Patent Description:
Examples of such multiple-access systems include fourth generation (<NUM>) systems such as a Long Term Evolution (LTE) systems or LTE-Advanced (LTE-A) systems, and fifth generation (<NUM>) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform-spread-OFDM (DFT-S-OFDM).

Certain wireless communication systems may be configured to support control information being sent in a control resource set (coreset) that includes a physical resource block (PRB) that is transmitted over a number of OFDM symbols. Such configurations provide frequency diversity by spreading the control information (e.g., physical downlink control channel (PDCCH) information) over the coreset. In some aspects, an unused (e.g., empty) coreset may be reused for data communications, e.g., downlink and/or uplink communications. Reuse of a coreset may be based on specific rules, known as reuse rules. Additionally, exceptions to the specific reuse rules, known as reuse exception rules, exist. The reuse exception rules allow for more liberal reuse of the coreset than that allowed by the reuse rules. Aspects of the present disclosure improve the reuse efficiency for unused control resources.

3GPP discussion and decision document <NPL>et al discusses a mechanism that can be used to achieve dynamic reuse and the general issues related to resource sharing between PDCCH and PDSCH.

The described techniques relate to improved methods, systems, devices, or apparatuses and processor-readable medium comprising processor-executable instructions that support search space-based reuse exception rules. Generally, the described techniques provide for reuse exception rules for region based reuse, such as search space-based (or sub-search space-based) rate matching reuse exception rules. For example, a base station selects and indicates to a user equipment (UE) reuse exception rules that are based on a search space. The reuse exception rule(s) are search space-based. Search spaces identified by the signaled reuse exception rule(s) may include a set of physical downlink control channel (PDCCH) decoding candidates (e.g., scheduled PDCCH signal locations), or the corresponding resource elements (REs), that the UE should assume its physical downlink shared channel (PDSCH) signal will not be mapped into (e.g., even if the UE is signaled by layer <NUM> (L1) signaling that the region is reusable). The base station signals the indication of the reuse exception rule(s) to the UE and the base station and UE communicate in accordance with the reuse exception rule(s). Signaling the reuse exception rule(s) may be implicit in that the one or more reuse exception rules are based on the search space.

A method of wireless communication performed at a base station BS is claimed according to claim <NUM> and another method of wireless communication performed at a user equipment UE is claimed according to claim <NUM>.

An apparatus for wireless communication at a base station BS is claimed according to independent claim <NUM> and another apparatus for wireless communication at a user equipment UE is claimed according to independent claim <NUM>.

A processor-readable medium comprising processor-executable instructions according to claim <NUM> is provided.

Advantageous features are provided in the dependent claims.

In some examples selecting the one or more reuse exception rules comprises: selecting the one or more reuse exception rules to be applied by the UE from a plurality of search space-based rate matching reuse exception rules.

Some examples may further include processes, features, means, or instructions for transmitting, in the UE-specific PDCCH search space, one or more PDCCH signals comprising a plurality of resource grants for the UE.

In some examples selecting the one or more reuse exception rules comprises: selecting a reuse exception rule that allows the UE to reuse the resource set and rate match around, for data communication, one or more resources of the control resource set based on a subset of a UE-specific PDCCH search space.

In some examples the UE-specific PDCCH search space may be determined by an aggregation level (AL) of a current PDCCH granting a PDSCH to the UE.

In some examples the subset of UE-specific PDCCH search space comprises one or more decoding candidates having the same AL as the AL of the current PDCCH granting the PDSCH to the UE.

In some examples the subset of UE-specific PDCCH search space comprises one or more decoding candidates having the same or lower AL as the AL of the current PDCCH granting the PDSCH to the UE.

Some examples include processes, features, means, or instructions for transmitting, in a search space associated with the UE, one or more PDCCH signals comprising one or more resource grants for the UE.

In some examples signaling the one or more reuse exception rules to the UE comprises: identifying an index associated with each of the one or more reuse exception rules. Some examples further include processes, features, means, or instructions for communicating an indication of the index to the UE.

In some examples signaling the one or more reuse exception rules to the UE comprises: identifying an index associated with a subset of rules of the one or more reuse exception rules. Some examples further include processes, features, means, or instructions for communicating an indication of the index to the UE.

Some examples further include processes, features, means, or instructions for transmitting radio resource control (RRC) signaling to configure the resource set. Some examples further include processes, features, means, or instructions for transmitting L1 signaling to indicate resource set reuse.

In some examples the resource set comprises a control resource set, or a set of control resource sets, or a subset of resources of a control resource set, or any combinations thereof.

In some examples the UE-specific PDCCH search space may be determined by an AL of a current PDCCH granting a PDSCH to the UE.

Wireless communication systems may be configured where a base station transmits control information to user equipment (UE) using a control resource set. The control resource set may be defined in conventional systems as a coreset that includes a physical resource block (PRB) spread over a certain number of orthogonal frequency division multiplexing (OFDM) symbols. That is, the control information (e.g., physical downlink control channel (PDCCH) signals) may be transmitted in a downlink transmission from the base station to the UE(s). However, in some instances the resources in the control resource set may be empty or unused. In this instance, the rule has been defined that the UE and base station may reuse the empty control set resources for data communications, e.g., downlink communications using physical downlink shared channel (PDSCH) transmissions and/or uplink communications using physical uplink shared channel (PUSCH) transmissions. While generic exceptions to the reuse rule have been defined, the generic exceptions are not applicable to many situations and may thus leads to low reuse efficiency. Aspects of the described techniques provide for additional reuse exception rules that improve reuse efficiency of unused control resources.

