CN113287365A

CN113287365A - Uplink retransmission indication

Info

Publication number: CN113287365A
Application number: CN201980088562.7A
Authority: CN
Inventors: 刘星; 郝鹏; 贺海港; 肖凯; 韩祥辉; 张晨晨; 任敏
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2019-01-11
Filing date: 2019-01-11
Publication date: 2021-08-20
Anticipated expiration: 2039-01-11
Also published as: CN113287365B; WO2020034573A1

Abstract

Methods, systems, and apparatus relating to digital wireless communications are described. An example method of wireless communication includes: at the first communication node, at least one indication of resources for uplink transmission is generated based on a policy set comprising a first retransmission policy. According to a first retransmission policy, the at least one indication comprises a first Resource Indication (RI) indicating whether at least one target resource is preempted and/or whether a first transmission requires retransmission. The example method further includes: the at least one indication is transmitted by the first communication node.

Description

Uplink retransmission indication

Technical Field

This patent document relates generally to digital wireless communications.

Background

Mobile communication technology is pushing the world to an increasingly interconnected and networked society. The rapid growth of mobile communications and advances in technology have resulted in greater demands for capacity and connectivity. Other aspects such as energy consumption, device cost, spectral efficiency, and latency are also important to meet the needs of various communication scenarios. Next generation systems and wireless communication technologies need to support higher data rates, large numbers of connections, ultra-low latency, high reliability and other emerging traffic demands than existing wireless networks.

Disclosure of Invention

This document relates to methods, systems, and apparatus related to digital wireless communications, and more particularly, to mechanisms for indicating uplink retransmissions.

In one exemplary aspect, a first wireless communication method is disclosed. The method comprises the following steps: at the first communication node, at least one indication of resources for uplink transmission is generated based on a policy set comprising a first retransmission policy. In accordance with the first retransmission policy, the at least one indication comprises a first Resource Indication (RI) indicating at least one of: (a) at least one target resource is preempted, or (b) a first transmission needs to be retransmitted. The method further comprises the following steps: the first communication node transmits the at least one indication.

In some embodiments, the first communication node comprises a base station. In some embodiments, the policy set further comprises a second retransmission policy, wherein the at least one indication comprises a second RI for indicating a resource occupancy state of at least a Reference Uplink Resource (RUR) according to the second retransmission policy. In some embodiments, the step of generating the at least one indication comprises selecting between at least the first retransmission strategy and the second retransmission strategy.

In some embodiments, the selection is made based at least in part on a predetermined condition. In some embodiments, the predetermined condition comprises a threshold on a number of symbols pre-configured with the unlicensed resource. In some embodiments, the first retransmission policy is selected if the number of symbols of the preconfigured unlicensed resource is less than or equal to the threshold. In some embodiments, the second retransmission policy is selected if the number of symbols of the preconfigured unlicensed resource is greater than the threshold.

In some embodiments, the selecting is based at least in part on Radio Resource Control (RRC) signaling. In some embodiments, a value of one bit in the RRC signaling indicates the selection.

In some embodiments, the first RI is sent between two adjacent uplink grant-free transmissions. In some embodiments, the first of the two adjacent uplink grant-free transmissions is a first grant-free transmission.

In some embodiments, the method further comprises: causing a second communication node to perform retransmission using the at least one target resource based at least in part on the first RI. In some embodiments, the second communication node comprises an unlicensed User Equipment (UE). In some embodiments, the second communication node detects the first RI according to one or more listening occasions. In some embodiments, the one or more listening occasions are determined based at least in part on a sum of the following time delays: (a) a time delay incurred by the first communication node to process data received via the first transmission, and (b) a time delay incurred by the first communication node to generate the first RI.

In some embodiments, the method further comprises: causing a third communication node to cancel or suspend transmission using the at least one target resource based at least in part on the first RI. In some embodiments, the third communication node comprises an authorization-based UE. In some embodiments, the one or more listening occasions are determined based at least in part on a sum of the following time delays: (a) the third communication node processing a time delay incurred by the first RI, and (b) a time delay for cancelling a transmission on the at least one target resource.

In some embodiments, the second RI indicates resources allocated to grant-based transmissions. In some embodiments, the method further comprises: causing a second communication node to change one or more transmission operations on the at least one target resource based at least in part on the second RI. In some embodiments, the one or more transmission operations are changed based at least in part on an overlap between resources allocated to grant-based transmissions and the at least one target resource. In some embodiments, altering the one or more transmission operations comprises at least one of switching to a candidate resource or boosting transmission power.

In another exemplary aspect, a second method of wireless communication is disclosed. The method comprises the following steps: at least one indication of resources for uplink transmission based on a policy set comprising a first retransmission policy is received at a second communication node. In accordance with the first retransmission policy, the at least one indication comprises a first Resource Indication (RI) indicating at least one of: (a) at least one target resource is preempted, or (b) a first transmission needs to be retransmitted. The method further comprises the following steps: the second communication node performs retransmission based at least in part on the at least one indication.

