Improvements to, or relating to, ul grant-free transmission - configuration and resource bundling

Abstract

The method for allocating resources for uplink unlicensed data transmission from the UE to the base station. Resources are allocated by the base station and indicated to be sent to the UE, where the same resource can be used by more than one UE. The RRC policy defines the resource selection process for initial transmissions and retransmissions following collisions.

Description

Technical Field

[0001] The present invention generally relates to wireless communication systems, and more particularly to devices and methods for enabling wireless communication devices, such as user equipment (UE) or mobile devices, to access radio access technology (RAT) or radio access network (RAN), particularly but not exclusively to improvements to UL unlicensed transmission-configuration and resource bundling, or related to such modifications. Background Technology

[0002] Wireless communication systems such as third-generation mobile phone standards and technologies are well-known. The 3G Partnership (3GPP) has developed such 3G standards and technologies. Generally speaking, third-generation wireless communication has been developed to the point of supporting macro cell mobile phone communication, and communication systems and networks have evolved towards broadband and mobile systems.

[0003] The 3G Partnership has developed the so-called Long Term Evolution (LTE) system, namely the Evolved Universal Mobile Communications System Territorial Radio Access Network (E-UTRAN), for mobile access networks supported by one or more macro cells, called eNodeBs or eNBs (evolved NodeBs). More recently, LTE has further evolved into the so-called 5G or NR (New Radio) system, in which one or more cells are supported by base stations called gNBs.

[0004] In the following sections, we will focus on 5G NR services that require lower latency transmissions compared to other services. These services typically involve transmitting high-priority, infrequent, small to medium-sized data packets, which can be transmitted via grant-free UL transmissions. The UE can autonomously schedule these grant-free transmissions under the policies and configurations set by the gNB through RRC.

[0005] The following are the 3GPP protocols related to unlicensed UL transmission.

[0006] RAN1#NR-AH2 (June 2017)

[0007] Types of unlicensed UL data transfer

[0008] Type 1: Unlicensed UL data transmission is based solely on RRC (reconfiguration) without any L1 signaling.

[0009] Type 2: Unlicensed UL data transmission is based on both RRC configuration and L1 signaling to activate / deactivate unlicensed UL data transmission.

[0010] Note: The modification function is activated via L1 signaling.

[0011] Type 3: Unlicensed UL data transmission is based on RRC configuration and allows L1 signaling to modify some parameters of the RRC configuration, but L1 signaling is not activated.

[0012] • For unlicensed UL data transfer, Type 1 and Type 2 have reached a consensus, while Type 3 is subject to further study (FFS).

[0013] Further research is needed on the reliability of L1 signaling.

[0014] • For Type 1 UL-licens-free UL transfers, the RRC (re-)configuration must include at least the following:

[0015] -Relative to SFN=0, the periodicity and offset of resources

[0016] -Time-domain resource allocation

[0017] Frequency domain resource allocation

[0018] - UE-specific DMRS configuration

[0019] -Notice:

[0020] • A TB is mapped to a resource consisting of at least time / frequency domain resources.

[0021] • For unlicensed UL data transmissions that are distinct from UL-licensed data transmissions specified in the Rel.15WI standard, RAN1 will not introduce specific resource allocations and DMRS configurations.

[0022] -MCS / TBS value

[0023] - Number of repetitions K

[0024] -Power control related parameters

[0025] - Further research on HARQ-related parameters

[0026] - Further investigation is needed to determine if multiple resources can be configured.

[0027] • For Type 2 UL-free transmissions

[0028] - The RRC (reconfiguration) of resources and parameters should include at least the following:

[0029] • Resource cyclicality

[0030] Power control related parameters

[0031] -At least the following other resource parameters are given by L1 signaling.

[0032] • The periodic-related offset relative to the timing reference indicated by the L1 signaling used for activation

[0033] Further research on time series references

[0034] • Time-domain resource allocation

[0035] Frequency domain resource allocation

[0036] UE-specific DMRS configuration

[0037] MCS / TBS value

[0038] ·Notice:

[0039] • One TB is mapped to one resource

[0040] • For unlicensed UL data transmissions that are distinct from UL-licensed data transmissions specified in the Rel.15WI standard, RAN1 will not introduce specific resource allocations and DMRS configurations.

[0041] - Further investigation is needed to determine if multiple resources can be configured.

[0042] - Further research on HARQ-related parameters

[0043] - Further investigation is needed to determine whether the number of repetitions K is configured by RRC signaling and / or indicated by L1 signaling.

[0044] In addition to RS parameters, time and frequency resources are also configured in a UE-specific manner.

[0045] Note: It is generally understood that the time and frequency resources configured for one UE may or may not conflict with another UE (which will be captured in LS).

[0046] • For unlicensed UL transmissions, NR supports more than one HARQ process.

[0047] -RAN1 believes that UL-free UL transmissions performed by the UE can be identified based on time / frequency resources and one or more RS parameters.

[0048] RAN1 believes that UL-free UL transmissions performed by the UE can be identified based on time / frequency resources and one or more RS parameters.

[0049] Regarding configuration:

[0050] RAN1#NR-AH1 (January 2017)

[0051] • For unlicensed UL transmission schemes

[0052] - Supports at least semi-static resource (reconfiguration)

[0053] Further research is needed: resource allocation should include at least physical resources and RS parameters in the time and frequency domains.

[0054] • Higher-level signaling may be similar to Rel-8 LTE SPS

[0055] Further research on MCS

[0056] RAN1#88

[0057] • For unlicensed UL transmission

[0058] - Resource configuration should include at least the following:

[0059] • Time and frequency resources, further research needed: implicitly or explicitly including repetitive resources.

