Subband operation in unlicensed spectrum of new radio

Abstract

The invention relates to sub-band operation in an unlicensed spectrum of a new radio. A subband (SB) indication and a listen before talk (LBT) result may be used to adjust communications between a device, such as a wireless terminal, and a base station. For example, a wireless terminal may receive an SB indication including an SB configuration of a base station and / or an LBT result, as well as other information such as a remapped CORESET. Similarly, the terminal may determine that a physical resource block (PRB) is invalid based at least in part on whether the PRB overlaps with the guard band. The terminal may be arranged to adjust its search and transmission based on the received SB indication, and provide LBT results of the terminal to the base station.

Description

[0001] This application is a divisional application of the invention patent application with application number 201980063367.9, filed on July 17, 2019, and invention name “Sub-band operation in unlicensed spectrum for new radio”. Technical Field

[0002] The present disclosure relates to communication technology and, more particularly, to sub-band operation in unlicensed spectrum for new radio. Background Art

[0003] Unlicensed spectrum in NR

[0004] In mmWave, there is a wide range of unlicensed spectrum that can be further exploited to achieve higher data rates than those achieved by operating in the sub-6 GHz bands. In previous study items (SI) and current work items (WI) on NR unlicensed, the process of enhancing the coexistence between NR-U and other technologies (e.g., WiFi devices, LTE-based LAA devices, other NR-U devices, etc.) operating in unlicensed and meeting regulatory requirements will be extensively studied and specified without NR-U devices experiencing much degradation in throughput and latency.

[0005] NR bandwidth adaptation

[0006] With Bandwidth Adaptation (BA), the UE's receive and transmit bandwidth does not have to be as large as the cell's bandwidth, and can be adjusted: the width can be commanded to change (e.g., shrink during times of low activity to save power); the location can be moved in the frequency domain (e.g., to increase scheduling flexibility); and the subcarrier spacing can be commanded to change (e.g., to allow different services). A subset of the total cell bandwidth of a cell is called a bandwidth part (BWP), and BA is implemented by configuring a UE with (one or more) BWPs and telling the UE which of the currently configured BWPs is active. A serving cell can be configured with up to four BWPs, and for an activated serving cell, there is always one active BWP at any point in time. Summary of the invention

[0007] Subband (SB) indication and listen-before-talk (LBT) results can be used to adjust the communication between a device such as a wireless terminal and a base station. For example, a wireless terminal device such as a user equipment (UE) can receive an SB indication including a SB configuration and / or an LBT result of a base station, and then use this information in various ways.

[0008] For example, the UE may receive a remapped control resource set (CORESET) from the base station. Similarly, the UE may determine that a physical resource block (PRB) is invalid based on whether the PRB overlaps with a guard band, where the PRB belongs to a group of PRBs in the CORESET. Similarly, the UE may determine that a group of PRBs is invalid based on whether the PRB overlaps with a guard band. In addition, the device may assume that any invalid PRB does not carry a physical downlink control channel (PDCCH).

[0009] The apparatus may be arranged to select a transmission opportunity for MSG3 transmission in a random access channel (RACH) procedure, wherein such transmission opportunities are separated in the frequency domain, the time domain, or both. For example, a transmission opportunity may be selected based on a random access response (RAR), wherein the RAR indicates a subband or bandwidth part (BWP) for MSG3. By applying a shift relative to a guard band, multiple transmission opportunities may be inferred. The opportunity may be determined by random selection or based on an identifier (ID) of the apparatus from among multiple MSG3 transmission opportunities provided by one or more MSG2 messages.

[0010] Similarly, the RACH MSG3 transmission opportunity may be selected in the time domain. For example, the transmission opportunity may be selected based on a random access response (RAR).

[0011] The apparatus may receive an indication of an LBT type for MSG3 of a RACH procedure. For example, the LBT type may be indicated in downlink control information (DCI) of a scheduling random access response (RAR) or in the RAR itself.

[0012] The device can determine whether a channel state information reference signal (CSI-RS) crossing a boundary between available and unavailable LBT subbands is completely dropped, partially dropped, or defined within an available subband. For example, an unavailable subband can be an LBT subband or a guard band indicated as unavailable based on an LBT result of a base station.

[0013] For example, the device may adjust the CSI-RS assumption by discarding one or more orthogonal frequency division multiplexing (OFDM) codewords carrying CSI-RS that are dropped before the base station successfully acquires the channel or by shifting one or more OFDM codewords carrying CSI-RS based at least in part on when the base station successfully acquires the channel.

[0014] The terminal device may provide auxiliary information to the base station, the auxiliary information being related to the LBT result of the device. For example, the device may then receive back an adjusted SB indication from the base station. One or more SB indications and the auxiliary information may be exchanged between the device and the base station during a first portion of the maximum channel occupancy time (MCOT), for example, wherein the adjusted SB indication is received during a second portion of the MCOT. The auxiliary information may include one or more preferred downlink (DL) subbands.

[0015] The SB indication may be carried in the group communication, for example, where one or more SB indications include a group identifier.

[0016] Additionally, the apparatus may adjust the search space based at least in part on the available subbands.

[0017] This summary is provided to introduce some concepts in a simplified form, which will be further described in the detailed description below. This summary is neither intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to limitations that address any or all disadvantages noted in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] A more detailed understanding can be obtained from the following description, which is given by way of example in conjunction with the accompanying drawings.

[0019] Figure 1 An example of bandwidth adaptation is illustrated.

[0020] Figure 2 (a) and (b) show the calling flow of an example random access procedure.

[0021] Figure 3 (A) and (B) show example bandwidth portions having multiple sub-bands, wherein (A) the sub-bands have equal bandwidths, and wherein (B) the sub-bands have different bandwidths.

[0022] Figure 4A and 4B An example of the difference between the two solution categories is illustrated. Figure 4A An example subband configuration not related to LBT is shown, and Figure 4B An example sub-band configuration solution related to LBT is shown.

[0023] Figure 5 An example of semi-statically constructing SB using RRC+MAC-CE is shown.

[0024] Figure 6 An example of UE behavior when the SB Inactivity Timer is configured is shown.

[0025] Figure 7 An example of a signaling subband (SB) configuration is shown.

[0026] Figure 8 An example of indicating an unavailable SB by signaling an SB bitmap through other available SBs is shown.

[0027] Fig. 9 The DCI is activated to select one of the subband configurations provided by RRC or RRC+MAC-CE.

[0028] 10A to 10E illustrate examples of different combinations of CORESETs that may be remapped due to SB 2 unavailability.

[0029] Fig.11 is a flow chart of an example process for a UE and a gNB to adjust the configuration of a CORESET based on available subbands.

[0030] Fig.12 An example configuration of CORESET_x based on the evolution of sub-band LBT results over time is illustrated.

[0031] Fig.13 An example of remapping frequency domain resources of a CORESET when the CORESET is fully allocated with a single subband is shown.

[0032] Fig.14 Another example of remapping frequency domain resources of a CORESET is shown.

[0033] Fig.15 is a flow chart of an example process for a UE and a gNB to adjust the configuration of a CORESET based on available subbands using pre-specified remapping rules and static / semi-static remapping configurations.

[0034] Fig.16 is an example in which multiple RARs are configured and each RAR is associated with a specific BWP.

[0035] Fig.17 An example of introducing resources for message 3 is shown.

[0036] Fig.18 are time and spectrum diagrams for an example in TDD, where the gNB and UE can operate on subbands available on both the gNB and UE sides.

[0037] Fig.19 are time and spectrum diagrams for examples in TDD, where the gNB and UE can operate on DL subbands and UL subbands corresponding to a single or multiple available subbands on both the gNB and UE sides.

[0038] Fig. 20 are time and spectrum diagrams of an example in FDD, where the DL subband and the UL subband occupy different frequency bands.

[0039] Fig.21 is a timing diagram illustrating an example of UE-assisted subband switching.

[0040] Fig.22A and 22B is a call flow diagram of an example procedure for signaling of UE-assisted subband switching.

[0041] Fig.23 are time and spectrum plots of an example channel get request.

[0042] Fig.24 is a timing diagram illustrating an example of a gNB indicating available DL subbands in addition to providing UL resources.

[0043] Fig.25 is a time and spectrum diagram of an example one-to-one CFRA transmission to indicate the availability of the DL subband.

[0044] Fig.26 2 are time and spectrum diagrams of an example of using SRS to indicate available DL subbands at the UE side.

[0045] Fig.27A An example communication system 100 is illustrated in which the methods and apparatus described and claimed herein may be implemented.

[0046] Fig.27B is a block diagram of an example apparatus or device configured for wireless communication according to embodiments described herein.

[0047] Fig.27C is a system diagram of an example radio access network and core network.

[0048] Fig.27D is a system diagram of another example of a radio access network and a core network.

[0049] Fig.27E is a system diagram of a third example radio access network and core network.

[0050] Fig.27F is a block diagram of an exemplary computing system in which Fig.27A , 27C , one or more devices of the communication network shown in 27D and 27E.

[0051] Figure 27G An exemplary communication system 111 is illustrated in which the methods and apparatus described and claimed herein may be implemented.

[0052] Fig.28 An example of CSRS-SB crossing the LBT subband boundary is illustrated.

[0053] Fig.29 An example of a CSRS-SB being completely or partially outside of an available LBT subband being discarded is illustrated.

[0054] Fig. 30A An example of contracting a CSRS-SB that overlaps with available and unavailable LBT subbands is illustrated.

[0055] Fig. 30B An example of restricting measurements to the available LBT sub-band is illustrated.

[0056] Fig.31 An example of discarding a CSRS-SB that completely or partially overlaps a guard band is illustrated.

[0057] Fig.32 An example of shrinking a CSRS-SB that overlaps an available LBT subband and a guard band is illustrated.

[0058] Fig.33 An example of calculating the size of the first and last CSRS-SB is illustrated.

[0059] Fig.34 An example of discarding CSI-RS in OFDM symbols that are dropped before the gNB successfully acquires the channel is shown.

[0060] Fig.35 An example of shifting an OFDM symbol carrying a CSI-RS is illustrated.

[0061] Fig.36 An example of a GC-PDCCH bit field is illustrated, which indicates the available LBT subbands for different UE groups.

[0062] Fig.37 An example of a GC-PDCCH bit field is illustrated, which indicates the available LBT subbands and group IDs.

[0063] Fig.38 An example of configuring a guard band is illustrated.

[0064] Fig.39 An example of a UE inferring a channel access procedure type based on a time gap between MSG2 and MSG3 is illustrated. DETAILED DESCRIPTION

[0065] Table 0 in the Appendix lists several acronyms used in this paper.

[0066] The term "process" generally refers to a method of performing operations to achieve a specific purpose. The term "process" is used instead of "method" to avoid confusion with the special meaning of the term "method" in the context of M2M and IoT applications. The steps described for a process are often optional and may be performed in various ways and in various orders. Therefore, the term "process" in this article should not be interpreted as referring to a rigid set and order of steps, but rather to a general method for achieving a result that can be modified in various ways.

[0067] Unlicensed spectrum in NR

[0068] In mmWave, there is a wide range of unlicensed spectrum that can be further exploited to achieve higher data rates than those achieved by operating in the sub-6 GHz bands. In previous study items (SI) and current work items (WI) on NR unlicensed, the process of enhancing the coexistence between NR-U and other technologies (e.g., WiFi devices, LTE-based LAA devices, other NR-U devices, etc.) operating in unlicensed and meeting regulatory requirements will be extensively studied and specified without NR-U devices experiencing much degradation in throughput and latency.

[0069] NR bandwidth adaptation

[0070] With Bandwidth Adaptation (BA), the UE's receive and transmit bandwidth does not have to be as large as the cell's bandwidth, and can be adjusted: the width can be commanded to change (e.g., shrink during times of low activity to save power); the location can be moved in the frequency domain (e.g., to increase scheduling flexibility); and the subcarrier spacing can be commanded to change (e.g., to allow different services). A subset of the total cell bandwidth of a cell is called a bandwidth part (BWP), and BA is implemented by configuring a UE with (one or more) BWPs and telling the UE which of the currently configured BWPs is active. A serving cell can be configured with up to four BWPs, and for an activated serving cell, there is always one active BWP at any point in time.

[0071] Figure 1 Describes 3 different scenarios for configuring BWP:

[0072] BWP1 with 40MHz width and 15kHz subcarrier spacing;

[0073] BWP2 with 10MHz width and 15kHz subcarrier spacing;

[0074] • BWP3 with a width of 20 MHz and a subcarrier spacing of 60 kHz.

[0075] NR random access process

[0076] The random access procedure is triggered by multiple events, for example, as described in 3GPP TS 38.300, NR; NR and NG-RAN general description; Stage 2 (Release 15), V15.0.0 and 3GPP TS 38.213, Physical layer procedures for control (Release 15), V15.1.0.

[0077] Initial access from RRC_IDLE;

[0078] RRC connection re-establishment process;

[0079] ·transfer;

[0080] · When the UL synchronization state is "out of sync", DL or UL data arrives during RRC_CONNECTED;

[0081] Transition from RRC_INACTIVE

[0082] · Requests to other SIs.

[0083] Beam failure recovery

[0084] In addition, if Figure 2 As shown in , the random access procedure adopts two different forms: contention-based and contention-free. Normal DL / UL transmission can be performed after the random access procedure.

[0085] For initial access in a cell configured with SUL, the UE selects the SUL carrier if and only if the measured DL quality is below the broadcast threshold. Once started, all uplink transmissions of the random access procedure remain on the selected carrier.

[0086] Example Challenge

[0087] Question 1: Subband configuration and LBT result indication

[0088] In NR-U, it is beneficial to operate at a frequency granularity (i.e., subband) that is smaller than a bandwidth part (BWP) to increase the probability of accessing a channel and to cope with channel unavailability that may be encountered in the following situations: Listen Before Talk (LBT) is performed on the entire frequency band allocated to the BWP and only a portion of this frequency band is occupied by other nodes. Therefore, it is of great interest to describe an efficient process for configuring subbands within a BWP. Moreover, it is important to develop a process for indicating the results of LBT across subbands within a BWP so that the UE can adjust its behavior when monitoring different signaling and channels.

[0089] Question 2: CORESET configuration when performing subband-based LBT

[0090] In NR, a control resource set (CORESET) is defined with respect to a BWP containing the frequency resources of a CORESET. Adopting subband-based LBT brings additional challenges depending on the relative position of the frequency domain resources of the CORESET to the subbands. For example, a subband that completely contains the frequency domain resources of the CORESET may be unavailable, while other subbands in the same BWP are available. Moreover, for a large CORESET with frequency domain resources spanning multiple subbands, if some of those subbands are unavailable, then the UE will most likely be unable to decode the associated downlink control indicator (DCI). Then, how can the CORESET be configured to increase its transmission opportunities and how can these configurations be indicated to the UE to appropriately monitor the CORESET.

[0091] Issue 3: Uplink BWP switching between RACH and BFR

[0092] Allowing dynamic UL BWP switching is also beneficial to increase the chances of UE accessing the channel and mitigate the impact of channel unavailability due to LBT failure. To this end, the problem of UL BWP switching during the random access procedure or during the beam failure recovery procedure needs to be solved. In addition, the problem of UL resource assignment to the UE that supports UL BWP switching during the random access procedure or during the beam failure recovery procedure needs to be solved for the transmission of MSG3 or for the transmission of the beam failure recovery request (BFRQ).

[0093] Subband configuration and indication process

[0094] Subband Configuration

[0095] In NR-U, channel access depends on the results of the deployed channel sensing process, which introduces uncertainty as to whether the gNB or UE should successfully acquire the channel when it should transmit any signal and / or channel. Sub-band operation can be beneficial in mitigating the harmful effects of channel unavailability, especially if a small portion of the allocated band operation BWP is occupied by other nodes while the remaining nodes are available. In sub-band operation, the BWP can be divided into equal or unequal bandwidths, such as in Figure 3 A and Figure 3 As shown in B. The essence of using subbands is to operate at a finer frequency granularity than the BWP to enhance the chance that the gNB or UE can acquire the channel.

[0096] The solutions we developed for configuring subbands fall into two main categories. In the first set of solutions, a set of subbands within an active DL BWP is configured to the UE. Based on the LBT results at the gNB, the UE monitors the available subbands from the initially configured set of subbands within the active DL BWP (associated with a successful LBT). Until such configuration is updated, the UE cannot monitor any other subbands outside the configured set of subbands in the active DL BWP. Hence, we refer to this type of solutions as LBT-independent subband configuration. In the second category, we propose another set of solutions in this paper where, based on the LBT results at the gNB, the gNB may indicate only the available subbands within the active DL BWP among the set of subband configurations. Hence, once a particular set of subbands within the active DL BWP is indicated as available, the UE is expected to monitor all of these subbands. This type of solution is referred to as LBT-dependent subband configuration. The key difference between these two categories is that in the former set of solutions, some of the configured subbands may not be available due to LBT failures, whereas in the latter set of solutions, all indicated subbands are always available. Moreover, in the former solution set, the gNB may explicitly indicate to the UE that some subbands are always dropped, whereas in the latter solution set, such indication may be achieved implicitly, as will be explained in this document.

