executed substantially simultaneously, or these boxes may sometimes be executed in reverse order, depending on the functions / actions involved. Although some diagrams include arrows on the communication path to indicate the main direction of communication, it should be understood that communication may occur in the direction opposite to the direction depicted by the arrows.

[0154] Computer program code used to perform the operations of the concepts described herein can be written in an object-oriented programming language, such as Python, Java®, or C++. However, computer program code used to perform the operations of this disclosure can also be written in a conventional procedural programming language, such as the "C" programming language. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer. In the latter case, the remote computer can be connected to the user's computer via a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computer (e.g., via the Internet through an Internet service provider).

[0155] In conjunction with the foregoing description and accompanying drawings, numerous different embodiments have been disclosed herein. It will be understood that it would be excessive and obscure to describe and illustrate each combination and sub-combination of these embodiments literally. Therefore, all embodiments can be combined in any manner and / or combination, and this specification, including the accompanying drawings, should be construed as constituting a complete written description of all combinations and sub-combinations of the embodiments described herein, as well as the ways and processes of making and using them, and should support the claims for any such combinations or sub-combinations.

[0156] Those skilled in the art will understand that the embodiments described herein are not limited to those specifically shown and described above. Furthermore, unless otherwise stated above, it should be noted that all figures are not drawn to scale. Based on the foregoing teachings, various modifications and variations are possible without departing from the scope of the appended claims.

Claims

1. A method implemented in a user equipment (UE) (22) configured to communicate with a network node (16), the method comprising: Receive (S16) auxiliary information from the network node (16) to assist the UE (22) in obtaining the time-domain channel attribute TDCP; In message 2 of the 4-step random access procedure, a trigger signal is received from the network node (16) (S17); TDCP measurement is performed (S20) based at least in part on the received auxiliary information; as well as In response to the trigger signal (S22), a TDCP report is transmitted to the network node (16) in message 3 of the 4-step random access procedure.

2. The method according to claim 1 further includes transmitting a TDCP report to the network node (16) during a scheduled Physical Uplink Shared Channel (PUSCH) transmission.

3. The method according to any one of claims 1 and 2, further comprising receiving at least one tracking reference signal (TRS) from the network node (16), the tracking reference signal being used by the UE (22) in a predefined time-frequency resource for TDCP measurement relative to a previously received signal.

4. The method according to any one of claims 1-3, further comprising receiving an indication of at least one aperiodic tracking reference signal TRS to be used by the UE (22) for TDCP measurement.

5. The method according to claim 4, wherein, The at least one aperiodic TRS to be used for TDCP measurement is indicated in message 2 of the 4-step random access procedure.

6. The method according to any one of claims 4 and 5, wherein, The at least one aperiodic TRS is transmitted in the second time slot corresponding to the first time slot, and in the first time slot, the physical downlink control channel (PDCCH) for message 2 of the four-step random access procedure is triggered.

7. The method according to any one of claims 4 and 5, wherein, The at least one aperiodic TRS is transmitted in a second time slot following the first time slot, and in the first time slot, the Physical Downlink Control Channel (PDCCH) for message 2 of the 4-step random access procedure is received.

8. The method according to any one of claims 1 and 2, further comprising receiving at least one periodic reference signal from the network node (16), the at least one periodic reference signal being used by the UE (22) for TDCP measurement in a predefined time-frequency resource.

9. The method according to any one of claims 1-8, wherein, The TDCP report mentioned is a non-periodic TDCP report.

10. The method according to any one of claims 1-9, wherein, The received auxiliary information includes the sample correlation values ​​of the tracking reference signal TRS.

11. A user equipment (UE) (22) configured to communicate with a network node (16), the UE (22) being configured to: Receive auxiliary information from the network node (16) to assist the UE (22) in obtaining the time-domain channel attribute TDCP; A trigger signal is received from the network node (16) on message 2 of the 4-step random access procedure; TDCP measurements are performed at least in part based on the received auxiliary information; and In response to the trigger signal, a TDCP report is transmitted to the network node (16) in message 3 of the 4-step random access procedure.

12. The UE (22) according to claim 11, wherein, The UE (22) is configured to transmit a TDCP report to the network node (16) in a scheduled Physical Uplink Shared Channel (PUSCH) transmission.

13. The UE (22) according to any one of claims 11 and 12, wherein, The UE (22) is configured to receive at least one tracking reference signal (TRS) from the network node (16), the tracking reference signal being used by the UE (22) in a predefined time-frequency resource for TDCP measurement relative to a previously received signal.

14. The UE (22) according to any one of claims 11-13, wherein, The UE (22) is configured to receive an indication of at least one aperiodic TRS to be measured by the UE (22) for TDCP.

15. The UE (22) according to claim 14, wherein, The at least one aperiodic TRS to be used for TDCP measurement is indicated in message 2 of the 4-step random access procedure.

16. The UE (22) according to any one of claims 14 and 15, wherein, The at least one aperiodic TRS is transmitted in a second time slot corresponding to the first time slot, in which the physical downlink control channel (PDCCH) for message 2 of the four-step random access procedure is triggered.