[0060] • Modulation and coding schemes, which may implicitly or explicitly include RV

[0061] • Reference signal parameters

[0062] Further research: specific details

[0063] Further research: Number of repetitions K

[0064] Further research: Can multiple Ks be configured into a single UE?

[0065] Further research on other parameters

[0066] RAN1#89

[0067] • If the network is configured, then without L1 signaling, semi-static resource configuration in RRC allows for UL data transmission without UL authorization.

[0068] • If the network is configured, L1 signaling can be used to activate / deactivate and / or modify parameters for UL data transmission without UL authorization.

[0069] RAN1 is discussing whether a mechanism is needed to differentiate between UL SPS and UL data transmission without UL authorization.

[0070] • R1-1709537's "Semi-static resource configuration in RRC" includes UE-specific semi-static configurations for RS.

[0071] Repetition and retransmission of unlicensed UL transmissions in 3GPP protocols

[0072] RAN1#NR-AH1 (January 2017)

[0073] • For UL transmission schemes requiring / not requiring authorization

[0074] - Supports K repetitions of the same transport block (K>=1), including the initial transport (with the same or different RVs, further investigation is needed for different MCSs).

[0075] Further research is needed to determine the method of K.

[0076] Further research: Frequency hopping mechanisms in transmission

[0077] RAN1#88

[0078] • For unlicensed UL transmission

[0079] - Further research suggests that the UE can continue repeating the TB until one of the following conditions is met:

[0080] Successfully received ACK from gNB

[0081] • The number of repetitions of TB reaches K

[0082] • For licensed / unlicensed TB transmissions, a UE is configured to repeat K times. This UE can continue repeating TB (further research could explore different RV versions and different MCSs) until one of the following conditions is met:

[0083] -If the same TB time slot / hourly slot successfully receives UL authorization

[0084] Further research: How to determine if the authorization is granted to the same TB

[0085] - Further investigation: Confirmation / indication of successful reception of this TB from gNB

[0086] -TB was repeated K times.

[0087] - Further investigation: Is it possible to determine whether the authorization was given to the same TB?

[0088] Note that this does not assume that UL licensing is based on time-slot scheduling, while unlicensed allocation is based on small time slots (and vice versa).

[0089] Note that other termination conditions may apply.

[0090] Channel structure for unlicensed UL transmission in 3GPP protocols

[0091] RAN1#NR-AH1 (January 2017)

[0092] • For unlicensed UL transmission schemes

[0093] -RS is transmitted along with data.

[0094] • A licensed data transmission channel structure can serve as a starting point

[0095] RAN1#88

[0096] • At least for CP-OFDM, NR supports a universal DMRS architecture for DL ​​and UL.

[0097] - DMRS on the same or different links can be configured to be orthogonal to each other.

[0098] - Further investigation is needed to determine the exact location, mode, and scrambling sequence of the general DMRS structure.

[0099] - For CP-OFDM, PN sequences are supported.

[0100] Further research: ZC sequence of CP-OFDM

[0101] RAN1#88bis

[0102] • For UL DFT-S-OFDM DMRS, ZC sequences are supported.

[0103] RAN1#NR-AH2 (June 2017)

[0104] • Working assumption (WA): Unlicensed UL transmissions support both DFT-S-OFDM and CP-OFDM.

[0105] Timing Advancement and Power Control for Unlicensed UL Transmission in 3GPP Protocols

[0106] For NR UL data transmission timing advance (TA) and power control mechanisms:

[0107] RAN1#NR-AH2 (June 2017)

[0108] • UL transmissions requiring or without UL authorization are subject to the same TA adjustment process / mechanism (including the end of the TA timer).

[0109] • For UL transmissions without UL authorization

[0110] -Supports open-loop power control based on path loss estimation

[0111] - Further research: Supporting closed-loop power control based on NW signals

[0112] • When there are no transport blocks to send, for UL-unlicensed UL transports, the UE must not perform any transports on the configured resources.

[0113] Further research: UL-licens-free UL transmission supports UCI with transport block.

[0114] Unlicensed UL transmission is a hot topic in RAN1, and it has become the subject of multiple protocols in recent meetings, especially at the recent 3GPP TSG RAN WG1 NR Ad-Hoc#2 (Qingdao), which produced 30 Tdocs and 4 protocols.

[0115] For unlicensed UL transmissions of Type 1 and Type 2 ULs, there has been consensus on using RRC to allocate separate UL resources to UEs operating on unlicensed ULTx at regular intervals. Furthermore, RRC configures the TBS / MCS value and the number of repetitions K.

[0116] Another agreement is:

[0117] In addition to RS parameters, time and frequency resources are also configured in a UE-specific manner.

[0118] Note: It is generally understood that the time and frequency resources configured for one UE may or may not conflict with another UE (which will be captured in LS).

[0119] Therefore, it has been agreed that the same resource block for an unlicensed Tx can be assigned to different UEs, and these UEs can then be distinguished by UE-specific DMRS.

[0120] When a user initiates an unlicensed transmission, the gNB must identify the user and the HARQ-related parameters for that transmission. In LTE, these are configured in DC1, which makes unlicensed transmissions impossible here.

[0121] Therefore, the present invention seeks to solve some or all of the problems related to pre-reserved resource allocation, RV indication, and PID indication. Summary of the Invention

[0122] This "Summary" is provided to introduce, in a simplified form, some selections of concepts that will be further described in the following "Detailed Description". This "Summary" is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0123] According to a first aspect of the invention, a method and system are provided for assigning a UE to a set of common, pre-reserved resources for a UL GF. Preferably, the gNB transmits a NAK with a collision indication.