In some embodiments, the second communication node comprises a User Equipment (UE). In some embodiments, the policy set further comprises a second retransmission policy, wherein the at least one indication comprises a second RI for indicating a resource occupancy state of at least a Reference Uplink Resource (RUR) according to the second retransmission policy. In some embodiments, the step of receiving the at least one indication comprises selecting between at least the first retransmission strategy and the second retransmission strategy.

In some embodiments, the first RI is sent from a first communication node. In some embodiments, the first RI is sent between two adjacent uplink grant-free transmissions, and wherein a first transmission of the two adjacent uplink grant-free transmissions is a first grant-free transmission. In some embodiments, the method further comprises: the second communication node performs the retransmission using the at least one target resource based at least in part on the first RI. In some embodiments, the step of receiving the at least one indication comprises the second communication node detecting the first RI according to one or more listening occasions. In some embodiments, the one or more listening occasions are determined based at least in part on a sum of the following time delays: (a) a time delay incurred by the first communication node to process data received via the first transmission, and (b) a time delay incurred by the first communication node to generate the first RI.

In some embodiments, the second RI indicates resources allocated to grant-based transmissions. In some embodiments, the method further comprises: the second communication node changes one or more transmission operations on the at least one target resource based at least in part on the second RI. In some embodiments, the one or more transmission operations are changed based at least in part on an overlap between resources allocated to grant-based transmissions and the at least one target resource. In some embodiments, altering the one or more transmission operations comprises at least one of switching to a candidate resource or boosting transmission power.

In another exemplary aspect, an apparatus for wireless communication is disclosed that is configured or operable to perform the above-described method as disclosed.

In another exemplary aspect, the above-described method is implemented in the form of processor executable code and stored in a computer readable program medium.

The above and other aspects and embodiments thereof are described in more detail in the accompanying drawings, the description and the claims.

Drawings

Fig. 1 illustrates an example method of performing retransmissions and indicating resource preemption with resource indications in accordance with some embodiments of the disclosed technology.

Fig. 2 illustrates a first retransmission strategy in accordance with some embodiments of the disclosed technology.

Fig. 3 illustrates an example scenario in which the retransmission policy of fig. 2 is not applicable, in accordance with some embodiments of the disclosed technique.

Fig. 4 and 5 illustrate example methods of an unlicensed (Grant Free) User Equipment (UE) determining a listening opportunity for receiving a first Resource Indication (RI), in accordance with some embodiments of the disclosed technology.

Fig. 6 and 7 illustrate example methods of determining a listening opportunity for receiving a first RI based on an authorization-based UE in accordance with some embodiments of the disclosed technology.

Fig. 8-10 illustrate example methods for an unlicensed UE to determine a listening opportunity for receiving a second RI in accordance with some embodiments of the disclosed technology.

Fig. 11 illustrates an example of a wireless communication system to which techniques in accordance with one or more embodiments of the disclosed technology may be applied.

Fig. 12 is a schematic block diagram of a portion of a wireless station.

Detailed Description

Examples of the techniques and embodiments herein may be used to improve performance in a multi-user wireless communication system. The term "exemplary" is used to mean an "… … example," and does not imply an ideal or preferred embodiment unless otherwise indicated. Section headings are used herein for ease of understanding, and do not limit the technology disclosed in the sections to only the corresponding sections.

The 4 th generation mobile communication technology (4G) Long Term Evolution (LTE) and/or long term evolution advanced (LTE-Advance/LTE-a) and the 5 th generation mobile communication technology (5G) face ever-increasing demands in various aspects. According to the current trend, 4G and/or 5G systems are seeking to support enhanced mobile broadband, ultra-high reliability, ultra-low latency transmission and massive connectivity.

To support the features of ultra-high reliability and ultra-low latency transmissions, it is desirable to utilize short transmission times to transmit certain high priority traffic (e.g., low latency and high reliability traffic). Illustratively, at least a portion of the resources used for transmitting low latency and high reliability traffic may be preempted prior to or while transmitting other traffic (e.g., traffic having a longer transmission time). Since the preempted transmission is not generally clear between different users of the upstream transmission, the preempted transmitting user may be informed of preemption indication information in order to minimize the performance impact on high reliability and low latency traffic. For example, at this point, transmission of traffic with longer transmission time intervals or uplink transmission of traffic with lower reliability requirements will be cancelled or suspended, thereby avoiding simultaneous transmission using the same resources as used for low latency and high reliability traffic and thus preventing and/or mitigating performance degradation.

For example, for downlink preemption transmission, 14 blocks are partitioned by { M, N } - {14, 1} or {7, 2} in the corresponding configured reference downlink resource, and the preemption state of each block can be notified to the user(s) in a bitmap manner. Here, M denotes the number of partitions divided in the time domain, and N denotes the number of partitions divided in the frequency domain. Currently, there is no effective preemption indication for uplink inter-UE multiplexing transmission.

