CN110999469B - Improved or related method and apparatus for hybrid automatic repeat request in new radios - Google Patents

Abstract

A method of allowing access to services provided by a radio access network between a first wireless communication device and a second wireless communication device, the method comprising: HARQ-ACK feedback is generated on the second wireless communication device based on the resources preempted during transmission of the transport block by the first wireless communication device so that the second wireless communication device can monitor the preempted resources.

Description

Improved or related method and apparatus for hybrid automatic repeat request in new radios

Technical Field

The present application relates generally to wireless communication systems, and more particularly to an apparatus and method for operating a wireless communication system, particularly but not exclusively reporting downlink data using hybrid automatic repeat request (Hybrid Automatic repeat requests, HARQ) feedback.

Background

Wireless communication systems, such as third generation (3G) mobile telephone standards and technologies, are well known. The 3G standard and technology was developed by the third generation partnership project (3GPP,Third Generation Partnership Project). Third generation wireless communications were developed to support macrocell mobile telephone communications. Communication systems and networks are evolving towards broadband mobile systems.

The third generation partnership project has developed a so-called long term evolution (LTE, long Term Evolution) system, i.e. an evolved universal terrestrial radio access network (E-UTRAN, evolved Universal Mobile Telecommunication System Territorial Radio Access Network), in which one or more macro cells are supported by a base station eNodeB or eNB (evolved NodeB). Recently, LTE has evolved further towards so-called 5G or NR (New Radio) systems, where one or more macro cells are supported by a base station gN.

In LTE, the duration of a Subframe (SF) is 1ms, and the subframe is the primary scheduling unit or transmission time interval (Transmission Time Interval, TTI) of a transmission. The duration of the TTI corresponds to a plurality of consecutive orthogonal frequency division multiplexing (Orthogonal Frequency division Multiplex, OFDM) symbols transmitted in the time domain (TR 38.804.5.4.7). A 14 symbol SF (for a normal cyclic prefix) consists of two sets of 7 symbol slots. Recently, the size of short TTIs (sTTIs), e.g. 2, 3 or 7 symbols, has also been introduced.

In NR, the term SF is used only as a time reference. SF is still 1 millisecond, but it is now not able to schedule a fixed number of OFDM symbols as in LTE. The slot is now a scheduling unit or TTI with 7 or 14 OFDM symbol lengths (for normal cyclic prefix). Mini-slots with a subset of 7 OFDM symbols (e.g., 1, 2, 4) are also defined.

A Transport Block (TB) is a set of information bits transmitted in one TTI, the bit size of which is specified by the transport block size (transport block size, TBs). A Code Block (CB) is a subset of TB information bits protected by a separate cyclic redundancy check (Cyclic Redundancy Check, CRC), possibly multiple CBs in each TB. The CB size is limited by a predefined maximum value, so as the TBS increases, the number of CBs increases. Some CBs in the TB may further constitute Code Block Groups (CBGs). 3GPP has agreed on NR to support CBG-level (re) transmission to improve efficiency. The term (re) transmission refers to the first transmission or retransmission of data.

Downlink (DL) HARQ refers to a process of transmitting DL data from the gNB to the UE via a physical downlink shared channel (Physical Downlink Shared Channel, PDSCH) in a first stage. Acknowledged/unacknowledged (ACK/NACK) information is sent from the UE to the gNB via a physical uplink control channel (Physical Uplink Control Channel, PUCCH) or a physical uplink shared channel (Physical Uplink Shared Channel, PUSCH). This is also called HARQ-ACK feedback. Finally, if the UE has received a NACK/discontinuous transmission (discontinuous Transmission, DTX), the data is retransmitted from the gNB to the UE via the PDSCH.

In LTE, each CB is also protected by a CRC, and it is possible for the UE to provide CB-level HARQ-ACKs. However, the decision in the standard only supports feedback of the HARQ-ACK at the TB level from the receiver to the sender (i.e. 1 bit informs the ACK or NACK of the TB). Advantages of having TB-level HARQ-ACK feedback include reducing HARQ-ACK feedback overhead and ensuring reliability of HARQ-ACK transmission in case of limited coverage because HARQ ACK codebook (codebook) is smaller. A disadvantage is that the transmission of data with a large payload is inefficient, since even one erroneous CB in the TB may result in retransmission of the entire TB. This was previously considered acceptable in view of the overhead savings of HARQ-ACK feedback, and the extreme case in LTE is that there are only 32 CBs per TB in DL (for 20mhz,110prb,2 spatial layer transmissions).

In NR, multi-bit HARQ-ACK feedback per TB agrees (in ran1_nr_ah#1). The reasons are as follows: the maximum CB size in NR has been agreed to be 8192 bits, 25% higher than LTE (6144 bits). However, enhanced mobile broadband (enhanced Mobile Broadband, eMBB) services require a much larger TBS than LTE to achieve the expected high throughput. This means that the number of CBs per TB increases compared to LTE (the expected extreme case may be > 100 CBs per TB when the eMBB data rate is higher). In addition, the introduction of preemptive multiplexing (and the possibility of other mini-slot transmissions resulting in CB-specific interference to the ebb slot transmissions) amplifies the possibility of having a single or few erroneous CBs in the TB.