[0124] Preferably, the UE uses a random strategy in both the frequency and time domains to select resources for the next transmission.

[0125] Preferably, the retransmission of low-latency UEs is random in the frequency dimension, while the retransmission of other UEs is random in the time dimension.

[0126] Preferably, the RRC configuration is unique for all blocks (the same TBS / MCS). Preferably, if the RRC configures several TBSs within the same group of resource blocks, the UE performs randomization for a subset of blocks with configurations that match their subsequent payload sizes.

[0127] According to another approach, a UL unlicensed transmission is provided, in which the HARQ procedure number is explicitly sent as uplink control information by breaking down data resource elements.

[0128] According to another aspect, a UL unlicensed transmission is provided, wherein the HARQ procedure number is explicitly sent as uplink control information by rate matching of data resource elements.

[0129] Preferably, data resource elements that are effectively used to send HARQ program numbers are selected to make detection robust, as they are close to the reference symbol.

[0130] On the other hand, a redundant version is provided for UL unlicensed transmission, which can be used in unlicensed scenarios without explicitly sending signaling.

[0131] According to another approach, the user is provided with an RV associated with the established RV sequence to send data on the first available GF occasion. For the remaining K-1 repetitions, this RV sequence continues in a cyclical manner.

[0132] Preferably, the present invention can be used for retransmission in communication based on unlicensed UL.

[0133] According to another aspect, in the case of an unlicensed UL transmission configured with K repetitions, the gNB can send a FAST ACK before receiving all K repetitions.

[0134] According to another approach, after receiving a FAST ACK before sending all K repetitions of GF UL, the user immediately stops and does not send any more repetitions.

[0135] According to another approach, for UL GF transmission, the gNB can send FAST NAK to the user before receiving all K repetitions.

[0136] Preferably, the NAK can be an explicit NAK, or it can be a form of UL unlicensed scheduling of users on different dedicated resources.

[0137] Preferably, FAST ACK or NAK can be sent in a group of common DCIs.

[0138] Preferably, the shared DCI of the group can be used for a group of users who have been allocated the same GF UL resources.

[0139] Preferably, after K repetitions, if the UE neither receives a HARQ response nor a UL authorization for the same TB, the GF transmission for the same TB can be restarted in the next available GF scenario.

[0140] Preferably, the radio access network is a new radio / 5G network.

[0141] According to another aspect of the present invention, a base station or UE suitable for performing the method of another aspect of the present invention is provided. According to another aspect of the present invention, a non-volatile computer-readable medium is provided having computer-readable instructions stored thereon for a processor to execute in order to perform the method of another aspect of the present invention.

[0142] The non-volatile computer-readable medium may include at least one of the following: hard disk, CD-ROM, optical storage device, magnetic storage device, read-only memory, programmable read-only memory, erasable programmable read-only memory, EPROM, electrically erasable programmable read-only memory, and flash memory. Attached Figure Description

[0143] The present invention will be described below by way of example only, in conjunction with the accompanying drawings, to provide further details, aspects, and embodiments. For simplicity and clarity, elements in the drawings are shown, and these elements are not necessarily drawn to scale. The same reference numerals are used throughout the various drawings for ease of understanding.

[0144] Figure 1 This shows the traditional resource allocation for unlicensed UL, with one UE per resource block, GF every 2 time slots, and K=3.

[0145] Figure 2 This shows the traditional resource allocation for unlicensed UL, with a single UE hopping frequency per resource block, GF every 2 time slots, and K=3.

[0146] Figure 3 The multi-UE allocation for each resource block is shown.

[0147] Figure 4 This shows multiple UEs being assigned to a set of common resource blocks.

[0148] Figure 5 The relationship between RV and GF scenarios is shown.

[0149] Figure 6 The relationship between RV and FG scenarios is shown, including issues in the traditional approach.

[0150] Figure 7 The association between RV and GF transmission scenarios proposed according to embodiments of the present invention is illustrated. Detailed Implementation

[0151] Those skilled in the art will recognize and understand that the specific details of the described examples are merely illustrative of some embodiments, and that the teachings set forth herein apply to various alternative configurations.

[0152] This invention focuses on unlicensed uplink (UL) transmission in new radio (NR). For URLLC type services, UL unlicensed transmission has been standardized in NR to reduce latency. More specifically, this invention focuses on:

[0153] - How to allocate pre-reserved resources to the UL GF UE and how to select a given UL GF resource for transmission.

[0154] - How to identify users and HARQ-related parameters when users are transmitting on UL GF resources. ACK / NAK procedures and the possibility of prematurely terminating UL GF transmissions are also discussed here.

[0155] In recent meetings, UL Unlicensed GF has become the target of multiple protocols, especially the 30 Tdocs and 4 protocols in the recent 3GPP TSG RAN WG1NR Ad-Hoc#2 (Qingdao). In LTE, the eNB configures UL transmissions in the DL control information, thus the eNB knows precisely what will be transmitted at certain times and in certain subframe time slots. In UL unlicensed transmission, the UE uses TF resources from a set of pre-reserved resources, and autonomously triggers such transmissions whenever the UE has a buffer to transmit. This invention proposes enhancements to the allocation of pre-reserved TF resources and improvements to the UE's selection of transmission opportunities.

[0156] Furthermore, since multiple users may be associated with the same time-frequency resources, and there is a possibility of UL transmission hopping, the gNB needs to identify the user transmitting data in a specific transmission scenario, and also needs to understand HARQ-related parameters, namely the HARQ program ID and redundancy version (RV) when multiple transmissions are configured. This invention proposes an efficient method and related signaling for conveying these parameters to the gNB, and further describes an early termination mechanism for situations where additional transmissions may not be required.