[0097] Another set of solutions that may be employed on top of both solution categories is called UE-assisted subband selection, where the UE assists the gNB in ​​determining the preferred downlink subbands. Such assistance may be beneficial in avoiding the hidden node problem, where if some downlink subbands are not available from the UE's perspective, then the UE may further narrow down the offered downlink subbands and indicate those selected subbands. Moreover, in time division duplex (TDD) or frequency division duplex (FDD) operation, the UE may only monitor those downlink subbands if the downlink subbands are available from the UE's perspective (LBT was successfully performed at the UE). Alternatively or additionally, the UE may only monitor those downlink subbands if the downlink subbands are available from the UE's perspective (LBT was successfully performed at the UE) and there is at least one UL subband with successful LBT. Similarly, the UE may not monitor downlink subbands even if they are available, even when there are no UL subbands available for the UE.

[0098] Figure 4 shows the main differences between the two solution categories. Figure 4AIn the case of , the UE receives an LBT-independent subband configuration that allocates SB0, SB2, and SB3 within the activated DL BWP. In this case, the UE monitors only those subbands. If any of them is unavailable, the gNB may indicate the unavailable subbands and the UE monitors only the available subbands among the initially configured subbands. To monitor the new subbands, the UE shall receive a new configuration. On the other hand, Figure 4B A high-level description of the second category of solutions is shown, e.g., subband configuration related to LBT, where the gNB indicates the subbands that the UE can monitor after each successful LBT at the gNB.

[0099] Figure 4 is a high-level diagram of the difference between the two solution categories. Figure 4A shows the subband configuration that is not related to LBT, while Figure 4B A sub-band configuration solution associated with LBT is shown.

[0100] Second worst static configuration

[0101] Subband configuration not related to LBT

[0102] If the subbands (SBs) have equal bandwidth, then the UE may be configured with an equal number of SBs and the associated bandwidth of the SBs for each configured BWP via higher layer parameters (e.g., NumEqSB and BandwidthSB). The UE may assume that the SB with the smallest subband index occupies the lowest physical resource block (PRB) in the BWP containing the subband, and the next subband index occupies the next set of PRBs in an ascending manner. The indices of the SBs are arranged in ascending order relative to the occupied PRBs, e.g., Figure 3 As shown in A.

[0103] Alternatively, we propose in this paper a higher-layer configuration message such as SB IE, an example of which is given in Information Element 1 of the Appendix, which can be used to configure each SB separately with unequal bandwidth and non-uniform frequency domain position, for example Figure 3 As shown in B. Each BWP can be composed of multiple SBs configured through multiple information elements.

[0104] See Example Information Element 1, SB Information Element in the Appendix.

[0105] Table 1 contains a description of the SB IE parameters.

[0106] To allow non-contiguous subbands, if applicable, we propose in this article to configure their frequency domain resources through high-level parameters such as frequencyDomainResoruces, RRC parameters instead of locationAndBandwidth. For example, this parameter can be a bit string of size 45 bits, where each bit can correspond to a group of 6 PRBs, whose grouping starts from PRB0, which is completely contained in the BWP containing the subband. Moreover, the most significant bit can correspond to the lowest frequency group that is completely contained in the BWP in which the subband is configured, and each next subsequent lower significant bit corresponds to the next lowest frequency group (if any) that is completely contained in the BWP in which the subband is configured. The bits corresponding to the groups that are not completely contained in the BWP in which the subband is configured are set to zero. Moreover, the parameter frequencyDomainResoruces can be relative to the actual component carrier containing the BWP and its subbands.

[0107] Moreover, we propose in this paper a compact high-layer message, such as SB-List, for example RRC IE, which can be used to configure multiple subbands at once. The message SB-List can consist of multiple blocks of the above SB IE, each block configuring one subband.

[0108] See Example Information Element 1, SB List Information Element in the Appendix.

[0109] Subband configuration related to LBT:

[0110] In this solution, we propose in this paper to use high-layer messages to configure the UE with a list of potential subband configurations with BWP. Then, based on the LBT results, one configuration will be selected. For each configuration, the proposed message can carry information about frequency domain resources, subcarrier spacing, cyclic prefix, etc. For example, Table 2 shows how different configuration indexes are on the subband. Index 0 of the configuration indicates that the frequency domain resources are Figure 3 The resources occupied by SB0 in the figure are the same as those occupied by SB0, and the configured index 5 indicates that the frequency domain resources are the same as those occupied by SB0 and SB3 in the figure.

[0111] To this end, the higher layer message may be referred to as BWP_SB_Configs, such as RRC IE, as in Information Element 3 in the Appendix, for example. The parameter SB-Config-Id indicates the index of the configuration as in Table 2, while the other parameters are defined as the same as in the above SB IE.

[0112] See Appendix for example information element 3, BWP_SB_Config information element.

[0113] SB semi-static configuration

[0114] Subband configuration not related to LBT

[0115] As another embodiment, the UE may be configured by a higher layer, for example, an RRC message such as SB-ConfigLists, with multiple SB configurations per BWP. For example, SB-ConfigLists may carry multiple SB-List-Ids. A medium access control element (MAC-CE) message may then be deployed to semi-statically activate a specific configuration by selecting an appropriate index in SB-ConfigLists. For example, Figure 5 The UE is shown receiving a high-level configuration of SBs to be activated by a MAC-CE. Next, the UE receives another activation MAC-CE, which changes the SBs from SBs with equal bandwidth to SBs with unequal bandwidths. Later, another MAC-CE selects a different SB configuration to divide the BWP into only three SBs instead of four SBs. Thus, the MAC-CE can be used to semi-statically add or delete SBs to the initially configured SBs.

[0116] In addition, the UE may be configured with a default SB configuration. It may be the SB configuration with the lowest index in the SB-ConfigLists, or configured separately by higher layer signaling. For example, in the absence of an activated MAC-CE, or after the expiration of an SB inactivity timer configured by a higher layer parameter such as SB-InactivityTimer, the UE may use the default SB configuration as a fallback state. The SB inactivity timer may be reset after receiving an activation MAC-CE or any other signal or channel, and may be decremented when no signal or channel is received. After the SB inactivity timer expires, the UE may assume that the gNB has switched to the default SB configuration. For example, in Figure 6 In the example, the UE sets the SB inactivity timer after receiving the activation MAC-CE. Subsequently, the UE receives other signals / channels or even another MAC-CE, and then the UE resets the SB inactivity timer. After not receiving a signal / channel for a sufficiently long period of time until the SB inactivity timer expires, the UE may fall back to the default SB configuration.

[0117] Subband configuration related to LBT:

[0118] In such solutions, higher layer parameters such as the aforementioned BWP_SB_Configs IE can provide so many configurations for the UE. Therefore, for example, we propose in this paper to deploy MAC-CE to select a subset of these configurations, which can be identified by an ID in the parameter SB-Config-Id.

[0119] Signaling subband configuration in NR-U

[0120] In this section, we propose several procedures herein to signal the subband configuration regardless of whether the solution belongs to LBT-independent subband configuration or LBT-dependent subband configuration.

[0121] Broadcast subband configuration

[0122] SB configuration through RRC or RRC+MAC-CE can be signaled in a physical downlink shared channel (PDSCH) carrying remaining system information (RMSI) scheduled by a type 0 PDCCH common search space with a DCI format, where the CRC is scrambled by the system information-radio network temporary identifier (SI-RNTI). Moreover, SB configuration can be signaled in a PDSCH carrying other system information (OSI) scheduled by a type 0A-PDCCH common search space with a DCI format, where the CRC is scrambled by the SI-RNTI.

[0123] Unicast subband configuration

[0124] Alternatively, the SB configuration may be signaled in a PDSCH carrying RRC or RRC+MAC-CE scheduled by PDCCH in a UE-specific search space using DCI format 1_0 or DCI format 1_1 scrambled by C_RNTI. For SB configuration by RRC+MAC-CE, the RRC message may be scheduled by DCI in a common search space, while the MAC-CE may be scheduled by DCI in a UE-specific search space (dedicated UE message).

[0125] To increase the chance of acquiring a channel, the search space can consist of several control resource sets (CORESETs) with different bandwidths, such as Figure 7 As shown in . Narrowband CORESET may be more suitable for less capable UEs, while wideband CORESET may be more suitable for PDCCHs with high aggregation levels. PDSCHs carrying RRC or RRC+MAC-CE may be allocated in the same SB spanned by the CORESET, and in the case where the CORESET spans multiple SBs, the associated PDSCHs carrying RRC or RRC+MAC configurations may also span multiple SBs, for example Figure 7 as shown in .

[0126] To further enhance the flexibility of channel access and alleviate the uncertainty caused by LBT, the gNB can configure a set of SBs to a specific UE even if the CORESET spans one or more subbands that may or may not belong to this set.

[0127] Indicative LBT results

[0128] Subband configuration not related to LBT:

[0129] In NR-U, since Listen Before Talk (LBT) is performed before accessing the channel, some of the configured subbands may not be available and the gNB cannot acquire those initially configured SBs. Dynamically indicating which subbands among the originally configured subbands are beneficial.

[0130] In this paper, we propose to use DCI to indicate the SBs that the gNB has successfully acquired. To this end, one of the following alternatives can be adopted.

[0131] UE-specific indication: DCI can be transmitted in a UE-specific search space using a UE-specific RNTI, for example, a bitmap field with a cellular radio network temporary identifier (C-RNTI), called the SB-bitmap field. The size of the SB-bitmap is equal to the number of configured SBs, where the most significant bit corresponds to the highest SB index. For example, when the corresponding SB is set to 1, the UE can expect that the SB is available. This DCI can be configured on each configured subband.

[0132] For example, Figure 8 A UE configured with three subbands SB1, SB2, and SB3 is shown. Also, the UE is configured with a UE-specific search space in each SB to monitor the DCI, where the CRC is scrambled by the C_RNTI to decode the SB-bitmap field. To enhance the robustness of the DCI, the gNB can transmit the DCI across different SBs at different times. In the first transmission opportunity, the SB-bitmap is equal to 101, while in the second transmission opportunity, the SB-bitmap is equal to 110.

[0133] Moreover, in order to avoid the DCI size being variable, the size of the SB-bitmap may be set to a fixed value, such as the maximum number of subbands per BWP, and its bits may be mapped to subbands according to a specific rule. For example, the most significant bit may correspond to the subband with the highest index, and each next subsequent less significant bit may correspond to the subband with the next subsequent smaller index. The remaining bits not mapped to the subband index are set to zero.

[0134] · Groupcast / Broadcast UE Indication: If the same subbands are configured for multiple UEs, the gNB can indicate the available subbands to all UEs sharing the same configuration. To this end, we introduce the Subband Indication - Radio Network Temporary Identifier (SBI-RNTI), which can be used to scramble the CRC of the DCI transmitted in the common search space. This DCI will carry the SB-bitmap field, which indicates which SBs are available for transmission.

[0135] For UE-specific indications or multicast / broadcast indications, DCI may be transmitted with a configured periodicity to indicate any changes in available subbands. DCI transmitted across different subbands may be shifted in time from one subband to another. For example, DCI on the subband with the highest index may appear first, followed by DCI on subbands with lower indices, such as Figure 8 As shown in . To reduce power consumption on the UE side, if the UE successfully decodes a DCI in a specific subband, the UE can ignore DCI transmitted from other subbands until the next monitoring time. DCI transmission can be restricted to a specific time position, such as occurring at the beginning of a time slot. DCI can also be transmitted periodically even if the availability of the configured subbands has not changed.

[0136] Some subbands may be configured as default subbands, which may always carry DCI indicating which subbands are available, e.g., SB-bitmap. For example, the subband with the smallest index may be the default subband. We also propose in this paper a high-level parameter, such as Default_SB, that may be used in RRC messages indicating the default subband.

[0137] Subband configuration related to LBT:

[0138] In this type of solution, we propose in this paper to transmit a DCI indicating a subband configuration index, such as one of the indices in Table 2, from the data configured by the higher layer parameters RRC or RRC+MAC-CE. In other words, we propose in this paper an RRC+DCI procedure, in which the RRC message provides multiple subband configurations, and the DCI selects one of them. Another procedure is RRC+MAC-CE+DCI, in which RRC provides multiple subband configurations, then MAC-CE provides a subset of these configurations, and then DCI selects a single configuration based on the LBT result. The DCI can have a bitmap to indicate, for example, which configuration is selected, and its size can be fixed to be equal to the number of maximum subband configurations.

[0139] To this end, the gNB may configure multiple CORESETs, which the gNB may use to send activation DCIs. Those CORESETs may be contained in a single SB, or span multiple subbands, such as Fig. 9 as shown in .

[0140] exist Fig. 9 In the example of , the activation DCI may be transmitted in a UE-specific search space with its CRC scrambled by the C-RNTI. Alternatively, the DCI may be transmitted in a common search space or via a group common PDCCH with a temporarily identified SB_act_radio network (SB_act-RNTI).

[0141] Also, the gNB can implicitly indicate that some subbands will not be used, so the UE can avoid monitoring them. This can be achieved by not configuring any CORESET in those subbands to be dropped.

[0142] Some subbands may be configured as default subbands, which may always carry activation DCI. For example, the subband with the smallest index may be the default subband. We also propose in this paper a higher layer parameter, such as Default_SB, which may be used in RRC messages indicating the default subband.

[0143] In carrier aggregation mode, for both solution categories, an activation / indication DCI may be transmitted in the licensed cell to indicate which subbands are active at any particular instance.

[0144] As another embodiment that can be used on top of both solution categories, we propose herein that the UE can assist the gNB in ​​determining which subbands the gNB can acquire for downlink transmissions. Such UE assistance can be quite useful in mitigating the hidden node problem. For time division duplex (TDD), both DL and UL transmissions occupy the same frequency band. Therefore, if there are some UL subbands that the UE cannot acquire due to LBT failure, then the gNB may not be able to acquire those subbands even though they are available from the gNB perspective, and the UE only monitors the available subbands from its perspective. The UE can indicate the available subbands in several ways. For example, if a handshake-like procedure is supported, the UE can explicitly indicate the preferred subband in its response. Moreover, the UE can implicitly indicate the preferred DL subband by making UL transmissions on this band. For example, the gNB can configure or schedule the UE with multiple UL resources across different subbands. The UE can then choose to transmit on the UL subband associated with the preferred DL subband. These resources may be used for different purposes, such as Sounding Reference Signal (SRS), Physical Uplink Channel (PUSCH), Physical Uplink Control Channel (PUCCH), preamble of Random Access Channel (RACH).

[0145] In Frequency Division Duplex (FDD), both DL and UL transmissions occupy different frequency bands. In this case, the UE can do LBT on DL subbands and indicate those subbands through UL transmissions. If a channel for UL transmission is available, then it can be used to indicate the index of the preferred DL subband. Also, if supported, a handshake-like process can be useful to carry such information. Also, some association between UL subbands and DL subbands can be defined so that when the UE performs UL transmission on any particular UL subband, the gNB can find out which DL subband is preferred.

[0146] UE-assisted subband switching

[0147] Due to the hidden node problem, the BWP(s) / subband(s) selected by the gNB for DL ​​transmission may not always be available at the UE side for receiving this DL, and vice versa for the BWP(s) / subband(s) selected by the UE for UL transmission as they may not be available at the gNB side for receiving UL transmission. Procedures are needed to avoid selecting BWP(s) / subband(s) that are not available at the UE side for DL ​​transmission and at the gNB for UL transmission.

[0148] To address this challenge, we propose in this paper that UE can assist gNB in ​​selecting subbands / BWPs that do not encounter any hidden node problems. Fig.18 is a time and spectrum diagram of an example in TDD, where the gNB and UE can operate on the subbands available to the gNB and UE sides. Fig.18 In the example of , although some DL subbands are available at the gNB side, the UE may not be able to receive on all of these subbands. In particular, Fig.18 It is shown that the available DL subbands on the gNB side are SB0, SB1 and SB2, while the available subbands for UL on the UE side are SB0, SB2 and SB3. Since both DL and UL use the same frequency band in TDD mode of operation, any successful transmission and reception must obtain the selected subband from both the gNB and UE perspectives.

[0149] In our example, although DL SB1 is available from the gNB side, this subband cannot be used for DL ​​because SB1 is not available for UL transmission, which means that the gNB cannot detect the presence of hidden nodes around the UE. Similarly, although UL SB3 is available on the UE side, it may not be used because SB3 is not available for UL (because SB3 is not available for DL ​​transmission, which means that there are hidden nodes around the gNB that cannot be detected by the UE).

[0150] This UE assistance may not only be useful for avoiding hidden nodes around the UE, but may also be used by the gNB to provide UL resources to the UE on available subbands indicated by the UE.