NR supports CBG based (re) transmission as one possible option to use multi-bit HARQ-ACK feedback. In addition, the results show that the CBG stage can significantly improve spectral efficiency (spectral efficiency, SE) relative to the TB stage HARQ-ACK feedback. As shown in fig. 1, at one critical point, the SE's advantage from transmission efficiency (i.e., fewer unnecessary CBs are retransmitted) is defeated by the HARQ-ACK feedback size.

The UE may be configured to receive PDSCH transmissions including retransmissions of Code Block Groups (CBGs) of transport blocks via higher layer parameters. In that case, the UE is also configured with a plurality of CBGs for generating respective HARQ-ACK information bits for the first reception of the transport block. HARQ-ACK reporting may be performed using a physical uplink shared channel (physical uplink shared channel, PUSCH) or a physical uplink control channel (physical uplink control channel, PUCCH) and various formats thereof.

NR also supports dynamic multiplexing of data with different transmission durations on the same resource. One way to agree on such sharing in DL is through preemption of longer transmissions. For example, if an eMBB and ultra-reliable low-latency communication (Ultra Reliable Low Latency Communication, URLLC) service are multiplexed in the DL, the gNB may schedule a latency intolerant UR LLC mini-slot transmission within the ongoing eMBB slot transmission, with part of the eMBB transmission to be interrupted, as shown in fig. 2. The URLLC transmission may also use a different value (numerology) (i.e., subcarrier spacing (subcarr ier spacing, SCS)) than the eMBB transmission. For example, fig. 2 may refer to a 15kHz-SCS eMBB transmission spanning 7 symbols of 0.5 ms, interrupted by a 4 symbol 30kHz-SCS UR LLC transmission spanning (2/7) ×0.5≡0.143 ms.

There is a common knowledge in 3GPP that CBs map onto physical resources by frequency priority to facilitate transmission flow (pipeline) processing, whereas CBs may not be restricted across multiple symbols, such as CB2 in fig. 2. Thus, CBGs are expected to map to physical frequency/time (f/t) resources continuously in time. This is shown as unsigned alignment in fig. 3. Adjacent CBGs may also overlap, e.g., several CBs may belong to CBG0 and CBG1 at the same time.

As a result, the preempted URLLC transmission will only interrupt one or a few CBGs of the eMBB transmission, and these CBGs may be partially interrupted (i.e., CBGs only have certain CBs preempted), as in the simplified scenario shown in fig. 4.

DL in NR also agrees to support preemption indications for eMBB UEs, indicating the time and/or frequency domain of the affected eMBB resources. The main purpose of this preemption indication is to aid in the decoding of the eMBB data by eliminating (ringing out) log-likelihood ratios (log-likelihood ratios, LLRs) on the affected eMBB resources. This preemption indication may be beneficial for the following situations: a) A small portion of CB is preempted and/or b) the code rate is low. The zero LLR for the above case has more opportunities to successfully decode CB than the random LLR. If the indication is received early enough at the UE, retransmissions may be reduced since the UE has enough time to decode the affected CB before the HARQ-ACK feedback generation time. At least the UE may improve its soft combining (soft combining) with the retransmission if the reception is delayed. For HARQ, one LLR value for part of the received data in the first transmission may be soft combined with another LLR value for the same part of the received data in the retransmission to improve the decoding success rate at the UE. However, for preemption, if the UE knows preemption, then the received individual LLR values reflect only URLLC transmissions, carry no useful information, and only ARQ (cancel old LLR) is better used. Fig. 5 shows the complete control signaling and feedback flow for the preemption indication and CBG based multi-bit HARQ-ACK feedback and retransmission protocol.

The potential benefit of having more optimal retransmissions than the CBG level (i.e., retransmissions with a granularity lower than the CBG level) is also considered. For example, the example shown in fig. 6 considers that a 4 symbol URLLC interrupts a 14 symbol eMBB slot and shows that having CB-level HARQ feedback and retransmission is more beneficial than CBG-level HARQ feedback and retransmission, especially when CBG is large (e.g., the 9 CBs considered in fig. 6 are the worst case).

Another example, as shown in fig. 7, facilitates subsequent transmissions after preemption and simulates a comparison of CBG-based and preemption resource-based transmissions. The subsequent transmission is defined as the resource transmission (first transmission or retransmission) after the first transmission of the scheduled TB but before the first Ack/Nack feedback. Then, the first subsequent transmission is case 2 where resources 2 and 4 are completely interrupted. The repeated subsequent transmission is case 3 where resources 2 and 3 are partially interrupted or interfered during the first transmission. In the comparative system level simulation, an uplink pilot time (Uplink Pilot Time, UPT) gain of between 10-15% may be provided.