[0157] This invention proposes a method to improve resource utilization and collision rate in UL unlicensed transmission, thereby enhancing the capacity, robustness, and latency of UL unlicensed operation mode.

[0158] -A new allocation mechanism is proposed for the TF resources pre-reserved by the UL GF. In this mechanism, multiple UEs are allocated to a group of resources to reduce the amount of pre-reserved unused resources and increase the flexibility of UE resource usage.

[0159] - A random-based resource selection mechanism is proposed for UEs to select their GF UL Tx. This utilizes the aforementioned scheme and reduces the collision rate through latency optimization.

[0160] The present invention also proposes a method to ensure full understanding of UL unlicensed transmissions from users, thereby avoiding ambiguity in HARQ program numbers and RVs.

[0161] - A novel design is proposed that associates RV with and uses RV for K unlicensed UL transmissions, in which no explicit information is sent, there is no delay, and the user is allowed to transmit in the first available UL GF situation.

[0162] - An early termination mechanism is proposed, which avoids the extra transmission of the same TB upon successful decoding, thereby generating significant advantages in terms of system spectral efficiency and user energy efficiency.

[0163] Allocation of pre-reserved resources for unlicensed UL transmissions

[0164] Allocation issues for individual UEs in each resource block during unlicensed UL transport

[0165] Considering that SPS is allocated periodically, while the transport of unlicensed UL Tx UEs is typically not periodic, it seems that allocating a single UE to each pre-allocated resource could result in significant capacity loss due to unused resources and could severely limit the number of unlicensed UEs that can be served per cell and per unit time.

[0166] Figure 1 This shows the traditional resource allocation for unlicensed UL, with one UE per resource block, GF every 2 time slots, and K=3.

[0167] Figure 2 This demonstrates traditional resource allocation for unlicensed ULs, with each resource block having a single UE using frequency hopping, a GF every 2 time slots, and K=3.

[0168] Figure 1 and Figure 2 Three different resource blocks are shown allocated to unlicensed ULs, one with frequency hopping and the other with frequency hopping, with each resource block specifically allocated to the same UE. To meet the stringent latency requirements of UrLLCs, the gNB must allocate periodic resources with relatively small periodicity. However, UrLLC UE transmissions are infrequent and typically not periodic. This results in a significant amount of unused resources for each allocated UE, which cannot be reused by other UEs.

[0169] Therefore, a large amount of resources are pre-allocated to each UE. In addition, the resources wasted by all UEs combined make this approach unscalable as the number of unlicensed UEs increases.

[0170] The problem of allocating multiple UEs in a single resource block

[0171] To mitigate resource waste, one solution is to allocate multiple UEs to each pre-reserved resource block. This reduces the amount of unused resources at the cost of intra-UE collisions.

[0172] Collisions or conflicts must be handled with care. For example, if two transmissions from different UEs collide, this collision prevents the decoding of any payload, which creates room for consecutive collisions (deadlock).

[0173] Figure 3 The multi-UE allocation for each resource block is shown.

[0174] Figure 3 The following scenario illustrates a situation where, after the initial collision, UE1 and UE3 are assigned to Chunk1, and both UEs attempt to immediately perform reTx, thus generating another collision.

[0175] Assigning several UEs to a single resource block introduces a certain probability of collisions, which increases dramatically with the number of UEs and their duty cycle. Furthermore, there is a risk of subsequent collisions following the initial one. This compromises the reliability and latency of unlicensed UL Tx UEs, a serious drawback for UrLLC UEs.

[0176] Randomized retransmissions can partially mitigate this by minimizing the collision risk of the next Tx attempt. However, randomization can only be applied to the time domain, and since each resource chunk can only contain one complete TBS, transport latency will still be negatively impacted, albeit to a smaller extent. It is important to note, however, that even with this mitigation method, the additional latency can still negatively impact any UE making a retransmission, even in the absence of collisions (e.g., retransmissions due to poor, invalid radio conditions).

[0177] Meanwhile, since multiple UEs can be distinguished by their RS, the gNB must listen to all possible RS corresponding to the UEs assigned in this Chunk. Therefore, due to the orthogonality or quasi-orthogonality of RS, the existence of multiple UE transmissions is detected at the gNB. The gNB can then feed back collision information to the UE so that the UE can adjust its behavior accordingly and avoid randomization in the absence of collisions (delay penalties are only applied in the case of collisions to avoid increased interference caused by Tx power increases).

[0178] When multiple UEs are assigned to a single pre-reserved resource block, the gNB sends a NAK with a collision indication.

[0179] In the new allocation scheme, multiple UEs are allocated to multiple resource blocks. A summary of the above allocation methods:

[0180] Allocation Mode 1: A single UE is allocated to each resource block.

[0181] Delay requirements lead to frequent resource allocation.

[0182] • Perform frequent resource allocation for infrequent UE transmissions.

[0183] ->Impact on cell capacity of unlicensed UL

[0184] This invention proposes allocation mode 2: multiple UEs are allocated to a single resource chunk.

[0185] • Enhance resource utilization

[0186] Collision risk

[0187] ->Impact on the reliability and delay of unlicensed UL

[0188] As a solution to the inherent bottleneck detailed above, a new allocation mode is proposed, in which multiple UEs are assigned to a common set of resource blocks. The UE should select resources within this common group for GF transmission. The main advantages of this new allocation mode are greater flexibility in UE GF transmission and a lower proportion of unused resources.

[0189] This invention proposes to allocate several UEs to a common set of resource blocks.