[0151] If the DL BWP and the UL BWP consist of different numbers of subbands or the same number of subbands with different bandwidths, a DL subband or a UL subband may be selected only if it overlaps with an available DL subband or UL subband. Fig.19 is a time and spectrum diagram of an example in TDD, where the gNB and UE can operate on DL subbands and UL subbands corresponding to a single or multiple available subbands at the gNB and UE side. Fig.19In the example of , although DL SB1 is available on the gNB side, it may not be used since it overlaps with two UL subbands and one of them SB1 is not available on the UE side. Similarly, UL SB3 cannot be used since it overlaps with DL SB3 which is not available at the gNB. Moreover, in the case of TDD, the number of DL subbands and UL subbands may be different and each DL subband may be associated with multiple UL subbands and vice versa. Moreover, since the DL BWP and UL BWP may have different bandwidths, the associated DL subbands and UL subbands may not even overlap. In this case, we propose in this article to adopt an explicit indication of the available DL subbands on the UE side and the procedures proposed for the FDD case may also be deployed.

[0152] In FDD operation, transmission and reception occur on different frequency bands, so the availability or unavailability of a particular subband in DL or UL does not necessarily mean whether the associated UL or DL ​​subband is available. Therefore, in addition to the available UL subbands, the UE can also explicitly indicate DL subbands that are not subject to hidden nodes. Fig. 20 An example of an FDD scenario with four DL and UL subbands is illustrated. In FDD, DL subbands and UL subbands occupy different frequency bands. The availability of a UL subband does not necessarily mean that the associated DL subband does not have a hidden node available, for example, on the UE side, and needs to be explicitly indicated. In contrast to the TDD case, although UL SB1 is not available for UL transmission on the UE side, it does not necessarily mean that DL SB1 suffers from the hiding problem since UL SB1 and DL SB1 occupy different frequency bands. Moreover, for FDD, the number of DL subbands and UL subbands cannot be equal. In this case, a single DL subband can be associated with multiple UL subbands and vice versa. This is why we propose in this article that the UE should explicitly indicate the available DL subbands on the UE side.

[0153] Procedure for UE-assisted subband / BWP switching

[0154] The MCOT duration can be divided into two parts (not necessarily equal). We call the first part the auxiliary window, which is mainly used for, but not limited to, exchanging information about available DL and UL subbands / BWPs on the gNB and UE side. The gNB can then use this information to adjust the DL subbands / BWPs and schedule UL transmissions on the available UL subbands / BWPs. The second part of the MCOT, e.g. marked as the DL / UL transmission window, can be used for actual DL and UL transmissions consisting of data, signaling or control. The DL / UL transmission window can contain a single or multiple DL-UL switching points. Moreover, the auxiliary window can be at the beginning of the MCOT, or can be repeated several times in case, for example, the subband / BWP is switched in the middle of the MCOT.

[0155] exist Fig.21 An example of a UE-assisted subband switching procedure is shown in , where the gNB senses and provides the UE with a list of possible DL subbands available at the gNB. The UE evaluates those DL subbands and senses any hidden nodes. The UE then signals the available subbands at the UE side. In FDD, this can be achieved by explicitly indicating the DL subbands that can be used to receive DL transmissions at the UE. In TDD, the UE can signal the available UL subbands at the UE side and the gNB can select a DL subband that overlaps with the available UL subbands at the UE side. A similar procedure can be used for BWP switching.

[0156] Fig.22A The high-level process of UE-assisted subband switching procedure is shown, where the signaling occurs on the same unlicensed cell suitable for dual connectivity (DC) and standalone (SA) NR-U. Alternatively, in carrier aggregation (CA) mode, the signaling can occur in the Pcell, such as Fig. 22B There are four main steps.

[0157] The first is to signal the available DL subbands. This signal can carry the available DL subbands associated with successful LBT at the gNB side.

[0158] The second is to signal the DL subbands that do not have hidden nodes. Before transmitting this signal, the UE can evaluate the channels on the DL subbands indicated in the previous signal to determine whether the UE can receive on those subbands. Similarly, some of them may not be available due to the presence of hidden nodes that the gNB cannot detect. The UE can then indicate the available DL subbands to the gNB at the UE side.

[0159] The third is to signal the selected DL subband. This signal can be used to indicate which subbands will be selected and can be optional for predefined rules that the gNB can use to select the DL gNB to avoid any ambiguity between the UE and the gNB.

[0160] Fourth, the gNB can start DL transmission of data, control, or signals. Moreover, the gNB can include single or multiple switching points within the MCOT.

[0161] A similar procedure as mentioned above may be adopted as a high-level procedure of the UE-assisted BWP switching procedure.

[0162] For the case where the UE is configured with multiple BWPs and only a single BWP is activated at any particular time if the entire DL BWP is available, we propose in this paper that the UE can assist the gNB in ​​determining whether there are any hidden nodes on this DL BWP. DL ) and UL BWP(iUL ) In the case of TDD occupying the same frequency band, once the gNB sends a signal to modulate the i DL If the UE can sense the DL BWP and transmit a signal to indicate its availability when no hidden node occupies the BWP, the UE can sense the DL BWP and transmit a signal to indicate its availability when no hidden node occupies the BWP. DL The ith DL BWP pair UL Furthermore, the UE may transmit the UE indication on any other UL BWP on the Scell ​​or Pcell that can be configured by the gNB (not associated with the i-th UL BWP). DL In the absence of such configuration, for example, some UL BWPs with a predefined rule / order may be used to determine the UL BWP, such as, for example, the initial UL BWP or the default UL BWP in the Scell ​​or PCell. DL and UL BWP i UL In the FDD case occupying different frequency bands, a DL BWP may be available without a hidden node even if the paired UL BWP is not available. Therefore, we propose in this article that when the gNB indicates the availability of a specific DL BWP, the gNB may indicate a single or multiple UL BWPs that the UE may use to indicate whether the DL BWP has a hidden node. The UE may attempt to transmit the indication on a UL BWP paired with the DL BWP or an additional UL BWP such as the initial UL BWP or the default UL BWP in the Scell ​​or Pcell (if it passes LBT). Moreover, the UE may follow specific rules / commands to select the UL BWP. For example, the UE may attempt to use the UL BWP paired with the DL BWP i DL Paired UL BWP i UL , the UE may then attempt to transmit the indication on a default UL BWP (if a default UL BWP is available), for example, followed by the initial UL BWP.

[0163] For the case where the UE is configured with multiple DL BWPs and multiple of those DL BWPs are activated at a time, if each activated DL BWP is paired one-to-one with a single UL BWP, then the above mentioned procedure can be used. If the pairing between DL and UL BWPs is more like a many-to-one relationship, for example, multiple activated DL BWPs are paired with a single UL BWP, then the above mentioned procedure can still be used, but the UE can indicate that the DL BWP has no other information of the hidden node, for example, the UE can provide the DL BWP ID.

[0164] In the following subsections, we propose several possible alternatives to the signals mentioned above.

[0165] Signaling available DL subbands / BWP

[0166] If the available DL subbands change dynamically from MCOT to another, then dynamic PHY indication may be employed. While for semi-static or static channels where the available subbands remain available for a long time, higher layer indications may be deployed.

[0167] Channel acquisition request

[0168] We propose in this paper that the gNB can transmit a channel acquisition request (CAR) to indicate which subbands are available at the gNB. For example, a CAR signal can be transmitted on each available DL subband to indicate that the subband carrying the CAR signal is available at the gNB to keep the CAR small, such as Fig.23 as shown in .

[0169] Alternatively, the CAR signal may be transmitted at the gNB on only one available subband using a bitmap field, for example labeled Avai_SBs, and each bit indicates the availability of one subband. The most significant bit may correspond to the subband with the highest ID, and each next subsequent less significant bit may correspond to the next subband ID. The size of Avai_SBs may be equal to the maximum number of DL subbands per DL BWP.

[0170] As another embodiment, the CAR signal may be transmitted on the Pcell for CA mode. In this case, we propose an additional parameter or field herein to indicate the Scell ​​ID containing the DL subband, which may be referred to as ScellID, for example. If the UE is configured with multiple non-licensed Scells, this parameter may allow the gNB to indicate to which Scell ​​the available DL subband belongs. The parameter or field ScellID may have size log2 (maximum number of configurable Scells to the UE).

[0171] The CAR signal may be carried in a DCI transmitted on a UE-specific search space scrambled with a C-RNTI, or in a common search space with a DCI format scrambled, for example, with a predefined RNTI such as CAR-RNTI. Using a common search space is beneficial because the gNB can broadcast available subbands for multiple UEs simultaneously. The CORESET carrying the PDCCH may be configured to be within each subband or across multiple subbands. Furthermore, the DCI may provide a UL grant to the UE for sending feedback from the UE. Different UEs may derive UL grants based on predefined rules. For example, the UE may apply specific time and frequency shifts relative to a function of the received DCI and UE ID to reduce the chance of collisions. Furthermore, if the UE is configured with multiple unlicensed UL resources, the UE may derive which unlicensed UL resource ID the UE may use to send feedback.

[0172] To reduce the overhead of signaling available DL subbands / BWPs at the gNB and collecting different UEs' evaluations of the presence of hidden nodes, we propose in this paper that the gNB can group UEs based on a source signal indicating the spatial QCL of the signal / channel that indicates the DL subbands / BWPs available at the gNB. If UEs belong to the same group, then those UEs are on the same beam and suffer from the same hidden nodes (if any). In this case, getting feedback from one UE is enough for the gNB to decide which DL subbands / BWPs to use. Other ways of grouping UEs may also be employed. To this end, we propose in this paper that the signal / channel indicates the available DL dedicated to the UE, for example, transmitted in a UE-specific search space.

[0173] For the case where the UE is configured with multiple BWPs and only a single BWP is activated at any particular time if the entire DL BWP is available, we propose in this paper that the CAR signal can be transmitted on the activated BWP on the Scell ​​for DC and SANR-U. Alternatively, the CAR signal can be transmitted on the Pcell carrying the ID of the activated BWP, which is beneficial for CA cases. As a possibility, the gNB can transmit a bitmap to indicate which DL BWP is available at the gNB, and the size of the bitmap can be equal to the number of configured BWPs. For the case of only one active DL BWP, the UE is not expected to set more than a single bit to one.

[0174] For the case where the UE is configured with multiple DL BWPs and multiple DL BWPs are activated at a time, the CAR signal can be transmitted on one BWP with a bitmap indicating the available DL BWPs at the gNB. In this case, the UE can expect more than a single bit to be set to one. The BWP carrying the CAR signal can be among the DL BWPs where the UE must verify the presence of the hidden node. It can be a different BWP, such as the initial BWP or the default BWP in the Pcell. Alternatively, the CAR signal can be transmitted on each DL BWP that the gNB intends to acquire.

[0175] Implicit indication of available DL subbands

[0176] We also propose in this paper that the gNB can implicitly indicate the available DL subbands at the gNB by transmitting a signal with low decoding complexity, for example, a low complexity correlator is required to detect this signal. Such a signal can be PSS, SSS, preamble, etc., which the UE can use to infer the availability of the subband carrying this signal, which we label as sequence-based signal.

[0177] Instead of transmitting a signal with low decoding complexity on each available subband, a sequence-based signal may indicate a bitmap to available DL subbands at the gNB. For example, the initialization value of the sequence-based signal may be mapped to a specific code point in the bitmap.

[0178] For the case where the UE is configured with multiple BWPs and only activates a single or multiple BWPs at any particular time when the entire (one or more) DL BWPs are available, we also propose in this paper that a sequence-based signal can be used to indicate the DL BWP that the gNB attempts to acquire. The sequence-based signal can be similar to the sequence-based signal used to indicate the available DL subbands.

[0179] Signaling DL subband / BWP without hidden nodes

[0180] In this section, we propose several procedures to allow the UE to indicate the preferred DL subband / BWP that is not affected by any hidden nodes, i.e., the available DL subbands on the UE side. In the TDD case, the UE can indicate the available UL subbands / BWP on the UE side, and then the gNB can infer the DL subband / BWP without hidden nodes. For FDD, the UE can explicitly indicate the available DL subband / BWP on the UE side.

[0181] As an embodiment, we propose herein that the gNB may not only signal the available DL subbands / BWPs at the gNB side, but the signal may also provide an indication of the UL resources that the UE may use to transmit the DL subbands / (one or more) BWPs without hidden nodes, e.g., the available DL subbands / (one or more) BWPs at the UE side. For example, if the gNB indicates the available DL subbands / (one or more) BWPs at the gNB using DCI, then the gNB may use this DCI to provide UL resources for PUCCH or PUSCH, e.g., Fig.24 As shown in . If the available DL subbands / (one or more) BWPs are indicated by a signal (e.g., a sequence-based signal) that no UL resources can be provided, then the UE can transmit using the configured grant. Moreover, when the gNB indicates the available DL subbands / BWPs at the gNB using DCI, it can activate the configured grant, which provides the UE with multiple UL opportunities that the UE can use to cope with UL channel unavailability. Moreover, we propose in this article that the configured grant can be activated (without activating DCI) after a predefined duration starting from the instance where an indication of available DL subbands / (one or more) BWPs is received at the gNB.

[0182] On the PUCCH or PUSCH, the UE may transmit a bitmap indicating available DL subbands / (one or more) BWPs without hidden nodes (e.g., DL subbands / (one or more) BWPs available on the UE side). The most significant bit may correspond to the subband / BWP with the highest ID, and each next subsequent lower significant bit may correspond to the next subband ID. The size of the bitmap may be equal to the maximum number of DL subbands per DL BWP or the maximum number of DL BWPs per component carrier (CC). Moreover, if a separate PUCCH or PUSCH is used to indicate the availability of each DL subband / BWP, one bit may be sufficient to indicate whether the DL subband has any hidden nodes, e.g., whether the DL subband / (one or more) BWP is not available on the UE side.

[0183] If PUCCH / PUSCH are scheduled or configured on the Pcell for power saving, then if those PUCCH / PUSCH resources are associated with DL subbands / BWPs with hidden nodes, then the UE may drop sending the indication of the hidden nodes, e.g., the DL subband / (one or more) BWPs are not available at the UE side.

[0184] Alternatively, if the gNB uses DCI to indicate the available DL subbands / BWPs at the gNB, it can also initiate a PRACH transmission, such as a PDCCH order. Different subbands / BWPs may be associated with different PRACH resources or different time-frequency resources or different preambles. To this end, we propose in this document to configure this association through higher-layer parameters (e.g., RRC IEs such as rach-ConfigSBs) to configure the contention-free random access opportunity for subband / BWP selection, which may include (but not limited to) the time-frequency resources and preambles for RACH transmission. This RRC parameter may be transmitted as part of the subband / BWP configuration. A one-to-one mapping procedure or a one-to-many mapping procedure may be used.

[0185] For the one-to-one mapping process, the UE may transmit the PRACH preamble on the associated resources of each DL subband without a hidden node, e.g., the DL subband is available at the UE side. Fig.25 In Figure 1, we illustrate an example of four DL subbands and their associated UL subbands. For each available DL subband, the gNB can initiate a RACH transmission on the associated UL subband. The UE can transmit the RACH preamble only if the DL subband is not affected by hidden nodes, i.e., the DL subband is available on the UE side, which can be applicable to both TDD and FDD cases.

[0186] Fig.25 An example of using one-to-one CFRA transmission to indicate the availability of DL subbands in the TDD case is shown. Fig.25 In the example of , the gNB cannot initiate contention-free RACH (CFRA) on UL SB3 associated with unavailable DL SB3. Also, the gNB may initiate CFRA on UL SB1 associated with available DL SB1 at the gNB. However, due to the presence of hidden nodes in SB1, the UE does not transmit a RACH preamble. Each time the gNB initiates CFRA on a specific subband, the gNB may trigger a timer to monitor the RACH preamble, which may be referred to as SB_switchingTimer, and when no RACH preamble is received after expiration of this timer, the gNB may infer that there are hidden nodes on this DL subband around the UE, e.g., the DL subband is unavailable at the UE side.

[0187] In addition to the PDCCH order scrambled with C-RNTI, we also propose in this paper that the PDCCH order can be transmitted in the common search space scrambled with a new RNTI, such as DL_SB_check-RNTI. This can be beneficial if there are DL subbands intended for multiple UEs. In this case, the gNB can transmit the PDCCH order to the group of intended UEs to obtain their evaluation of the hidden nodes on this subband.

[0188] For the case where the UE is configured with multiple BWPs and if the entire DL BWP is available and only a single BWP or multiple BWPs are activated at any particular time in TDD mode of operation, the PRACH time-frequency resources will be located on the paired UL BWP. However, for FDD, if the UL BWP paired with the DL BWP being evaluated is not available due to LBT failure on the UE side, then this DL BWP being evaluated will not be affected by the hidden node, for example, the DL BWP is available on the UE side. Therefore, we propose in this article that the UE can switch the active UL BWP to another available UL BWP. For this purpose, the gNB can provide RACH resources across different UL BWPs. Moreover, to reduce the burden of detecting PRACH preambles on the gNB, the UE can attempt to transmit PRACH preambles between different UL BWPs in a certain order after the configured timer (e.g., BWP_access_timer) configured for each UL BWP expires. For example, the UE can attempt to access the UL BWP paired with the DL BWP being evaluated until the timer BWP_access_timer expires. When this timer expires, the UE may switch to another UL BWP according to a predefined order. The UE may then continue to attempt to access a new UL BWP until its associated timer expires.