In the case of CBG level retransmission configured, the most straightforward approach to CBG-based HARQ-ACK feedback is to let one bit per CBG represent the ACK or NACK of the CBG as a whole. However, this design has a number of drawbacks for preemptive transfer. These disadvantages include the following. If the preemption indication is configured, this information is not taken into account when performing the HARQ operation. As a result, when a single CB is not successfully decoded due to preemption, HARQ-ACK feedback for preempting CBG is NACK even though preemption is partial preemption from the CBG perspective. Then, the spectral efficiency (spectral efficiency, SE) may be very low, especially when the CBG size is configured to be relatively high, resulting in a similar problem in LTE with 1-bit TB-level HARQ-ACK feedback. For example, CBG size configuration from the gNB may also be a slow procedure if performed by radio resource control (Radio Resource Control, RRC). In this case, scattered URLLC traffic (traffic) will not be considered, and therefore the gNB will not be able to perfectly align the URLLC transmissions with the CBG configuration, often resulting in a partially interrupted CBG.

One extreme solution to this low SE problem might be to report Ack/Nack for each CB. As previously mentioned, although this approach most accurately informs the gNB of each erroneous CB, it is very inefficient. The following table shows the trend of the HARQ-ACK payload increase when the number of failed CB indexes needs to be reported.

Therefore, the HARQ-ACK feedback for preemption should be designed as: the preemption indication is considered so that the throughput advantage of better retransmissions than the CBG level can be obtained while maintaining the low signaling advantage of CBG level HARQ-ACK feedback.

Considering the impact of preemption, it is proposed to design HARQ-ACK feedback for the UE and HARQ retransmission for the gNB based on the HARQ-ACK feedback. As shown in fig. 8, this is achieved by splitting the CB into a severely affected CB (by interruption) and an unaffected CB, and generating HARQ-ACK feedback based on the CB-level CRC of the unaffected CB. This split is preemptive, but depends on whether it is desirable to be able to decode the CB. This approach has some very significant drawbacks. First, the CBG-based problem (only TB and CB are mentioned) is not directly solved. Even if the proposed method is converted to CBG, for example if the TB in the solution is considered to be CBG, the Ack/Nack fed back to the gNB does not provide any information about the correct/incorrect CBs in the CBG. Furthermore, if the CB in the solution is considered as CBG, no suitable method is proposed as to how to cope with the lost preemption indication at the UE. This proposal has not solved the requirement that a consensus be reached between the UE and the gNB that can be considered as severely affected CB. Even if a concise selection rule is chosen for the eNB to indicate that the CB is severely impacted, if the preemption indication is lost at the UE, misunderstanding of the UE and the gNB in this respect cannot be avoided.

The above examples, proposals and schemes are either inefficient or do not address all of the problems associated with CBG based HARQ-ACK feedback when using a preemption indication to inform a receiver to preempt resources during transmission of some or all of the code blocks or transport blocks.

The present invention seeks to address at least some of the outstanding problems in this field.

Disclosure of Invention

This summary presents some concepts in a simplified form as a more detailed description detailing the detailed description. This summary is not intended to identify key features 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.

In a first aspect, the present application provides a method of allowing access to a service provided by a radio access network between a first wireless communication device and a second wireless communication device, the method comprising:

HARQ-ACK feedback is generated on the second wireless communication device based on the resources preempted during transmission of the transport block by the first wireless communication device so that the second wireless communication device can monitor the preempted resources.

Preferably, the consensus between the first wireless communication device and the second wireless communication device is taken into account by both devices based on a notification of preemption resources from the first wireless communication device.

Any one of the first wireless communication device and the second wireless communication device is configured to generate HARQ-ACK feedback.

Preferably, any one of the first wireless communication device and the second wireless communication device is configured to automatically monitor HARQ-ACK feedback from the other one of the first wireless communication device and the second wireless communication device.

Preferably, the HARQ-ACK feedback comprises a plurality of bits for each CBG that is partially interrupted.

Preferably, for the interrupted code block, the HARQ-ACK feedback comprises a plurality of bits.

Preferably, the HARQ-ACK feedback comprises a plurality of bits for an uninterrupted code block or CBG.

Preferably, the HARQ-ACK feedback comprises 1 bit for each CBG, wherein an acknowledgement message is used to indicate correct decoding of the uninterrupted resource.

Preferably, the method comprises reporting resources subject to bursty interference.

Preferably, the second wireless communication device provides an interrupt indication receipt acknowledgement to the first wireless communication device.

Preferably, for a given TB, one or more CBGs or code blocks are corrupted by an interrupt; the second wireless communication device can send a feedback ACK or NACK for the entire TB.

Preferably, for a given CBG, one or more code blocks are corrupted by an interrupt, and one or more code blocks are corrupted by another cause; the second wireless communication device can send a feedback NACK for the entire CBG.