A coreset may include a subset of the coreset, a single coreset, or a set of coresets. Conventionally, coresets are defined semi-statically, e.g., using radio resource control (RRC) signaling, and reusable coreset(s) (e.g., empty coreset(s)) may be signaled using layer <NUM> (L1) signaling. The exceptions to the reuse rules (the reuse exception rules) may allow reuse of unused portions of a coreset that are mapped for PDCCH signals. For example, the L1 signaling may indicate that a region of the coreset is mapped (e.g., being used), but the coreset may include a PDCCH signal that grants PDSCH resources for the unused regions of the coreset. The UE may rate match around the PDCCH for the unused region(s) of the coreset(s) for data communications using the unused resources. Other examples include the UE rate matching around wideband reference signals configured for a coreset. Rate matching may allow improved coreset reuse when there is additional information e.g., the information is free when a PDCCH signal is used because the UE knows where the PDCCH signal is located when the PDSCH signal is received.

Aspects of the disclosure are initially described in the context of a wireless communications system. In some aspects, a base station may identify, determine, or otherwise select a reuse exception rule(s) for a UE to apply when reusing unused resources in a resource set (e.g., a subset of, all, or multiple control resource sets). The unused resources may be resources within a control resource set and the reuse exception rule(s) may be based on a search space that is known by the UE, e.g., configured by the base station. The search space may include a common search space-based (e.g., known by all UEs), a group common search space-based (e.g., known by a set of UEs, such as a GC-PDCCH search space), and/or a UE-specific search space-based (e.g., known by a particular UE). The base station and/or UE may be preconfigured with all available reuse exception rules and the base station may signal an indication of the selected (or active) reuse exception rule(s) that are to be applied by the UE. In some aspects, signaling the reuse exception rule(s) may be implicit in that defining the search space known by UE(s) carries the indication of the reuse exception rule to be applied. In some aspects, the base station may signal the reuse exception rule(s) using an index value/parameter that is known by the UE. The UE may use the index to access a set of reuse exception rule(s) to determine which reuse exception rule(s) is to be applied. Accordingly, the UE and base station may communicate in accordance with the search space-based reuse exception rule(s).

Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to search space-based reuse exception rules.

<FIG> illustrates an example of a wireless communications system <NUM> in accordance with various aspects of the present disclosure. The wireless communications system <NUM> includes base stations <NUM>, UEs <NUM>, and a core network <NUM>. In some examples, the wireless communications system <NUM> may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, or a New Radio (NR) network. In some cases, wireless communications system <NUM> may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, or communications with low-cost and low-complexity devices.

The wireless communications system <NUM> may include, for example, a heterogeneous LTE/LTE-A or NR network in which different types of base stations <NUM> provide coverage for various geographic coverage areas <NUM>.

In one example, a base station <NUM> may use multiple antennas or antenna arrays to conduct beamforming operations for directional communications with a UE <NUM>. For instance, some signals (e.g. synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a base station <NUM> multiple times in different directions, which may include a signal being transmitted according to different beamforming weight sets associated with different directions of transmission. Transmissions in different beam directions may be used to identify (e.g., by the base station <NUM> or a receiving device, such as a UE <NUM>) a beam direction for subsequent transmission and/or reception by the base station <NUM>. Some signals, such as data signals associated with a particular receiving device, may be transmitted by a base station <NUM> in a single beam direction (e.g., a direction associated with the receiving device, such as a UE <NUM>). In some examples, the beam direction associated with transmissions along a single beam direction may be determined based at least in in part on a signal that was transmitted in different beam directions. For example, a UE <NUM> may receive one or more of the signals transmitted by the base station <NUM> in different directions, and the UE <NUM> may report to the base station <NUM> an indication of the signal it received with a highest signal quality, or an otherwise acceptable signal quality. Although these techniques are described with reference to signals transmitted in one or more directions by a base station <NUM>, a UE <NUM> may employ similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE <NUM>), or transmitting a signal in a single direction (e.g., for transmitting data to a receiving device).

In some cases a subframe may be the smallest scheduling unit of the wireless communications system <NUM>, and may be referred to as a transmission time interval (TTI).

The organizational structure of the carriers may be different for different radio access technologies (e.g., LTE, LTE-A, NR, etc.).

Devices of the wireless communications system <NUM> (e.g., base stations <NUM> or UEs <NUM>) may have a hardware configuration that supports communications over a particular carrier bandwidth, or may be configurable to support communications over one of a set of carrier bandwidths. In some examples, the wireless communications system <NUM> may include base stations <NUM> and/or UEs that can support simultaneous communications via carriers associated with more than one different carrier bandwidth.

Wireless communications systems such as an NR system may utilize any combination of licensed, shared, and unlicensed spectrum bands, among others. The flexibility of eCC symbol duration and subcarrier spacing may allow for the use of eCC across multiple spectrums. In some examples, NR shared spectrum may increase spectrum utilization and spectral efficiency, specifically through dynamic vertical (e.g., across frequency) and horizontal (e.g., across time) sharing of resources.

One or more of the base stations <NUM> may select, for a UE <NUM>, one or more reuse exception rules to be applied by the UE <NUM> when reusing one or more resource sets for data communication. The one or more base stations <NUM> may signal the one or more reuse exception rules to the UE <NUM>. The one or more base stations <NUM> may communicate with the UE <NUM> in accordance with the one or more reuse exception rules.

From another perspective, one or more of the UEs <NUM> may receive a signal from a base station <NUM> identifying one or more reuse exception rules to be applied by the UE <NUM> for reusing one or more resource sets for data communication. The one or more UEs <NUM> may communicate with the base station <NUM> in accordance with the one or more reuse exception rules.