[0189] For the one-to-many mapping process, instead of transmitting a PRACH preamble for each available DL subband / BWP without hidden nodes (e.g., DL subbands / BWPs available on the UE side), the UE may use a specific time-frequency resource or preamble to indicate, for example, multiple subbands / BWPs available on the UE side without hidden nodes. For example, the UE may transmit one PRACH preamble on the CFRA resources associated with one available DL subband / BWP on the UE side. However, different preambles may be used for different combinations of available DL subbands / BWPs on the UE side. Therefore, once the gNB receives the RACH preamble, the gNB may infer which combination of DL subbands / BWPs will not suffer from hidden nodes.

[0190] We also propose in this paper to adopt Sounding Reference Signal (SRS) as an indicator for DL ​​subbands / BWPs without hidden nodes (e.g., available at the UE side). To this end, we propose in this paper to add more use cases to the SRS high-layer parameter usage, such as, for example, SB_indication / BWP_indication. The main feature of this SRS usage is that the UE can choose not to transmit SRS associated with a DL subband. For example, for each available DL subband, the gNB can activate SRS with SB_indication usage, such as Fig.26 As shown in , each SRS is associated with a specific DL subband / BWP. The UE may only transmit SRS associated with DL subbands without hidden nodes (e.g., available on the UE side). The gNB may set a timer, such as called SRS_SB-timer, to receive SRS. After this timer expires and the gNB does not detect an SRS transmission, the gNB may infer that the DL subband is not available on the UE side. If the UL subband does not overlap with the DL subband, a procedure similar to that used for FDD may be employed.

[0191] For FDD, if the DL subband / BWP has no hidden node, but the UE cannot access the UL subband / BWP that should carry the SRS, then the UE can try other UL subbands / BWPs if the gNB provides resources on other UL subbands / BWPs. The UE can follow a specific order when trying to transmit SRS on other UL subbands / BWPs (e.g., subband / BWP IDs). The UE can continue to try to access each UL subband / BWP for a certain duration. To this end, we propose a timer in this article that the UE can use to switch to other UL subbands / BWPs when this timer expires.

[0192] Signaling selected DL subband / BWP

[0193] After exchanging information with the UE, the gNB may need to select one or more subbands from those indicated by the UE to have no hidden nodes. A possible solution set is to adopt the solution mentioned above to signal the subband configuration and indicate the LBT result. As another solution set, the selected DL subbands can be selected according to specific rules so that both the gNB and the UE have the same understanding about which DL subbands will be used for transmission. For example, the DL subband with the lowest ID is the subband that the gNB can use.

[0194] After exchanging information between the UE and the gNB, if a single DL BWP is not affected by hidden nodes and only one active DL BWP can be activated at any time, the UE can switch to this DL BWP. On the other hand, if multiple DL BWPs are not affected by hidden nodes and only one active DL BWP can be activated at any time, the UE can expect to receive BWP activation on the PCell that can be used in CA mode. For DL ​​or SA NR-U, the UE can monitor BWPs with IDs according to a certain rule. For example, the UE can monitor the BWP with the smallest ID among the BWPs indicated as having no hidden nodes.

[0195] After information is exchanged between the UE and the gNB and for the case where the UE is configured with multiple DL BWPs and multiple DL BWPs can be activated at any particular time if the entire DL BWP is available, then the UE monitors those DL BWPs (if they are available) without hidden nodes. If a subset of the initially activated DL BWPs has no hidden nodes, then the UE monitors this subset of DL BWPs. Also, on the Pcell, we propose in this article that the UE can receive a DCI on the Scell ​​to activate multiple BWPs. This DCI can have a bitmap field to indicate which DL BWPs are activated on the Scell, which we can call multiple DL BWP activation at one time.

[0196] Moreover, we propose in this paper that the gNB can send multiple DCIs to activate those multiple DL BWPs sequentially, for example, one DCI activates one DL BWP. Here, we propose a bit field to indicate that the UE should monitor the newly activated DL BWP in addition to the earlier activated DL BWP, because this indication bit field is not toggled. Once this bit field is toggled, the UE can interpret the DCI activation command as a DL BWP switching command, and the UE can deactivate the old (one or more) active BWPs and activate the indicated new BWP.

[0197] In DC or SA NR-U, the UE may monitor only one DL BWP without hidden nodes. For example, if this DL BWP has no hidden nodes, this DL BWP may be selected based on specific rules such as the DL BWP with the smallest ID or the initial DL BWP. Then, when DCI is transmitted on the Scell ​​on this special DL BWP, a similar process as above may be used to add multiple DL BWPs.

[0198] Subband Indicator Enhancement

[0199] Explicit or implicit indication may be used to indicate available or unavailable DL subbands. It may be beneficial to indicate different information about available subbands to different groups of UEs. For example, the gNB may successfully acquire the entire LBT subbands in a particular BWP and indicate such information to one group of UEs while indicating a subset of those available LBT subbands to a different group of UEs.

[0200] UEs may be grouped based on some criteria such as their capabilities, power saving requirements, channel quality, UE location, etc., and it is expected that all UEs belonging to the same group may receive the same available indication. For example, one or more group indexes of a UE may be indicated by higher layer signaling, an RRC parameter such as SBgroupID. Moreover, multiple group IDs may be configured to a UE by higher layer signaling, and then the MAC-CE may be used to semi-statically assign the UE to a single or multiple groups by indicating the ID of the MAC-CE. Additionally or alternatively, the DCI may dynamically assign a UE to (one or more) specific groups by introducing a new field in the DCI, which provides, for example, an UL / DL authorization indicating the group ID. For example, such a field may be a bitmap indicating the group (one or more) to which the UE belongs.

[0201] GC-PDCCH can be used to indicate the available LBT subbands to different UEs or UE groups. GC-PDCCH may include a dedicated bit field for each UE or each UE group to indicate the available subbands to them. For example, assuming that the gNB constructs a G1, ..., G N For each UE or UE group, M bits can be used to indicate Fig.36 , where M is set to 4 bits as an example. The total number of constructed groups and the number of bits required to indicate the available LBT subbands, i.e., N and M, respectively, may be indicated by higher layer signaling. This allows the size of the GC-PDCCH to be fixed and known to all UEs configured to receive the GC-PDCCH and all UEs belonging to any group so that they know which LBT subband indication bits they should read, e.g., G1 UE reads the 4 least significant bits, G2 UE reads the next 4 bits, and so on. The GC-PDCCH may contain other fields that carry other information that is common to all UEs or specific to certain groups of UEs only. For example, a single MCOT value may be indicated to all UEs by specifying a dedicated field for each group of UEs, or different MCOT values ​​may be indicated to different groups of UEs.

[0202] Alternatively, the GC-PDCCH may include two fields. Fig.37As shown in , the first field can indicate the available LBT subbands, for example, called the SB indication field, and the second field can indicate which UE or UE group this GC-PDCCH addresses, for example, called the group indication field. The group indication field can carry a group ID, which allows the GC-PDCCH to indicate the available LBT subbands to a single UE or a group of UEs. It consists of Log2 (the number of groups) bits. We can call this GC-PDCCH a group-specific PDCCH. The group indication field can be a bit string with a length equal to the number of UEs or UE groups, and each bit indicates to a specific UE or UE group. For example, the most significant bit can represent G N , while the least significant bit may indicate G1. This allows the gNB to signal the same available LBT subbands to multiple UEs or a group of UEs, whenever applicable. The size of the first and second fields in the GC-PDCCH may be configured by higher layer signaling. The GC-PDCCH may contain other fields that carry information to all UEs or groups of UEs, or only some UEs or groups of UEs. For example, a single MCOT value may be indicated to all UEs or a group of UEs, or a single MCOT value may be indicated to a subset of UEs or groups of UEs indicated by the group indication field, whenever applicable.

[0203] Another possible solution is that the gNB may configure multiple two-tuples of the group ID and the ID of the available subband(s) that the UE may assume is available, e.g., (group ID, ID of available subband), whereupon the gNB may activate or trigger single or multiple tuples via GC-PDCCH, reference signals, etc. For example, Table 7 shows how different K tuples and group IDs are associated with specific available LBT subband(s). Such a configuration may be signaled via higher layer signaling. Then, based on the result of the LBT, a single row or multiple rows may be indicated to the UE. For example. The GC-PDCCH may contain a bit field of K bits, each bit corresponding to a specific configuration. The GC-PDCCH may then indicate multiple configurations to be activated simultaneously. Alternatively, the GC-PDCCH may indicate the tuple ID by using a field of Log2(K) bits instead of a bitmap of K bits. The same approach may be employed if other signals or channels are deployed to carry single or multiple tuple IDs. For example, characteristics of those reference signals (eg, DMRS, CSI-RS, SSS, PSSS) (such as initialization sequence, pattern, etc.) are mapped to a specific tuple ID. This mapping may be indicated by higher layer signaling.

[0204] Table 7 Different tuples of UE group ID and available subbands

[0205]

[0206] Another possible solution is to associate each UE or UE group with a dedicated RNTI, for example, a subband group RNTI (SBG-RNTI). The group ID and its associated SBG-RNTI may be configured by high-layer signaling. Moreover, multiple group IDs and their associated SBG-RNTIs may be configured by high-layer signaling, and MAC-CE and / or DCI may be used to semi-statically / dynamically select the group to which the UE belongs. Alternatively, the UE may be able to infer the SBG-RNTI from its group ID. For example, the SBG-RNTI may be equal to the group ID + common reference RNTI, which may be SI-RNTI, P-RNTI, etc. Moreover, a truncated version of any of those RNTIs may be used to calculate the SBG-RNTI, where some bits of the SI-RNTI, P-RNTI, etc. are adopted, for example, the highest / least significant K bits are truncated so that the length of the remaining bits is the same as that of a conventional RNTI. The universal reference RNTI may also be set by high-layer signaling for all UEs, or it may be specified. The UE may only attempt to decode the GC-PDCCH scrambled with the RNTI associated with its group(s).

[0207] A UE may belong to multiple groups simultaneously, and the indicated available LBT subbands for those UEs or UE groups may be different. The UE may then assume that a specific combination of indicated LBT subbands for different groups is available. For example, the UE may assume that only the common LBT subbands in all indications are available, or the UE may assume that the union of the indicated LBT subbands is available.

[0208] As yet another solution, we propose in this article to deploy a two-step subband indication. In the first step, the gNB may explicitly or implicitly indicate all available LBT subbands to all UEs, for example via GC-PDCCH, DMRS and / or other reference signals. Then in the second step, the gNB may indicate a subset of available LBT subbands to a single UE or (one or more groups of) UEs, so that those (one or more) UEs may monitor only those LBT subbands during the remaining part of the COT. For example, (one or more) UEs may assume that the subset of available LBT subbands carrying the first DL transmission, signal and / or channel is the subset of LBT subbands that the (one or more) UEs must monitor during the remaining COT.

[0209] Alternatively, for example, the BWP ID field in the DCI of format 1-1 DCI can be interpreted as an LBT subband ID, and an additional one-bit field can be introduced to distinguish whether the BWP ID field is used for BWP switching or for indicating a subset of available subbands. In addition, a new field can be introduced to indicate a selected subset of available LBT subbands, and its size can be configured by higher layer signaling or set equal to the number of subbands within the activated BWP. This bit field can simply indicate the index of the available LBT subband. This bit field can be a bitmap that can indicate multiple LBT subbands.

[0210] If other reference signals (such as DMRS, CSI-RS, SSS, PSS, etc.) are used to indicate the available LBT subbands, similar concepts in the above-mentioned embodiments can be deployed. For example, each UE or a group of UEs can be associated with a specific initialization sequence, antenna port or mode.

[0211] CORESET Monitoring

[0212] In NR, CORESETs other than CORESET 0 are configured by higher layer parameters, for example, RRC IE, ControlResourceSet, which contains the parameter frequencyDomainResources to configure its frequency domain resources within the BWP in which the CORESET is configured. The parameter frequencyDomainResources is a bit string of size equal to 45 bits, where each bit corresponds to a group of 6 RBs, grouping starting from PRB 0, which is completely contained in the bandwidth part in which the CORESET is configured. The most significant bit corresponds to the lowest frequency group that is completely contained in the bandwidth part in which the CORESET is configured, and each next subsequent lower significant bit corresponds to the next lowest frequency group that is completely contained in the bandwidth part in which the CORESET is configured (if any). The bits corresponding to the groups that are not completely contained in the bandwidth part in which the CORESET is configured are set to zero.

[0213] In NR-U, such configuration may not be appropriate when LBT is performed on subbands within a BWP. If a PRB configured as part of a CORESET is contained in an unavailable subband due to LBT failure, then this CORESET will be punctured. The lack of knowledge about how to map the CORESET time / frequency resources only to available subbands greatly reduces the possibility of successful PDCCH decoding. In the above-mentioned embodiments, we proposed different solutions to allow the gNB to indicate which subbands are available and which are not available in the configured BWP for subband configurations that are not related to LBT or subband configurations that are related to LBT. However, another solution and set of procedures may be needed to define the behavior of the UE monitoring differently configured CORESETs. For example, Figure 10A shows that a CORESET is configured to span three consecutive subbands SB1, SB2, and SB3. Due to channel unavailability on SB2, this CORESET can be remapped to other available SBs. One solution is to maintain the duration of the new CORESET, for example, the number of symbols of the CORESET and the number of frequency domain resources fixed. For example, as shown in FIG. 10B , the duration of the new CORESET is the same as the duration of the original CORESET, while the frequency domain resources of the CORESET are remapped on the available subbands so that the original and new CORESET have the same number of frequency domain resources. Another possible solution is to change the duration of the CORESET and the number of frequency domain resources. For example, in FIG. 10C and FIG. 10D , the new CORESET may have a greater duration than the original CORESET and fewer frequency domain resources than the original CORESET. In FIG. 10C and FIG. 10D , the frequency domain resources are all distributed over non-contiguous subbands. Alternatively, the frequency domain resources may be distributed over contiguous subbands, such as, for example Fig.10E As shown. Other configurations of the new CORESET may be the same as the original CORESET, or the new CORESET may require a different set of configurations. Examples of such configurations are: 1) the mapping method of control channel elements (CCEs) to resource element groups (REGs), 2) the number of REGs in a REG bundle, 3) interleaver-related parameters, 4) quasi-co-location (QCL) configuration, 5) PDCCH demodulation reference signal (DMRS) scrambling initialization, etc.

[0214] There are many possibilities to remap the time and frequency domain resources of the old CORESET to the new CORESET, in addition to other configurations that may need to be modified. Therefore, based on the results of subband LBT, the gNB and UE should have the same understanding of the CORESET remapping and its configuration. Next, we propose several procedures to establish this understanding between the gNB and UE.

[0215] CORESET remapping based on configuration

[0216] The UE may be configured or signaled with information about CORESET remapping. To this end, we propose the following method in this paper.

[0217] Static configuration: In this case, higher layer parameters, such as ControlResourceSetReMapping given in, for example, RRC IE, Information Element 4 in the Appendix, may be used to configure the remapping information of the CORESET identified by controlResourceSetId, which was originally allocated in the ID of the subband identified by OldSB-Id. Since subband-based LBT is performed, those subbands identified by OldSB-Id may not always be available, and the gNB may remap the CORESET identified by controlResourceSetId to the subband identified by NewSB-ID based on the result of the subband LBT.

[0218] The parameters OldSB-Id and NewSB-Id may consist of a single subband ID or multiple subband IDs and may be used if the frequency domain resources of the CORESET are distributed in multiple subbands.

[0219] The CORESET configuration on the new subband may include parameters such as frequencyDomainResources which may configure the frequency domain resources for the CORESET on the new subband. The parameter frequencyDomainResources may still use a 45-bit bit string, identical to the similar parameter in the ControlResourceSet IE. Each bit corresponds to a group of 6 PRBs, with the grouping starting with PRB 0 belonging to the BWP containing the subset. The most significant bit corresponds to the lowest frequency group that is completely contained in the BWP containing the subband on which the CORESET is configured, and each next subsequent less significant bit corresponds to the next lowest frequency group that is completely contained in the BWP of the bandwidth containing the subband on which the CORESET is configured (if any). Bits corresponding to groups that are not completely contained in the BWP containing the subband on which the CORESET is configured are set to zero. Furthermore, the parameter frequencyDomainResources may be absolute relative to the BWP containing the CORESET or to the component carrier carrying the CORESET.

[0220] The parameter duration may be used to configure the duration of the CORESET on the new subband. The remaining parameters may be interpreted as being the same as the corresponding parameters in the ControlResourceSet IE. However, in the ControlResourceSetReMapping IE, all of these parameters are optional, and in the absence of these parameters, the UE may use the corresponding values ​​in the ControlResourceSet IE for the CORESET identified by the ControlResourceSetId. See example Information Element 4, ControlResourceSetReMapping Information Element, in the Appendix.