Preferably, the HARQ retransmission occurs based on HARQ-ACK feedback using at least one different option; only the corrupted resources or the undecoded CBs are retransmitted; recombining the CBG and retransmitting the CBG comprising the corrupted CB; alternatively, the CBGs that are partially interrupted are adapted to include only the undecoded CBs and these CBGs are retransmitted.

Preferably, the HARQ-ACK feedback includes using at least one different PUCCH format; different PUCCH resources; different scrambling of uplink control information UCI bits; different cyclic redundancy checks attached to UCI bits; upon decoding, additional bits of the separate part of the HARQ-ACK feedback.

Preferably, the HARQ-ACK feedback includes a predetermined number of additional ACK/Nack bits, including information of the interrupted CBG.

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

In a second aspect, the present application further provides a base station capable of performing the method described in the first aspect of the present application.

In a third aspect, the present application further provides a user equipment capable of performing the method described in the first aspect of the present application.

In a fourth aspect, the present application also provides a non-transitory computer readable storage medium storing computer readable instructions adapted to be loaded by a processor to perform the method of the first aspect.

The non-transitory computer readable storage medium may include at least one of a hard disk, a compact disk Read Only Memory (CD-ROM, compact Disc Read Only Memory), an optical Memory, a magnetic Memory, a Read Only Memory (ROM), a programmable Read Only Memory (PROM, programmable Read Only Memory), an erasable programmable Read Only Memory (EPROM, erasable Programmable Read Only Memory), an electrically erasable programmable Read Only Memory (EEPROM, electrically erasable programmable Read Only Memory), and a Flash Memory (Flash Memory).

Drawings

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Elements in the figures have been simplified and are not necessarily drawn to scale. Reference numerals have been included in the various figures to facilitate understanding.

FIG. 1 is a graph of signal-to-noise ratio (SNR) V spectral efficiency in the prior art;

FIG. 2 is a simplified diagram of a prior art interrupted partial eMBB transmission;

FIG. 3 is a schematic diagram of prior art CBG mapping onto physical f/t resources in time domain succession;

FIG. 4 is a schematic diagram of a prior art CBG that may be partially interrupted;

fig. 5 is a schematic diagram of control signaling and feedback flow for preemption indication and CBG based multi-bit HARQ-ACK feedback and retransmission in the prior art;

FIG. 6 is a simplified diagram of a prior art 4 symbol URLLC interrupting a 14 symbol eMBB slot;

FIG. 7 is a schematic diagram of a prior art preemptive follow-up transmission;

fig. 8 is a suggested exemplary diagram of a prior art CB split into severely affected and non-severely affected CBs;

FIG. 9 is a simplified illustration of a solution provided by an embodiment of the present application;

fig. 10 is a schematic diagram of a scheme for handling bursty interference according to an embodiment of the present application;

FIG. 11 is a schematic diagram of CBG validation provided by embodiments of the present application;

FIG. 12 is a schematic diagram of signaling of a scheme provided by an embodiment of the present application;

fig. 13 is a schematic diagram of sub options of a solution provided in an embodiment of the present application.

Detailed Description

The embodiments described herein are intended to be merely some, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application.

The present application relates to communication systems (e.g., 5G/NR, 4G/LTE) that use HARQ feedback from a UE to an eNB to report downlink data of an ACK or NACK. The present application is particularly directed to the scenario of dynamic multiplexing services, i.e. when DL data at different transmission times use the same resources, where the system is configured to allow shorter time transmissions to preempt longer time ongoing transmissions. In that case, the preemption indication may also be configured to inform the UE (i.e., the intended recipient of the longer transmission, e.g., an eMBB UE) of the preemption transmission. In this case, bursty interference from shorter transmissions from neighboring cells is also apparent.

The purpose of the present application is to provide an efficient mechanism for an eMBB UE to create a smaller ACK/NACK payload based on successful or failed decoding of the received data, determining the exact HARQ-ACK bit number for an eNB/gNB UE to send.

The present application discloses a new design of CBG based HARQ-ACK feedback if a preemption indication is used to inform the receiver that resources are preempted during transmission of a transport block. The proposed preemptive HARQ-ACK feedback takes into account the consensus between the gcb and the UE received from the preemption indication and provides feedback to the gcb at the low-load CBG level to obtain finer granularity knowledge of the successfully decoded CBs (granularity knowledge). In addition, for the complete HARQ operation using the method, the common knowledge of gNB-UE on the HARQ-ACK feedback size can be solved, and the operation of a fallback (fall-back) TB stage can be adjusted to realize retransmission better than that of a CBG stage.