[0190] It is important to note that pre-reserved resources can be allocated on a time-slot basis or a smaller time-slot basis. In the first case, different resource blocks are advantageously separated in the frequency dimension to provide flexibility in resource selection in terms of frequency and thus limit latency spikes. In the second case, both frequency and time separation can be used, as both can meet UrLLC latency requirements.

[0191] Resource selection strategy for unlicensed UL transmission

[0192] The proposed allocation method 3 offers better flexibility and resource utilization compared to modes 1 and 2, but it cannot solve the problem of consecutive collisions. However, a simple resource selection rule including some random components can be applied at the UE level to select the transport block to be used by the UE during the next GF execution. The UE should be identified by the gNB based on its RS (which is now generally agreed upon).

[0193] The risk of collision still exists, but the main benefit of this solution is:

[0194] - It suppresses the risk of consecutive collisions caused by two UEs repeatedly transmitting along their respective Tx.

[0195] - The randomization chosen by the GF scenario can be performed by the UE in the frequency dimension, which is highly effective in minimizing the impact of latency. Latency is a key performance indicator (Kpl) of GF Tx.

[0196] - In addition to the preferred frequency domain randomization, time domain randomization is also feasible as a complementary degree of freedom if certain categories of UEs can accept the corresponding delay loss.

[0197] Then, each UE can randomly or partially randomly select resources for its initial transmission and possible retransmissions within the set of resource blocks configured by the gNB, based on some predefined RRC policies. For retransmissions, different categories of UEs can be defined according to delay requirements so that they prioritize frequency or time in the randomization scheme.

[0198] Figure 4 This shows multiple UEs being assigned to a set of common resource blocks.

[0199] Figure 4The diagram illustrates allocation mode 3 (K=3) for 3 resource blocks allocated to 5 UEs. A first collision occurs between UE1 and UE3, which is resolved with minimal delay impact due to frequency-based randomization of retransmissions. A second collision occurs between UE3 and UE5, which is resolved in both the time and frequency domains, with UE5 experiencing a greater delay penalty than UE3 during the resolution process.

[0200] If resource blocks have the same size, it is much easier to design an efficient randomization pattern with fairness controlled, so it is proposed that different resource blocks allocated to a group of UEs have the same TBS size.

[0201] This invention proposes that the RRC configuration be unique for all blocks (the same TBS / MCS).

[0202] This invention proposes that the UE uses a uniform random mechanism to randomly select from the pre-reserved resource blocks allocated to it the GF transmission scenarios in which it should be used for its upcoming GF transmission.

[0203] - Option 1: Randomly select to execute only in the frequency direction and execute immediately (in the next set of pre-reserved resources). This is the preferred option for slot-based GF.

[0204] - Option 2: Randomly select to execute in terms of frequency and time dimensions.

[0205] This invention proposes to define UE categories, wherein retransmission of low-latency UEs is preferably randomized in the frequency dimension, while others are preferably randomized in the time dimension.

[0206] If, for some reason, the block size cannot be restricted to a unique value, time-frequency randomization can still be applied, but with less flexibility in latency optimization. In that case, resource blocks are categorized by size, and the UE can apply randomization to the block group that is compatible with the size of their subsequent payload.

[0207] This invention proposes that if the RRC configures several TBSs within the group of resource blocks, the UE performs randomization for a subset of blocks with configurations that conform to their subsequent payload sizes.

[0208] UL unlicensed transmission configuration

[0209] For unlicensed UL transmissions, a set of resources is pre-allocated to a terminal for a period of time, allowing the UE to begin its transmission without waiting for downlink scheduling messages. When a user's buffer has no relevant data, it will not transmit any data on its pre-allocated UL unlicensed time-frequency resources (this is explicitly agreed upon by 3GPP). It is generally understood that multiple UEs will share unlicensed resources. Therefore, in situations where multiple UEs share the same time-frequency resources and there is a possibility of UL frequency hopping transmissions, the gNB needs to identify the user transmitting data on a particular unlicensed resource from the set of users allocated this resource. 3GPP has agreed to support more than one HARQ procedure for unlicensed ULs. This means the gNB must have some mechanism to identify the HARQ procedure number. Furthermore, since 3GPP agrees to the repetition of the same transport block up to K times with the same or different redundancy versions (RVs), the gNB needs to know the exact RV of the received transmissions to correctly combine these versions.

[0210] In summary, unlike licensed transport configurations, where the gNB configures a HARQ procedure ID (HPID) and RV for a specific user on specific resources in the downlink DL, for unlicensed transport, the gNB must somehow know these parameters to identify the user and combine / demodulate HARQ data. 3GPP has made progress in this direction, reaching an agreement at the R1-AH2 Qingdao meeting to achieve UE identification through time-frequency resources and DMRS configuration. This means that users allocated the same time-frequency resources for possible unlicensed UL transport must be configured with different DMRS sequences. Even after implementing UE identification, the gNB still needs to know the HPID and RV.

[0211] For HPID, if the UE is configured with a single HARQ procedure, it is not necessary to indicate HPID. However, if the UE is configured with multiple HARQ procedures for GF transmission, to avoid any misunderstandings between the UE and gNB regarding transmission and retransmission, it is recommended that the UE explicitly transmit it as part of the uplink control information (UCI).

[0212] Sending HPD in UCI has already been proposed. Our approach offers more possibilities for how to send UCI via puncturing or rate matching.