17. The UE (22) according to any one of claims 14 and 15, wherein, The at least one aperiodic TRS is transmitted in a second time slot following the first time slot, and in the first time slot, the Physical Downlink Control Channel (PDCCH) for message 2 of the 4-step random access procedure is received.

18. The UE (22) according to any one of claims 11 and 12, further comprising receiving at least one periodic reference signal from the network node (16), the at least one periodic reference signal being used by the UE (22) for TDCP measurement in a predefined time-frequency resource.

19. The UE (22) according to any one of claims 11-18, wherein, The TDCP report mentioned is a non-periodic TDCP report.

20. The UE (22) according to any one of claims 11-19, wherein, The received auxiliary information includes the sample correlation values ​​of the tracking reference signal TRS.

21. A method implemented in a network node (16) configured to communicate with a user equipment (UE) (22), the method comprising: Transmit (S10) information to the UE (22) to assist the UE (22) in obtaining the time-domain channel attribute TDCP; The UE (22) is configured (S12) by a trigger signal in message 2 of the 4-step random access procedure, the trigger signal causing the UE (22) to transmit a TDCP report; as well as Receive (S14) TDCP report in message 3 of the 4-step random access procedure.

22. The method of claim 21, further comprising receiving a TDCP report from the UE (22) during a scheduled Physical Uplink Shared Channel (PUSCH) transmission.

23. The method according to any one of claims 21 and 22, further comprising transmitting at least one tracking reference signal TRS to the UE (22), the tracking reference signal being used by the UE (22) for TDCP measurement relative to a previously received signal in a predefined time-frequency resource.

24. The method according to any one of claims 21-23, further comprising indicating at least one non-periodic tracking reference signal TRS for TDCP measurement of the UE (22).

25. The method according to claim 24, wherein, The at least one aperiodic TRS to be used for TDCP measurement is indicated in message 2 of the 4-step random access procedure.

26. The method according to any one of claims 24 and 25, further comprising receiving the at least one aperiodic TRS in the same time slot of the physical downlink control channel (PDCCH) of message 2 that triggers the four-step random access procedure.

27. The method according to any one of claims 24 and 25, further comprising receiving the at least one aperiodic TRS in a time slot following the time slot of receiving message 2 of the four-step random access procedure via the Physical Downlink Control Channel (PDCCH).

28. The method according to any one of claims 21-27, wherein, The TDCP report mentioned is a non-periodic TDCP report.

29. The method according to any one of claims 21-28, wherein, The transmitted information includes the correlation values ​​of the sample-related tracking reference signal TRS.

30. The method according to any one of claims 21-29, further comprising transmitting at least one periodic reference signal to the UE (22), the at least one periodic reference signal being used by the UE (22) for TDCP measurement in a predefined time-frequency resource.

31. A network node (16) configured to communicate with a user equipment (UE) (22), said network node (16) being configured to: Transmit information to the UE (22) to assist the UE (22) in acquiring the time-domain channel attribute TDCP; The UE (22) is configured by a trigger signal in message 2 of the 4-step random access procedure, the trigger signal causing the UE (22) to transmit a TDCP report; and The TDCP report is received in message 3 of the four-step random access procedure.

32. The network node (16) according to claim 31, wherein, The network node (16) is configured to receive a TDCP report from the UE (22) in a scheduled Physical Uplink Shared Channel (PUSCH) transmission.

33. The network node (16) according to any one of claims 31 and 32, wherein, The network node (16) is configured to transmit at least one tracking reference signal (TRS) to the UE (22), the tracking reference signal being used by the UE (22) for TDCP measurement relative to a previously received signal in a predefined time-frequency resource.

34. The network node (16) according to any one of claims 31-33, wherein, The network node (16) is configured to indicate at least one non-periodic tracking reference signal (TRS) for TDCP measurement of the UE (22).

35. The network node (16) according to claim 34, wherein, The at least one aperiodic TRS to be used for TDCP measurement is indicated in message 2 of the 4-step random access procedure.

36. The network node (16) according to any one of claims 34 and 35, wherein, The at least one aperiodic TRS is received in the same time slot of the Physical Downlink Control Channel (PDCCH) of message 2 that triggers the four-step random access procedure.

37. The network node (16) according to any one of claims 34 and 35, wherein, The at least one aperiodic TRS is received in a time slot following the time slot of the Physical Downlink Control Channel (PDCCH) of message 2 of the four-step random access procedure.

38. The network node (16) according to any one of claims 31-37, wherein, The TDCP report mentioned is a non-periodic TDCP report.

39. The network node (16) according to any one of claims 31-38, wherein, The transmitted information includes the correlation values ​​of the sample-related tracking reference signal TRS.

40. The network node according to any one of claims 31-39, wherein, The network node is configured to transmit at least one periodic reference signal to the UE (22), which will be used by the UE (22) for TDCP measurement in a predefined time-frequency resource.

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