The proposed CBG-aware HARQ-ACK feedback can achieve advantages over CBG-level retransmissions, resulting in higher SE and/or more stable (robust) retransmissions, which can reduce the latency caused by multiple retransmissions for a TB. The low signaling advantage of CBG level HARQ-ACK feedback is maintained while the completion is completed; the UE may report only one enhanced (using the re-planned bit or just a few additional bits) low-loaded CBG pass/fail bitmap and information if the preemption indication was successfully received (if needed) instead of feeding back to the gNB a large CB pass/fail bitmap.

Embodiments of the present application will be described in detail below. The UE is configured to send specific HARQ-ACK feedback for each CBG that is partially interrupted upon receipt of the preemption indication. This can be achieved in a number of different ways.

In a first example, multiple (e.g., 2) bits may be sent for each CBG that is partially interrupted in order to give more information about which CBs the UE can actually decode within the CBG. For a fully broken CBG, only 1 bit is used to represent a NACK. For example, for 2 bits, if the decoding in CBG is correct, the UE may inform the gNB: all CBs; a set of uninterrupted CBs; and a set of interrupted CBs, as shown in fig. 9.

A first additional advantage of using multiple bits per interrupted CBG is that there is an opportunity to inform the CB decoding result that is experiencing bursty interference, if both the gNB and the UE are aware of and have a common knowledge of such interference. For example, considering one scenario, the neighboring cell (cell B) also allows for a short URLLC transmission, which can result in bursty interference of the eMBB transmission to the UE in the cell of interest (cell a). If the gNB has a way to timely inform the UE of such transmissions occurring in neighboring cells, the UE can use the proposed CBG-based HARQ-ACK feedback that is preemptive to inform its gNB to successfully decode a set of CBS affected by such bursty interference. To achieve this, the gNB may perform some or all of the following functions, for example: exchanging neighboring short transmission information (e.g., f/t resources used by URLLC over time slot X) over an interface equivalent to LTE X1; but in a faster way, for example < 4ms. Timing Advance (TA) information may be considered. The gNB may signal to its UE f/t resources of bursty interference on previously received resources. In other words, these may be included in the preemption indication.

In a given CBG, there may be some CBs damaged by interruption at the same time, and some CBs damaged by other reasons (e.g., low channel quality). In that case, the UE should feedback NACK for the entire CBG (for the interrupted part and the remaining part of the CBG). The disadvantage of the above described embodiment of preemptive HARQ-ACK feedback is the unnecessary higher UL control signaling compared to the conventional 1 bit per CBG a/N approach. In this case, one solution may be to employ a "CBG level fallback operation" for such CBGs, which means that in this case the UE may choose (or be configured by the gNB) to indicate an unintentional interruption to the gNB, and feedback a NACK using 1 bit as usual. In a second example, each CBG may only send 1 bit, but for example, when the UE is configured with an outage indication, the ACK may be reused to represent "ACK = correctly decoded non-outage region", as shown in fig. 11.

One disadvantage of the 1-bit option compared to the 2-bit option is that even if a partially preempted CB has been successfully decoded at the UE, it must be assumed that all CBs associated with the interrupt area are decoded in error. This may lead to a considerable throughput loss of some DL data, for example in case the partly interrupted CBG consists of several (even in extreme cases even only one) stably transmitted CBs. This 1 bit example is combined with the mechanism by which the UE acknowledges receipt of the interrupt indication, as described below. Thus, the gNB can determine which exact resources need to be retransmitted and prevent that the entire CBG has to be retransmitted in case the UE loses the preemption indication (thus, the interrupted CBG sends a NACK instead of an ACK). In addition, rules (which may be ambiguous and not fit all scenarios) need not be selected for the severely affected CB. It should be sufficient to bind/sort CBs in the CBG as (fully or partially) interrupted or not interrupted.

In a third example, a predetermined number of additional ACK/Nack bits are added in the HARQ-ACK feedback of the CBG level, which bits contain useful information about the interrupted CBG. This alternative increases the control overhead even if no interruption occurs, but it does not require additional mechanisms to handle the gNB-UE misunderstanding (misinding) on the HARQ-ACK codebook.

When CBG level retransmission is not configured, TB level HARQ-ACK feedback (1 ACK/Nack bit per TB as in LTE) is required. When CBG level retransmissions are configured, it should also be possible to fall back to TB level retransmissions, especially if the UE recognizes that there are no or too many errors in the entire TB.

It is contemplated that TB-level HARQ-ACK feedback will be supported when CBG based retransmissions are configured, and that the downward selection (down-selection) in rans1#90 may be made at least considering the following options. Option 1: adding 1 bit to the CBG level HARQ-ACK bit; option 2: all NACKs using CBG level HARQ-ACK bits; and, option 3: different PUCCH formats or PUCCH resources are used. Any of these three options may be used with the proposed preemptive CBG level feedback.

Another approach is to use one of the following proposals to indicate TB-level fallback operation for the UE to acknowledge the interrupt indication reception to the gNB. In that case, taking the proposed explicit signaling method as an example, at decoding, the additional bits in the first part of the HARQ-ACK feedback may indicate to the gNB whether ACK/Nack of CBG or TB level is provided in the uplink control information (Uplink Control Information, UCI). Other implicit signaling methods (e.g., UCI bits or scrambling of CRC) are also contemplated.