[0213] There are two possibilities for sending UL data along with UCI:

[0214] HPID (UCI) can be sent by breaking down a certain number of resource elements in the uplink data, just as DL HARQ ACK / NAK is transmitted in LTE. Since HPID is critical information, it should be correctly decoded at the gNB side before the data itself. After LTE HARQ ACK / NAK transmission in UL, resource elements can be selected in a robust location (e.g., very close to DMRS).

[0215] Another possible approach to sending the HPI in the UCI along with the UL data is rate matching. This strategy is used in LTE to send DL CQI, PMI, and RI in the uplink direction within the resource elements allocated to the data.

[0216] Since only a few bits are needed to transmit the HPD, it may be more interesting to transmit the HPD via the breakdown method compared to transmitting the HPD (UCI) via PUSCH rate matching (which adds additional processing complexity at the user end).

[0217] This invention proposes that HPI can be explicitly sent in the UCI. It can be added to the PUSCH data by breaking down data elements. The broken-down resource elements in the PUSCH for HPI transmission can be selected based on their location, making them more robust due to their position.

[0218] This invention proposes that, for original UL-licensed transmissions, RVs can be implicitly sent to the gNB by associating them with UL-unlicensed scenarios. For fixed RV sequences, to avoid waiting for suitable scenarios, the RV sequence can be fixed, but can start cyclically at any point.

[0219] For retransmissions, the RV or RV sequence can be explicitly indicated by the gNB, come from a mapping table, or be an implicit protocol where the RV used for retransmission is associated with a resource.

[0220] If we associate the K transmissions of RV with UL unlicensed scenarios in the traditional way, and the sequence of RV is a fixed sequence consisting of three versions RV0, RV1, and RV2, then K=3 transmissions would look like the diagram below. Here, we assume that the unlicensed scenario module 3 specifies when the UE can transmit. This example shows that unlicensed (GF) resources are configured in each time slot, and GF transmissions are performed in each time slot. Then, the transmission must start from RV0, which can be transmitted in time slots numbered 0, 3, 9, etc.

[0221] Figure 5 The relationship between RV and GF scenarios is shown.

[0222] exist Figure 5 In this process, the UE receives data from a higher layer before having some blank time slot 0 that can be encoded, and then transmits RV0 at the beginning of time slot 0. At this point, the delay is minimal.

[0223] Figure 6 The relationship between RV and FG scenarios—problems with traditional methods, for example, if data from a higher layer arrives at a certain location in slot 0 a little later, such as... Figure 6 As shown, Figure 6 The association between RV and FG scenarios—a problem with the direct and simple approach—means that the UE must wait for the next module K scenario before it can begin transmission. Using the setup adopted here, the UE must wait for more than two full time slots before it can begin RV0 in time slot #3. Since the primary motivation for GF transmission is to reduce latency and round-trip time due to scheduling authorization, the latency of multiple GF scenarios may be unacceptable for URLLC services.

[0224] This limitation can be overcome by maintaining the same RV sequence and the same mapping of resources, but allows the UE to transmit with the corresponding RV in any GF situation, and then continue with the complete RV sequence in a circular buffer manner. Figure 7 An example is shown in the image. Figure 7 The proposed correlation between RV and GF transmission scenarios.

[0225] Figure 7 The correlation between the proposed RV and GF transmission scenarios is shown.

[0226] When the GF UL is configured with K repetitions, the UE can start at any time and then iterate through these repetitions in sequence.

[0227] Assume K = 3 repetitions are configured, and the index of the RV version is as follows:

[0228] RV_Sequence:

[0229] A number can be implicitly assigned for each GF transmission occasion (within a slot, subframe, or longer interval T) where rv[0] = 0, rv[1] = 2, rv[2] = 3 (close to the LTE UL non-adaptive HARQ RV sequence). When the UE must send a data packet in occasion number N, it can send an RV version corresponding to an index derived as follows:

[0230] Indicator = N%K

[0231] Therefore, the first transmission from the UE will be for the version corresponding to rv[index], and the next K-1 transmissions will be performed in a cyclic manner according to RV_Sequence.

[0232] Figure 7 As shown, through the proposed mechanism, each GF (Gateway Context) is associated with one RV (Relay Container Registry) in the RV sequence. Once the UE receives data from the higher layer and is able to transmit, it transmits a transport block in the first available GF, a process achieved by selecting the RV corresponding to that GF. In the figure, when data triggers arrive at slot 0, the UE prepares all RVs and, starting with RV1 in the first available slot (slot #1 in this case), completes the remaining K-1 transmissions of the RV sequence in a cyclical manner. This demonstrates a significant advantage in latency compared to conventional methods.

[0233] Early termination and related signaling

[0234] If the unlicensed (GF) UL is configured with K repetitions, the following may occur:

[0235] If the gNB is able to successfully decode the transport block (TB) before all K repetitions have been sent, it may be beneficial to stop the UE from sending the remaining repetitions for the following reasons:

[0236] 1. Energy efficiency of UE battery.

[0237] 2. When multiple UEs are allocated on the same resource by the gNB (whether it is one resource or multiple resources with certain frequency hopping mechanisms), potential collisions of TF resources are avoided.

[0238] 3. Better spectrum efficiency, because the gNB can allocate more resources for licensed UL transmissions.

[0239] If multiple users share the same resource, and two or more users happen to be active simultaneously and may continue their K transmissions in the next instance, causing further interference, it may be beneficial to quickly move some users to different resources. Therefore, in this situation, the gNB would like to send an early termination instruction to the user, which is an efficient FAST NAK. This may be accompanied by a new resource allocation dedicated to that user. For example, if two or three users simultaneously begin their K UL GF repetitions in the same instance, and the gNB can identify these users due to the good correlation of DMRS, it can quickly move all users, rather than just one, to different dedicated resources to increase the chance of successful detection.