Uplink transmissions typically include two types: grant-based uplink transmission and grant-free uplink transmission. Grant-based uplink transmission generally refers to uplink transmission performed by a User Equipment (UE) (or terminal) according to an uplink grant made by a corresponding base station, where transmission resources are predetermined. Unlicensed uplink transmission generally refers to uplink transmission autonomously selected by a UE from a semi-statically configured set of unlicensed resources. For unlicensed uplink transmissions, the base station cannot predetermine on which candidate resource a particular transmission occurs. Thus, when a certain high priority unlicensed uplink transmission overlaps with other low priority transmission(s) on the transmission resource, the base station may not be able to notify the preempted user(s) in advance. Other mechanisms may be needed to address these situations. For example, the UE may increase the transmit power of the high priority unlicensed uplink transmission, thereby providing better transmission performance. Since various transmission types may coexist in the same carrier, various resolution mechanisms and their related indication methods may be introduced. The disclosed technology addresses these issues.

SUMMARY

According to some embodiments of the disclosed technology, multiple unlicensed retransmission policies may be defined. For example:

retransmission strategy 1: between two Uplink (UL) grant-free transmissions, a base station (e.g., a gNB) uses a first Resource Indication (RI) to indicate to the relevant UEs for the grant-based service whether certain resources are preempted and whether the grant-free transmission requires retransmission.

Retransmission strategy 2: the base station uses the second RI to indicate to the associated unlicensed UE the resource occupancy status of the reference uplink resource that has been allocated to the grant-based transmission. The unlicensed UE determines whether a particular unlicensed resource overlaps an allocated grant-based transmission resource in order to determine whether it should change its unlicensed transmission policy.

Further, the selection of the retransmission policy may be determined based on predetermined conditions and/or Radio Resource Control (RRC) signaling. Illustratively, the predetermined condition may be a threshold number of symbols of the unlicensed resource. For example, when the number of symbols of the configured unlicensed resource is greater than a threshold, retransmission policy 2 is used; otherwise, retransmission strategy 1 is used.

The disclosed techniques also include the determination of listening occasions for a first RI by two classes of (i.e., grant-based and unlicensed) UEs, and the determination of listening occasions for a second RI by an unlicensed UE.

First embodiment

Fig. 1 illustrates a method of performing retransmissions and indicating resource preemption with resource indications in accordance with some embodiments of the disclosed technology.

Specifically, as shown in fig. 1, the resources (i.e., the first resource and the second resource) in the dashed

boxes

102a and 102b are two resources pre-configured for the adjacent uplink grant-free transmission. According to a slot-based retransmission mechanism, resources for two adjacent transmissions occupy corresponding symbols of adjacent slots.

Illustratively, the first resource is used for first-time unlicensed transmission, and the second resource is used for first-time unlicensed retransmission, then when the uplink unlicensed service arrives, the UE selects the first resource for first-time transmission. If the associated base station (e.g., the gNB) detects an unlicensed transmission on the first resource but does not properly receive the transmission, it reserves a second resource for retransmission of the unlicensed service. The gNB may use the RI to indicate to UEs scheduled in slot 2 (e.g., grant-based UEs) that the second resource is preempted by the grant-free traffic; the gNB may also use the same RI to indicate to the unlicensed UE (which performed the first unlicensed transmission) whether a retransmission is needed. In this case, after the first transmission, the unlicensed UE also listens to and detects the RI. Illustratively, if the resources indicated in the RI include the second resource, the unlicensed UE needs to retransmit the unlicensed service on the second resource.

Illustratively, the RI may be used to indicate occupancy information for unlicensed traffic within future time-frequency resources. For example, the RI may be Downlink Control Information (DCI) carried on a Physical Downlink Control Channel (PDCCH), and Cyclic Redundancy Check (CRC) bits of the RI may be scrambled with a common Radio Network Temporary Identifier (RNTI).

Illustratively, the base station does not (or does not need to) send the RI if the base station detects the first unlicensed transmission and receives it correctly. Thus, the unlicensed UE does not detect the RI and does not (or does not need to) retransmit the unlicensed service. In this case, the second resource may be scheduled to time slot 2 for use by grant-based traffic.

If the unlicensed UE detects the RI but the resources indicated in the RI do not include the second resource, the unlicensed UE does not (or does not need to) retransmit the unlicensed service on the second resource.

In some embodiments, the aforementioned detection of the unlicensed transmission by the gNB includes or corresponds to detection of an unlicensed transmission of data carried on a Physical Uplink Shared Channel (PUSCH). Illustratively, the gNB may determine whether there is an unlicensed transmission by listening to a demodulation reference signal (DMRS) carried on the PUSCH. In this case, the case where the gbb successfully detects the PUSCH DMRS but fails to decode the PUSCH corresponds to the base station (e.g., the gbb) detecting the unlicensed transmission on the first resource but not receiving the transmission correctly, as described above.

Second embodiment

In accordance with some embodiments of the disclosed technology, exemplary methods are described for determining a retransmission policy based on a threshold number of unlicensed resource symbols.