<FIG> illustrates an example of a process <NUM> that supports search space-based reuse exception rules in accordance with various aspects of the present disclosure. In some examples, process <NUM> implement aspects of wireless communication system <NUM>. Process <NUM> may include a UE <NUM> and a base station <NUM>, which may be examples of the corresponding device described herein. Broadly, process <NUM> illustrates one example of a base station selecting and indicating a reuse rule(s) to the UE <NUM> to be applied for communications between the UE <NUM> and the base station <NUM>.

Generally, process <NUM> illustrates one example of defining reuse exception rules for region based reuse. In some aspects, process <NUM> introduces search space-based (or sub-search space-based) rate matching reuse exception rules. For example, certain regions of a control resource set may be defined and, when unused, available for reuse. The defined regions may be referred to as coresets, in some examples. Base station <NUM> may select the reuse exception rule(s) for the UE <NUM> to apply and indicate to the UE <NUM> the rate matching reuse exception rule(s) based on a search space. In some aspects, the rate matching reuse exception rule based on the search space may include a set of PDCCH decoding candidates (or the corresponding resource elements (REs)) that the UE <NUM> should assume its PDSCH will not be mapped into even when it is indicated by the L1 signaling that the region is usable for reuse. In some aspects, the decoding candidates in the search space may not be transmitted (in which case the PDSCH reuse may be less optimal), but this is a reasonable cost to pay to have reasonable reuse at low cost with ambiguity. In some aspects, all UEs involved in the reuse know how the reuse exception is defined, e.g., are preconfigured with all reuse exception rules. In aspects of the present disclosure, the definition is indicated to the UE implicitly in that the reuse exception rule is associated with known search spaces.

At <NUM>, the base station <NUM> may select reuse exception rule(s) for UE <NUM>. The reuse exception rule(s) may be selected so as to be applied by the UE <NUM> when reusing resource set(s) for data communications. In some aspects, the reuse exception rule(s) may be selected based on a search space, e.g., search space-based reuse exception rule(s). A search space may refer to the resources in a slot assigned or allocated to the UE <NUM> for finding its PDCCH. That is, the search space may include a set of control channel elements (CCEs) from which the UE <NUM> may find its PDCCH signal. There may be three types of search space: the common search space, the group common search space, and the UE-specific search space. The common search space may carry the common downlink control information (DCI) that is broadcast to all UEs. The group common search space may carry the common DCI that is broadcast to a group of UEs. The UE-specific search space may carry the DCI for a specific UE, such as UE <NUM>. Each UE may monitor a predetermined search space in a PDCCH region (e.g., control region <NUM> in <FIG>) of a downlink slot.

Because <NUM> NR can support a bandwidth significantly wider than current <NUM>/<NUM> networks, the control resources (e.g., REs, CCEs) may be partitioned or grouped into different control resource sets. Each control resource set (or coreset) may include one more search spaces as described above. References to a resource set may refer to a control resource set, a portion or subset of a control resource set, or a group of control resource sets. The coresets may be determined based on sub-bands or carriers such that a UE with a limited bandwidth can be assigned to the proper coreset in a bandwidth that can be supported by the UE <NUM>. In some examples, the control resources of a coreset may be located in a sub-band region or a subset of carriers of the entire bandwidth supported by the base station <NUM>. A coreset may be a common coreset, a group common coreset, or a UE-specific coreset. The base station <NUM> may configure the common coreset for all UEs and optionally one or more group common or UE-specific coresets for different UEs. The common coreset may include the common coreset, group common coresets, and/or UE-specific coresets of one or more UEs. The coresets may be configured and reconfigured by using a RRC signaling configuration or other semi-static procedure. A common coreset may be reconfigured to other frequency(ies), for example, when UEs with different capabilities join and/or leave the network.

When control resources are reallocated for downlink data (e.g., reused), the base station <NUM> may configure the UE <NUM> to rate-match the PDSCH based on various rules to utilize the additional resources, such as the described reuse exception rule(s). Generally, rate matching around resources of the resource set may include matching the number of bits in a transport block (TB) or unit to the number of bits that can be transmitted in the given allocation or resources. For example, rate-matching may involve sub-block interleaving, bit collection, pruning, and the like.

Aspects of the present disclosure provide various methods and apparatuses configured to reuse or reallocate unused resources (e.g., downlink control resource sets) for downlink payload data. However, the present disclosure is not limited to the downlink examples described below, the concept may be extended to reuse control resources for uplink data transmission in both FDD and TDD configurations.

Thus, in some examples the base station <NUM> may select a reuse exception rule that allows the UE <NUM> to reuse the resource set and rate match around, for data communication, one or more resources of the resource set based on a group common physical downlink control channel (GC-PDCCH) search space (or coreset). In other words, resources of the resource set may be reused for data communication by rate matching based on a GC-PDCCH search space. In some examples, the base station <NUM> may select a reuse exception rule that allows the UE <NUM> to reuse the resource set and rate match around, for data communication, one or more resources of the resource set based on a common PDCCH search space (or coreset). In other words, resources of the resource set may be reused for data communication by rate matching based on a common PDCCH search space. In some examples, the base station <NUM> may select a reuse exception rule that allows the UE <NUM> to reuse the resource set and rate match around, for data communication, one or more resources of the resource set based on a UE-specific PDCCH search space (or coreset). In other words, resources of the resource set may be reused for data communication by rate matching based on a UE-specific PDCCH search space. The base station <NUM> may transmit PDCCH signal(s) in the UE-specific PDCCH search space that carry multiple grants for the UE <NUM>. Rate matching around the resources of the resource set for data communication may include, in some examples, the UE <NUM> matching the number of bits in a TB or unit to the number of bits that can be transmitted in the given allocation or resources. For example, rate-matching may involve sub-block interleaving, bit collection, pruning, and the like.