[0240] Sequence for UE to receive early termination (ET)

[0241] The gNB receives the TB and successfully decodes the data. It prepares an ET indication (HARQ ACK feedback) and sends it in the DL. There may be a transmission scenario for this ET indication, which may introduce additional latency. UEs in the transmission phase should be prepared to receive such an indication. The relevant UE receives the indication, decodes it, but does not transmit the remaining TB repetition because it received the early termination HARQ response.

[0242] Early termination can be handled in the following ways.

[0243] The gNB should send an indication of successful TB decoding. Possibility:

[0244] A physical channel specifically designed for HARQ feedback, like PHICH in LTE.

[0245] Group common DCI.

[0246] UE-specific DCI.

[0247] UL authorization can be used to send ACKs (although it has many parameters and incurs significant overhead).

[0248] A normal HARQ response with the same ACK / NAK mechanism for early termination and UL unlicensed transmissions may be of interest for HARQ feedback responses in UL unlicensed transmissions.

[0249] Suppose that there are K repetitions of the UL unlicensed transport configuration, where K is an integer at least equal to 1.

[0250] We will now discuss the relevant scenarios that may occur when the UE sends a TB (K repetitions) on an unlicensed UL resource.

[0251] If the gNB can successfully decode the transport block, it may send an ACK. This allows the UE to release its HARQ buffer and avoid retransmitting the correctly received data.

[0252] If gNB data decoding fails, gNB will want to retransmit the same TB.

[0253] The following are the possibilities for retransmission:

[0254] The gNB sends a NAK to the UE, and the UE begins retransmitting the same TB in the next UL GF transmission.

[0255] Instead of sending a NAK, the gNB can decide not to send anything (which can be assumed to be an implicit NAK), and the UE will retransmit the same TB in the next GL instance.

[0256] Instead of explicitly sending NAK, gNB can use the same HARQ procedure number (HPN).

[0257] Sending a UL grant, with the process number configured for retransmission of the same TB. This effectively signifies a transition from "unlicensed" to "licensed." This can be helpful if the gNB detects collisions on unlicensed resources from multiple UEs, and if these UEs continue to experience further potential collisions on unlicensed resources. UL grants allocated to resources on other PRBs may allow the GNB to flexibly and quickly control such interference situations.

[0258] If gNB cannot identify a user even from RS (if K=1, the probability of no duplicates is greater) because the user is far away or there is strong interference from multiple users, then the following approach is possible.

[0259] In the simplest case, the gNB transmits nothing. However, this should be considered in conjunction with the possibility of the UE automatically retransmitting in the next GF transmission.

[0260] If resources are allocated exclusively to that user and the gNB is able to detect at least some transmission power, the gNB will know a priori that only that UE can transmit. The gNB can then resort to sending a NAK for retransmission, or sending a UL grant for retransmission on the same or different resources.

[0261] If a resource is allocated to multiple users, which is the typical case as we understand it, then the gNB can send a group common UL grant that is associated with the GF resource to some extent. This can have an indication that a negative response (NAK) is given on that specific resource.

[0262] The current transmission will not be retransmitted on the resources for which the relevant UL authorization was sent. Other UEs already allocated the same resources may be able to listen to the UL authorization, but only the user performing this transmission should retransmit. Additionally, a solution can be found for situations where two or more users are transmitting and the gNB cannot identify a collision.

[0263] Although not shown in detail, any device or apparatus forming part of the network may include at least a processor, a storage unit, and a communication interface, wherein the processor unit, storage unit, and communication interface are configured to perform the methods of any aspect of the present invention. Further options and choices are described below.

[0264] The signal processing functions of embodiments of the present invention, particularly the gNB and UE, can be implemented using computing systems or architectures known to those skilled in the art. Computing systems such as desktop computers, laptops or notebook computers, handheld computing devices (PDAs, cellular phones, PDAs, etc.), mainframes, servers, clients, or any other type of dedicated or general-purpose computing device that may be desired or suitable for a given application or environment can be used. The computing system may include one or more processors, which can be implemented using general-purpose or dedicated processing engines (such as, for example, microprocessors, microcontrollers, or other control modules).

[0265] The computing system may also include main memory, such as random access memory (RAM) or other dynamic memory, for storing instructions and information to be executed by the processor. Such main memory may also be used to store temporary variables and other intermediate information to be executed by the processor during instruction execution. The computing system may also include read-only memory (ROM) or other static storage devices for storing static information and instructions for the processor.

[0266] The computing system may further include an information storage system, which may include, for example, a media drive and a removable storage interface. The media drive may include a drive or other mechanism to support fixed or removable storage media, such as a hard disk drive, floppy disk drive, magnetic tape drive, optical disc drive, compact disc (CD) or digital video drive (DVD) read or write drive (R or RW), or other removable or fixed media drive. The storage media may include, for example, a hard disk, floppy disk, magnetic tape, optical disc, CD or DVD, or other fixed or removable media read or written by a media drive. The storage media may include a computer-readable storage medium having specific computer software or data stored therein.

[0267] In alternative embodiments, the information storage system may include other similar components for allowing computer programs or other instructions or data to be loaded into the computing system. Such components may include, for example, removable storage units and interfaces, such as program boxes and box interfaces, removable memory (e.g., flash memory or other removable memory modules) and memory slots, as well as other removable storage units and interfaces that allow software and data to be transferred from the removable storage units to the computing system.