It must also be considered what each interrupted CBG has the meaning of a number of bits, and what happens when an interruption indicates that it is sent by the gNB but lost by the UE. In this case, the consensus between the gNB and the UE for the transmitted HARQ-ACK codebook will be broken, as the gNB will translate the large number of UCI bits received as HARQ-ACK feedback, which is not the case. In general, HARQ-ACK feedback requires high reliability because undetectable error events occur, and an upper layer takes a long time to detect errors and schedule retransmissions.

Interrupt indication transmission through downlink control information (Downlink Control Information, DCI) is expected to be very stable. However, if the UE fails to receive it, it will misunderstand the HARQ-ACK codebook. In addition, misunderstanding of other UCI types may also have an impact. When this situation is considered an important issue, the present application may introduce an interrupt indication acknowledgement mechanism. Additional indications in the Uplink (UL) may, for example, inform the gNB if the UE has correctly received the preemption indication sent in the DCI.

The UL indication for the interrupt indication reception acknowledgement may be separately encoded within UCI bits through explicit signaling. For example, one solution is to split the HARQ-ACK feedback into two steps and send an acknowledgement in the first step. Thus, the HARQ-ACK feedback may consist of two fields, where the first field includes a preemptive receipt indication and the second field includes the actual HARQ-ACK feedback bits. Fig. 11 illustrates such an example.

Another solution may be to send UL indication for interrupting the indication to receive acknowledgement via implicit signaling. For example, a different PUCCH format, PUCCH resource, scrambling of UCI bits or CRC may be used to indicate whether the UE has constructed HARQ-ACK feedback considering the received outage indication. Also, in the case that UCI (e.g., larger UCI) uses polar coding (polar coding), the implicit indication of the receipt of acknowledgement may be used with the preemption indication by a specific sequence of one or more reliable data bit scrambling of polar coding.

In view of the proposed preemptive HARQ-ACK feedback, at least three options for HARQ retransmission may be employed and provide beneficial performance.

Option 1 is a resource/CB based retransmission, which is based on the proposed HARQ-ACK feedback. The retransmission may include only preempted resources because these resources are indicated by the preemption indication. Alternatively, both the gNB and the UE may know exactly which CBs in the CBG are interrupted and then retransmit only those CBs. Fig. 12 illustrates that in CBG of size 3, retransmission is saved from the sub option described above when only 1 CB is partially interrupted.

Option 2 is a CBG based retransmission with a suitable CBG size. The solution can perform a better level of retransmission than the CBG level of the first transmission while maintaining the retransmission operation of the CBG level. This will allow for adjustment/repartition of CBG within the TB between the first transmission and retransmission. For example, consider a TB having 2 CBGs (CBG-1 and CBG-2), each CBG being 30 CBs in size. When the middle 20 CBs are interrupted due to URLLC preemption, the CBG may be reconfigured after the gcb receives the proposed preemptive CBG level HARQ-ACK feedback. For example, through DCI scheduling of retransmissions, the gNB may reconfigure the CBG to the UE as: CBG-1, comprising the first 20 CBs correctly decoded, CBG-2, comprising the last 20 CBs correctly decoded, CBG-3, comprising the CBs interrupted. The gNB may then retransmit only CBG-3 to the UE. However, if DCI scheduling and retransmission of the re-assembled CBG are missed, an additional mechanism may be needed to avoid any confusion.

In some related cases, it may be assumed that each CBG of a TB has the same CB set for both the first transmission and retransmission. In this case, option 2 cannot be implemented. Option 3 is a CBG-based stable retransmission, while each CBG maintains the same CB set. In other words, there is no need to reassemble CBGs, but for retransmission of CBGs that are partially interrupted, the gNB includes only CBs that are actually interrupted in the respective transmission resources. Thus, with this option, retransmission can be performed using fewer resources, and even CBs can be extended over the retransmission resources to make retransmission more stable. With the proposed CBG level HARQ-ACK feedback that is aware of preemption, the gNB and UE will agree on what the UE has lost about the interrupted CBG. Thus, for example, if only 10 of the 30 CBs transmitted for the first time in CBG-1 are interrupted, the gNB may retransmit CBG-1 at a lower coding rate (e.g., using a simple rate matching mechanism) by only including the interrupted CBs. The UE will expect only missing CBs from CBG-1 and possibly perform soft combining separately, using, for example, knowledge of the interrupt indication and the first transmitted stored information in its soft buffer, only for CBs that were partially interrupted.