In some examples, the base station <NUM> may select a reuse exception rule that allows the UE <NUM> to reuse the resource set and rate match around, for data communication, one or more resources of the control resource set based on a subset of a UE-specific PDCCH search space. The UE-specific PDCCH search space may be determined based on an aggregation level of the current PDCCH granting the PDSCH for the UE <NUM>. An aggregation level (AL) of a PDCCH transmission may refer to the number of CCEs utilized for the transmission. In some examples, the PDCCH may be transmitted using AL1, AL2, AL4, and/or AL8. For AL1, one CCE may be used to carry the PDCCH. For AL2, two CCEs may be used to carry the PDCCH. For AL <NUM>, four CCEs may be used to carry the PDCCH. For AL8, eight CCEs may be used to carry the PDCCH. In some aspects, the subset of UE-specific PDCCH search space may include decoding candidates having the same AL as the AL of the PDCCH granting the PDSCH for the UE <NUM>. In some aspects, the subset of UE-specific PDCCH search space may include decoding candidates having the same or lower AL as the AL of the PDCCH granting the PDSCH for the UE <NUM>.

At <NUM>, the base station <NUM> may signal the reuse exception rule(s) to the UE <NUM>. For example, the base station <NUM> may identify an index associated with each (or a group or subset) of the selected reuse exception rule(s). The UE <NUM> (and all UEs) may be preconfigured with each possible reuse exception rule, with each reuse exception rule having an associated index that is stored on each device. The base station <NUM> may communicate an indication of the index to the UE <NUM> and the UE <NUM> may access the preconfigured reuse exception rules and use the index to identify which (individually or a group or subset of) reuse exception rule(s) are to be applied by UE <NUM>.

At <NUM>, the UE <NUM> and the base station <NUM> may communicate in accordance with the reuse exception rule(s). Communicating in accordance with the reuse exception rule(s) may include the base station <NUM> transmitting a PDCCH signal in a search space associated with the UE <NUM> that carries resource grant(s) for the UE <NUM>. The search space that the PDCCH signal is transmitted in may include empty or unused resources that can be reused in accordance with the applicable reuse exception rule(s). The UE <NUM> may rate match around the resources in the resource set used to carry the grants, e.g., the UE <NUM> may communicate PDSCH transmissions to base station <NUM> where the PDSCH transmissions are rate matched with the PDCCH signal carrying the resource grant.

<FIG> illustrates an example of a slot configuration <NUM> that supports search space-based reuse exception rules in accordance with various aspects of the present disclosure. In some examples, slot configuration <NUM> may implement aspects of wireless communication system <NUM> and/or process <NUM>. Aspects of slot configuration <NUM> may be implemented by a UE and/or a base station, which may be examples of the corresponding device described herein. Broadly, slot configuration <NUM> illustrates one example of a base station selecting and indicating reuse rule(s) to the UE to be applied for communications between the UE and the base station.

Slot configuration <NUM> may include one physical resource block (PRB) <NUM> spanning one slot <NUM>. The slot <NUM> may consist of a number of REs in the time domain and a number of carriers in the frequency domain. The slot <NUM> may be divided into a control region <NUM> and a data region <NUM>. The control region <NUM> may be subdivided into search spaces. The control region <NUM> may be used to carry or otherwise convey control information to UE(s) operating within the coverage area of a base station. Examples of the configurable search spaces include a common search space <NUM>, a group common search space <NUM>, a UE-specific search space <NUM>, and unused control resources <NUM>. The data region <NUM> may carry PDSCH transmissions scheduled for UEs.

The number of subcarriers (or tones or frequencies) occupying the slot <NUM> may establish the system bandwidth <NUM>. In one example, the system bandwidth <NUM> may include <NUM> subcarriers, or some other number of subcarriers. As discussed above, an intersection of one subcarrier occurring during one symbol period may constitute a RE and the control information may be carried in one or more CCEs (e.g., REs forming resource element groups (REGs) and REGs forming CCE(s)). One or more CCEs may be assigned to a search space of one or more UEs, and the UE can find its PDCCH in the assigned CCEs. In some aspects, the UE may be configured to support the full system bandwidth (e.g., system bandwidth <NUM>) or may be configured to support a subset of the full system bandwidth.

The number of CCEs available for carrying the PDCCH may be variable depending on the number of OFDM symbols used, the bandwidth of the system, and/or a number of antenna ports present at the base station. In some examples, consecutive CCEs may be mapped into REGs that are distributed (i.e., non-consecutive) in frequency. Consecutive CCEs may refer to CCEs that are consecutive in their numbering or ordering in the logical space. Two REGs are not consecutive when they are not adjacent to each other.

(separated by one or more REs). This may be referred to as distributed CCE-to-REG mapping. In some examples, consecutive CCEs are mapped to REGs that are consecutive in frequency. This may be referred to as localized CCE-to-REG mapping. For example, consecutive or adjacent REGs are not separated from each other by one or more REs.

The general principals of CCE-to-REG mapping for coresets (or search spaces) are agreed. For example, in a single symbol operation, only a frequency first mapping is used. This implies a REG bundle of size <NUM>, <NUM>, or <NUM> (may down select) in frequency domain. When a two symbols operation is defined, a time first mapping may be used. This implies at least that a REG bundle of size <NUM> in frequency domain may be supported. When a three symbols operation is defined, a time first mapping is also used, which implies at least that a REG bundle of size <NUM> in frequency domain may be supported. Thus, it is to be understood that the particular mapping/arrangement of CCE(s) into search spaces may vary and the slot configuration <NUM> illustrated in <FIG> is one example only. That is, there may be more or fewer common search spaces <NUM>, group common search spaces <NUM>, UE-specific search spaces <NUM>, and/or unused control resources <NUM>, and each search space may have a different size and/or arrangement than is illustrated in slot configuration <NUM>.