A threshold value for the number of unlicensed resource symbols may be predefined. For example, the threshold may be predefined in the protocol, or the gNB may indicate the threshold to the UE through RRC signaling, physical layer signaling, or physical layer channels. In this embodiment, the threshold number of unlicensed resource symbols is 2 symbols, as an example. Accordingly, the retransmission policy selection can be based on whether the number of symbols of the preconfigured unlicensed resource is (a) less than or equal to a threshold, or (b) greater than a threshold.

Fig. 2 illustrates a first retransmission strategy in accordance with some embodiments of the disclosed technology. Referring to fig. 2, retransmission strategy 1 is described as follows: when the pre-configured number of unlicensed resource symbols is less than or equal to a threshold (e.g., 2 symbols), the unlicensed UE detects a first RI on an nth symbol after a first transmission of the unlicensed UE to determine whether to retransmit on the second resource. Illustratively, in the present embodiment, the number of symbols of the pre-configured unlicensed resource is 2.

According to the retransmission mechanism based on the time slot, the adjacent two transmissions occupy corresponding symbols of the adjacent time slot, that is, the number of symbols between the adjacent two transmissions is T-14-the number of symbols of the unlicensed resource is 14-2-12; during this time (i.e., 12 symbols), the relevant gNB may first detect whether an unlicensed transmission is present on the first resource. If an unlicensed transmission is detected, the gNB can determine whether the unlicensed transmission was decoded correctly and which subsequent operation(s) to perform.

If the gNB detects an unlicensed transmission on the first resource but does not receive the transmission correctly, the corresponding second resource needs to be reserved for retransmission of the unlicensed service. At this time, the gNB generates first RI information. Illustratively, the delay incurred by the gNB for decoding the data received on the first resource and for generating the RI information is N1, then the transmission location of the first RI should be greater than or equal to N1, as measured from the first resource end symbol. Referring to fig. 2, assuming that the value of N1 is 4.5 symbols at a subcarrier interval of 30kHz, the start symbol of the first RI may be configured on the sixth symbol after the first resource. Illustratively, the first RI includes second resource information that needs to be occupied for the unlicensed retransmission.

The unlicensed UE (which performs the first unlicensed transmission) and any grant-based UEs scheduled to perform UL transmissions on the second resource may listen and detect the first RI. In response to detecting the first RI, the grant-based UE may cancel its transmission on the second resource in accordance with the first RI. Exemplarily, referring to fig. 2, a shaded area 202 represents uplink transmission resources scheduled in advance to the unlicensed UE, and data transmission on an overlapping area between the second resource (as indicated by a dashed box 204) and the shaded area is cancelled. In response to detecting the first RI, the unlicensed UE determines whether the first RI indicates an entire second resource preconfigured to the unlicensed UE. If so indicated, the unlicensed UE will perform a retransmission on the second resource.

In order to cancel the prescheduled grant-based transmission, the first RI needs to meet certain processing latency requirements. Illustratively, the first RI should occur at least a certain time before the transmission to be cancelled. The time difference may be greater than or equal to a sum of (a) a latency incurred by the grant-based UE to process the first RI and (b) a latency required to cancel data transmission on the corresponding resource. For example, if the first RI is DCI carried on a PDCCH, the delay in processing the first RI corresponds to the delay in decoding the PDCCH. As another example, if the first RI employs the sequence form indication information, a delay of processing the first RI corresponds to a delay of sequence detection. Referring to fig. 2, assuming that the time delay is N2 and the value of N2 is 5.5 symbols at 30kHz, grant-based transmissions that can be cancelled by the first RI are separated from the first RI by at least 6 symbols.

If the gNB detects that an unlicensed transmission exists on the first resource and the transmission data is correctly received, the unlicensed transmission need not be retransmitted and the second resource can be allocated to the grant-based service according to the pre-scheduling information. The gNB does not (or need not) generate and transmit the first RI. Thus, while the unlicensed UE and the grant-based UE scheduled to perform UL transmission on the second resource may still listen (e.g., passively listen) to the first RI on the respective resources, the unlicensed UE and the grant-based UE will not detect the first RI. The unlicensed UE will not perform retransmissions and the grant-based UE will not cancel transmissions scheduled on the second resource. Of course, if the gNB does not detect any unlicensed transmission on the first resource, it will not generate and send the first RI.

According to the above description, the retransmission strategy 1 satisfies certain timing requirements. More specifically, the time interval between two adjacent transmissions is greater than or equal to

Wherein N is_RIIs the number of symbols of the first RI. In other words, the number of symbols of the unlicensed resource

And a threshold on the number of unlicensed resources is predetermined to meet these timing requirements.

Corresponding to retransmission policy 1, retransmission policy 2 according to some embodiments of the disclosed technology is described as follows: when the pre-configured number of grant-free resource symbols is greater than the threshold, scheduled grant-based transmissions cannot be reliably or efficiently cancelled by sending the first RI between transmissions. That is, as shown in fig. 3, after detecting the first RI, the transmission is cancelled based on the granted UE before it is time to transmit on the second resource. Thus, in this case, the unlicensed UE may determine how to perform its own transmission based on the resource occupancy state of the grant-based transmission in slot 2.