Although DL data transmission with UL feedback of NR is considered in the above discussion, the present application can be used for many different transmissions. These include the following examples. LTE: sTTI transmission, in which a theme equivalent to URLLC is defined. Preemptive based multiplexing of the present application may be relevant. UL data transmission with DL feedback may also benefit from the present application. Similar to DL, HARQ feedback proposal can be applied to UL HARQ when preemption or bursty interference occurs in UL transmissions.

Although not specifically illustrated any device or means forming part of a network may include at least one processor, memory unit and communication interface, wherein the processor, memory unit and communication interface are configured to perform the methods of any aspect of the present application. Further options will be described below.

The signal processing functions in the embodiments of the present application, and in particular, the signal processing capabilities of the gNB and the UE, may be implemented by computing systems or architecture known to those skilled in the art. The computing system may be a desktop, laptop or notebook computer, hand-held computing device (PDA, cell phone, palmtop, etc.), mainframe, server, client, or any other type of special or general purpose computing device as may be satisfied by or otherwise employed in a given application or environment. The computing system may include one or more processors that may execute a general-purpose or special-purpose processing engine, such as a microprocessor, single-chip microcomputer or other control module.

The computing system may also include a main memory, such as random access memory (Random Access Memory, RAM) or other dynamic memory, for storing information and instructions to be executed by the processor. The main memory may also be used for storing temporary variables or other intermediate information during execution of instructions by the processor. The computing system may also include a Read Only Memory (ROM) or other static storage device for storing static information and instructions for execution by the processor.

The computing system may also include an information storage system including, for example, a media drive and a removable storage interface. The media drive may include a drive or other mechanism that supports fixed or removable storage media, such as a hard disk drive, floppy disk drive, magnetic tape drive, optical disk drive, compact disk drive (CD) or Digital Video Drive (DVD) read-write drive (R or RW), or other fixed or removable media drive. Storage media may include, for example, hard disk, floppy disk, magnetic tape, optical disk, CD, DVD, or other fixed or removable medium that is read by and written to by media drives. The storage medium may include a computer-readable storage medium storing specific computer software or data.

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. These components may include, for example, removable storage units and interfaces such as program cartridge and cartridge interfaces, removable memory (such as flash memory or other removable memory modules) and memory slots, and other removable storage units and interfaces that allow software and data to be transferred from the removable storage unit to the computing system.

The computing system may also include a communication interface. The communication interface may be used to allow software and data to be transferred between the computing system and an external device. For example, the communication interface can include a modem, a network interface (such as an Ethernet or other network card), a communication port (such as a Universal Serial Bus (USB) port), a PCMCIA slot and card, etc. Software and data transferred via the communications interface are in the form of signals which may be electronic, electromagnetic, optical or other signals capable of being received by the communications interface medium.

In this application, the terms "computer program product," "computer-readable medium," and the like 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. These instructions, which are typically referred to as "computer program code" (which may be grouped in the form of computer programs or other groupings), when executed, enable the computer system to perform functions of embodiments of the present application. It is noted that the code may direct a processor to perform specified operations, or may be compiled to perform specified operations and/or combined with other software, hardware, and/or firmware elements (e.g., libraries that perform standard functions).

The non-computer readable medium may include at least one of the group consisting of: hard disk, compact disk Read Only (CD-ROM, compact Disc Read Only Memory), optical storage, magnetic storage, read Only Memory (ROM), programmable Read Only Memory (PROM, programmable Read Only Memory), erasable programmable Read Only Memory (EPROM, erasable Programmable Read Only Memory), electrically erasable programmable Read Only Memory (EEPROM, electrically erasable programmable Read Only Memory), and Flash Memory (Flash Memory).

In an embodiment implemented by software, the software may be stored in a computer readable medium and loaded into a computing system using, for example, a removable storage drive. A control module (e.g., software instructions or executable computer program code) executed by a processor in a computer system causes the processor to perform the functions as described herein.

Further, the present application may be applied in any circuit in a network element for performing signal processing functions. For example, it is further contemplated that a semiconductor manufacturer may employ innovative concepts in the design of a stand-alone device, which may be a microcontroller (DSP) of a digital signal processor, an Application Specific Integrated Circuit (ASIC), and/or any other subsystem element.

For clarity of description, the above description describes embodiments of the present application with reference to single processing logic. However, the present application may equally implement the signal processing function by a plurality of different functional units and processors. Thus, references to specific functional units are only to be seen as references to suitable means for providing the described functionality rather than indicative of a strict logical, physical structure, or organization.

Aspects of the present application may be implemented in any suitable form including hardware, software, firmware or any combination of these. The present application may optionally be implemented at least in part as computer software, as computer software components such as FPGA devices running on one or more data processors and/or digital signal processors or configurable modules. Thus, the elements and components of an embodiment of the disclosure may be physically, functionally and logically implemented in any suitable way. Indeed the functionality may be implemented in a single unit, in a plurality of units or as part of other functional units.