In some scenarios, some control resources of the downlink control region <NUM> may be reused by the downlink data portion <NUM> for carrying downlink data. This situation may occur when the downlink control region has more than sufficient resources to transmit the downlink control information (e.g., PDCCH) in the slot <NUM>.

The resources of the downlink control region may be reused or reallocated to the downlink data portion using different methods. A time-domain only method expands the downlink data portion in the time domain only with respect to the PDSCH. That is, the base station can inform the UE of the starting symbol position of its PDSCH in the time domain. For example, if the PDSCH originally is scheduled to start at symbol <NUM> of a slot, the expanded PDSCH can start at symbol <NUM> or <NUM> that is originally scheduled for the downlink control portion.

In another method, the base station may inform the UE of the time and frequency locations of the resources that can be reallocated to the downlink data portion. This method allows the resources to be identified independent of the PDSCH. For example, in the time domain, the base station may indicate the starting symbol position only, or both starting and ending symbol positions. In the frequency domain, the scheduling entity may indicate the starting and ending frequencies or reused CCE(s) corresponding to the reallocated control resources.

When control resources are reallocated for downlink data, the base station may configure the UE to rate-match the PDSCH based on various rules to utilize the additional resources. The function of rate matching is to match the number of bits in TB or unit to the number of bits that can be transmitted in the given allocation or resources. For example, rate-matching may involve sub-block interleaving, bit collection, and pruning.

In some reuse scenarios, the scheduling entity can configure a UE to rate-match its PDSCH outside the search spaces. In one example, the base station ensures not to configure or reallocate REs that overlap with the search spaces of other UEs. Then, the UE rate-matches its PDSCH around or outside the search space. In another example, the base station informs the UE about the UE-specific search spaces <NUM> of other UEs, then the UE can rate-match its PDSCH around or outside all the informed search spaces.

In another reuse scenario, the UE may rate-match its PDSCH outside the configured search spaces. In one example, the scheduling entity ensures not to configure or reallocate resource elements that overlap with the UE-specific search spaces of other UEs, then the subject UE can rate-match around or outside the common search space <NUM> and its own group specific search space <NUM> and/or UE-specific search space <NUM> (if configured). In case that wideband reference signal is used for the common search space, the UE may rate-match around all the wideband reference signals in the common search space <NUM>. In another example, the base station may inform a UE about the UE-specific search space <NUM> of other UEs, then the UE can rate-match around or outside all the informed search spaces.

In another reuse scenario, the UE can rate-match its PDSCH around all the decoded PDCCHs. In one example, the base station ensures not to configure resource elements that overlap with other UE's PDCCHs.

In some reuse scenarios, the base station may transmit an indicator (e.g., an index) in the downlink control portion to inform a UE how the reallocated control resources are to be used in the downlink data portion or PDSCH. For example, the base station may transmit an indicator to provide a predetermined or selected rule in the DCI or via RRC or other semi-static signaling. For example, this rule informs the UE how to rate-match the PDSCH to utilize the reallocated control resources based on the search space. The base station may also transmit an indicator to provide a predetermined or selected resource reuse type in the DCI or via RRC or other semi-static signaling. The resource reuse type may be the same as the time-domain only expansion with respect to the PDSCH, or time and frequency domain expansion independent of the PDSCH, and the like.

Thus, a base station may select a reuse exception rule(s) to be applied by a UE when reusing resource set(s) for data communication. The reuse exception rule(s) may be selected based on a search space associated with the UE, e.g., a common search space <NUM>, a group common search space <NUM>, and/or a UE-specific search space <NUM>. The base station may send an indication to the UE of the selected reuse exception rule(s) and then the base station and UE may communicate according to the reuse exception rule(s), e.g., using the reuse scenarios described above. Any of the described search spaces may have sufficient REs that are unused (e.g., the PDCCH signal does not occupy the full search space) to schedule and perform the communications using the unused resources of the resource set.

In some aspects, the unused control resources <NUM> may be reused in accordance with signaling from the base station. For example, the base station may use L1 signaling to schedule the resources in the unused control resources <NUM> for reuse for data communications.

In one example of a reuse exception rule, the search space is composed of one single decoding candidate that carries the group common search space <NUM>. This may be useful when the group common search space <NUM> is configured to be transmitted, e.g., the PDCCH signal is configured to be transmitted in the group common search space <NUM>. In the situation where the group common PDCCH is not transmitted in slot <NUM>, the rate matching loss in this instance may be one DCI. In some aspect, this scenario is helpful when all the coreset is empty except the group common search space <NUM>. This rule can be combined with other rules such as the reuse exception rules where the PDCCH schedules the PDSCH.

In another example of a reuse exception rule, the search space can be a common search space <NUM>. The UE may monitor the common search space <NUM> (e.g., the common search space <NUM> is common to all UEs). All UEs know the common search space <NUM> composition, i.e., no additional signaling is needed to define it for rate matching. From the base station perspective, the base station may bias towards using the common search space <NUM> whenever it can to avoid using the UE-specific search space <NUM> to improve reuse efficiency. This rule may be useful when the base station can try to put all the grants in the common search space <NUM>.

In another example of a reuse exception rule, the reuse exception search space is the UE-specific search space <NUM> that the UE is currently monitoring and detects the PDCCH granting the PDSCH from. This reuse exception rule supports sending the UE multiple DCIs in the same UE-specific search space <NUM> (e.g., including other downlink grants or uplink grants). Without this rule, if there are additional grants being sent to the same UE, the coreset cannot be reused under conventional reuse exception rules. In some aspects, this rule does not target the most accurate reuse as the entire UE-specific search space <NUM> is in exception, as there is no mechanism to safely indicate which decoding candidate is used.