Illustratively, the unlicensed UE may receive a second RI indicating a set of resources. For example, the second RI may indicate a resource allocation for grant based transmission in the predefined area. If the resource allocated for grant-based transmission overlaps with the second resource, the unlicensed UE may alter its transmission operation, e.g., by increasing transmit power or switching to a candidate or backup resource. The candidate or backup resource may be another set of unlicensed resources configured to the unlicensed UE through RRC signaling or an unlicensed resource indicated to the unlicensed UE in the DCI. If there is no overlap between the grant-based transmission resource and the second resource indicated by the second RI, the unlicensed UE does not change its transmission operation with respect to the second resource, e.g., using the same Modulation and Coding Scheme (MCS) as on the first resource.

Other thresholds (e.g., thresholds for the time interval between two adjacent transmissions) may be used to select between retransmission strategies. For example, if the time interval between two adjacent transmissions is greater than or equal to a certain time interval threshold, retransmission strategy 1 is selected. Otherwise, retransmission strategy 2 is selected.

Third embodiment

In accordance with some embodiments of the disclosed technology, exemplary methods are described for determining a retransmission policy based on an indication via RRC signaling.

Illustratively, an Information Element (IE) for specifying a retransmission policy is defined in RRC signaling. For example, 1 bit may be used to indicate whether retransmission strategy 1 or retransmission strategy 2, respectively, is employed, as described according to the second embodiment.

In particular, the bit value of "0" may represent a retransmission policy, wherein both the unlicensed UE and the grant-based UE listen to the first RI. In response to detecting the first RI, the grant-based UE cancels its transmission on the second resource in accordance with the first RI. Referring to fig. 2, a shaded area indicates uplink transmission resources scheduled in advance to a grant-based UE, and data transmission on an overlapping area between a second resource (as indicated by a dotted-line box 204) and the shaded area 202 is cancelled. In response to detecting the first RI, the unlicensed UE determines whether the first RI indicates an entire second resource preconfigured to the unlicensed UE. If so, the unlicensed UE will perform a retransmission on the second resource.

The bit value of "1" may represent a retransmission policy of 2, where the unlicensed UE listens to the second RI. If the resources indicated in the second RI that have been allocated to grant based transmission overlap with the second resources, the unlicensed UE will change its transmission operation. Otherwise, the unlicensed UE does not change its transmission operation on the second resource.

Fourth embodiment

In accordance with some embodiments of the disclosed technology, an example method is described for an unlicensed UE to determine a listening opportunity to receive a first RI (as described above).

According to the retransmission policy of the first embodiment and the retransmission policy 1 of the second and third embodiments, the unlicensed UE should determine to listen to the resources of the first RI. Illustratively, there are three ways to achieve this.

The method comprises the following steps: as shown in fig. 4, the unlicensed resource is illustratively configured with 1 symbol located on symbol # 7. In this method, the start symbol of the first RI is defined as a symbol spaced N symbols apart from the first resource (or previous transmission). For example,

wherein N is₁Is the time delay caused by the corresponding gNB decoding the data received on the first resource and generating the first RI indication information. If the ending symbol index of the first resource is n, the starting symbol index of the first RI is

When in use

Then, the first RI starts in the same slot as the second resource (or the start symbol of the first RI is in a slot after the slot in which the first resource resides); when in use

The first RI starts in the same slot as the first resource (or the start symbol of the first RI is in a slot before the slot in which the second resource resides).

The method 2 comprises the following steps: as shown in fig. 5, the unlicensed resource is illustratively configured with 1 symbol located on symbol # 7. In this method, an end symbol of the first RI is defined as a symbol spaced M symbols apart from a start symbol of the second resource (or retransmission resource). For example,

wherein N is₂A sum of (a) a time delay incurred by processing the first RI for the grant-based UE and (b) a time delay for cancelling data transmission on the corresponding resource. Illustratively, if the first RI is DCI carried on a PDCCH, the delay of processing the first RI corresponds to the delay of decoding the PDCCH. As another example, if the first RI employs the sequence form indication information, a delay of processing the first RI corresponds to a delay of sequence detection.

If the starting symbol index of the second resource is m, the starting symbol index of the first RI is

Wherein N is_RIIs the number of symbols of the first RI. When in use

The method 3 comprises the following steps: the interval between the first RI and the first resource and/or the interval between the first RI and the second resource may be configured using RRC signaling.

Fifth embodiment

In accordance with some embodiments of the disclosed technology, an example method is described for determining a listening opportunity to receive a first RI (as described above) based on an authorized UE.

According to the retransmission policy of the first embodiment and the retransmission policy 1 of the second and third embodiments, the UE based on authorization may determine to listen to the resources of the first RI. Illustratively, there are two ways to achieve this.

The method comprises the following steps: as shown in fig. 6, grant based resources are illustratively configured with 1 symbol. In this method, the end symbol of the first RI is defined as a symbol spaced M apart from the start symbol of the second resource (or retransmission resource), e.g.,

wherein N is₂Is the sum of (a) the time delay incurred by the grant-based UE to process the first RI and (b) the time delay to cancel the data transmission on the corresponding resource. For example, if the first RI is DCI carried on a PDCCH, the delay in processing the first RI corresponds to the delay in decoding the PDCCH. As another example, if the first RI employs the sequence form indication information, a delay of processing the first RI corresponds to a delay of sequence detection.