[0221] Alternatively, instead of the index of the old subbands of the frequency domain resources that originally contained the CORESET, we propose in this paper to define the CORESET remapping rules based on the available subbands only. Basically, in this solution, we discard the dependency on the old subband index of the frequency domain resources that originally contained the CORESET. Higher-level parameters that configure the remapping configuration, such as ControlResourceSetReMappingV2, e.g., RRC IE, may cover all subband configurations in the associated BWP, e.g., as given in Table 2. We propose in this paper a compact version of the RRC IE, see example information element 5, ControlResourceSetReMappingV2 information element in the Appendix.

[0222] Once the subbands are configured and the UE receives the CORESET remapping information, the UE can adapt to the results of the subband-based LBT at the gNB and can adjust the configuration of the different CORESETs that the UE assumes to monitor. Fig.11 This process for adjusting the configuration of a CORESET is shown.

[0223] exist Fig.12In Figure 1, we show an example for CORESET_x, which is configured to transmit on SB2. Later, due to LBT failure, SB2 is unavailable. Assuming that the UE has received a ControlResourceSetReMapping IE with OldSB-Id and NewSB-Id set to {0, 1, 2, 3} and {0, 1, 3} respectively, or a ControlResourceSetReMappingV2IE with BWP-SB-Confis-Id and indices associated with SB0+SB1+SB3, then once the UE knows that SB2 is unavailable and other subbands are available, the UE immediately knows on which subband the CORESET_x can be transmitted and the associated configuration, which in our example is SB0. The UE continues to monitor CORESET_x in SB0 until this subband is no longer available. When this happens, the UE can use the ControlResourceSetReMapping IE with OldSB-Id and NewSB-Id set to {0, 1, 3} and {1, 2, 3}, or use the BWP-SB-Confis-IdControlResourceSetReMappingV2IE with the BWP-SB-Confis-Id having an index associated with SB1+SB2+SB3. The UE then immediately knows on which subband the CORESET_x and the associated configuration can be transmitted, which in our example is SB1.

[0224] To avoid any ambiguity, for any tuple containing a CORESET ID, the index of the old and new subbands, e.g., (controlResourceSetId, OldSB-Id, NewSB-Id) used in the ControlResourceSetReMapping IE, there is a unique configuration set that defines the mapping of the CORESET identified by the controlResourceSetId and allocated in the subbands indexed by the OldSB-Id and the available subbands indexed by the NewSB-Id. Similarly, for the ControlResourceSetReMappingV2IE, there is a unique configuration set that defines the mapping of the CORESET identified by the controlResourceSetId when it is mapped to the subbands associated with the BWP-SB-Confis-Id.

[0225] Semi-static configuration To allow more flexibility and enable the same tuple consisting of CORESET ID, index of old and new subbands, e.g., (controlResourceSetId, OldSB-Id, NewSB-Id) or CORESET Id and subbands associated with BWP-SB-Confis-Id to be associated with multiple CORESET remapping configurations, we propose in this paper to use MAC-CE to select downward among those configurations. In other words, the higher layer parameters ControlResourceSetReMapping or ControlResourceSetReMappingV2 can provide the UE with multiple CORESET remapping information for the same tuple (controlResourceSetId, OldSB-Id, NewSB-Id) or BWP-SB-Confis-Id, and then MAC-CE can select the configuration that the UE can follow, e.g., ControlResourceSetReMappingId or CORESET_Remapping-Id. In the absence of MAC-CE, the UE can use the configuration with the lowest Id, e.g., ControlResourceSetReMappingId or CORESET_Remapping-Id.

[0226] DCI for scheduling configuration: For static and semi-static configuration by RRC and RRC+MAC-CE respectively, the DCI scheduling the PDSCH carrying RRC and MAC-CE can be signaled in the UE-specific search space using its C-RNTI, or it can be signaled in the common search space or in the group-common PDCCH with a dedicated RNTI (e.g., CORESET_Remapping_RNTI).

[0227] Remap based on a pre-specified CORESET

[0228] Alternatively, the CORESET remapping information can be pre-specified and executed according to predefined rules to reduce signaling overhead. We propose the following rules in this paper:

[0229] CORESET fully allocated with a single subband: The UE may assume that the configuration of all CORESETs remains unchanged except for the frequency domain resources. If the PRBs of CORESET x allocated in the subband identified by SB-Id y are no longer available, then the UE may assume that the PRBs of the CORESET are centered around the center of the nearest subband, initially configured to carry CORESET x. If there are two available subbands around the unavailable subband, then the CORESET may be remapped to the subband with the smallest ID. For example, in Fig.13 In , CORESET x is initially configured to be allocated on SB2, which is unavailable due to LBT failure. Provided that SB0, SB2, and SB3 are available and the subbands closest to SB2 are SB1 and SB3, then CORESETx can be remapped to near the center of SB1.

[0230] Other subband orders may be used to remap a CORESET that was originally configured on an unavailable subband. For example, instead of remapping the CORESET to the center of the subband closest to the initial configuration, the CORESET may be remapped to the center of the available subband with the smallest ID. Fig.13 In the example of , CORESET x will be remapped to SB0 instead of SB1. Also, it is not necessary to remap the CORESET to a new subband so that it is near the center of the subband. It can be relative to any other reference point. For example, the frequency domain resources of the CORESET may start from the lowest PRB in the selected subband. For example, the frequency domain resources of the CORESET may end at the highest PRB in the selected subband.

[0231] CORESET spans multiple subbands: If the frequency domain resources of a CORESET span multiple subbands and some of those subbands are unavailable, then the frequency domain of the CORESET can be remapped to the center of all available subbands. Fig.14 In , the frequency resources of CORESET x are initially mapped to SB2 and SB3, but due to LBT failure, SB2 is not available. Since SB0, SB1, and SB3 are available, the same number of frequencies initially configured as CORESET x can be remapped equally around the center of all available subbands, as shown in the figure.

[0232] Instead of remapping the CORESET across all available subbands, the CORESET can be remapped to a subset of available subbands according to specific rules. For example, if the CORESET is mapped across two subbands, it can be remapped to the center of the two available subbands with the smallest ID. In the previous example, it is SB0 and SB1. Moreover, the CORESET can be remapped to continuous frequency domain resources starting from a specific reference point in the selected subband. In general, the reference point can be any PRB or frequency point within or outside the selected subband. For example, it can be the lowest or highest PRB in the selected subband.

[0233] As another embodiment, we propose herein to configure CORESET remapping through RRC or RRC+MAC-CE combined signaling, or to deploy predetermined rules without any signaling. For example, if there is no CORESET remapping configuration, then a pre-specified CORESET remapping rule may be used. Fig.15 A procedure combining these two approaches is shown. Upon receiving an indication of a subband change, if the UE receives a static or semi-static CORESET remapping configuration for the specific CORESET identified by controlResoruceSetId, both the gNB and the UE will use the signaled configuration. However, if no remapping configuration exists, the gNB and the UE may use pre-specified rules.

[0234] Guard Band Indicator and Its Impact on CORSET Configuration

[0235] Guard bands may be needed at the edge(s) of the available subbands to reduce power leakage to adjacent bands.Several methods are proposed to indicate the guard band configuration to UEs operating in NR-U based on the available LBT subbands.

[0236] The size of the guard band may be specified so that, for example, L is reserved at the edge of the available LBT subband(s). GB PRBs, and it can be assumed that there is no guard band between adjacent available LBT subbands. Fig.38 An example of a BWP is shown, which is divided into four sub-bands SB0, SB1, SB2 and SB3, where the inner sub-bands SB1 and SB2 are available, and the outer sub-bands SB0 and SB3 are not available. In this case, L is reserved between (SB0 and SB1) and (SB2 and SB3). GB There are no guard bands between adjacent available subbands (SB1 and SB2). For any available subband, the guard band width at the upper edge of the subband (e.g., L GB,UP ) can be combined with the guard band width at the lower edge (e.g., represented by LGB,Down Indicates) are different. And you can specify L at the same time GB,UP and L GB,Down If the available LBT subband is located at the upper edge or lower edge of the active BWP, then there may be no need to set a guard band at the upper edge or lower edge of this subband, respectively.

[0237] Alternatively, the guard band size may be configured by higher layer signaling, such as UpperGB and LowerGB or GB for both upper and lower edges, e.g., RRC parameters. If only one parameter is indicated to the UE, the UE may assume that the guard band sizes at the upper and lower edges of the available LBT subbands are equal and both are set equal to the indicated size.

[0238] The start of the guard band may be indicated by higher layer signaling with reference to a specific PRB, such as the first PRB in a carrier, a BWP, or an available subband.

[0239] There is a chance that some of the PRBs in a CORESET may overlap with the guard band. As specified for Release 15 New Radio, a CORESET may consist of groups of PRBs that may be contiguous or non-contiguous and each group consists of 6 contiguous PRBs, which may be modified. Therefore, we propose in this paper that if any group of 6 PRBs is configured for a CORESET and it completely overlaps with the guard band, then the UE may assume that this group of 6 PRBs is invalid and does not carry PDCCH. This is equivalent to modifying the configured frequencyDomainResources, the RRC parameter that configures the frequency domain resources of the CORESET, by setting the bit associated with the PRB group to zero instead of one.

[0240] Moreover, if any group of 6 PRBs is configured for CORESET and it partially overlaps the guard band, the UE can assume that the entire group of 6 PRBs is invalid and does not carry PDCCH, or the UE can assume that only the PRBs that fully or partially overlap the guard band are invalid and do not carry PDCCH, while other PRBs that do not overlap the guard band can still be used to carry PDCCH.

[0241] The CORSET may be configured to span multiple subbands, while the PDCCH may be transmitted only within the CORESET portion of the available subbands. The PDCCH may be completely confined to a subband, or it may be interleaved across multiple subbands.

[0242] If the PDCCH is restricted to a subband, then the UE may assume that the PDCCH is not transmitted if this subband is indicated to be unavailable due to LBT failure on the gNB side. Alternatively, the UE may attempt to decode the PDCCH in other available subbands within the configured CORESET.

[0243] The UE may receive an indication that the PDCCH is restricted to a subband through higher layer signaling, for example, an RRC parameter such as SB_Confined_PDCCH. Furthermore, higher layer signaling such as an RRC parameter may provide the UE with a subband index containing the PDCCH. Furthermore, the UE may be indicated, for example, through higher layer signaling, whether to assume that the PDCCH is not transmitted if its subband is unavailable, or may still transmit it in other available subbands in the CORESET.

[0244] If the PDCCH is interleaved across several subbands and some of those subbands are not available, the UE may assume that the interleaved parts of the PDCCH in those subbands are not transmitted. Higher layer signaling may indicate the subbands that carry the interleaved parts of the PDCCH. Alternatively or additionally, the UE may assume that all subbands spanned by the CORESET may carry the interleaved parts of the PDCCH.

[0245] Subband Search Space

[0246] Since the CORESET can change based on the available subbands, the search space associated with this CORESET can also change. For example, the monitoring time slot, periodicity, offset, aggregation level, etc. can change as the available subbands change based on the results of LBT. Therefore, we propose the following embodiments in this article to address this challenge.

[0247] We propose to associate not only the search space (SS) configuration with the CORESET ID, but also with the subband Id. To this end, higher layer parameters such as the RRC SearchSpaceSB IE in the example information element 6 in the appendix can be used to include (one or more) subbands that contain the frequency domain resources of the CORESET identified by the ControlResourceSetId. For example, this can be captured in the parameter SB-Id, which carries a single or multiple subband Ids containing the frequency domain resources of the CORESET.

[0248] See example information element 6, SearchSpaceSB information element.

[0249] In NR Release 15, the search space is associated with a CORESET through higher layer signaling. Due to the uncertainty of channel access, part or the entire CORESET may not be available. Therefore, multiple CORESETs with different IDs can be configured to the UE. Then, based on the LBT results at the gNB, the search space can be associated with the correct CORESET ID.

[0250] The UE may be configured with an appropriate CORESET ID associated with the search space for each possible LBT result at the gNB through higher layer signaling. For example, if a particular search space is associated with CORESET 1 if subband 0 is available, and with CORESET 2 if subband 3 is available, and so on. To this end, for example, assuming that the BWP consists of M subbands, the following RRC parameters may be introduced: SB_0, SB_1, ..., SB_M-1, each indicating the correct CORESET ID if this subband is available.

[0251] Alternatively, the UE may infer the CORESET ID associated with the search space based on certain rules depending on some parameters (such as search space ID, available subband IDs, etc.).

[0252] Uplink BWP / subband switching for RACH and BFR

[0253] Uplink BWP / subband switching for RACH

[0254] In NR, once the initial access procedure is started, specifically a particular UL BWP with a Physical Random Access Channel (PRACH) preamble transmission commonly referred to as Message 1 (Msg 1), it is assumed that Message 3 (Msg 3) in the RACH procedure will be transmitted on the same UL BWP as the one used for the Msg 1 transmission. The time and frequency resources for Msg3 are indicated in the gNB's response to Msg 1, which is called the Random Access Response (RAR) and denoted as Message 2 (Msg 2). In particular, in Msg2, the gNB transmits a DCI format 1_0 scrambled with the RACH-RNTI (RA-RNTI) and the UE must decode it within a time window called the RAR window. Once the DCI is correctly decoded, the UE can proceed to decode the PDSCH carrying the RAR, which indicates the time / frequency resources for Msg 3. The frequency domain resources for Msg 3 are allocated using uplink resource allocation type 1 indicating resources to the scheduled UEs within the active UL BWP.

[0255] In NR-U, the time between transmitting Msg 1 and Msg 3 can be long enough for other nodes to obtain the UL BWP / subband containing frequency domain resources, which may no longer be available. To address this challenge, we propose the following embodiments in this article.

[0256] The UE may receive multiple RARs within a RAR window, which may also be extended. Each RAR may provide time and frequency resources within a specific BWP. The reserved bits in the RAR may be used to indicate the BWP index, or new bits may be introduced for this purpose. Fig.16 An example of multiple RARs is shown, which provide frequency domain and time domain resources on different BWPs / subbands.Then, depending on the LBT result, the UE can transmit Msg3 on the available BWP / subband according to the associated uplink grant.

[0257] In order to limit the overhead due to having multiple Msg3 resources per UE, and also to limit the risk of Msg3 collisions and hence the risk of detection failures at the gNB, we propose in this paper:

[0258] 1. The UE may randomly select among multiple Msg3 resources (eg, BWPs or subbands) a resource to be used for Msg3 transmission if there are multiple available ULBWPs / subbands.

[0259] 2. The Msg3 resource can be deterministically selected based on the UE ID. For example, let us assume that K Msg3 resources are signaled to the UE, where the indexes of the Msg3 resources are 0, 1, 2...K-1. The UE selects a resource index that satisfies the following condition: Selected resource index = UE_ID Mod K.

[0260] As another embodiment, we propose in this article to define resource remapping rules based on resources provided in another UL BWP / subband, which can indicate time domain and frequency domain resources on other BWP / subbands. For example, the UE can introduce frequency domain resources for Msg 3 on a UL BWP / subband by moving the configured resources only on a specific UL BWP / subband. Fig.17 An example is shown where the RAR explicitly provides frequency domain and time domain resources for Msg 3 on BWP0. Therefore, the UE can introduce resources on other BWPs by moving the frequency domain resources to the same position as in BWP0 while maintaining the same time position. In addition to the rules with explicit configuration, different rules can be applied to implicitly provide resources for Msg 3 on a BWP. For example, the frequency domain resources can be moved to the center of another BWP / subband. The time domain resources can be the same across all BWPs, but can also be different, for example due to some shift based on the BWP / subband Id.

[0261] Alternatively, we propose in this paper that the gNB can transmit only a single RAR, but with a larger size than the original size of the RAR that carries frequency and time domain resources for Msg 3 over multiple BWPs / subbands. Here, we propose that a single RAR can carry time and frequency resources of different BWPs / subbands.

[0262] Regarding message 4, if the UE selects a BWP other than the one originally used in the transmission of Msg 1, it means that the UE may be surrounded by other nodes using the frequency domain corresponding to the BWP. Therefore, it may be better to transmit Msg 4 on the DL BWP associated with the UL BWP selected by the UE for the transmission of Msg 3.

[0263] Enhancements for MSG3

[0264] It may be beneficial to provide multiple transmission opportunities for MSG3 in the time domain and / or frequency domain to increase the chance of accessing the channel. To provide multiple time domains, we propose the following procedures or their combination herein.

[0265] The MSG3 PUSCH Time Resource Allocation field in the RAR, i.e., MAC PDU, may be extended. Contrary to what is specified for Release 15 New Radio, instead of using this field to indicate a single row of the time domain allocation list TimeDomainAllocationList provided by higher layer signaling or a default specified list, we propose in this document to extend this field to, e.g., 16 bits and use it to indicate multiple rows in the time domain allocation list. In other words, for example, this field may be considered as a bitmap and its length may be set equal to the number of rows in the time domain allocation list. Each bit may correspond to a single row or multiple rows. The UE may consider the indicated rows as alternatives to each other and may select only one candidate starting position based on the LBT result.

[0266] For example, Table 3 shows that the example time resource allocation bitmap field is extended to 16 bits. Each bit corresponds to a specific slot offset K2, a start symbol S, and an allocation length L. For example, if the bits corresponding to the settings in the first and second rows are set to 1, the UE can assume that two candidate starting positions at OFDM symbols 0 and 1 are indicated, and the UE can select one of them based on the LBT result.