In another example of a reuse exception rule, the reuse exception search space is a sub-space of the UE-specific search space <NUM> that the UE is currently monitoring and detects the PDCCH granting the PDSCH from. The sub-space can be defined as the decoding candidates that has the same AL as the current PDCCH granting the PDSCH. In some aspects, this rule rules out all other decoding candidates covered by these if a nested decoding candidate structure is introduced. The base station may not need to use a mixed AL to grant UEs, so likely other grants will have the same AL. This is a slightly more efficient rule, but with a small loss in flexibility. The UE knows the AL for the current PDCCH, and can rate match around all decoding candidates of the same AL.

<FIG> shows a block diagram <NUM> of a wireless device <NUM> that supports search space-based reuse exception rules in accordance with aspects of the present disclosure. Wireless device <NUM> may be an example of aspects of a base station <NUM> as described herein. Wireless device <NUM> may include receiver <NUM>, base station communications manager <NUM>, and transmitter <NUM>. Wireless device <NUM> may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

Receiver <NUM> may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to search space-based reuse exception rules, etc.). Information may be passed on to other components of the device. The receiver <NUM> may be an example of aspects of the transceiver <NUM> described with reference to <FIG>. The receiver <NUM> may utilize a single antenna or a set of antennas.

Base station communications manager <NUM> may be an example of aspects of the base station communications manager <NUM> described with reference to <FIG>.

Base station communications manager <NUM> and/or at least some of its various sub-components may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions of the base station communications manager <NUM> and/or at least some of its various sub-components may be executed by a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure. The base station communications manager <NUM> and/or at least some of its various sub-components may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical devices. In some examples, base station communications manager <NUM> and/or at least some of its various sub-components may be a separate and distinct component in accordance with various aspects of the present disclosure. In other examples, base station communications manager <NUM> and/or at least some of its various sub-components may be combined with one or more other hardware components, including but not limited to an I/O component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

Base station communications manager <NUM> may select, for a UE, one or more reuse exception rules to be applied by the UE when reusing one or more resource sets for data communication, signal the one or more reuse exception rules to the UE, and communicate with the UE in accordance with the one or more reuse exception rules.

<FIG> shows a block diagram <NUM> of a wireless device <NUM> that supports search space-based reuse exception rules in accordance with aspects of the present disclosure. Wireless device <NUM> may be an example of aspects of a wireless device <NUM> or a base station <NUM> as described herein. Wireless device <NUM> may include receiver <NUM>, base station communications manager <NUM>, and transmitter <NUM>. Wireless device <NUM> may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

Base station communications manager <NUM> may also include reuse exception rule selector <NUM>, reuse exception rule signaler <NUM>, and resource reuse manager <NUM>.

Reuse exception rule selector <NUM> may select, for a UE, one or more reuse exception rules to be applied by the UE when reusing one or more resource sets for data communication In some cases, the resource set includes a control resource set, or a set of control resource sets, or a subset of resources of a control resource set, or any combinations thereof.

Reuse exception rule signaler <NUM> may signal the one or more reuse exception rules to the UE.

Resource reuse manager <NUM> may communicate with the UE in accordance with the one or more reuse exception rules.

<FIG> shows a block diagram <NUM> of a base station communications manager <NUM> that supports search space-based reuse exception rules in accordance with aspects of the present disclosure. The base station communications manager <NUM> may be an example of aspects of a base station communications manager <NUM>, a base station communications manager <NUM>, or a base station communications manager <NUM> described with reference to <FIG>, <FIG>, and <FIG>. The base station communications manager <NUM> may include reuse exception rule selector <NUM>, reuse exception rule signaler <NUM>, resource reuse manager <NUM>, search space manager <NUM>, index manager <NUM>, and signaling manager <NUM>. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses).

Reuse exception rule selector <NUM> may select, for a UE, one or more reuse exception rules to be applied by the UE when reusing one or more resource sets for data communication In some cases, the resource set includes a control resource set, or a set of control resource sets, or a subset of resources of a control resource set, or any combinations thereof. In some cases, selecting the one or more reuse exception rules includes: selecting the one or more reuse exception rules to be applied by the UE from a set of search space-based rate matching reuse exception rules. In some cases, selecting the one or more reuse exception rules includes: selecting a reuse exception rule that allows the UE to reuse the resource set and rate match around, for data communication, one or more resources of the resource set based on a GC-PDCCH search space. In some cases, selecting the one or more reuse exception rules includes: selecting a reuse exception rule that allows the UE to reuse the resource set and rate match around, for data communication, one or more resources of the resource set based on a common PDCCH search space. In some cases, selecting the one or more reuse exception rules includes: selecting a reuse exception rule that allows the UE to reuse the resource set and rate match around, for data communication, one or more resources of the resource set based on a UE-specific PDCCH search space. In some cases, selecting the one or more reuse exception rules includes: selecting a reuse exception rule that allows the UE to reuse the resource set and rate match around, for data communication, one or more resources of the control resource set based on a subset of a UE-specific PDCCH search space.

Search space manager <NUM> may transmit, in the UE-specific PDCCH search space, one or more PDCCH signals including a set of resource grants for the UE and transmit, in a search space associated with the UE, one or more PDCCH signals including one or more resource grants for the UE. In some cases, the UE-specific PDCCH search space is determined by an AL of a current PDCCH granting a PDSCH to the UE. In some cases, the subset of UE-specific PDCCH search space includes one or more decoding candidates having the same AL as the AL of the current PDCCH granting the PDSCH to the UE. In some cases, the subset of UE-specific PDCCH search space includes one or more decoding candidates having the same or lower AL as the AL of the current PDCCH granting the PDSCH to the UE.