[0268] The computing system may also include a communication interface. Such a communication interface can be used to allow software and data to be transferred between the computing system and external devices. Examples of communication interfaces may include modems, network interfaces (such as Ethernet or other NIC cards), communication ports (such as, for example, Universal Serial Bus (USB) ports), PCMCIA slots and cards, and so on. Software and data transmitted via the communication interface are in the form of signals, which may be electrical, electromagnetic, and optical signals, or other signals that can be received by the communication interface medium.

[0269] In this document, the terms "computer program product," "computer-readable medium," and "non-transitory computer-readable medium" are generally used to refer to tangible media, such as memory, storage devices, or storage units. These and other forms of computer-readable media may store one or more instructions for use by a processor, including a computer system, to cause the processor to perform specified operations. Instructions, generally referred to as "computer program code" (which may be grouped as computer programs or otherwise), when executed, enable a computing system to perform the functions of embodiments of the present invention. Note that the code may directly cause the processor to perform specified operations, be compiled to do so, and / or be combined with other software, hardware, and / or firmware elements (e.g., libraries for performing standard functions) to do so.

[0270] The non-volatile computer-readable medium may include at least one of the following: hard disk, CD-ROM, optical storage device, magnetic storage device, read-only memory, programmable read-only memory, erasable programmable read-only memory, EPROM, electrically erasable programmable read-only memory, and flash memory.

[0271] In embodiments where the components are implemented in software, the software may be stored in a computer-readable medium and loaded into a computing system, for example, using a removable storage drive. The control module (in this example, software instructions or executable computer program code), when executed by a processor in the computer system, causes the processor to perform the functions of the invention as described herein.

[0272] Furthermore, the inventive concept can be applied to any circuit used to perform signal processing functions within a network element. It is further foreseeable that, for example, semiconductor manufacturers can utilize the inventive concept when designing stand-alone devices and / or any other subsystem elements such as application-specific integrated circuits (ASICs) or digital signal processors (DSPs).

[0273] It will be appreciated that, for clarity, the above description has referred to embodiments of the invention with reference to a single processing logic. However, the inventive concept can also be implemented by a number of different functional units and processors to provide signal processing functionality. Therefore, references to specific functional units should be considered merely as references to appropriate means for providing the described functionality, and not as indications of a strict logical or physical structure or organization.

[0274] Various aspects of the present invention can be implemented in any suitable form, including hardware, software, firmware, or any combination thereof. The present invention can optionally be implemented, at least in part, as computer software running on one or more data processors and / or digital signal processors, or as configurable module components of a device such as an FPGA. Therefore, the elements and components of embodiments of the present invention can be implemented physically, functionally, and logically in any suitable manner. In practice, the functionality can be implemented in a single unit, in multiple units, or as part of other functional units.

[0275] Although the invention has been described in conjunction with some embodiments, it is not intended to be limited to the specific forms set forth herein. Rather, the scope of the invention is defined only by the appended claims. Furthermore, although features appear to be described in conjunction with specific embodiments, those skilled in the art will recognize that the various features of the described embodiments can be combined according to the invention. In the claims, the term "comprising" does not exclude the presence of other elements or steps.

[0276] Furthermore, although listed individually, multiple means, elements, or method steps may be implemented by a single unit or processor. Additionally, while a single feature may be included in different claims, these may also be advantageously combined, and including a feature in different claims does not imply that such a combination is not feasible and / or advantageous. Moreover, including a feature in a claim of one class does not imply limitation to that class, but rather indicates that the feature is equally applicable to other claim classes where appropriate.

[0277] Furthermore, the order of features in the claims does not imply a specific order in which any feature must be performed, and in particular, the order of individual steps in a method claim does not imply that the steps must be performed in that order. Rather, the steps may be performed in any suitable order. Moreover, singular references do not exclude plurals. Therefore, references to “a,” “first,” “second,” etc., do not exclude plurals.

[0278] Although the invention has been described in conjunction with some embodiments, it is not intended to be limited to the specific forms set forth herein. Rather, the scope of the invention is defined only by the appended claims. Furthermore, although certain features have been described in conjunction with specific embodiments, those skilled in the art will recognize that different features of the described embodiments can be combined according to the invention. In the claims, the term "comprising" does not exclude the presence of other elements.

Claims

1. A method for unlicensed data transmission from a user equipment to a base station, the method being performed by the user equipment and comprising the following steps: Receive an indication from a user equipment of a set of resources that can be used for unlicensed data transmission, wherein the same set of resources can be used by other user equipment for unlicensed transmission; Receive an instruction of at least one radio resource control policy to select resources for unlicensed transmission from the set of resources available for unlicensed transmission, wherein the policy includes randomly selecting resources in at least one of the time domain and the frequency domain; Based on the at least one radio resource control policy, select the resources for unlicensed transmission; Try using the selected resource to transfer data; as well as If the attempt to transmit data fails, a retransmission attempt is made using the resources selected according to the at least one radio resource control policy.

2. The method according to claim 1, wherein a plurality of radio resource control policies for selecting resources are received.

3. The method according to claim 1 or 2, wherein the at least one radio resource control policy includes a policy for selecting resources for initial transmission and / or retransmission.

4. The method of claim 2, wherein the radio resource control policy for selecting resources is selected based on the latency requirements of the data to be transmitted.

5. The method of claim 1, wherein at least one radio resource control policy instructs the random selection of frequency resources.

6. The method of claim 5, wherein if the user equipment is a low-latency user equipment, the frequency resources are randomly selected.

7. The method of claim 1, wherein the allocated resources comprise a plurality of resource blocks.

8. The method of claim 7, wherein all blocks are of the same size.

9. A user equipment comprising: Memory, which stores computer-readable instructions; and The processor reads computer-readable instructions stored in the memory to perform the method of any one of claims 1 to 8.

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