[0267] Table 3 Time domain resource allocation using bitmap

[0268]

[0269] Alternatively, the size of the time resource allocation bit field in the RAR may remain the same as specified for Release 15 New Radio, but the bitmap may be interpreted differently. Specifically, each bit may correspond to multiple rows in the time domain allocation list. For example, Table 4 shows that the time resource allocation bit field is 4 and each bit corresponds to four different PUSCH configurations for MSG3. The UE may select the best PUSCH configuration based on the LBT result.

[0270] Table 4

[0271] Temporal resource allocation using bitmaps where each bit corresponds to multiple rows

[0272]

[0273] In addition, the size of the configured or default time domain allocation list can be increased, thereby adding more rows representing new configurations for PUSCH. The PUSCH configurations can be grouped so that each row represents multiple configurations. In this case, the time resource allocation bit field still indicates the row index, but each row provides multiple starting positions for PUSCH. For example, 4 bits of the time resource allocation bit field can indicate the index of 16 rows, and each row can carry multiple configurations.

[0274] As another possible solution, some parameters of the time domain allocation list can be modified only, without adding more rows or reinterpreting the time resource allocation bit field or increasing its size. In some rows, multiple K2 values ​​can be used to provide multiple candidate starting positions across different time slots. For example, in some rows of Table 5, K2 and K2+β are two different slot offset values, and the UE can select the appropriate slot offset based on the LBT result. Similarly, multiple starting symbols can be provided in some rows. Table 5 shows an example of providing S and S+α as possible starting OFDM symbols, and the UE can select the appropriate starting symbol based on the LBT result. Parameters β and α can be configured by high-level signaling. If they are not configured, parameters β and α can be specified and they can be functions of other system parameters (such as numerology).

[0275] Table 5 Time domain resource allocation using row indexes with multiple K2 and S values

[0276]

[0277] Alternatively, the RAR may indicate multiple slot offsets or starting symbol values, and a new field may be introduced for this purpose. This field may indicate the periodicity of the candidate starting positions, which may be represented, for example, by δ. Specifically, if the indicated slot offset is K2, then the UE may assume that it can be shifted by K2, K2+δ, K2+2δ, ... or K maxMSG3PUSCH is transmitted in the time slot of K max is the maximum allowed slot offset that can be indicated by higher layer signaling, derived or specified according to some rules. If the indicated starting symbol is S, then the UE can assume that it can be in symbol S, S+δ, S+2δ, ... or S max MSG3PUSCH is transmitted at max is the maximum allowed start symbol index that can be indicated by higher layer signaling, according to some rules (such as S max =14-L) derived or specified. The field indicating δ has Log2(the number of possible values ​​of δ) bits. For example, δ K and δ S To deploy and represent different periodicity values ​​for slot offset and start symbol. In this case, two separate fields may be needed to indicate δ K and δ S .

[0278] Instead of using an additional field in the RAR to indicate the periodicity of the slot offset or the starting symbol of the MSG3 PUSCH to provide multiple candidate starting positions, the periodicity periods δ, δ can be configured through higher layer signaling or specified without higher layer signaling. K and δ S .

[0279] If the RAR provides multiple candidate starting positions for the PUSCH of MSG3, then multiple MCSs may need to be indicated to the UE for each or some of the provided PUSCH configurations. Multiple MCS fields in the RAR may each be tied to a specific starting position. The UE may use some rules to derive a new MCS based on the candidate starting position and the length of the PUSCH carrying MSG3. For example, if the length of the MSG3 PUSCH of the candidate starting position is the same as the length of the MSG3 PUSCH of the original starting position, then the UE may use the same MCS provided for the original starting position. In another example, if the length of the MSG3 PUSCH of the candidate starting position is half the length of the MSG3 PUSCH of the original starting position, then the UE may use double the MCS provided for the original starting position. For example, the MCS for the candidate starting position may be expressed as follows

[0280]

[0281] Where L old and MCS old is the length of the original starting position of the MSG3 PUSCH and the indicated MCS, while L new is the length of MSG3PUSCH (depending on its new starting position).

[0282] Advantageously, MSG2 indicates the channel access procedure type(s) for MSG3 in the RACH procedure. In some cases, the same channel access procedure type may be deployed for all candidate starting positions of MSG3. In other cases, the channel access procedure type may depend on the candidate starting position of MSG3.

[0283] For a single starting position or multiple candidate starting positions that deploy the same channel access procedure for MSG3, then a field in the DCI that schedules the RAR PDSCH (e.g., DCI format 1_0 scrambled with RA RNTI) can be used to indicate the channel access procedure for MSG3. The size of this field can be equal to Log2 (number of channel access procedures).

[0284] If the UE cannot access the channel for transmission according to the first starting position indicated in the RAR, there are several options. The UE may attempt to access the channel and transmit the PUSCH at other candidate starting positions. Similarly, or for example, the channel access procedure may be indicated in the RAR itself by a Log2(Number of Channel Access Procedures) field in a dedicated RAR MAC PDU. Alternatively, the indication of the channel access procedure may be divided between the DCI-scheduled RAR PDSCH and the RAR in case there are not enough bits in the DCI or RAR to carry this indication by themselves.

[0285] For the case where the channel access procedure can change from a candidate starting position to another position, we propose in this paper to add an additional column in the time domain allocation list so that for each indicated candidate starting position, the associated channel access procedure type is indicated. This approach can be combined with the above-mentioned process to indicate the candidate starting position. For example, in Table 6, a new column is added to indicate the channel access type.

[0286] Table 6

[0287] Time domain resource allocation, indicating the channel access process associated with each candidate starting position of MSG3

[0288]

[0289] Moreover, the UE may infer the type of channel access procedure based on certain rules depending on several factors, such as the time gap between the first symbol carrying MSG3 and the last symbol carrying RAR, the length of MSG3, numerology, etc. For example, if the time interval between the first symbol carrying MSG3 and the last symbol carrying RAR is less than and / or greater than a certain threshold(s), then a specific type of channel access procedure may be applied. Fig.39An example is shown where MSG2 provides 4 candidate starting positions for MSG3. If the UE successfully accesses the channel at the first or second candidate starting position to transmit PUSCH, then a type 1 channel access procedure may be deployed. If the UE successfully accesses the channel at the third or fourth candidate starting position to transmit PUSCH, then a type 2 channel access procedure may be deployed. The threshold(s) and associated channel access type procedures may be configured or specified by higher layer signaling.

[0290] Uplink BWP switching for BFR

[0291] In BFR, we propose in this paper that the gNB can configure PRACH resources for UEs across different BWP / subbands to increase the chances of the UE acquiring a channel to transmit a beam failure recovery request (BFRQ). Some of these PRACH resources can be associated with contention-free PRACH, while others can be associated with contention-based PRACH.

[0292] Furthermore, we propose herein that the gNB response may be transmitted on a BWP with a different ID than the BWP used for BFRQ transmission. In order to reduce the power consumption of the UE when monitoring the gNB's response, some of the above-mentioned embodiments may be employed to configure the CORESET associated with the recoverySearchSpaceId and monitor the gNB responses across different BWP / subband IDs.

[0293] As another embodiment, we propose herein that the UE may monitor the CORESETs associated with recoverySearchSpaceId on different BWPs / subbands in a specific order. For example, the UE may start monitoring this CORESET on the BWP / subband in which it is initially configured. Then, the UE may monitor this CORESET on BWPs in the following order: default BWP->initial BWP->BWP0->BWP1->…, etc. Similarly, the UE may monitor this CORESET on subbands in the following order: SB0->SB1->SB2->…, etc.

[0294] CSI-RS Enhancement

[0295] CSI-RS can be configured for a variety of purposes including channel acquisition, beam management, beam failure recovery, radio link monitoring, radio resource management, etc. For any of these use cases, the CSI-RS can be configured to occupy the full bandwidth or only a small portion of the BWP configured for the UE. With wideband operation, the gNB may not always have access to the entire frequency band carrying the CSI-RS, i.e., the gNB successfully performs LBT on the set of subbands that make up this BWP. Therefore, if (one or more) CSI-RS are configured to span multiple subbands, then there is no guarantee that all those subbands are always available at the same time. Therefore, we propose several enhancements to CSI-RS in this paper to address this challenge.

[0296] The channel acquisition indication(s) may be used to let the UE adjust its receive filter(s). The explicit or implicit channel acquisition indication(s) may indicate the subbands acquired by the gNB. In this case, the UE may assume that only REs within the available subbands are carrying the configured CSI-RS, while other REs within the unavailable subbands are not transmitted and should not be considered during the measurement process. For example, the UE should not average REs in the unavailable subbands.

[0297] For New Radio Release 15, CSI-RS can be configured to be transmitted on a portion of the DL BWP. Specifically, the BWP is divided into CSI-RS subbands (CSRS-SB) of consecutive PRBs, and the size of this CSRS-SB depends on the size of the BWP as shown in Table 7, and different CSRS-SB sizes can be introduced. For each size of BWP, there are two possible CSRS-SB sizes, and the selected size can be configured through higher layer signaling.

[0298] Table 7 CSRS-SB dimensions

[0299] Bandwidth Part (PRBs) CSRS-SB Dimensions (PRBs) <24 N / A 24–72 4，8 73–144 8，16 145–275 16，32

[0300] For example, CSRS-SB can cross LBT subband boundaries, such as Fig.28 If one of the LBT subbands for carrying the configured CSRS-SB to the UE is not available, e.g. Fig.28 If SB3 in the protocol is used, the UE may adopt one of the following alternatives.

[0301] In the first alternative, if any of the CSRS-SBs spans two LBT subbands and one of them is unavailable, the UE may assume that no CSI-RS is transmitted in this CSRS-SB, i.e., discard the measurement on this CSRS-SB and no reporting is required for this CSRS-SB. Fig.29, where all configured CSRS-SBs that are fully or partially outside of the available subbands are dropped from the measurement and no reporting is required for them. Furthermore, if the measurements are averaged across all subbands within the DL BWP, the UE may not include averaging in the unavailable (one or more) SBs to avoid corrupting the averaging.

[0302] In another alternative, if any of those LBT subbands is unavailable, the configured CSRS-SBs spanning two LBT subbands may not be completely dropped. Instead, the CSRS-SB PRBs that are fully or partially in the unavailable LBT subband will be dropped, and other PRBs in the same CSRS-SB may still carry CSI-RS and contribute to the measurement. This is equivalent to shrinking the last CSRS-SB to contain fewer PRBs than other CSRS-SBs that are far from the subband boundary. For example, Fig. 30A It is shown that the CSRS-SB spanning SB2 and SB3 is partially dropped because SB3 is unavailable. In this case, the CSI-RS can only be transmitted on PRBs that are completely located in SB2.

[0303] Furthermore, even if multiple consecutive LBT subbands are available, we propose in this paper to restrict the measurement to the LBT subbands. If the configured CSRS-SB spans two consecutive available subbands, then this CSRS-SB can be divided into two CSRS-SBs, each of which is completely contained in one LBT subband. If there is a PRB that crosses the boundary between any consecutive LBT subbands, then this PRB can be discarded and the UE can assume that no CSI-RS is transmitted in this PRB. Fig. 30B An example of a CSRS-SB spanning (SB0, SB1) and another spanning (SB1, SB2) is shown, and each of those CSRS-SBs is then split into two CSRS-SBs, one in each available LBT subband. If the UE is configured to report CSI on a CSRS-SB (parent CSRS-SB) spanning two consecutive LBT subbands, then the UE may assume that CSI reporting is configured for the child CSRS-SB, and the resulting new CSRS-SB splits the parent CSRS-SB.

[0304] In new radio (NR) based access to unlicensed spectrum, guard bands may be employed to avoid interference with adjacent channels. Thus, for example, some CSRS-SBs may fully or partially overlap with the guard bands, such as Fig.31. If any of those CSRS-SBs are configured for the UE to measure, then the UE may assume, for example, that no CSI-RS REs are transmitted on those CSRS-SBs. In other words, the UE may discard those CSRS-SBs from the configured measurements. Furthermore, if there are CSRS-SBs configured to carry CSI-RS REs that fall into unusable subbands, then the UE may assume that measurements should not be made on those CSRS-SBs.

[0305] Alternatively, if the CSRS-SB completely overlaps with the guard band or spans the unavailable LBT subband and the guard band, i.e., the CSRS-SB is located at the boundary between the unavailable LBT subband and the guard band, then the UE can assume that no measurements should be made on them and the entire CSRS-SB is discarded. However, for CSRS-SBs spanning the available LBT subband and the guard band, the UE can assume that the PRBs that fall completely or partially into the guard band cannot carry CSI-RS and do not make any measurements on them. However, the UE can assume that the PRBs that fall completely into the available LBT subband can still carry CSI-RS and can be measured on them. Fig.32 An example is shown where CSRS-SBs completely overlap or span both unavailable LBT subbands or guard bands, and the UE can then discard them. On the other hand, for those CSRS-SBs that span available subbands and guard bands, the UE can assume that its PRBs in available subbands can carry CSI-RS and can measure on those PRBs. In other words, the UE can assume that the size of those CSRS-SBs is smaller than the size of other CSRS-SBs that are far away from the guard band.

[0306] The size of the first and last CSRS-SB can be given according to the location of the LBT sub-band, the size of the guard band, the location of the BWP, etc. For example, the lowest available LBT sub-band in the BWP j The size of the first CSRS-SB can be determined by Given, where It is the size of CSRS-SB. is from reference PRB to BWP i The number of PRBs in the first PRB, From BWP i The first PRB in the LBT sub-band j The number of PRBs in the first PRB, and It is in LBT sub-band j The number of PRBs used as guard bands in . Fig.33If the guard band PRB is not required, then Set to zero.

[0307] if Then the highest available LBT sub-band in the BWP k The size of the last CSR-SB in can be given by Given, where M is the number of consecutively available LBT subbands, is the size of the LBT subband in PRBs and It is in LBT sub-band k The number of PRBs used as guard bands in Then you can Give the highest available LBT sub-band in the BWP k If the available LBT subbands have different sizes, then the item Replace with in is the size of the qth available LBT subband.

[0308] For the case of discontinuous available LBT sub-bands, the above mentioned examples can be applied by processing the available LBT sub-bands separately.

[0309] In New Radio Release 15, CSI-RS can be configured to occupy multiple ODSM symbols within a slot. Due to the uncertainty of channel access, the gNB may not be able to access the channel at the configured (one or more) time domain locations. To address this challenge, the following alternatives or any combination of them can be adopted.

[0310] In the first alternative, the UE may assume that the CSI-RS in the OFDM symbols dropped before the gNB successfully acquires the channel are discarded. In other words, if the gNB fails to acquire the channel before them, then the UE may assume that the OFDM symbols carrying CSI-RS are punctured. For example, Fig.34 An example of CSI-RS configured for transmission in OFDM symbols 3 and 9 is shown. In this example, the gNB acquires the channel at OFDM symbol 6. Therefore, the UE can assume that OFDM symbol 9 is still carrying CSI-RS while OFDM symbol 3 carrying CSI-RS is punctured, as originally configured.

[0311] As a possible other solution, if any (one or more) codewords carrying CSI-RS are punctured, then the UE can assume that other (one or more) OFDM codewords carrying CSI-RS will also be punctured, even if they fall within the COT of the gNB. It is worth mentioning that when we propose to puncture OFDM codewords carrying CSI-RS in this paper, this OFDM codeword may still carry other DL transmissions. Only REs configured to carry CSI-RS in this OFDM codeword are punctured. Those REs can carry DL transmissions to this UE or any other UE. Especially if CSI-RS is time-domain CDM, then this solution will be of great interest.

[0312] Alternatively, the UE may assume that the (one or more) OFDM codewords carrying the CSI-RS may be shifted. For example, the shift value may be explicitly indicated to the UE dynamically in a UE-specific DCI or a group-common DCI. The UE-specific DCI may be scrambled by the C-RNIT and the group-common DCI may be scrambled with an RNTI similar to the SFI. The shift value may also be indicated by the MAC-CE. If it is assumed that any signal / channel should be received earlier, then the shift value may be implicitly indicated to the UE by noting the time shift, for example, a time shift in DMRS, PSS, SSS, SSB may serve this purpose. If the (one or more) OFDM codewords carrying the CSI-RS are shifted to fall outside the gNB MCOT, then the UE may assume that those OFDM codewords are punctured. In Fig.35 In , we show an example of a CSI-RS that is configured to be transmitted in OFDM symbols 3 and 9, and the gNB cannot access the channel due to LBT failure. Therefore, when the gNB acquires the channel, it can indicate a shift of 3 OFDM symbols, and then the UE can assume that the CSI-RS that should be transmitted in OFDM symbols 3 and 9 are transmitted in OFDM symbols 6 and 12, respectively.