Although the present application has been described with reference to the preferred embodiments, the preferred embodiments are not intended to limit the application, but rather the scope of the application is defined by the claims. Furthermore, although a description of features associated with a particular embodiment may occur, those skilled in the art may obtain a variety of features of the described embodiment in light of the instant application. In the claims, the term "comprising" does not exclude the presence of other elements or steps.

Further, although individually listed, a plurality of means, elements or method steps may be implemented by e.g. a single unit or processor. Furthermore, although different features may be included in different claims, these may possibly be advantageously combined, and the inclusion in different claims does not imply that a combination of features is not feasible and/or advantageous. Likewise, the inclusion of a feature in one set of claims does not imply a limitation to this set of claims but rather indicates that the feature is equally applicable to other classes of claims where appropriate.

Further, the ordering of features in the claims does not imply that the features must be performed in a specific order, and in particular the order of individual steps in a method claim does not imply that the steps must be performed in this order. Rather, the steps may be performed in any suitable order. In addition, singular references do not exclude a plurality. Thus, the singular references of "a", "an", "the" and "second" do not exclude a plurality.

Although the present application has been described with reference to the preferred embodiments, the preferred embodiments are not intended to limit the application, but rather the scope of the application is defined by the claims. Furthermore, although a description of features associated with a particular embodiment may occur, those skilled in the art may obtain a variety of features of the described embodiment in light of the instant application. In the claims, the term "comprising" or "including" does not exclude the presence of other elements.

Claims (18)

1. A method of allowing access to services provided by a radio access network between a first wireless communication device and a second wireless communication device, the method comprising:

generating HARQ-ACK feedback on the second wireless communication device based on the resources preempted during transmission of the transport block by the first wireless communication device, so that the second wireless communication device can monitor the preempted resources,

wherein the payload of the HARQ-ACK feedback corresponding to each CBG that is partially interrupted has a plurality of bits, and the payload of the HARQ-ACK feedback corresponding to each CBG that is completely interrupted has 1 bit.

2. The method of claim 1, wherein the consensus between the first wireless communication device and the second wireless communication device is considered by both devices based on a notification of preemptive resources from the first wireless communication device.

3. The method of claim 1 or 2, wherein either of the first wireless communication device and the second wireless communication device is configured to generate HARQ-ACK feedback.

4. The method of claim 3, wherein any one of the first wireless communication device and the second wireless communication device is configured to automatically monitor HARQ-ACK feedback from the other of the first wireless communication device and the second wireless communication device.

5. The method of claim 1, 2 or 4, wherein the HARQ-ACK feedback comprises a plurality of bits for each CBG that is partially interrupted.

6. The method of claim 1, 2 or 4, wherein the HARQ-ACK feedback comprises a plurality of bits for the interrupted code block.

7. The method of claim 1, 2 or 4, wherein the HARQ-ACK feedback comprises a plurality of bits for an uninterrupted code block or CBG.

8. The method of claim 1, 2 or 4, comprising reporting resources subject to bursty interference.

9. The method of claim 1, 2 or 4, wherein the second wireless communication device provides an interrupt indication receipt acknowledgement to the first wireless communication device.

10. The method of claim 1, 2 or 4, wherein for a given TB, one or more CBGs or code blocks are corrupted by an interrupt; the second wireless communication device can send a feedback ACK or NACK for the entire TB.

11. The method of claim 1, 2 or 4, wherein for a given CBG, one or more code blocks are corrupted by an interrupt and one or more code blocks are corrupted by another cause; the second wireless communication device can send a feedback NACK for the entire CBG.

12. The method of claim 1, 2 or 4, wherein HARQ retransmission occurs based on HARQ-ACK feedback using at least one different option; only the corrupted resources or the undecoded CBs are retransmitted; recombining the CBG and retransmitting the CBG comprising the corrupted CB; alternatively, the CBGs that are partially interrupted are adapted to include only the undecoded CBs and these CBGs are retransmitted.

13. The method of claim 9, wherein HARQ-ACK feedback comprises using at least one different PUCCH format; different PUCCH resources; different scrambling of uplink control information UCI bits; different cyclic redundancy checks attached to UCI bits; upon decoding, additional bits of the separate part of the HARQ-ACK feedback.

14. The method of claim 1, 2 or 4, wherein the HARQ-ACK feedback comprises a predetermined number of additional ACK/Nack bits, including information of the interrupted CBG.

15. The method according to claim 1, 2 or 4, characterized in that the radio access network is a new radio network/5G network.

16. A user equipment, UE, comprising a processor, a memory unit and a communication interface, characterized in that the processor, the memory unit and the communication interface are adapted to perform the method of claim 1, 2 or 4.

17. A base station, BS, comprising a processor, a memory unit and a communication interface, characterized in that the processor, the memory unit and the communication interface are adapted to perform the method of claim 1, 2 or 4.

18. A non-transitory computer readable storage medium, characterized in that the storage medium stores computer readable instructions adapted to be loaded by a processor to perform the method of claim 1, 2 or 4.