Index manager <NUM> may communicate an indication of the index to the UE. In some cases, signaling the one or more reuse exception rules to the UE includes: identifying an index associated with each of the one or more reuse exception rules. In some cases, signaling the one or more reuse exception rules to the UE includes: identifying an index associated with a subset of rules of the one or more reuse exception rules.

Signaling manager <NUM> may transmit RRC signaling to configure the resource set and transmit L1 signaling to indicate resource set reuse.

<FIG> shows a diagram of a system <NUM> including a device <NUM> that supports search space-based reuse exception rules in accordance with aspects of the present disclosure. Device <NUM> may be an example of or include the components of wireless device <NUM>, wireless device <NUM>, or a base station <NUM> as described herein. Device <NUM> may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including base station communications manager <NUM>, processor <NUM>, memory <NUM>, software <NUM>, transceiver <NUM>, antenna <NUM>, network communications manager <NUM>, and inter-station communications manager <NUM>. These components may be in electronic communication via one or more buses (e.g., bus <NUM>). Device <NUM> may communicate wirelessly with one or more UEs <NUM>.

Processor <NUM> may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a central processing unit (CPU), a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, processor <NUM> may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into processor <NUM>. Processor <NUM> may be configured to execute computer-readable instructions stored in a memory to perform various functions (e.g., functions or tasks supporting search space-based reuse exception rules).

Software <NUM> may include code to implement aspects of the present disclosure, including code to support search space-based reuse exception rules. Software <NUM> may be stored in a non-transitory computer-readable medium such as system memory or other memory. In some cases, the software <NUM> may not be directly executable by the processor but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

Inter-station communications manager <NUM> may manage communications with other base station <NUM>, and may include a controller or scheduler for controlling communications with UEs <NUM> in cooperation with other base stations <NUM>. In some examples, inter-station communications manager <NUM> may provide an X2 interface within an LTE/LTE-A wireless communication network technology to provide communication between base stations <NUM>.

<FIG> shows a block diagram <NUM> of a wireless device <NUM> that supports search space-based reuse exception rules in accordance with aspects of the present disclosure. Wireless device <NUM> may be an example of aspects of a UE <NUM> as described herein. Wireless device <NUM> may include receiver <NUM>, UE communications manager <NUM>, and transmitter <NUM>. Wireless device <NUM> may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

UE communications manager <NUM> may be an example of aspects of the UE communications manager <NUM> described with reference to <FIG>.

UE communications manager <NUM> and/or at least some of its various sub-components may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions of the UE communications manager <NUM> and/or at least some of its various sub-components may be executed by a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure. The UE communications manager <NUM> and/or at least some of its various sub-components may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical devices. In some examples, UE communications manager <NUM> and/or at least some of its various sub-components may be a separate and distinct component in accordance with various aspects of the present disclosure. In other examples, UE communications manager <NUM> and/or at least some of its various sub-components may be combined with one or more other hardware components, including but not limited to an I/O component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

UE communications manager <NUM> may receive a signal from a base station identifying one or more reuse exception rules to be applied by the UE for reusing one or more resource sets for data communication and communicate with the base station in accordance with the one or more reuse exception rules.

<FIG> shows a block diagram <NUM> of a wireless device <NUM> that supports search space-based reuse exception rules in accordance with aspects of the present disclosure. Wireless device <NUM> may be an example of aspects of a wireless device <NUM> or a UE <NUM> as described herein. Wireless device <NUM> may include receiver <NUM>, UE communications manager <NUM>, and transmitter <NUM>. Wireless device <NUM> may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

UE communications manager <NUM> may be an example of aspects of the UE communications manager <NUM> described with reference to <FIG>. UE communications manager <NUM> may also include reuse exception indication manager <NUM> and resource reuse manager <NUM>.

Reuse exception indication manager <NUM> may receive a signal from a base station identifying one or more reuse exception rules to be applied by the UE for reusing one or more resource sets for data communication.

Resource reuse manager <NUM> may communicate with the base station in accordance with the one or more reuse exception rules.

<FIG> shows a block diagram <NUM> of a UE communications manager <NUM> that supports search space-based reuse exception rules in accordance with aspects of the present disclosure. The UE communications manager <NUM> may be an example of aspects of a UE communications manager <NUM> described with reference to <FIG>, <FIG>, and <FIG>. The UE communications manager <NUM> may include reuse exception indication manager <NUM>, resource reuse manager <NUM>, search space manager <NUM>, index manager <NUM>, signaling manager <NUM>, and reuse exception rule selector <NUM>. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses).

Reuse exception indication manager <NUM> may receive a signal from a base station identifying one or more reuse exception rules to be applied by the UE for reusing one or more resource sets for data communication. In some cases, the one or more reuse exception rules signaled to the UE are search space-based rate matching reuse exception rules.