[0313] Furthermore, it may be beneficial to remove the time dependency in the initial sequence generator of the CSI-RS. For example, the initialization sequence may be given by:

[0314]

[0315] in It can be a timeslot number relative to the beginning of the COT. If the gNB acquires the channel in the middle of a timeslot, then this partial timeslot can be counted as the first timeslot in the gNB's COT. Parameter l is the OFDM symbol number within the timeslot, and for the first timeslot in the gNB's COT, l must not be less than the index of the first OFDM symbol in the gNB's COT. Parameter n ID and are equal to the higher layer parameters and the number of OFDM symbols in a time slot, respectively.

[0316] Alternatively, can be the slot number within the radio frame, and l can be the OFDM symbol number relative to the beginning of the COT of the gNB. The other parameters in the equation remain unchanged.

[0317] In New Radio Release 15, reporting CSRS-SBs may be configured by higher layer signaling that carries a bitmap whose size is equal to the number of CSRS-SBs in the BWP. In the above mentioned solution, if the size of the CSRS-SB is reduced due to crossing an available LBT subband and another unavailable LBT subband, the indication bit corresponding to the original CSRS-SB may be used to indicate the modified CSRS-SB size. Moreover, for a parent CSRS-SB that is divided into two child CSRS-SBs due to crossing an available LBT subband, the same indication bit corresponding to the original CSRS-SB may be used to indicate the two child CSRS-SBs.

[0318] The Third Generation Partnership Project (3GPP) develops technical standards for cellular telecommunication network technologies, including radio access, core transport networks, and service capabilities - including work on codecs, security, and quality of service. Recent radio access technology (RAT) standards include WCDMA (commonly referred to as 3G), LTE (commonly referred to as 4G), and LTE-Advanced standards. 3GPP has begun work on the standardization of the next generation of cellular technology, which is called New Radio (NR), also known as "5G". The development of the 3GPP NR standard is expected to include the definition of the next generation radio access technology (new RAT), which is expected to include the provision of new flexible radio access below 6 GHz, and the provision of new ultra-mobile broadband radio access above 6 GHz. Flexible radio access is expected to include new, non-backward compatible radio access in new spectrum below 6 GHz, and is expected to include different operating modes that can be multiplexed together in the same spectrum to address a wide set of 3GPP NR use cases with different requirements. Ultra-mobile broadband is expected to include cmWave and mmWave spectrum, which will provide opportunities for ultra-mobile broadband access for, for example, indoor applications and hotspots. In particular, ultra-mobile broadband is expected to share a common design framework with sub-6 GHz flexible radio access, with cmWave- and mmWave-specific design optimizations.

[0319] The Third Generation Partnership Project (3GPP) develops technical standards for cellular telecommunication network technologies, including radio access, core transport networks, and service capabilities - including work on codecs, security, and quality of service. Recent radio access technology (RAT) standards include WCDMA (commonly referred to as 3G), LTE (commonly referred to as 4G), and LTE-Advanced standards. 3GPP has begun work on the standardization of the next generation of cellular technology, which is called New Radio (NR), also known as "5G". The development of the 3GPP NR standard is expected to include the definition of the next generation radio access technology (new RAT), which is expected to include the provision of new flexible radio access below 6 GHz, and the provision of new ultra-mobile broadband radio access above 6 GHz. Flexible radio access is expected to include new, non-backward compatible radio access in new spectrum below 6 GHz, and is expected to include different operating modes that can be multiplexed together in the same spectrum to address a wide set of 3GPP NR use cases with different requirements. Ultra-mobile broadband is expected to include cmWave and mmWave spectrum, which will provide opportunities for ultra-mobile broadband access for, for example, indoor applications and hotspots. In particular, ultra-mobile broadband is expected to share a common design framework with sub-6 GHz flexible radio access, with cmWave- and mmWave-specific design optimizations.

[0320] 3GPP has identified a variety of use cases that NR is expected to support, resulting in various user experience requirements for data rates, latency, and mobility. Use cases include the following general categories: enhanced mobile broadband (e.g., broadband access in dense areas, ultra-high broadband access indoors, broadband access in crowds, ubiquitous 50+Mbps, ultra-low-cost broadband access, in-vehicle mobile broadband), critical communications, massive machine-type communications, network operations (e.g., network slicing, routing, migration and interworking, energy saving), and enhanced vehicle-to-everything (eV2X) communications, which may include vehicle-to-vehicle communications (V2V), vehicle-to-infrastructure communications (V2I), vehicle-to-network communications (V2N), vehicle-to-pedestrian communications (V2P), and vehicle-to-other-entities communications. Specific services and applications in these categories include, for example, surveillance and sensor networks, device remote control, two-way remote control, personal cloud computing, video streaming, wireless cloud-based offices, first responder connectivity, car ecalls, disaster alerts, real-time gaming, multi-person video calls, autonomous driving, augmented reality, tactile Internet, and virtual reality, among others. All of these use cases and others are contemplated herein.

[0321] Fig.27AAn embodiment of an example communication system 100 is illustrated in which the methods and apparatus described and claimed herein may be implemented. As shown, the example communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, 102e, 102f, and / or 102g (generally or collectively referred to as WTRUs 102), a radio access network (RAN) 103 / 104 / 105 / 103b / 104b / 105b, a core network 106 / 107 / 109, a public switched telephone network (PSTN) 108, the Internet 110, other networks 112, and a V2X server (or ProSe function and server) 113, although it should be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d, 102e, 102f, 102g may be any type of device or apparatus configured to operate and / or communicate in a wireless environment. Figures 27A-27E , but it should be understood that for the various use cases anticipated for 5G wireless communications, each WTRU may include or be implemented in any type of device or apparatus configured to transmit and / or receive wireless signals, including, by way of example only, a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a pager, a cellular phone, a personal digital assistant (PDA), a smart phone, a laptop, a tablet computer, a netbook, a notebook computer, a personal computer, a wireless sensor, a consumer electronics product, a wearable device (such as a smart watch or smart clothing), a medical or e-health device, a robot, an industrial equipment, a drone, a vehicle (such as a car, truck, train or airplane, etc.).

[0322] The communication system 100 may also include a base station 114a and a base station 114b. The base station 114a may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, and 102c to facilitate access to one or more communication networks (such as the core network 106 / 107 / 109, the Internet 110, and / or other networks 112). The base station 114b may be any type of device configured to wiredly and / or wirelessly interface with at least one of the RRHs (remote radio heads) 118a, 118b, TRPs (transmission and reception points) 119a, 119b, and / or RSUs (roadside units) 120a, 120b to facilitate access to one or more communication networks (such as the core network 106 / 107 / 109, the Internet 110, other networks 112, and / or V2X servers (or ProSe functions and servers) 113). The RRH 118a, 118b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102c to facilitate access to one or more communication networks, such as the core network 106 / 107 / 109, the Internet 110, and / or other networks 112. The TRP 119a, 119b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102d to facilitate access to one or more communication networks, such as the core network 106 / 107 / 109, the Internet 110, and / or other networks 112. The RSU 120a and 120b may be a device configured to wirelessly interface with at least one of the WTRUs 102e or 102f to facilitate access to one or more communication networks, such as the core network 106 / 107 / 109, the Internet 110, other networks 112, and / or a V2X server (or ProSe function and server) 113. For example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a site controller, an access point (AP), a wireless router, etc. Although the base stations 114a, 114b are each depicted as a single element, it should be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0323] The base station 114a may be part of the RAN 103 / 104 / 105, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), a relay node, etc. The base station 114b may be part of the RAN 103b / 104b / 105b, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), a relay node, etc. The base station 114a may be configured to transmit and / or receive wireless signals within a specific geographic area, which may be referred to as a cell (not shown). The base station 114b may be configured to transmit and / or receive wired and / or wireless signals within a specific geographic area, which may be referred to as a cell (not shown). The cell may be further divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in an embodiment, the base station 114a may include three transceivers, for example, one transceiver for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple-output (MIMO) technology and may therefore use multiple transceivers for each sector of the cell.

[0324] The base station 114a may communicate with one or more of the WTRUs 102a, 102b, 102c over an air interface 115 / 116 / 117, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible light, cmWave, mmWave, etc.). The air interface 115 / 116 / 117 may be established using any suitable radio access technology (RAT).

[0325] The base station 114b may communicate with one or more of the RRHs 118a, 118b, the TRPs 119a, 119b, and / or the RSUs 120a, 120b via a wired or air interface 115b / 116b / 117b, which may be any suitable wired (e.g., cable, optical fiber, etc.) or wireless communication link (e.g., radio frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible light, cmWave, mmWave, etc.). The air interface 115b / 116b / 117b may be established using any suitable radio access technology (RAT).

[0326] The RRHs 118a, 118b, TRPs 119a, 119b and / or RSUs 120a, 120b may communicate with one or more WTRUs 102c, 102d, 102e, 102f via an air interface 115c / 116c / 117c, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible light, cmWave, mmWave, etc.). The air interface 115c / 116c / 117c may be established using any suitable radio access technology (RAT).

[0327] The WTRUs 102a, 102b, 102c, 102d, 102e, 102f and / or 102g may communicate with each other via an air interface 115d / 116d / 117d (not shown), which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible light, cmWave, mmWave, etc.). The air interface 115d / 116d / 117d may be established using any suitable radio access technology (RAT).

[0328] More specifically, as described above, the communication system 100 may be a multiple-access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base station 114a in the RAN 103 / 104 / 105 and the WTRUs 102a, 102b, 102c or the RRHs 118a, 118b, TRPs 119a, 119b and / or RSUs 120a, 120b in the RAN 103b / 104b / 105b and the WTRUs 102c, 102d, 102e, 102f may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may use Wideband CDMA (WCDMA) to establish the air interface 115 / 116 / 117 or 115c / 116c / 117c, respectively. WCDMA may include communication protocols such as High Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink Packet Access (HSDPA) and / or High Speed ​​Uplink Packet Access (HSUPA).

[0329] In an embodiment, the base station 114a and the RRH 118a, 118b, TRP 119a, 119b and / or RSU 120a, 120b in the WTRU 102a, 102b, 102c or RAN 103b / 104b / 105b, and the WTRU 102c, 102d may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may use Long Term Evolution (LTE) and / or LTE-Advance (LTE-A) to establish an air interface 115 / 116 / 117 or 115c / 116c / 117c, respectively. In the future, the air interface 115 / 116 / 117 may implement 3GPP NR technology. LTE and LTE-A technologies include LTE D2D and V2X technologies and interfaces (such as sidelink communications, etc.). 3GPP NR technologies include NR V2X technologies and interfaces (such as sidelink communications, etc.).

[0330] In an embodiment, the base station 114a in the RAN 103 / 104 / 105 and the WTRUs 102a, 102b, 102c or the RRHs 118a, 118b, the TRPs 119a, 119b and / or the RSUs 120a, 120b and the WTRUs 102c, 102d, 102e, 102f in the RAN 103b / 104b / 105b may implement a radio technology such as IEEE 802.16 (e.g., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 IX, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile Communications (GSM), Enhanced Data Rates for GSM Evolution (EDGE), GSM EDGE (GERAN) etc.

[0331] For example, Fig.27AThe base station 114c in the example may be a wireless router, a Home Node B, a Home eNode B, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in a local area, such as a business location, a home, a vehicle, a campus, etc. In an embodiment, the base station 114c and the WTRU 102e may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114c and the WTRU 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114c and the WTRU 102e may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, etc.) to establish a picocell or a femtocell. Fig.27A As shown in FIG, base station 114b may have a direct connection to the Internet 110. Therefore, base station 114c may not be required to access the Internet 110 via core network 106 / 107 / 109.

[0332] The RAN 103 / 104 / 105 and / or the RAN 103b / 104b / 105b may be in communication with a core network 106 / 107 / 109, which may be any type of network configured to provide voice, data, applications, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. For example, the core network 106 / 107 / 109 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions (such as user authentication).

[0333] Although not in Fig.27A 105b and / or the core network 106 / 107 / 109 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 103 / 104 / 105 and / or the RAN 103b / 104b / 105b or a different RAT. For example, in addition to being connected to the RAN 103 / 104 / 105 and / or the RAN 103b / 104b / 105b, which may utilize an E-UTRA radio technology, the core network 106 / 107 / 109 may also be in communication with another RAN (not shown) that employs a GSM radio technology.

[0334] The core network 106 / 107 / 109 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d, 102e to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network that provides plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and the Internet Protocol (IP) in the TCP / IP Internet Protocol suite. The networks 112 may include wired or wireless communication networks owned and / or operated by other service providers. For example, the networks 112 may include another core network connected to one or more RANs, which may employ the same RAT as the RAN 103 / 104 / 105 and / or the RAN 103b / 104b / 105b or a different RAT.

[0335] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication system 100 may include multi-mode capabilities, e.g., the WTRUs 102a, 102b, 102c, 102d, and 102e may include multiple transceivers for communicating with different wireless networks via different wireless links. Fig.27A The WTRU 102e shown in FIG. 1 may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114c, which may employ an IEEE 802 radio technology.

[0336] Fig.27B 1 is a block diagram of an example apparatus or device (such as, for example, WTRU 102) configured for wireless communication according to the embodiments described herein. Fig.27B As shown in , the example WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad / indicator 128, a non-removable memory 130, a removable memory 132, a power supply 134, a global positioning system (GPS) chipset 136, and other peripherals 138. It should be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with the embodiment. Moreover, the embodiments contemplate that the base stations 114a and 114b, and / or nodes of the base stations 114a and 114b may represent, for example, but not limited to, a transceiver station (BTS), a Node B, a site controller, an access point (AP), a home node-B, an evolved home node-B (eNodeB), a home evolved node-B (HeNB), a home evolved node-B gateway, and a proxy node, etc. may include Fig.27BPart of some or all of the elements described in and described herein.

[0337] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. Although Fig.27B The processor 118 and transceiver 120 are depicted as separate components, but it will be appreciated that the processor 118 and transceiver 120 may be integrated together in an electronic package or chip.

[0338] The transmission / reception element 122 may be configured to transmit signals to a base station (e.g., base station 114a) or receive signals from a base station (e.g., base station 114a) via an air interface 115 / 116 / 117. For example, in an embodiment, the transmission / reception element 122 may be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmission / reception element 122 may be a transmitter / detector configured to, for example, transmit and / or receive IR, UV, or visible light signals. In yet another embodiment, the transmission / reception element 122 may be configured to transmit and receive RF and light signals. It should be appreciated that the transmission / reception element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0339] In addition, although the transmit / receive element 122 is Fig. 22B Although depicted as a single element in the figure, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in an embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 115 / 116 / 117.

[0340] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As described above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate via multiple RATs (e.g., such as UTRA and IEEE 802.11).

[0341] The processor 118 of the WTRU 102 may be coupled to a speaker / microphone 124, a keypad 126, and / or a display / touchpad / indicator 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit), and may receive user input data therefrom. The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad / indicator 128. In addition, the processor 118 may access information from and store data in any type of suitable memory, such as a non-removable memory 130 and / or a removable memory 132. The non-removable memory 130 may include a random access memory (RAM), a read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In an embodiment, the processor 118 may access information from and store data in a memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0342] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control the power to other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries, solar cells, fuel cells, etc.

[0343] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to or in lieu of the information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) over the air interface 115 / 116 / 117 and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by any suitable location-determination method while remaining consistent with an embodiment.

[0344] The processor 118 may also be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include various sensors such as accelerometers, biometric (e.g., fingerprint) sensors, electronic compasses, satellite transceivers, digital cameras (for photos or videos), universal serial bus (USB) ports or other interconnect interfaces, vibration devices, television transceivers, hands-free headsets, modules, FM radio units, digital music players, media players, video game player modules, internet browsers, etc.

[0345] The WTRU 102 may be implemented in other devices or equipment, such as sensors, consumer electronics, wearable devices (such as smart watches or smart clothing), medical or e-health equipment, robots, industrial equipment, drones, vehicles (such as cars, trucks, trains or airplanes), etc. The WTRU 102 may be connected to other components, modules or systems of such devices or equipment via one or more interconnect interfaces (such as an interconnect interface that may include one of the peripheral devices 138).

[0346] Fig.27C 1 is a system diagram of the RAN 103 and the core network 106 according to an embodiment. As described above, the RAN 103 may employ UTRA radio technology to communicate with the WTRUs 102a, 102b, and 102c over the air interface 115. The RAN 103 may also be in communication with the core network 106. Fig.27C As shown in FIG. 1 , the RAN 103 may include Node-Bs 140a, 140b, 140c, each of which may include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 115. The Node-Bs 140a, 140b, 140c may each be associated with a particular cell (not shown) within the RAN 103. The RAN 103 may also include RNCs 142a, 142b. It will be appreciated that the RAN 103 may include any number of Node-Bs and RNCs while remaining consistent with an embodiment.

[0347] like Fig.27C As shown in , Node B 140a, 140b can communicate with RNC 142a. In addition, Node B 140c can communicate with RNC 142b. Node B 140a, 140b, 140c can communicate with corresponding RNC 142a, 142b via Iub interface. RNC142a, 142b can communicate with each other via Iur interface. Each of RNC 142a, 142b can be configured to control the corresponding Node B 140a, 140b, 140c connected thereto. In addition, each of RNC 142a, 142b can be configured to perform or support other functions, such as outer loop power control, load control, admission control, packet scheduling, handover control, macro diversity, security functions, data encryption, etc.