Grant-based transmission resource if the starting symbol index of the grant-free resource overlapping with the grant-based transmission resource is nThe UE of the right listens for the starting symbol index of the first RI to be m, which may be calculated as follows:

wherein N is_RIIs the number of symbols of the first RI. If it is not

The first RI resides in the same time slot as the grant-based resource; otherwise, the first RI resides in a time slot preceding the time slot in which the grant-based resource resides. Since there may be multiple unlicensed resources that overlap with the grant-based resources, n may take multiple values resulting in different values of m, where the grant-based UE listens to the first RI.

The method 2 comprises the following steps: as shown in fig. 7, an exemplary grant based resource is configured with 1 symbol. In this method, the start symbol of the first RI is defined as a symbol spaced apart from the first resource (or previous transmission) by N, e.g.,

wherein N is₁Is the time delay caused by the corresponding gNB decoding the data received on the first resource and generating the first RI indication information.

If the ending symbol index of the unlicensed resource that overlaps with the grant-based transmission resource is n, the grant-based UE listens for the starting symbol index of the first RI to be m, which may be calculated as follows:

wherein if

The first RI resides in the same time slot as the grant based resource; otherwise, the first RI resides in a time slot preceding the time slot in which the grant-based resource resides. Since there may be multiple unlicensed resources that overlap with the grant-based resources, there is no need for a dedicated resourceN may take a plurality of values resulting in different values of m, where the grant-based UE listens to the first RI.

Sixth embodiment

In accordance with some embodiments of the disclosed technology, exemplary methods are described for an unlicensed UE to determine a listening opportunity to receive a second RI (as described above).

According to the retransmission policy 2 of the second and third embodiments, the unlicensed UE may determine to listen to the resources of the second RI. Illustratively, there are two ways to achieve this.

The method comprises the following steps: as shown in fig. 8, exemplarily, both RI1 and RI2 are the second RI, and the listening occasion of the second RI is the same as the PDCCH used for scheduling grant-based transmission. Referring to fig. 8, a Reference Uplink Resource (RUR) region 802, which is surrounded by a dotted line, is an indication region corresponding to RI1, i.e., RI1 indicates all grant-based transmissions scheduled to the range of region 802. The RUR is separated from its corresponding RI by N symbols. For example,

wherein N is₂Is the sum of (a) the time delay incurred by the grant-based UE to process the first RI and (b) the time delay to cancel the data transmission on the corresponding resource. Illustratively, if the second RI is DCI carried on a PDCCH, the delay of processing the second RI corresponds to the delay of decoding the PDCCH. As another example, if the second RI employs the sequence form indication information, the delay of processing the second RI corresponds to the delay of sequence detection.

Illustratively, the time domain length of the RUR is equal to a listening period of the second RI or a time offset between two adjacent second RIs. The unlicensed UE may listen to a second RI corresponding to the RUR in which the unlicensed resource is located. For example, referring to fig. 8, the unlicensed resources of the unlicensed UE are indicated by the shaded area 804, and the RUR of the unlicensed UE corresponds to one of the second RIs, i.e., RI 1. Thus, the unlicensed UE listens to the RI 1.

As shown in fig. 9, when the unlicensed resource spans multiple rrs, the unlicensed UE may listen to all second RIs indicating unlicensed resource information. Specifically, referring to FIG. 9, the unlicensed resource resides partially in RUR1 and partially in RUR 2. Thus, an unlicensed UE may listen to two second RIs, RI1 and RI 2.

The method 2 comprises the following steps: as shown in fig. 10, the second RI listens for configuration bindings to the unlicensed resource. For example, the unlicensed resource includes two symbols, and the RURs are divided at the time domain granularity of the unlicensed resource. The entire RUR corresponds to an upstream BWP or upstream carrier in the frequency domain. Each of the RURs corresponds to a second RI, and the second RI indicates resource allocation based on the authorized transmission in a range of the corresponding RUR. In this RI listening configuration, the unlicensed UE may listen only to a particular second RI corresponding to the RUR of the unlicensed resource that the unlicensed UE desires to camp on.

For example, referring to fig. 10, an uplink unlicensed traffic of an unlicensed UE arrives and it is expected to occupy unlicensed resource 1, and unlicensed resource 1 belongs to the RUR1 corresponding to RI 1. Therefore, the unlicensed UE first listens to the RI1 before sending uplink traffic using unlicensed resource 1. If the resources allocated to grant-based transmissions, as indicated by RI1, overlap with unlicensed resource 1, in order to provide quality performance of the unlicensed transmissions, the unlicensed UE may change its transmission operation, for example, by switching transmission resources according to a predetermined rule or by performing a power-up transmission.