Search space manager <NUM> may receive, in a search space associated with the UE, one or more PDCCH signals including one or more resource grants for the UE, and apply a reuse exception rule of the one or more reuse exception rules that allows the UE to reuse the resource set and rate match around, for data communication, one or more resources of the resource set based on a search space. In some examples, the search space manager <NUM> may identify a GC-PDCCH search space associated with the UE, and apply a reuse exception rule that allows the UE to reuse the resource set and rate match around, for data communication, one or more resources of the resource set based on the GC-PDCCH search space. In other examples, the search space manager <NUM> may identify a common PDCCH search space associated with the UE, and apply a reuse exception rule of the one or more reuse exception rules that allows the UE to reuse the resource set and rate match around, for data communication, one or more resources of the resource set based on the common PDCCH search space. In still other examples, the search space manager <NUM> may identify a UE-specific PDCCH search space associated with the UE, and apply a reuse exception rule of the one or more reuse exception rules that allows the UE to reuse the resource set and rate match around, for data communication, one or more resources of the resource set based on the UE-specific PDCCH search space. In some aspects, the search space manager <NUM> may identify a subset of a UE-specific PDCCH search space associated with the UE, and apply a reuse exception rule of the one or more reuse exception rules that allows the UE to reuse the resource set and rate match, for data communication, one or more resources of the resource set based on the subset of the UE-specific PDCCH search space. The search space manager <NUM> may receive, in the UE-specific PDCCH search space, one or more PDCCH signals including a set of resource grants for the UE. In some cases, the UE-specific PDCCH search space is determined by an AL of a current PDCCH granting a PDSCH to the UE. In some cases, the subset of UE-specific PDCCH search space includes one or more decoding candidates having the same AL as the AL of the current PDCCH granting the PDSCH to the UE. In some cases, the subset of UE-specific PDCCH search space includes one or more decoding candidates having the same or lower AL as the AL of the current PDCCH granting the PDSCH to the UE.

Index manager <NUM> may receive an indication of an index associated with each of the one or more reuse exception rules, identify the one or more reuse exception rules based on the indication, and receive an indication of an index associated with a subset of rules of the one or more reuse exception rules.

Signaling manager <NUM> may receive RRC signaling configuring the resource sets and receive L1 signaling indicating resource set reuse.

Reuse exception rule selector <NUM> may manage aspects of the resource set including a control resource set, or a set of control resource sets, or a subset of resources of a control resource set, or any combinations thereof.

<FIG> shows a diagram of a system <NUM> including a device <NUM> that supports search space-based reuse exception rules in accordance with aspects of the present disclosure. Device <NUM> may be an example of or include the components of UE <NUM> as described herein. Device <NUM> may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including UE communications manager <NUM>, processor <NUM>, memory <NUM>, software <NUM>, transceiver <NUM>, antenna <NUM>, and I/O controller <NUM>. These components may be in electronic communication via one or more buses (e.g., bus <NUM>). Device <NUM> may communicate wirelessly with one or more base stations <NUM>.

Processor <NUM> may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, processor <NUM> may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into processor <NUM>. Processor <NUM> may be configured to execute computer-readable instructions stored in a memory to perform various functions (e.g., functions or tasks supporting search space-based reuse exception rules).

<FIG> shows a flowchart illustrating a method <NUM> for search space-based reuse exception rules in accordance with aspects of the present disclosure. The operations of method <NUM> may be implemented by a base station <NUM> or its components as described herein. For example, the operations of method <NUM> may be performed by a base station communications manager as described with reference to <FIG>. In some examples, a base station <NUM> may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station <NUM> may perform aspects of the functions described below using special-purpose hardware.

At block <NUM> the base station <NUM> may select, for a UE, one or more reuse exception rules to be applied by the UE when reusing one or more resource sets for data communication. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a reuse exception rule selector as described with reference to <FIG>.

At block <NUM> the base station <NUM> may signal the one or more reuse exception rules to the UE. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a reuse exception rule signaler as described with reference to <FIG>.

At block <NUM> the base station <NUM> may communicate with the UE in accordance with the one or more reuse exception rules. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a resource reuse manager as described with reference to <FIG>.

At block <NUM> the base station <NUM> may transmit, in a search space associated with the UE, one or more PDCCH signals comprising one or more resource grants for the UE. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a search space manager as described with reference to <FIG>.

<FIG> shows a flowchart illustrating a method <NUM> for search space-based reuse exception rules in accordance with aspects of the present disclosure. The operations of method <NUM> may be implemented by a UE <NUM> or its components as described herein. For example, the operations of method <NUM> may be performed by a UE communications manager as described with reference to <FIG>. In some examples, a UE <NUM> may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE <NUM> may perform aspects of the functions described below using special-purpose hardware.

At block <NUM> the UE <NUM> may receive a signal from a base station identifying one or more reuse exception rules to be applied by the UE for reusing one or more resource sets for data communication. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a reuse exception indication manager as described with reference to <FIG>.

At block <NUM> the UE <NUM> may communicate with the base station in accordance with the one or more reuse exception rules. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a resource reuse manager as described with reference to <FIG>.

At block <NUM> the UE <NUM> may receive an indication of an index associated with each of the one or more reuse exception rules. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a index manager as described with reference to <FIG>.

At block <NUM> the UE <NUM> may identify the one or more reuse exception rules based at least in part on the indication. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a index manager as described with reference to <FIG>.

Claim 1:
A method for wireless communication performed at a base station, BS, the method comprising:
identifying a type of search space associated with a user equipment, UE, the identified type being one of a group common PDCCH, GC-PDCCH search space, a common PDCCH search space, or a UE-specific PDCCH search space;
selecting (<NUM>; <NUM>; <NUM>), for the UE, one or more reuse exception rules to be applied by the UE when reusing one or more physical downlink control channel, PDCCH, resource sets for data communication, the one or more reuse exception rules allowing the UE to reuse a first subset of resources of the one or more PDCCH resource sets for data communications, the one or more reuse exception rules configured to indicate a second subset of resources of a search space within the first subset of resources around which the data communication is to be rate matched, wherein the one or more reuse exception rules are selected based at least in part on the identified type of search space;
implicitly signaling (<NUM>; <NUM>; <NUM>) the one or more reuse exception rules to the UE based at least in part on the identified type of search space; and
communicating (<NUM>; <NUM>; <NUM>) with the UE in accordance with the one or more reuse exception rules.