[0348] Fig.27CThe core network 106 shown in FIG. 1 may include a media gateway (MGW) 144, a mobile switching center (MSC) 146, a serving GPRS support node (SGSN) 148, and / or a gateway GPRS support node (GGSN) 150. Although each of the foregoing elements is depicted as part of the core network 106, it should be appreciated that any of these elements may be owned and / or operated by an entity other than a core network operator.

[0349] The RNC 142a in the RAN 103 may be connected to the MSC 146 in the core network 106 via an IuCS interface. The MSC 146 may be connected to the MGW 144. The MSC 146 and the MGW 144 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices.

[0350] The RNC 142a in the RAN 103 may also be connected to the SGSN 148 in the core network 106 via an IuPS interface. The SGSN 148 may be connected to the GGSN 150. The SGSN 148 and the GGSN 150 may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0351] As described above, core network 106 may also be connected to networks 112, which may include other wired or wireless networks owned and / or operated by other service providers.

[0352] Fig.27D 1 is a system diagram of the RAN 104 and the core network 107 according to an embodiment. As described above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, and 102c over the air interface 116. The RAN 104 may also be in communication with the core network 107.

[0353] The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to, and receive wireless signals from, the WTRU 102a.

[0354] Each of the eNode-Bs 160a, 160b, and 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the uplink and / or downlink, etc. Fig.27D As shown in FIG, eNode-Bs 160a, 160b, 160c may communicate with each other via an X2 interface.

[0355] Fig.27D The core network 107 shown in FIG. 1 may include a mobility management gateway (MME) 162, a serving gateway 164, and a packet data network (PDN) gateway 166. While each of the foregoing elements is depicted as part of the core network 107, it should be appreciated that any of these elements may be owned and / or operated by an entity other than a core network operator.

[0356] The MME 162 may be connected to each of the eNode-Bs 160a, 160b, and 160c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, etc. The MME 162 may also provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM or WCDMA.

[0357] The serving gateway 164 may be connected to each of the eNode-Bs 160a, 160b, and 160c in the RAN 104 via an S1 interface. The serving gateway 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The serving gateway 164 may also perform other functions, such as anchoring the user plane during an inter-eNode B handover, triggering paging when downlink data is available for the WTRUs 102a, 102b, 102c, managing and storing the context of the WTRUs 102a, 102b, 102c, and the like.

[0358] The serving gateway 164 may also be connected to the PDN gateway 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0359] The core network 107 may facilitate communications with other networks. For example, the core network 107 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the core network 107 may include, or may be in communication with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the core network 107 and the PSTN 108. In addition, the core network 107 may provide the WTRUs 102a, 102b, 102c with access to the networks 112, which may include other wired or wireless networks owned and / or operated by other service providers.

[0360] Fig.27E 1 is a system diagram of the RAN 105 and the core network 109 according to an embodiment. The RAN 105 may be an access service network (ASN) that employs IEEE 802.16 radio technology to communicate with the WTRUs 102a, 102b, and 102c over the air interface 117. As discussed further below, the communication links between the different functional entities of the WTRUs 102a, 102b, 102c, the RAN 105, and the core network 109 may be defined as reference points.

[0361] like Fig.27EAs shown in the figure, the RAN 105 may include base stations 180a, 180b, 180c and an ASN gateway 182, but it should be appreciated that the RAN 105 may include any number of base stations and ASN gateways while remaining consistent with the embodiment. The base stations 180a, 180b, 180c may each be associated with a particular cell in the RAN 105 and may include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 117. In an embodiment, the base stations 180a, 180b, 180c may implement MIMO technology. Thus, the base station 180a, for example, may use multiple antennas to transmit wireless signals to the WTRU 102a and receive wireless signals from the WTRU 102a. The base stations 180a, 180b, 180c may also provide mobility management functions, such as handover triggering, tunnel establishment, radio resource management, traffic classification, quality of service (QoS) policy enforcement, and the like. The ASN gateway 182 may serve as a traffic aggregation point and may be responsible for paging, caching of subscriber profiles, routing to the core network 109, and the like.

[0362] The air interface 117 between the WTRUs 102a, 102b, 102c and the RAN 105 may be defined as an R1 reference point that implements the IEEE 802.16 specification. In addition, each of the WTRUs 102a, 102b, and 102c may establish a logical interface (not shown) with the core network 109. The logical interface between the WTRUs 102a, 102b, 102c and the core network 109 may be defined as an R2 reference point, which may be used for authentication, authorization, IP host configuration management, and / or mobility management.

[0363] The communication link between each of the base stations 180a, 180b, and 180c may be defined as an R8 reference point, which includes protocols for facilitating WTRU handover and data transfer between the base stations. The communication link between the base stations 180a, 180b, 180c and the ASN gateway 182 may be defined as an R6 reference point. The R6 reference point may include protocols for facilitating mobility management based on mobility events associated with each of the WTRUs 102a, 102b, 102c.

[0364] like Fig.27EAs shown in , the RAN 105 may be connected to a core network 109. The communication link between the RAN 105 and the core network 109 may be defined as an R3 reference point, which includes protocols for facilitating, for example, data transfer and mobility management capabilities. The core network 109 may include a mobile IP home agent (MIP-HA) 184, an authentication, authorization, accounting (AAA) server 186, and a gateway 188. While each of the foregoing elements is depicted as part of the core network 109, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the core network operator.

[0365] The MIP-HA may be responsible for IP address management and may enable the WTRUs 102a, 102b, and 102c to roam between different ASNs and / or different core networks. The MIP-HA 184 may provide the WTRUs 102a, 102b, and 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, and 102c and IP-enabled devices. The AAA server 186 may be responsible for user authentication and supporting user services. The gateway 188 may facilitate interworking with other networks. For example, the gateway 188 may provide the WTRUs 102a, 102b, and 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, and 102c and traditional land-line communication devices. In addition, the gateway 188 may provide the WTRUs 102a, 102b, 102c with access to the networks 112, which may include other wired or wireless networks that are owned and / or operated by other service providers.

[0366] Although not in Fig.27E 105 may be connected to other ASNs and the core network 109 may be connected to other core networks. The communication link between the RAN 105 and the other ASNs may be defined as an R4 reference point, which may include protocols for coordinating the mobility of the WTRUs 102a, 102b, 102c between the RAN 105 and the other ASNs. The communication link between the core network 109 and the other core networks may be defined as an R5 reference, which may include protocols for facilitating interworking between a home core network and a visited core network.

[0367] This article describes and Fig.27A , 27CThe core network entities shown in 27D and 27E are identified by the names given to those entities in certain existing 3GPP specifications, but it should be recognized that in the future, those entities and functions may be identified by other names, and that certain entities or functions may be combined in future specifications published by 3GPP (including future 3GPP NR specifications). Fig.27A , 27B The specific network entities and functions described and illustrated in 27C, 27D and 27E are provided by way of example only, and it should be understood that the subject matter disclosed and claimed herein may be implemented or realized in any similar communication system, whether currently defined or defined in the future.

[0368] Fig.27F is a block diagram of an exemplary computing system 90 in which Fig.27A , 27C , 27D and 27E, such as certain nodes or functional entities in the RAN 103 / 104 / 105, the core network 106 / 107 / 109, the PSTN 108, the Internet 110 or other networks 112. The computing system 90 may include a computer or a server and may be primarily controlled by computer-readable instructions, which may be in the form of software, wherever or in whatever manner such software is stored or accessed. Such computer-readable instructions may be executed within the processor 91 to enable the computing system 90 to operate. The processor 91 may be a general-purpose processor, a special-purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. The processor 91 may perform signal encoding, data processing, power control, input / output processing, and / or any other function that enables the computing system 90 to operate in a communication network. Coprocessor 81 is an optional processor distinct from main processor 91 that may perform additional functions or assist processor 91. Processor 91 and / or coprocessor 81 may receive, generate, and process data related to the methods and apparatus disclosed herein.

[0369] In operation, processor 91 fetches, decodes and executes instructions, and transfers information to and from other resources via the computing system's main data transfer path, namely, system bus 80. Such a system bus connects components in computing system 90 and defines a medium for data exchange. System bus 80 typically includes data lines for sending data, address lines for sending addresses, and control lines for sending interrupts and for operating the bus. An example of such a system bus 80 is a PCI (Peripheral Component Interconnect) bus.

[0370] The memory coupled to the system bus 80 includes a random access memory (RAM) 82 and a read-only memory (ROM) 93. Such memory includes a circuit system that allows information to be stored and retrieved. ROM 93 generally contains stored data that is not easily modified. The data stored in RAM 82 can be read or changed by a processor 91 or other hardware device. Access to RAM 82 and / or ROM 93 can be controlled by a memory controller 92. The memory controller 92 can provide an address translation function that translates a virtual address into a physical address when an instruction is executed. The memory controller 92 can also provide a memory protection function that isolates processes within the system and isolates system processes from user processes. Therefore, a program running in the first mode can only access memory mapped by its own process virtual address space; unless memory sharing between processes has been set up, it cannot access memory within the virtual address space of another process.

[0371] In addition, the computing system 90 may include a peripheral device controller 83 that is responsible for transmitting instructions from the processor 91 to peripheral devices such as a printer 94 , a keyboard 84 , a mouse 95 , and a disk drive 85 .

[0372] The display 86 controlled by the display controller 96 is used to display the visual output generated by the computing system 90. Such visual output may include text, graphics, animated graphics, and video. The visual output may be provided in the form of a graphical user interface (GUI). The display 86 may be implemented with a CRT-based video display, an LCD-based flat panel display, a gas plasma-based flat panel display, or a touch pad. The display controller 96 includes the electronic components required to generate the video signal sent to the display 86.

[0373] Additionally, computing system 90 may include communications circuitry, such as a network adapter 97, which may be used to connect computing system 90 to an external communications network, such as a Fig.27A , 27B , RAN 103 / 104 / 105 of 27C, 27D and 27E, core network 106 / 107 / 109, PSTN 108, Internet 110 or other network 112) to enable computing system 90 to communicate with other nodes or functional entities of those networks. Alone or in combination with processor 91, the communication circuit system can be used to perform the transmission and reception steps of certain devices, nodes or functional entities described herein.

[0374] Figure 27GAn embodiment of an example communication system 111 is illustrated in which the methods and apparatus described and claimed herein may be implemented. As shown, the example communication system 111 may include wireless transmit / receive units (WTRUs) A, B, C, D, E, F, base stations, a V2X server, and RSUs A and B, but it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. One or several or all of the WTRUs A, B, C, D, E may be out of range of the network (e.g., outside the cell coverage boundary shown by the dashed lines in the figure). WTRUs A, B, C form a V2X group, where WTRU A is the group leader and WTRUs B and C are group members. WTRUs A, B, C, D, E, and F may communicate via a Uu interface or a sidelink (PC5) interface.

[0375] It should be understood that any or all of the devices, systems, methods, and processes described herein may be implemented in the form of computer executable instructions (e.g., program code) stored on a computer-readable storage medium, which, when executed by a processor (such as processor 118 or 91), causes the processor to perform and / or implement the systems, methods, and processes described herein. Specifically, any step, operation, or function described herein may be implemented in the form of such computer executable instructions executed on a processor of a device or computing system configured for wireless and / or wired network communications. Computer-readable storage media include volatile and non-volatile, removable and non-removable media implemented in any non-transient (e.g., tangible or physical) method or technology for storing information, but such computer-readable storage media do not include signals. Computer-readable storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disk (DVD) or other optical disk storage, cassettes, tapes, disk storage or other magnetic storage devices, or any other tangible or physical media that can be used to store desired information and can be accessed by a computing system.

[0376] appendix

[0377] Table 0

[0378] Abbreviations

[0379]

[0380]

[0381]

[0382] Table 1

[0383] SB IE Field Description

[0384]

[0385] Table 2

[0386] Subband Configuration Example

[0387]

[0388] Example Information Element 1

[0389] SB Information Element

[0390]

[0391] Example Information Element 2

[0392] SB-List Information Element

[0393]

[0394] Example Information Element 3

[0395] BWP_SB_Configs Information Element

[0396]

[0397] Example Information Element 4

[0398] ControlResourceSetReMapping Information Element

[0399]

[0400]

[0401]

[0402] Example Information Element 5

[0403] ControlResourceSetReMappingV2 Information Element

[0404]

[0405]

[0406] Example Information Element 6

[0407] SearchSpaceSB Information Element

[0408]

[0409]

[0410]

[0411]

[0412]

Claims

1. A wireless transmission / reception unit WTRU, comprising a processor, wherein the processor is configured to: receiving a higher layer signaling including guard band information, the guard band information indicating the start of a guard band and the number of resource blocks associated with the guard band; receiving downlink control information (DCI), the DCI comprising a bitmap indicating one or more subbands that a base station has determined to be unavailable, wherein each bit in the bitmap indicates an availability status of a corresponding subband; and Reception of at least one channel state information reference signal CSI-RS configured in the one or more subbands indicated by the DCI as unavailable is canceled.

2. The WTRU of claim 1 , wherein: The DCI also includes channel occupancy time information.

3. The WTRU of claim 1 , wherein: The higher layer signaling corresponds to radio resource control RRC signaling.

4. The WTRU of claim 1 , wherein: The processor being configured to cancel reception of at least one CSI-RS includes the processor being configured to determine that the base station will not transmit the at least one CSI-RS.

5. The WTRU of claim 1 , wherein: Downlink control information is received in a Physical Downlink Control Channel (PDCCH) transmission.

6. The WTRU of claim 5, wherein: The PDCCH transmission is received via a common search space.

7. The WTRU of claim 5, wherein: The PDCCH is received via a group common radio network temporary identifier.

8. The WTRU of claim 1 , wherein: The processor is configured to: Transmitting a random access preamble; A random access response (RAR) is received, wherein the RAR indicates a type of channel access procedure to be performed by the WTRU for transmitting a random access message 3 (msg3).

9. The WTRU of claim 1 , wherein the processor is configured to: Determine to receive at least a second CSI-RS configured in at least one subband indicated as available by the DCI.

10. The WTRU of claim 1 wherein: The guard band is located at an edge of at least one of the one or more sub-bands.

11. A method implemented by a wireless transmit / receive unit WTRU, the method comprising: receiving a higher layer signaling including guard band information, the guard band information indicating the start of a guard band and the number of resource blocks associated with the guard band; receiving downlink control information (DCI), the DCI comprising a bitmap indicating one or more subbands that a base station has determined to be unavailable, wherein each bit in the bitmap indicates an availability status of a corresponding subband; as well as Reception of at least one channel state information reference signal CSI-RS configured in the one or more subbands indicated by the DCI as unavailable is canceled.

12. The method of claim 11, wherein: The DCI also includes channel occupancy time information.

13. The method of claim 11, wherein: The higher layer signaling corresponds to radio resource control RRC signaling.

14. The method of claim 11, wherein: Canceling reception of the at least one CSI-RS includes determining that the base station will not transmit the at least one CSI-RS.

15. The method of claim 11, wherein: Downlink control information is received in a Physical Downlink Control Channel (PDCCH) transmission.

16. The method of claim 15, wherein: The PDCCH transmission is received via a common search space.

17. The method of claim 15, wherein: The PDCCH is received via a group common radio network temporary identifier.

18. The method of claim 11, further comprising: Sending a random access preamble; A random access response (RAR) is received, wherein the RAR indicates a type of channel access procedure to be performed by the WTRU for transmitting a random access message 3 (msg3).

19. The method of claim 11, further comprising: Determine to receive at least a second CSI-RS configured in at least one subband indicated as available by the DCI.

20. The method of claim 11, wherein the guard band is located at an edge of at least one of the one or more sub-bands.

21. A wireless transmit / receive unit WTRU, comprising a processor, wherein the processor is configured to: receiving a subband configuration message via higher layer signaling, the subband configuration message including a list of subbands within an active bandwidth part (BWP), the list indicating a set of available subbands for monitoring based on a listen-before-talk (LBT) result; Monitor the indicated subband to obtain the control resource set CORESET; Dynamically adjusting the monitoring behavior by excluding at least one unavailable subband based on a subband bitmap received in downlink control information DCI; receiving data associated with the CORESET on at least one available subband; as well as Assistance information is sent to a base station, the assistance information identifying an interference-free subset of the available subbands based on subband quality measurements performed by the WTRU.

22. The WTRU of claim 21 wherein: The subband configuration message also includes a radio resource control (RRC) parameter identifying a default subband for monitoring when no DCI is received.

23. The WTRU of claim 21 wherein the CORESET spans multiple sub-bands having unequal bandwidths and the WTRU is configured to preferentially monitor a CORESET having a narrower sub-band during low power operation.

24. The WTRU of claim 21 wherein the assistance information comprises a preferred subband list generated by the WTRU based on subband activity and interference levels.

25. The WTRU of claim 21, wherein the subband quality measurements include both a channel quality indicator (CQI) and a signal-to-noise ratio (SNR) value for each monitored subband.

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