Fig. 11 illustrates an example of a wireless communication system to which techniques in accordance with one or more embodiments of the disclosed technology may be applied. The wireless communication system 1100 may include one or more Base Stations (BSs) 1105a, 1105b, one or more wireless devices (e.g., UEs or terminals) 1110a, 1110b, 1110c, 1110d, and an access network 1125.

Base stations

1105a, 1105b may provide wireless service to

wireless devices

1110a, 1110b, 1110c, and 1110d in one or more wireless sectors. In some embodiments, the

base stations

1105a, 1105b include directional antennas that generate two or more directional beams to provide wireless coverage in different sectors.

An access network 1125 may communicate with one or

more base stations

1105a, 1105 b. In some embodiments, the access network 1125 includes one or

more base stations

1105a, 1105 b. In some embodiments, the access network 1125 communicates with a core network (not shown in fig. 11) that provides connectivity to other wireless and wireline communication systems. The core network may include one or more service subscription databases to store information related to subscribed

wireless devices

1110a, 1110b, 1110c, and 1110 d. The first base station 1105a may provide wireless service based on a first radio access technology and the second base station 1105b may provide wireless service based on a second radio access technology. Depending on the deployment scenario, the

base stations

1105a and 1105b may be co-located or may be separately installed in the field. The access network 1125 may support multiple different radio access technologies.

In some embodiments, a wireless communication system may include multiple networks using different wireless technologies. A dual-mode or multi-mode wireless device includes two or more wireless technologies that may be used to connect to different wireless networks.

Fig. 12 is a schematic block diagram of a portion of a wireless station (e.g., a type of wireless communication node). A wireless station 1205, e.g., a base station or terminal (or UE), may include processor electronics 1210, such as a microprocessor implementing one or more of the wireless technologies presented herein. The wireless station 1205 may include transceiver electronics 1215 to transmit and/or receive wireless signals through one or more communication interfaces, such as an antenna 1220. The wireless station 1205 may include other communication interfaces for sending and receiving data. The wireless station 1205 may include one or more memories (not explicitly shown) configured to store information, e.g., data and/or instructions. In some implementations, the processor electronics 1210 may include at least a portion of the transceiver electronics 1215. In some embodiments, at least some of the disclosed techniques, modules, or functions are implemented using a wireless station 1205.

Some embodiments described herein are described in the general context of methods or processes, which may be implemented in one embodiment by a computer program product, embodied in a computer-readable medium, including computer-executable instructions, such as program code, executed by computers in networked environments. Computer-readable media may include removable and non-removable storage devices, including but not limited to Read Only Memory (ROM), Random Access Memory (RAM), Compact Disks (CDs), Digital Versatile Disks (DVDs), and the like. Generally, program modules may include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Computer-or processor-executable instructions, associated data structures, and program modules represent examples of program code for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps or processes.

Some embodiments disclosed may be implemented as a device or module using hardware circuitry, software, or a combination thereof. For example, an implementation of a hardware circuit may include separate analog and/or digital components, e.g., integrated as part of a printed circuit board. Alternatively or additionally, the disclosed components or modules may be implemented as Application Specific Integrated Circuits (ASICs) and/or Field Programmable Gate Array (FPGA) devices. Some embodiments may additionally or alternatively include a Digital Signal Processor (DSP), which is a special-purpose microprocessor having an architecture optimized for the operational needs of the digital signal processing associated with the functions disclosed herein. Similarly, various components or sub-components within each module may be implemented in software, hardware, or firmware. Connections between modules and/or components within modules may be provided using any of the connection methods and media known in the art, including, but not limited to, communications over the internet, wired, or wireless networks using an appropriate protocol.

While this patent document contains many specifics, these should not be construed as limitations on the scope of any invention or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular inventions. Certain features that are described in this patent document in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Moreover, the separation of various system components in the embodiments described in this patent document should not be understood as requiring such separation in all embodiments.

Only some embodiments and examples are described, and other embodiments, enhancements and variations can be made based on what is described and illustrated in this patent document.

Claims

1. A method of wireless communication, comprising:

at a first communication node, generating at least one indication of resources for uplink transmission based on a policy set comprising a first retransmission policy, wherein according to the first retransmission policy the at least one indication comprises a first Resource Indication (RI) indicating at least one of: (a) at least one target resource is preempted, or (b) a first transmission needs to be retransmitted; and

the first communication node transmits the at least one indication.

2. The method of claim 1, wherein the first communication node comprises a base station.

3. The method of claim 1, wherein the set of policies further comprises a second retransmission policy, wherein the at least one indication comprises a second RI for indicating a resource occupancy state of at least a Reference Uplink Resource (RUR) according to the second retransmission policy.

4. The method of claim 3, wherein generating the at least one indication comprises: selecting between at least the first retransmission policy and the second retransmission policy.

5. The method of claim 4, wherein the selecting is based at least in part on a predetermined condition.

6. The method of claim 5, wherein the predetermined condition comprises a threshold on a number of symbols pre-configured with the unlicensed resource.

7. The method of claim 6, wherein the first retransmission policy is selected if the number of symbols of the preconfigured unlicensed resource is less than or equal to the threshold.

8. The method of claim 6, wherein the second retransmission policy is selected if the number of symbols of the preconfigured unlicensed resource is greater than the threshold.

9. The method of claim 4, in which the selecting is based at least in part on Radio Resource Control (RRC) signaling.

10. The method of claim 9, wherein a value of one bit in the RRC signaling indicates the selection.

11. The method of claim 1, wherein the first RI is transmitted between two adjacent uplink grant-free transmissions.

12. The method of claim 11, wherein a first transmission of the two adjacent uplink grant-free transmissions is a first grant-free transmission.

13. The method of claim 1, further comprising: causing a second communication node to perform retransmission using the at least one target resource based at least in part on the first RI.

14. The method of claim 13, wherein the second communication node comprises an unlicensed User Equipment (UE).

15. The method of claim 13, wherein the second communication node detects the first RI according to one or more listening occasions.

16. The method of claim 15, wherein the one or more listening occasions are determined based at least in part on a sum of: (a) a time delay incurred by the first communication node to process data received via the first transmission, and (b) a time delay incurred by the first communication node to generate the first RI.

17. The method of claim 1, further comprising: causing a third communication node to cancel or suspend transmission using the at least one target resource based at least in part on the first RI.

18. The method of claim 17, wherein the third communication node comprises an authorization-based UE.

19. The method of claims 15 and 17, wherein the one or more listening occasions are determined based at least in part on a sum of the following time delays: (a) the third communication node processing a time delay incurred by the first RI, and (b) a time delay for cancelling a transmission on the at least one target resource.

20. The method of claim 3, wherein the second RI indicates resources allocated to grant-based transmissions.

21. The method of claim 20, further comprising: causing a second communication node to change one or more transmission operations on the at least one target resource based at least in part on the second RI.

22. The method of claim 21, wherein the one or more transmission operations are changed based at least in part on an overlap between resources allocated for grant-based transmissions and the at least one target resource.

23. The method of claim 22, wherein altering the one or more transmission operations comprises: at least one of switching to a candidate resource or boosting transmission power.

24. A method of wireless communication, comprising:

receiving, at a second communication node, at least one indication of resources for uplink transmission based on a policy set comprising a first retransmission policy, wherein according to the first retransmission policy the at least one indication comprises a first Resource Indication (RI) indicating at least one of: (a) at least one target resource is preempted, or (b) a first transmission needs to be retransmitted; and

the second communication node performs retransmission based at least in part on the at least one indication.

25. The method of claim 24, wherein the second communication node comprises a User Equipment (UE).

26. The method of claim 24, wherein the set of policies further comprises a second retransmission policy, wherein the at least one indication comprises a second RI for indicating a resource occupancy state of at least a Reference Uplink Resource (RUR) according to the second retransmission policy.

27. The method of claim 26, wherein receiving the at least one indication comprises: selecting between at least the first retransmission policy and the second retransmission policy.

28. The method of claim 27, wherein the selecting is based at least in part on a predetermined condition.

29. The method of claim 28, wherein the predetermined condition comprises a threshold on a number of symbols pre-configured with the unlicensed resource.

30. The method of claim 29, wherein the first retransmission policy is selected if the number of symbols of the preconfigured unlicensed resource is less than or equal to the threshold.

31. The method of claim 29, wherein the second retransmission policy is selected if the number of symbols of the preconfigured unlicensed resource is greater than the threshold.

32. The method of claim 27, wherein the selecting is based at least in part on Radio Resource Control (RRC) signaling.

33. The method of claim 32, wherein a value of one bit in the RRC signaling indicates the selection.

34. The method of claim 24, wherein the first RI is transmitted from a first communication node.

35. The method of claim 34, wherein the first RI is transmitted between two adjacent uplink grant-free transmissions, and wherein a first transmission of the two adjacent uplink grant-free transmissions is a first grant-free transmission.

36. The method of claim 35, further comprising: the second communication node performs the retransmission using the at least one target resource based at least in part on the first RI.

37. The method of claim 34, wherein receiving the at least one indication comprises: the second communication node detects the first RI according to one or more listening occasions.

38. The method of claim 37, wherein the one or more listening occasions are determined based at least in part on a sum of: (a) a time delay incurred by the first communication node to process data received via the first transmission, and (b) a time delay incurred by the first communication node to generate the first RI.

39. The method of claim 26, wherein the second RI indicates resources allocated to grant-based transmissions.

40. The method of claim 39, further comprising: the second communication node changes one or more transmission operations on the at least one target resource based at least in part on the second RI.

41. The method of claim 40, wherein the one or more transmission operations are changed based at least in part on an overlap between resources allocated for grant-based transmissions and the at least one target resource.

42. The method of claim 41, wherein altering the one or more transmission operations comprises: at least one of switching to a candidate resource or boosting transmission power.

43. An apparatus for wireless communication that performs the method of any of claims 1-42.

44. A non-transitory computer-readable medium having code stored thereon, which, when executed by a processor, causes the processor to implement the method of any one of claims 1-42.